Search

Ginseng Radix et Rhizoma (GRR) and Schisandrae Chinensis Fructus (SCF) are frequently used as herb pairs in traditional herbal formulas especially for the synergetic beneficial effects on lung and heart. Shengmai-yin (SMY), a noted formula, was first published in the traditional Chinese medicine classic named Yixue Qiyuan written by Zhang Yuansu in the Jin Dynasty, and has been used for deficiency of both qi and yin, palpitation, shortness of breath and spontaneous sweating. In SMY, GRR, a sovereign herb, plays an essential role in tonifying lung and supplementing qi, and SCF as an adjuvant herb contributes to the effects of nourishing yin and promoting fluid production, both of which are traditionally used as invigorants in China, Korea, Japan, and Russia. However, the underlying compatibility mechanism of GRR-SCF has remained unknown. In order to explore the impact and underlying mechanism of schisandra chinensis extract (SCE) on the absorption of ginsenosides Rb 1 , Rc, Rb 2 and Rd belonging to protopanaxdiol (PPD)-type and ginsenosides Rg 1 and Re belonging to protopanaxtriol (PPT)-type, pharmacokinetic studies, molecular docking technique and single-pass intestinal perfusion (SPIP) experiment were conducted. Preliminarily, pharmacokinetic characteristics of ginseng extract (GE) in the presence and absence of SCE were studied. Thereafter, molecular docking was used to predict whether ginsenosides were P-glycoprotein (P-gp) or cytochrome P450 isoenzyme 3A4 (CYP3A4) substrates. Finally, the effects and underlying mechanism of SCE on the absorption of GE were further investigated by in situ SPIP experiment. Our findings indicated that SCE could increase exposure in vivo and the intestinal absorption of distinct ginsenosides. Additionally, we found that the PPD-type ginsenosides Rb 1 , Rc, Rb 2 , and Rd were substrates for P-gp, and the PPT-type ginsenosides Rg 1 and Re were substrates for CYP3A4 rather than P-gp. SCE, which has been found with extensive inhibitory effects on P-gp and CYP3A4, could remarkably promote the intestinal absorption of ginsenosides Rg 1 , Re, Rb 1 , Rc, Rb 2 , and Rd, obtaining similar effects comparable with ketoconazole known as a classic dual inhibitor of P-gp and CYP3A4. The study demonstrated that SCE could improve the absorption of GE, and revealed the underlying compatibility mechanism of GRR and SCF from the perspective of P-gp and CYP3A4-mediated interactions to some extent, which provided a certain scientific reference for the compatibility and clinical practice of GRR-SCF as common herb pairs in traditional prescriptions such as SMY. Moreover, this study also furnished a strategy for improving the oral bioavailability of different types of ginsenosides by drug combinations. [Display omitted] • Schisandra schisandra chinensis extract could promote the absorption of PPD-type and PPT-type ginsenosides in vivo. • The underlying mechanism was revealed based on P-gp and CYP3A4-mediated interactions. • A feasible insight was provided for improving the oral bioavailability of ginsenosides. [ABSTRACT FROM AUTHOR]

Functional dyspepsia (FD) is a disorder caused by abnormal gut–brain axis regulation and is highly prevalent in China. Cynanchum auriculatum (CA) is often used to treat FD in the ethnic minority areas of Guizhou. Although several CA-based products are currently available in the market, it is unclear which components of CA are efficacious and what their oral absorption mechanism is. This study aimed to screen anti-FD components of CA based on the spectrum-effect relationship. In addition, the study evaluated the intestinal absorption mechanism of these components using transporter inhibitors. The fingerprinting of compounds from CA extract and plasma after oral administration was conducted using ultra-high-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS). The intestinal contractile parameters were then measured in vitro using the BL-420F Biofunctional Experiment System. Multivariate statistical analysis of the result of spectrum-effect relationship assessment was used to elucidate the correlation between prominent peaks of CA-containing plasma and intestinal contractile activity. The effect of ATP-binding cassette (ABC) transporter inhibitors, such as the P-gp inhibitor verapamil, the MRR inhibitor indomethacin, and the BCRP inhibitor Ko143, on the directional transport of the predicted active ingredients was assessed in vivo. Twenty chromatographic peaks were identified in the CA extract. Of these, three were C 21 steroids, four were organic acids, and one was a coumarin, and acetophenone by comparing with reference compounds. Additionally, it is discovered that there are totally 39 migratory components in CA-containing plasma, which was found to significantly promote the contractility of the isolated duodenum. Moreover, multivariate analysis of the spectrum-effect relationship demonstrated that 16 characteristic peaks (3, 6, 8, 10, 11, 13, 14, 18, 21, m1–m4, m7, m15, and m24) in CA-containing plasma were significantly associated with the anti-FD effect. These compounds included seven prototype compounds, i.e., cynanoneside A, syringic acid, deacylmetaplexigenin, ferulic acid, scopoletin, baishouwubenzophenone, and qingyangshengenin. The inhibition of ABC transporters demonstrated that the inhibitors verapamil and Ko143 significantly increased (P < 0.05) the uptake of scopoletin and qingyangshengenin. Thus, these compounds may be substrates for P-gp and BCRP. The potential anti-FD components of CA and the effect of ABC transporter inhibitors on these active components were preliminarily clarified. These findings lay a foundation for subsequent in vivo studies. [Display omitted] • Twenty compounds were identified from the effective fraction of CA by UPLC–QTOF–MS. • The anti-FD components of CA were explored by spectrum-effect relationship analysis. • The effect of ABC transporter inhibitors on CA active components were preliminarily clarified. [ABSTRACT FROM AUTHOR]

Abstract Ethnopharmacological relevance Copaiba oleoresin has been used in folk medicine in the treatment of bronchitis, syphilis, skin diseases and ulcers due to its anti-inflammatory and antiseptic activities, but there is no information about major compounds oral absorption to support the traditional use. Aim of study Considering the potential of copalic (CA) and kaurenoic acid (KA) – major biological activity (in vitro) diterpenes found in the oleoresin, this study aimed to evaluate the intestinal permeability of CA and KA using Caco-2 cells model as predictive test for oral drug absorption. Materials and methods Chemical stability at pH 1.2 and 7.4 and plasma stability were evaluated to mimic physiological conditions of the gastrointestinal tract. The intestinal permeability of CA and KA was evaluated in Caco-2 cells in the presence and absence of the P-glycoprotein inhibitor verapamil. Results CA and KA were rapidly degraded at pH 1.2 (0.2 M Clark-Lubs buffer). At pH 7.4 (0.1 M phosphate buffer), CA was stable for up to 24 h and KA for up to 6 h. In human plasma, CA and KA can be considered stable for 24 h and 12 h at 37 °C, respectively. Caco-2 cells were considered viable when incubated with CA or KA in the range of 3.9–250 μM for 24 h. CA and KA exhibited moderate apparent permeability (P app) of 4.67 (±0.08) × 10−6 cm/s and 4.66 (±0.04) × 10−6 cm/s, respectively. Simultaneous incubation with verapamil showed that P-glycoprotein does not play a relevant role on CA and KA oral absorption, with P app of 4.48 (±0.26) × 10−6 cm/s and 5.37 (±0.72) × 10−6 cm/s observed for CA and KA, respectively. Conclusion The oral absorption of both CA and KA is driven by mainly passive permeability, is not limited by p-glycoprotein, but enteric-coated dosage forms should be used to avoid chemical instability in the gastric pH. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract Ethnopharmacological relevance Arbutus unedo L., (Ericaceae) is one of the most traditional plants commonly used to treat diabetes in people living in Eastern Morocco region particularly in Taza and Beni Mellal. Aim of the study The aim of the study was to find if there is a scientific support to the ethnopharmacological relevance use of Arbutus unedo L., roots bark (AU) to treat diabetes. Materials and methods We studied the effects of crude aqueous extract of AU on intestinal glucose absorption using short-circuit current technique in vitro and oral glucose tolerance test in vivo. Results The aqueous extract of AU (10 µg/mL to 1 mg/mL) induced concentration-dependent inhibition of sodium-dependent glucose transport across isolated mouse jejunum. The maximal inhibition was obtained with 1 mg/mL, which exhibited more than 80% of the Phloridzin inhibition with an IC 50 close to 216 µg/mL. A 6-week AU ingestion (2 g/(kg day)), improved oral glucose tolerance as efficiently as metformin (300 mg/(kg day)). Arbutus unedo L. and metformin also reduced body weight. Conclusions Arbutus unedo L. roots bark aqueous extract directly inhibited the electrogenic intestinal absorption of glucose in vitro. In addition it improved oral glucose tolerance and lowered body weight in rats after chronic oral administration in vivo. These results add a scientific support to the ethnopharmacological relevance use of Arbutus unedo L. roots bark to treat diabetes. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract Ethnopharmacological relevance Polygonum multiflorum Thunb (Heshouwu, HSW) is commonly used in clinical medicine, while the hepatotoxicities of HSW are reported increasingly in recent years. Currently, researchers have demonstrated an essential role of Bile Acids (BAs) in liver diseases. The occurrence of hepatotoxicity cases linked to HSW are characterized by jaundice and cholestasis, suggesting an interaction that between BAs and HSW Aim of the study This study was designed to investigate the HSW-induced liver functional and histological changes in mice and the role of HSW on bile acid synthesis, metabolism, clearance and intestinal absorption. Materials and methods The mice were intragastrically (i.g.) given HSW at doses of 1.275 and 3.825 g/kg (Crude extracts /body weight) once a day for seven days. Liver function was evaluated by measuring the serum levels of enzymes and analyzing the liver histology. The LC/MS analysis was performed to quantify BAs from liver, ileum and serum. Moreover, the expression of bile metabolic-related transporters and metabolic enzymes at both protein and mRNA levels were observed to elucidate the underlying mechanisms. Results Oral administration of HSW for 7 days could not cause liver damage. A significant change was observed for the concentrations of liver and serum BAs in treatment groups compared with normal control. The mRNA expression levels of bile acid excretory transporter (Bsep) and basolateral uptake transporter (Ntcp) were increased with the development of HSW. The concentrations of unconjugated BAs increased in mice intestines after the administration of HSW. Western blot and qRT-PCR analyses showed that HSW upregulated the protein and mRNA expression of Shp and Fgf15 in the ileum of the mice. Conclusion HSW treatment for 7days did not cause liver damage. HSW accelerated bile acid enterohepatic circulation and changed the composition of intestinal BAs, leding to the activation of Fxr-Fgf15 signal in intestines, and further inhibited the expression of Cyp7a1 in the liver. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract Ethnopharmacological relevance In traditional Chinese medicine, processed aconite root (lateral root of Aconitum carmichaelii Debx.) is used as the principle herb of the Si-Ni decoction (SND) formula due to its cardiotonic effect, while its cardiotoxicity and neurotoxicity caused by diester and monoester diterpenoid alkaloids are reduced by compatibility of dried ginger and honey-processed liquorice in SND. Aim of the study To investigate the detoxification of processed aconite root by compatibility of SND from the perspective of intestinal absorption with metabolism in intestinal bacteria. Materials and methods Decoctions of processed aconite root (AD), processed aconite root and honey-processed liquorice (ALD), and SND with the same amount of each herb were prepared, then were incubated in human intestinal bacteria juice (IBJ) in vitro for different durations. Bidirectional transmembrane transports of these decoctions and their IBJ-incubated decoctions were conducted on Caco-2 monolayers. Correlation between efflux ratios changes of benzoylmesaconine, benzoylaconine, benzoylhypaconine (monoester-diterpenoid alkaloids, MDAs) and hypaconitine (diester-diterpenoid alkaloids) from processed aconite root, and metabolic trends of compounds from honey-processed liquorice and dried ginger were also performed. Results The absorption of MDAs from processed aconite root was increased by combination with honey-processed liquorice in ALD, but they were decreased significantly by the addition of dried ginger in SND. Take benzoylhypaconine for example, the P app, AP to BL soared from (3.13 ± 0.18) × 10−7 cm/s in AD to (23.32 ± 3.51) × 10−7 cm/s in ALD, while it dropped to (1.12 ± 0.17) × 10−7 cm/s in SND. When herb combined decoctions metabolised by intestinal bacteria for 12 h, the efflux ratio of benzoylhypaconine were both increased from 0.56 to 1.21 in ALD and from 1.10 to 2.61 in SND, which was correlative with the generation of davidigenin and glycyrrhetic acid (the metabolites of chalcones and pentacyclic triterpenoids from liquorice) in ALD and with the metabolism of [6]-gingerol (the major compound from dried ginger) in SND, respectively. Conclusions Compatibility of SND altered the intestinal absorption of toxic MDAs and hypaconitine from processed aconite root. In SND, dried ginger rather than honey-processed liquorice played the role of detoxification of these toxic compounds in the intestinal absorption. The intestinal detoxification of SND was significantly and strongly correlative with metabolism of dried ginger and honey-processed liquorice by intestinal bacteria, simultaneously. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Boiled silkworm cocoons have been used to treat 'Xiaoke disease' (diabetes mellitus) recorded in Chinese medicine for over 800 years. In recent years, it has been found that the active substance silk sericin (SS) has therapeutic benefits in treating type 2 diabetes mellitus (T2DM). SS promotes pancreatic islet signalling, the proliferation of pancreatic islet cells, and insulin secretion. It is inferred that SS enters the bloodstream after oral administration and plays a role in the body's circulation. As a natural protein, SS needs to resist digestion by proteases in the gastrointestinal tract and cross the gastrointestinal barrier after oral administration. It is currently unclear how SS crosses the gastrointestinal barrier and whether it exerts therapeutic effects on T2DM by entering the circulation. To study how SS crosses the gastrointestinal barrier and whether it enters the body circulation to exert a therapeutic effect on T2DM. SS was extracted from silkworm cocoons using an alkaline method with sodium carbonate. The antidigestive capacity of SS was detected using SDS-PAGE gel electrophoresis experiments. The mode of uptake and translocation of orally consumed SS in vivo was analysed using the AP-side to BL-side and BL-side-AP-side translocations, apparent Permeability coefficient (Papp), and Exocytosis rates (ER). The study compared the differences between the adSS group and the adSS + EDTA group by using Ethylenediaminetetraacetic acid (EDTA) to separate the tight junctions between Caco-2 cells. The aim was to analyze whether the transport mode of oral filaggrin proteins in vivo could be absorbed by bypass transport. By administering SS through oral and intraperitoneal injection to type 2 diabetic mice, we measured its concentration in the blood, as well as blood glucose and insulin levels, to determine its effectiveness in treating diabetes and its ability to enter the body's circulation for treatment. The molecular weight of SS decreased from 10k∼25 kDa to 10k∼15 kDa after in vitro simulated gastrointestinal fluid digestion, indicating its good antidigestive properties. The apparent Papp was greater than 1 × 10−6 cm·s-1, and the ER was between 0.5 and 1.5, indicating that adSS was well-absorbed and mainly passively transported. The Caco-2 cell model showed that the addition of EDTA promoted the transport of adSS, resulting in significantly larger Papp and ER values, indicating that adSS was absorbed by bypass transport. After oral administration of SS, the concentration of SS in the blood was lower than after intraperitoneal injection, which is 60% of intraperitoneal administration. Mice with a T2DM model who were administered SS for 5 weeks showed significant improvement in insulin resistance and glucose tolerance. Additionally, the pancreatic tissue appeared more regular. In the treatment of T2DM, injections of SS have been shown to be more effective than oral administration. Both oral and intraperitoneal injections have been partially involved in the circulation. SS is enzymatically cleaved by proteolytic enzymes in the gastrointestinal tract. The smaller molecules are partially absorbed into the body's circulation through passive and paracrine transport, exerting a therapeutic effect on T2DM. [Display omitted] [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Bofutsushosan (fangfengtongshengsan in Chinese, BTS) is a formula in traditional Japanese Kampo medicine and Chinese medicine comprising 18 crude drugs that is used for treating obesity and metabolic syndrome. Aim of the study We evaluated the promotive effects of BTS on lipid and cholesterol elimination in mice. Materials and methods Mice were reared with a high-fat diet containing boiled water extract of BTS for 30 days, and their biochemical parameters as well as the weight and lipid content of feces were measured. We also measured cholesterol uptake into Caco-2 cells cultured with or without BTS extract. Results The body weight and amounts of visceral fat and subcutaneous fat on day 28; the weights of epididymal, perirenal, and mesenteric fat; and the serum concentrations of triglyceride, glucose, and hemoglobin A1c on day 30 were significantly lower in the BTS extract-treated groups than in the control in a dose-dependent manner. The amounts of lipid and cholesterol in the feces collected from day 6–23 were significantly greater than in the control. When Caco-2 cells were incubated with BTS extract, the uptake of cholesterol into cells was significantly reduced in a concentration-dependent manner. Among the components of BTS, the methanol extracts of Platycodi Radix and Zingiberis Rhizoma contribute but the extracts of Ephedrae Herba and Rhei Rhizoma counteract the suppressive effect of BTS on cholesterol uptake into Caco-2 cells. Conclusions BTS has beneficial effects on obesity and metabolic syndrome, and its mechanisms of action include the promotion of lipid elimination and the inhibition of cholesterol absorption in the intestine. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Polysaccharides and small molecules commonly co-exist in decoctions of traditional Chinese medicines (TCMs). Our previous study outlined that ginseng polysaccharides (GP) could interact with co-existing ginsenosides to produce synergistic effect in an over-fatigue and acute cold stress model via gut microbiota involved mechanisms. Aim of the study This study aimed to verify the interactions by examining the impact of GP on oral pharmacokinetics of ginsenoside Rb1 (Rb1), the dominant protopanoxadiol (PPD)-type ginsenoside in Ginseng, on a dextran sulphate sodium (DSS) induced experimental colitis model which was characterized by gut dysbiosis, and to delineate the underlying mechanisms in vitro . Materials and Methods Rats received drinking water (normal group), 5% DSS (UC group), or 5% DSS plus daily oral administration of GP (GP group) for 7 days and fecal samples were collected on day −3, 0 and 6. On day 7 all animals received an oral dosage of Rb1 and blood samples were withdrawn for pharmacokinetic study. The in vitro metabolism study of Rb1 in gut microbiota from normal and UC rats and the transport study of Rb1 across Caco-2 cell monolayer were carried out in presence/absence of GP. Rb1 and its bacterial metabolites ginsenoside Rd (Rd), ginsenoside F2 (F2), Compound K (CK) and PPD were determined using LC-MS/MS. Total and target bacteria in fecal samples were determined by using 16S rRNA-based RT-PCR. β-Glucosidase activity was determined by measuring 4-nitrophenol formed from 4-nitrophenyl-β-D-glucopyranoside hydrolysis. Results DSS induction did not alter AUC 0−t and C max of Rb1, which, however, were doubled together with elevated AUC 0−t of the metabolites, in particular Rd and CK, in GP group. GP influenced the microbial composition and showed a prebiotic-like effect. Accordingly, GP treatment could partially restore the β-glucosidase activity which was reduced by DSS induction. The presence of GP resulted in quicker microbial metabolism of Rb1 and higher Rd formation in first 8 h of incubation, while the impact on F2 and CK formation/conversion became obvious after 8 h. More interestingly, GP slightly stimulated Caco-2 cell growth and facilitated Rb1 transport across the Caco-2 monolayer in both directions, increasing the P app of Rb1 from 10 −7 cm/s to 10 −6 cm/s. Conclusions: GP alleviated DSS-induced colitis-like symptoms and enhanced the systemic exposure of Rb1 through enhancing microbial deglycosylation and intestinal epithelial absorption of Rb1. These findings further demonstrated the important role of gut microbiota in the multifaceted action of polysaccharides in the holistic actions of traditional decoction of TCMs. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Khat, the leaves of Catha edulis, is used as a “natural amphetamine-like” stimulant in eastern and southern Africa, as well as in the Arabian Peninsula. Leaves are masticated to elicit a state of euphoria. Although the psychostimulatory effects of the leaves are attributed to the presence of phenylpropylamino alkaloids ( i.e. cathinone, cathine and norephedrine), the extent of permeation of these alkaloids across the oral and intestinal mucosa has not been established. Materials and methods Cathinone was isolated in the form of the oxalate salt from young buds, following acid-base extraction. High performance countercurrent chromatography (HPCCC) was used to isolate cathine and norephedrine, following borohydride reduction of a mixture of the three alkaloids. The in vitro permeability of these three alkaloids in their pure form, as well as in a crude extract, was evaluated across Caco-2 cell monolayers and across excised porcine intestinal, sublingual and buccal tissues. Results The purities of the isolated cathine and norephedrine were in excess of 90%, thereby proving that HPCCC can be applied for efficient separation of these alkaloids from extracts of Khat. The apparent permeability (P app ) coefficients for the Khat alkaloids in their pure form were all above 1.0×10 −6 cm/s, indicating that the transport of the three alkaloids across the selected biological membranes is comparable to that of the highly permeable reference compound, caffeine. Although readily transported across the various membranes, the alkaloids were transported to a lesser extent when present in a leaf extract, suggesting that other phytochemicals present in the extract influence their permeation. Conclusions These results provide evidence that chewing of Khat contributes to the buccal and sublingual absorption of the psychoactive alkaloids in the bloodstream directly across the oral mucosal membranes. In addition, it confirms that these metabolites will be readily absorbed from the gastrointestinal tract when swallowed. [ABSTRACT FROM AUTHOR]

Although Mexican oregano inhibits digestive enzymes in vitro its effect on the absorption of carbohydrates and lipids in vivo has not been addressed. Assess the effect of Mexican oregano (Lippia graveolens Kunth) on carbohydrates and lipids absorption in vivo. The antioxidant activity also was investigated. Enzymatic inhibitory action of lipase, α-amylase, and α-glucosidase was evaluated in vitro. Oral lipid (OLTT) and starch tolerance tests (OSTT) were conducted with L. graveolens acetone (O-A) and ethanol (O-E) extracts (at 102 mg/kg body weight equivalent to a 1 g human doses) in male Wistar rats. The antioxidant activity was evaluated through inhibition of lipid peroxidation and scavenging radical. Both extracts exhibited higher inhibitory median concentration (IC 50) of lipase activity (1.9 μg/μL for O-E and 1.8 μg/μL for O-A) than the positive control (Orlistat) (0.07 μg/μL). The IC 50 of α-amylase was higher (41.8 μg/μL for O-E and 25.2 μg/μL for O-A) than the Acarbose (2.5 μg/μL); while α-glucosidase results showed not statistically differences between groups (∼1.7 μg/μL). The OLTT results showed that both extracts significantly reduced serum triglycerides (∼147 mg/dL for O-E and ∼155 mg/dL for O-A) as compared with negative control group (only lipid load). In the OSTT, glucose levels showed a significant decrease (∼31 mg/dL for O-E and ∼17 mg/dL for O-A) than the negative control group (only starch load). About in vitro antioxidant evaluation, not statistically differences between extracts and positive control (Trolox) were observed for scavenged free radicals (∼2.0 μg/μL); whereas O-A inhibited lipid peroxidation similar to the Trolox (∼0.8 μg/μL IC 50). The main chemical composition of both extracts was coumaric acid, luteolin, rutinoside, naringenin, and carvacrol. Both extracts reduce lipid absorption; whereas O-E decreases carbohydrate absorption in vivo. Both extracts inhibit lipid peroxidation and scavenging free radicals in vitro. [Display omitted] • Lippia graveolens extracts decreased the absorption of dietary carbohydrates. • Lippia graveolens extracts decreased the absorption of dietary lipids. • Lippia graveolens extracts exhibit lipid peroxidation and scavenging radicals in vitro. [ABSTRACT FROM AUTHOR]

Piper methysticum G. Forst, popularly known as kava, is a traditional medicinal plant native from South Pacific islands and widely used to treat anxiety, depression and stress. The psychoactive properties are related to the kavalactones, mainly kavain. To evaluate the biopharmaceutical properties of synthetic kavain and when present in kava dried extracts by means of equilibrium solubility and intestinal permeability studies in the Caco-2 cell model. The equilibrium solubility of kavain was performed using a shake flask incubator at 37 °C in different media at physiological pH range (1.2–6.8). The intestinal permeability of kavain evaluated in Caco-2 cells in the presence and absence of the P-glycoprotein inhibitor verapamil. Kavain concentrations were determined by reversed phase high performance liquid chromatography (HPLC). HPLC methods were developed and fully validated for kavain quantitation. Kavain demonstrated low solubility and the pH of the aqueous media did not affect its solubility. Kavain was found to be highly permeable and efflux of kavain mediated by P-glycoprotein was not significant during intestinal permeation. The results of biopharmaceutical studies provided useful information for predicting availability of kavain from the gastrointestinal tract and this compound was ranked as BCS Class II, exhibiting dissolution rate-limited absorption. [Display omitted] [ABSTRACT FROM AUTHOR]

Our previous studies found that the ethanol extract of Gynura procumbens (EEGS) reduced hepatic steatosis in alcoholic fatty liver disease (AFLD). To explore the active ingredients from EEGS and their relevant mechanism of action in alleviating alcoholic liver injuries. To explore the active ingredients from EEGS and their intestinal absorption characteristics as an approach for understanding mechanism of action in alleviating alcoholic liver injuries. Monitored by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC), chemical constituents from the prepared EEGS were isolated by means of solvent extraction, repeated column chromatography, preparative HPLC and other methods, and their structures were identified based on spectroscopic methods. The in vivo intestinal absorption rate of chlorogenic acid (CA), the active component of the EEGS, both in a single form and in the EEGS were monitored by the single-pass intestinal perfusion (SPIP) method in rats. The protective effect of EEGS and its active components on alcoholic liver injuries was evaluated in the alcoholic liver injury model of C57BL/6J male mice induced by Lieber-DeCarli alcohol liquid feed. Three noncaffeoyl quinic acid components were isolated and identified from the EEGS, namely, 3-trans- p -coumaroyl quinic acid (0.9%), 3-cis- p -coumaroyl quinic acid (2.7%), and trans- p -coumaric acid (0.6%). In vivo intestinal absorption of CA decreased with the increase of pH value of perfusion solution in the range of 5.5–7.8. The maximum absorption percentage of CA alone was 6.7 ± 2.4%, while the maximum absorption percentage of CA in the EEGS was 16.0 ± 2.2%, which was 2.4 times higher than that of CA alone. The results of animal experiments showed that the degree of fatty liver of mice treated with EEGS was significantly lower than that of the CA, trans- p -coumaric acid, and the combination group of CA and trans- p -coumaric acid alone. The above results indicated that trans- p -coumaric acid isolated from the dried stems of Gynura procumbens assisted CA being absorbed into the body and worked together with CA to improve the function of liver lipid metabolism, reduce hepatic lipid accumulation in a mouse model of AFLD and effectively counteract alcohol-induced fatty liver disease. [Display omitted] • Three coumaric acids were firstly isolated from ethanol extract of Gynura procumbens. • Trans- p -coumaric acid can improve the intestinal absorption of chlorogenic acid (CA). • Trans- p -coumaric acid together with CA play a reversal effect of AFLD. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Jiegeng (Radix Platycodi), the dried root of Platycodon grandiflorum A. DC (Campanulaceae), has been used to treat cough, sore throat, bronchitis, and bronchial asthma for thousands of years. It is commonly prescribed with Gancao (Radix et Rhizoma Glycyrrhizae ) as a herbal combination in traditional Chinese medicine (TCM) to produce synergistic effects. Aim of the study To elucidate the herbaceous compatibility of Jiegeng and Gancao, we investigated the comparative pharmacokinetics, intestinal absorption, and microbial metabolism of platycodin D (PD) and deapio-platycodin D (DPD), the platycodins contained in Jiegeng. Materials and methods In the comparative pharmacokinetic study, the concentrations of PD and DPD in Jiegeng extract (JE) and the Jiegeng–Gancao herb pair (JGHP) were determined in rat plasma using liquid chromatography–tandem mass spectrometry (LC–MS/MS). In addition, the main pharmacokinetic parameters were calculated using data analysis software (DAS). Furthermore, in vitro studies using Caco-2 cells and fecal lysates were performed to contradistinguish the intestinal absorption and microbial metabolism of PD and DPD in JE from those in JGHP. Results The peak concentration ( C max ) and area under the plasma concentration curve ( AUC ) of PD in rats orally administrated JGHP significantly increased compared to that in rats treated with JE. In addition, the time to reach peak concentration ( T max ) and half-life ( t 1/2 ) of PD and DPD in combination with JGHP were all prolonged compared with those of JE. There was no significant difference in the absorption of PD between JE and JGHP in Caco-2 cells. However, the hydrolysis of both PD and DPD in JGHP were weaker than that in JE after a 2-h incubation in fecal lysate which might be responsible for the different pharmacokinetic profiles of the platycodins in JE and JGHP. Conclusion In this study, we discovered that Gancao might influence the pharmacokinetic profiles of PD and DPD in Jiegeng. Furthermore, the difference in profiles may be attributable to the inequable microbial metabolism rather than intestinal absorption of the platycodins in JE and JGHP. The results of this study elucidated the pharmacokinetic compatibility and rationale for the use of JGHP. [ABSTRACT FROM AUTHOR]

Painong San is a prescription composed of traditional Chinese medicine, which has been used to treat colitis. The Painong San's usage recorded in "Jingui Yaolve" by Zhongjing Zhang in the Later Han Dynasty is powder. However, the decoction is often used in reality. It's unclear which dosage form of Painong San is more suitable for colitis treatment and why? This study aims to evaluate the different therapeutic effects of Painong San (a powder of Painong San) and Painong Decoction (a decoction of Painong San) on a dextran sulfate sodium salt-induced colitis model and the possible reasons of these different effects. The contents of paeoniflorin, naringin, heperidin and neohesperidin in Painong San and Painong decoction were determined by an ultra-performance liquid chromatography system. The therapeutic effect on colitis was evaluated by intragastric administration of Painong San or Painong Decoction in dextran sulfate sodium salt-induced mouse model. The accumulated release rate of Painong San in vitro was analyzed with artificial gastric juice, artificial intestinal juice, and artificial colon juice. The concentrations of four compounds in the blood, intestinal contents, and intestinal fluids were detected by an-ultra performance liquid chromatography-tandem quadrupole mass spectrometry system. In situ intestinal perfusion experiments were used to observe the adhesion of Painong San to the intestine's surface. The expression of Mucin-2 and Trefoil Factor 3 in the colon was studied by immunohistochemistry. There was no significant difference in the contents of the four compounds in Painong San and Painong Decoction. In vivo , Painong San has a better therapeutic effect than Painong Decoction in the treatment of colitis. Painong San could be released slowly in the simulated human digestion environment in vitro , and more Painong San particles were released on the intestinal surface in the colitis state in the healthy state. Painong San could increase the bioavailability of hesperidin and neohesperidin, and their concentrations in local intestinal tissue, intestinal fluid and intestinal contents. The expression of trefoil Factor 3 protein on the surface of the colon tended to be in the intestinal cavity and overlapped with the expression of mucin-2. Trefoil Factor 3 accumulates in the intestinal cavity of the colon in the state of colitis, which may increase the adhesion of Painong San particles. In conclusion, this experiment proved that Painong San is a more suitable dosage form for the treatment of dextran sulfate sodium salt-induced colitis than Painong Decoction, which may be related to the enhancement of Painong San particle adhesion to the intestine in colitis. This study provides a reference for the selection of clinical dosage forms for traditional Chinese medicine. [Display omitted] [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Glycyrrhizae radix et rhizoma (Gancao) is often prescribed together with Sophorae flavescentis radix (Kushen) in traditional Chinese medicinal practice to increase the efficacy on the treatment of hepatitis and hepatic fibrosis. Meanwhile, long-term single used Gancao can cause adverse reactions, lead to pseudohypercorticosteroidism especially. But the side effects of Gancao are significantly reduced when combined with Kushen; the reasons are still unknown. The aim of this study was to elucidate potential pharmacokinetic interaction between Kushen and Gancao, and to provide guidance for clinical medicine safety. Materials and methods A specific and rapid HPLC–MS method was established to quantify the four main activity ingredients matrine (MT), oxymatrine (OMT), glycyrrhizin (GL) and glycyrrhetinic acid (GA) in rat plasma. In this study, the pharmacokinetic parameters and the pharmacokinetic differences of the four main activity ingredients MT, OMT, GL and GA in single herb and Kushen–Gancao couple were obtained. Results Compared with oral administration of Gancao extract, K 10 and T max of GA significantly increased to 0.43 h −1 and 30 h after giving Kushen–Gancao ( p <0.05), but T 1/2 and V d were reduced to 0.73 L kg −1 and 4.98 h ( p <0.05). In addition, the AUC of GA was increased, and the other three activity ingredients all decreased. Conclusion GA as the main factor leading to the sodium–water retention side effects of Gancao. The result found that the absorption of GA was significantly slowed down and the metabolism rate was accelerated in Kushen–Gancao than single herb. So the attenuated toxicity mechanism may be because the accumulation of GA reduced in vivo. The conclusion has important meaning to the compatibility of Chinese med. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Mahuang decoction, Ephedra combined with Cassia twig, Bitter apricot kernel and Prepared licorice, has been widely used as a multi-herb prescription in traditional Chinese medicine (TCM). Many modern pharmacological studies have shown that the compatibility application of these four herbs has promising therapeutic effects on respiratory infection, acute glomerulonephritis and chronic renal failure. However, the underlying principles for governing the formulation of Mahuang decoction remain unknown. In this study, we used a Caco-2 cell monolayer model to explicate the possible compatibility mechanism of Mahuang decoction from the perspective of intestinal absorption. Material and methods Firstly, the apical-to-basolateral and basolarteral-to-apical transport of the main characteristic active alkaloids in Ephedra, l -ephedrine (LEP), d -pseudoephedrine (DPEP) and l -methylephedrine (LMEP), as a single compound, was investigated. Secondly, the influence of main components in Cassia twig, Bitter apricot kernel and Prepared licorice on the transport of LEP, DPEP and LMEP was investigated. Finally, the bidirectional transport of these three alkaloids in single Ephedra extract, in Mahuang decoction and in drug pair extracts, such as Ephedra–Cassia twig, Ephedra–Bitter apricot kernel, Ephedra–Prepared licorice, was assessed. Results The investigated LEP, DPEP and LMEP could transport through the Caco-2 cell monolayer at a high level, with the efflux ratio (ER) of 1.41, 1.33 and 1.30, respectively, when the cells were treated with each single compound solution. In the presence of verapamil, the permeability from apical side to basolateral side ( P AB ) of the three alkaloids increased significantly ( P <0.05), and their ERs decreased. The treatment of cells with Mahuang decoction and the drug pair extracts from Ephedra–Cassia twig, Ephedra–Bitter apricot kernel and Ephedra–Prepared licorice appreciably decreased P AB of LEP, DPEP and LMEP with increased ERs, compared to the treatment with single Ephedra extract. When concomitant administration with herbal drugs and their main ingredients (including cinnamaldehyde–cinnamyl alcohol–cinnamic acid group, volatile oil from Cassia twig, liquiritin–glycyrrhizic acid group from Prepared licorice, Cassia twig extract, Bitter apricot kernel extract and Prepared licorice extract), was adopted, P AB of LEP, DPEP and LMEP were reduced significantly and the ERs of the corresponding compounds were promoted appreciably. Only amygdalin (from Bitter apricot kernel) had little influence on the transport of Ephedra alkaloids. Conclusion The findings indicate that LEP, DPEP and LMEP in Ephedra extract have similar absorption as in the pure solution of each compound. The intestinal absorption of LEP, DPEP and LMEP is through passive diffusion and these compounds may be P-gp substrates. The compatibility application of Cassia twig, Bitter apricot kernel and Prepared licorice, and their main components except amygdalin can suppress the absorption of the three main Ephedra alkaloids across the Caco-2 cell monolayer. On the basis of our results, Cassia twig, Bitter apricot kernel and Prepared licorice in Mahuang decoction decrease the absorption of Ephedra alkaloids, which may alleviate the drastic diaphoretic function and toxicity of Ephedra. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance It is said that black tea is effective against type 2 diabetes mellitus because it can help modulate postprandial hyperglycemia. However, the mechanism underlying its therapeutic and preventive effects on type 2 diabetes mellitus is unclear. In this study, we focused on the effect of black tea on the carbohydrate digestion and absorption process in the gastrointestinal tract. We examined whether black tea can modulate postprandial hyperglycemia. Materials and methods The freeze-dried powder of the aqueous extract of black tea leaves (JAT) was used for in vitro studies of α-amylase activity, α-glucosidase activity, and glucose uptake by glucose transporters in Caco-2 cells; ex vivo studies of small intestinal α-glucosidase activity; and in vivo studies of oral sugar tolerance in GK rats, an animal model of nonobese type 2 diabetes mellitus. Results Half maximal inhibitory concentration values indicated that JAT significantly reduced α-glucosidase activity, but weakly reduced α-amylase activity. Kinetic studies of rat small intestinal α-glucosidase activity revealed that the combination of JAT and the α-glucosidase inhibitor, acarbose, showed a mixed-type inhibition. JAT had no effect on the uptake of 2′-deoxy- d -glucose by glucose transporter 2 (GLUT2) and the uptake of α-methyl- d -glucose by sodium-dependent glucose transporter 1 (SGLT1). In the oral sucrose tolerance test in GK rats, JAT reduced plasma glucose levels in a dose-dependent manner compared with the control group. The hypoglycemic action of JAT was also confirmed: JAT, in combination with acarbose, produced a synergistic inhibitory effect on plasma glucose levels in vivo . In contrast to the oral sucrose tolerance test, JAT showed no effect in the oral glucose tolerance test. Conclusions JAT was demonstrated to inhibit the degradation of disaccharides into monosaccharides by α-glucosidase in the small intestine. Thereby indirectly preventing the absorption of the dietary source of glucose mediated by SGLT1 and GLUT2 transporters localized at the apical side of enterocytes in the small intestine. The results indicate that black tea could be useful as a functional food in the dietary therapy for borderline type 2 diabetes mellitus that could modulate postprandial hyperglycemia. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Radix Isatidis called “Ban-Lan-Gen” is one of the most commonly-used traditional Chinese medicines for antiviral, anti-inflammatory, antioxidant and antipyretic purposes. Investigate the bioaccessibility of uridine, epigoitrin, adenosine, clemastanin B, indigoticoside A and isolariciresinol as well as the antioxidant and anti-inflammatory activities during an in vitro gastro-intestinal digestion of the Radix Isatidis extract (RIE). Materials and methods High performance liquid chromatography (HPLC) technique was adopted to determine the bioaccessibility of six bioactive compounds in RIE. Antioxidant activities of RIE in different digestive stages were determined by 1,1-Diphenyl-2-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radical scavenging abilities. Anti-inflammatory activity was assayed by the inhibitions of inflammatory cytokines such as nitrous oxide (NO), prostaglandin E 2 (PGE 2 ) and tumor necrosis factor α(TNF-α) producted by lipopolysaccharide (LPS) stimulated RAW264.7 cells. Results The bioaccessibility of uridine, epigoitrin, adenosine, clemastanin B, indigoticoside A and isolariciresinol were 15.38%, 18.28%, 24.01%, 6.50%, 8.65% and 17.78%, respectively. Also, the digestion products still possessed certain antioxidant activities. The antioxidant activity was highly correlated with lignans (clemastanin B, indigoticoside A and isolariciresino). The anti-inflammation activity of the three samples decreased in the order: IN sample (the solution that had diffused into the dialysis tubing)>Nondigested sample (RIE solution)>Gastric sample (post-gastric digestion)>OUT sample (material that remained in the gastro-intestinal tract). Conclusions Results obtained in this research reveal the amount of bioactive compounds from RIE that could be available for absorption in vivo . The antioxidant activity decreased significantly but the anti-inflammatory activity was enhanced in serum-available fraction after gastro-intestinal digestion in vitro . This study could provide a scientific basis for a deeper pharmacological activity study of Radix Isatidis and a simple method for pharmacodynamic material basis research. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: Although the increased usage of herbal medicine leading to herb–drug interactions is well reported, the mechanism of such interactions between herbal medicines with conventionally prescribed drugs such as warfarin is not yet fully understood. Our previous rat in vivo study demonstrated that co-administration of Danshen–Gegen Formula (DGF), a Radix Salvia miltiorrhiza (Danshen) and Radix Puerariae lobatae (Gegen) containing Chinese medicine formula recently developed for the treatment of cardiovascular disease, with warfarin could cause significant herb–drug interactions. The current study aims to explore the pharmacokinetics-based mechanism of the DGF–warfarin interactions during absorption, distribution and metabolism processes. Materials and methods: Caco-2 cell monolayer model and rat in situ intestinal perfusion model were used to study the DGF–warfarin interactions during the intestinal absorption processes. Male Sprague–Dawley rats were orally administered warfarin in presence and absence of DGF for consecutive 5 days. The microsomal activity and expression of the liver CYP isozymes were determined and compared among different treatment groups. Blood from the rats administered DGF was employed to evaluate effects of DGF on the plasma protein binding of warfarin. Results: Absorption studies demonstrated that DGF could potentially increase the intestinal absorption of warfarin (32% and 75% increase of warfarin P app in Caco-2 and intestinal perfusion models, respectively) via altering the regional pH environment in GI tract. DGF administration could lead to significant increase in liver microsomal activity and mRNA expression of CYP1A1 and CYP2B1, indicating the potential induction on the liver metabolism of warfarin by DGF. Moreover, it has been proven by ex vivo study that the single-dose administration of DGF could decrease the protein binding of warfarin in plasma by at least 11.6%. Conclusion: Collectively, current study demonstrated that DGF could significantly induce the liver phase I metabolism of warfarin, and to a less extent, potentially increase the intestinal absorption and decrease the plasma protein binding of warfarin. The inductive effects of DGF on the liver phase I metabolism of warfarin may be dominantly responsible for the DGF–warfarin pharmacokinetics interactions. [Copyright &y& Elsevier]

Dianbaizhu (Gaultheria leucocarpa var. yunnanensis) as a Chinese folk medicine exerts significant treatment effects on rheumatoid arthritis (RA) with a long historical time. Our previous reports showed that the anti-rheumatic arthritis fraction (ARF) extracted and enriched from Dianbaizhu possessed good druggability, which was better than its single active ingredients. However, the intestinal transport characteristics and mechanism of ARF have not been elucidated to date. In order to illustrate the role of active ingredients of ARF in alleviating RA and promoting the development of dosage forms, the intestinal metabolism, absorption properties and mechanism of ARF in vitro and in situ models were investigated. Firstly, after incubating with 4 intestinal segments (duodenum, jejunum, ileum, and colon), 7 key components in ARF, including MATG-B, (+)-catechin, MSTG-A, Gaultherin, chlorogenic acid, quercetin, and kaempferol were quantitatively analyzed by a high-performance liquid chromatography (HPLC). Secondly, combining the physiological and pathological rats, the in situ single-pass intestinal perfusion and in vitro everted gut sacs of rats were performed to investigate the absorption features and transport mechanisms of ARF using HPLC and HPLC-Q-TOF-MS/MS. Subsequently, in situ studies were employed to determine the effect of P-glycoprotein (P-gp) inhibitor (verapamil) on the transport characteristics of ARF in RA model rats. Comparing the absorption parameters of ARF incubated in different intestinal segments, data showed that the absorption of ARF in the small intestine was significantly stronger than that of the colon (P < 0.01). The number of characterized prototype components was subjected to the incubation time, drug concentration and rat body condition, but not the intestinal segments. There were no significant differences in the number of metabolites among different intestinal segments, administration concentrations and incubation time. The best small intestinal absorption site of ARF was duodenum and ileum in normal and model rats, respectively. The P eff values of 7 index compounds were all higher than 0.2 × 10−4cm/s, and the F a values of 7 index compounds were all greater than 20% in the in situ perfusion investigation. The results showed that MSTG-B, MSTG-A and Gaultherin were likely to be substrates of P-gp as verapamil significantly enhanced their P eff and K a values, while other ingredients were not P-gp substrates. The intestinal membrane permeability of ARF was good. Its intestinal absorption mechanisms mainly involved active transportation processes and passive diffusion. Besides, this report provided data support and basis for clinical development, bioavailability improvement and formulation design. [Display omitted] • 7 components were determined to evaluate the gut absorption characteristics of ARF. • The gut transport mechanism of ARF was explored by in vitro and in situ models. • The best absorption segment of ARF was ileum. • MSTG-A, MST-B and Gaultherin in ARF might be P-gp subtracts. [ABSTRACT FROM AUTHOR]

In traditional Chinese Medicine, Rehmannia glutinosa (Gaertn.) DC., as the principle herb of ShengDiHuang Decotion (SDHD), has the effect of cooling blood and hemostasis, and tonifying the yin and kidney. Rheum L., as adjuvant herbs, assist Rehmannia glutinosa (Gaertn.) DC. to promote blood circulation to remove blood stasis. To study the mechanism of Rhein (RH) involved in the promotion of Rehmannioside D (RD) absorption by pharmacokinetic studies, single-pass intestinal perfusion, Caco-2 cell models, molecular docking technique and western blotting. Initially, the intestinal absorption of RD in the presence or absence of RH was conducted through pharmacokinetic studies. Thereafter, the intestinal absorption of RD and RH was studied using the single-pass intestinal perfusion and Caco-2 cell models. Finally, using molecular docking technique and western blotting. We found that the promotion of RD absorption by RH was mediated by breast cancer resistance and multidrug resistance-associated protein 2, thereby affecting the permeability of the intestinal epithelium. Additionally, RH and RD can competitively bind to breast cancer resistance and multidrug resistance-associated protein 2, and that RH inhibits the expression of breast cancer resistance and multidrug resistance-associated protein 2 in the ileum to promote the intestinal absorption of RD. This study reveals the mechanisms associated with the RH-mediated promotion of RD absorption and provides a basis for further exploring the synergistic effect of Rehmannia glutinosa (Gaertn.) DC and rhubarb. [Display omitted] [ABSTRACT FROM AUTHOR]

Luohanguo (LHG) extract major contenting mogrosides, as a nonnutritive sweetener, has been reported to exert a hypoglycemic effect on diabetic patients and animals. As the pharmacokinetics and pharmacodynamics of drugs were changed with diabetes, it may lead to the different pharmacological of mogrosides between diabetic and normal subjects. To characterise the pharmacokinetic profiles of mogrosides in T2DM rats. High-fat diet and streptozocin induced type 2 diabetic mellitus rats were used to investigate the pharmacokinetic behavior of mogroside V and mogrosides IIIA 1 , IIA 1 , and IA 1 after T2DM rats orally administrated with mogroside V and 1–3 glucose residues' mogrosides, respectively. The validated convenient UPLC-QTOF/MS and UPLC-MS/MS methods were established to use in the pharmacokinetic studies of mogrosides in normal and T2DM rats. Additionally, the expression of the intestinal tight junction protein zonula occludens-1 (ZO-1) was also detected by immunohistochemical analysis, which assessed the function of passive intestinal permeability in T2DM rats. The results showed that for rats treated with mogroside V, its metabolite mogroside IIIA 1 has a significant increase (p < 0.05) in maximum plasma concentration (C max , 163.80 ± 25.56 ng/mL) and area under the plasma concentration (AUC 0-t , 2327.44 ± 474.63 h·ng/mL) in T2DM rats compared with in normal rats. The mean residence time (MRT 0-t , 12.04 ± 0.97 h) of mogroside V showed a significant decrease (p < 0.05) in T2DM rats. However, the mogrosides IIIA 1 , IIA 1 and IA 1 showed no statistical differences in the normal and T2DM rats after administered with 1–3 glucose residues' mogrosides. Furthermore, the expression level of ZO-1 in the duodenum and colon of T2DM rats were downregulated. The pharmacokinetic profiles of mogroside V and its metabolite mogroside IIIA 1 in T2DM rats and normal rats showed some difference, it might be affected by the metabolic changes in the pathological state of T2DM. [Display omitted] • The absorption behavior of mogroside V and its metabolite mogroside IIIA 1 were influenced by the T2DM condition in T2DM rats. • After administrated with mogrosides, the absorption of mogrosides IIIA1, IIA1 and IA1 showed no marked changes in T2DM rats. • The expression of ZO-1 protein in the T2DM rat's duodenum and colon were decreased. • It provides reference for understanding the pharmacokinetics and pharmacodynamics of mogrosides in both normal and T2DM rats. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: Traditional Chinese medicine (TCM) has been used in clinical practice for several thousand years. TCM has played an indispensable role in the prevention and treatment of disease, especially the complicated and chronic ones. In TCMs, many ingredients which are known to have biological effects just pass through the gut, they do not get into the bloodstream. Study on interactions of these active ingredients with the intestinal bacteria is very helpful to unravel how TCM works. Radix scutellariae was widely used alone or in combination with other medicinal herbs to the treatment of type 2 diabetes mellitus for a long time in China even in Asia. Additionally, the incidence of type 2 diabetes is closely related to the changes of intestinal flora. In this paper, the metabolism of baicalin in Radix scutellariae extract by normal and type 2 diabetic mice intestinal bacteria were firstly investigated. Materials and methods: Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/QTOF-MS) technique combined with MetabolynxTM software was used for analysis of the metabolic profile of baicalin in Radix scutellariae extracts by the intestinal bacteria from normal and type 2 diabetic mice. Results: The amount of baicalin׳s aglycone (baicalein) in type 2 diabetic mice samples were remarkably more than that in normal mice samples and oroxylin A only existed in type 2 diabetic mice samples. Intestinal bacteria produced not only a small amount of baicalein, but also some conjugates such as hydrogenated baicalin and methylated baicalin. Conclusions: We proposed that β-d-glucuronidases contributed to the deglycosylation prior to absorption. Intestinal bacteria from pathological state mice produced more baicalein, which was well absorbed contributing to the treatment of type 2 diabetes. Additionally, the pharmacological effects of oroxylin A were associated with type 2 diabetes. Hence, the production of metabolites of baicalin might influence the effects of traditional medicines. Thus the study on the metabolism of baicalin by intestinal bacteria from normal and type 2 diabetic mice was of great importance to understanding the effects of traditional medicines. Furthermore, this work demonstrated the potential of the ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry approach with MetaboLynx for quite rapid, simple, reliable and automated identification of metabolites of natural products. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Diabetes mellitus, characterized by abnormal blood glucose evaluation, is a serious chronic disease. In the treatment of the disease, α-glycosidase inhibitors play an important role for controlling the postprandial blood glucose level. Cortex Mori, a traditional Chinese herbal medicine, has a long history of use for the treatment of headaches, cough, edema and diabetes. Modern pharmacological studies have shown that the herb has beneficial effects on the suppression of postprandial blood glucose levels by inhibiting α-glycosidase activity in the small intestine. 1-Deoxynojirimycin (DNJ), the main active ingredient of this herb, is recognized as a potent α-glycosidase inhibitor. Our previous studies have shown that the hypoglycemic effect of Cortex Mori extract (CME) was significantly improved when giving CME in combination with Radix Pueraria flavonoids (RPF). In the present study, the pharmacokinetics and intestinal permeability of DNJ were comparatively investigated in rats after being given orally or by intestinal perfusion with CME alone or in CME–RPF pairs, to explore the mechanism of this synergistic effect. Materials and methods: The role of RPF on the plasma and urine concentrations of DNJ from CME orally administered was investigated. Four groups of rats received a single oral dose of either CME or CME–RPF, at DNJ equivalent doses of 20 and 40mg/kg, respectively. After dosing, plasma and urine were collected and assayed by LC/MS/MS. In addition, another two groups of rats were used for small intestinal perfusion with CME or CME–RPF at DNJ concentration of 10µM. Results: Compared to the data when dosing with CME alone, the C max of DNJ were decreased from 5.78 to 2.94µg/ml (p<0.05) and 10.66 to 5.35µg/ml (p<0.01); T max were delayed from 0.40 to 0.55h and 0.35 to 0.50h (p<0.05); and MRT were significantly prolonged from 1.14 to 1.72h (p<0.05) and 0.95 to 1.62h (p<0.01), after dosing with CME–RPF at DNJ doses of 20 and 40mg/kg, respectively. In addition, the urinary recovery of DNJ over the first 4h after dosing significantly decreased from 48.76% to 33.86%. Effective permeability (P eff) of DNJ was decreased from 7.53×10−3 to 3.09×10−3 cm/s (p<0.05) when RPF was added to CME, when it was evaluated using the rat intestinal perfusion model. Conclusions: All the above results demonstrate that RPF was able to suspend and delay the absorption of DNJ, but did not affect the total amount of DNJ in the body. The resulting higher concentration of DNJ in the small intestine produced a relatively stronger effect of depressing the elevation of the postprandial blood glucose level. These findings support the important role of RPF in the application of CME on blood glucose control. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Angelicae Dahurica (Hoffm.) Benth. & Hook. f. ex Franch. & Sav combined with Radix Scutellariae baicalensis Georgi has been widely used in traditional Chinese medicine (TCM) as an antipyretic analgesic and anti-inflammatory drug. Modern pharmacological studies have demonstrated that the compatible application of these two drugs is an effective treatment for hepatitis. A previous study indicated that a Radix Angelicae Dahuricae extract enhanced the intestinal absorption of the baicalin found in Radix Scutellariae; however, the underlying compatibility mechanism of these two herbs remains unknown. In this study, we further examined the effect of a Radix Angelicae Dahuricae extract on the absorption and transport properties of baicalin in a Caco-2 cell model to determine the compatibility mechanism of these two herbs. Aim of the study: The aim of this work was to study the transport properties of baicalin in Radix Scutellariae across cell membranes and the effects of a Radix Angelicae Dahuricae extract on baicalin absorption using the well-characterized, human-based intestinal Caco-2 cell model. Materials and methods: We assessed the absorption, bidirectional transport and toxicity of baicalin using a range of parameters, including drug concentration, pH, a P-glycoprotein (P-gp) inhibitor (Verapamil), an MRP inhibitor (MK-571) and EDTA-Na2 (tight junction modulator). Next, we studied the influence of a Radix Angelicae Dahuricae extract on the transport of baicalin under the same conditions. Drug concentration was measured by HPLC, and the apparent permeability coefficient (Papp) and apparent permeability ratio (PDR) were subsequently calculated. Results: The results showed that baicalin is non-toxic within a concentration range of 800µg/mL to 4800µg/mL. The transport of baicalin showed time and concentration dependence. The absorption of baicalin was optimal at pH 7.4 in 37°C; however, the absorption decreased at 4°C. The Papp of baicalin transport through the Caco-2 cell monolayer model was altered when specific inhibitors of P-gp or MRP were added to the cells. However, there was no significant difference in the PDR value. The Papp of baicalin improved when it was combined with the Radix Angelicae Dahuricae extract. The influence of EDTA-Na2 on the transport of baicalin showed that the permeability of baicalin significantly increased. The result further indicated that the mechanism of baicalin intestinal absorption in the Caco-2 cell monolayer involves passive transcellular diffusion. Conclusions: Passive diffusion is the main mode of intestinal absorption of bacalin and it involved in the efflux of proteins. The enhanced intestinal absorption of baicalin by Radix Angelicae Dahuricae can be due to opening of the tight junctions between cells and inhibition of MRP efflux protein expression or function. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Traditional Chinese medicine (TCM), used in clinical practice for thousands of years, has been taken as a new way to tackle chronic diseases. In Chinese medicine, many ingredients which are known to have biological effects just pass through the gut, they do not get into the bloodstream. Study on interactions of these active ingredients with the intestinal bacteria is very helpful to unravel how TCM works. Aim of the study: Hyperoside is a major active constituent in many medicinal plants which are traditionally used in Chinese medicines for their neuroprotective, anti-inflammatory and anti-oxidative effects. It would be metabolized by intestinal bacteria after oral administration which leads to the variation of ethnopharmacological profile of these traditional medicines. Thus, it is necessary to investigate the metabolic routes and metabolites of hyperoside produced by human intestinal bacteria. Materials and methods: Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/QTOF-MS) technique combined with Metabolynx™ software was used for analysis of the metabolic profile of hyperoside by the isolated human intestinal bacteria from the human feces. Results: Parent compound and 6 metabolites (M1-M7) were detected in the isolated bacterial samples compared with blank samples. Quercetin, 3, 4-dihydroxyphenylacetic acid and 3, 4-dihydroxyphenylbenzoic acid (M2-M4) were only found in the sample of Bacteroides sp. 45. Dehydroxylation of hyperoside and the conjugates: acetylation and hydroxylation of hyperoside (M5–M7) were identified in the majority of isolated intestinal bacterial samples. Conclusions: Only Bacteroides sp. 45 could metabolize hyperoside to form its aglycone quercetin, thereafter, quercetin was further metabolized to 3,4-dihydroxyphenylacetic acid and 3,4-dihydroxyphenylacetic acid. Furthermore, the majority of bacteria could metabolize hyperoside to dehydroxylation of hyperoside and the conjugates: hydroxylation and acetylation of hyperoside. In this study, the metabolic routes and metabolites of hyperoside produced by the different intestinal bacteria were investigated for the first time. Furthermore, the production of metabolites of hyperoside might influence the effects of traditional medicines. Thus, the study on the metabolism of hyperoside by human intestinal bacteria is of great importance to an understanding of the effects of traditional medicines. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Aconitum carmichaelii Debx. (Fuzi in Chinese) has been widely clinically used to treat heart failure and rheumatism. Whereas its serious toxicity, Radix et Rhizoma Glycyrrhizae (Gancao in Chinese) was combined with it as traditional Chinese medicine (TCM) herb-pair for toxicity reduction and pharmacological effect improvement. Though some previous viewpoints about that has been reported, the underlying interaction mechanism of two herbs remain unknown and definitely worthy of investigating. Aim of study: In present study, we focus on Fuzi–Gancao herb-pair precipitation (FGP), considering it related to the compatibility mechanism of Fuzi–Gancao herb-pair. The intestinal absorption and pharmacokinetic characters of 3 diester diterpenoid alkaloids in the precipitation were investigated. Materials and methods: Both everted gut sac model and in situ single-pass intestinal perfusion model were used to investigate rat small intestinal permeability and transport mechanism of aconitine, hypaconitine and mesaconitine. Moreover, by means of determination of the plasma concentration, the pharmacokinetic characters of 3 alkaloid compounds in rats have been developed. Results: In everted gut sac permeability experiment, the permeability of hypaconitine appeared best in ileum. Furthermore, their uptakes were increased in the presence of P-glycoprotein (P-gp) inhibitors. In situ single-pass intestinal perfusion uptake experiment, results revealed that the transport mechanism may fit the active transport mechanism. And 3 alkaloids in FPG could be absorbed well in rats, fitting 2-compartment model with 1st order absorption and lag time. Conclusions: Our results in present study indicated that 3 diester diterpenoid alkaloids in FGP could be dissolved out in gastrointestinal tract firstly and then absorbed in blood after oral administration, which could result in prolonging their mean residence time and adding their absorbed doses, avoiding dose dumping. The current study has significant enlightenments for further investigation on the interaction mechanisms of other acid-base herb-pairs as well as Fuzi–Gancao herb-pair. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Rhein (Rh), baicalin (BG) and berberine (Be) are important coexisted constituents of San-Huang-Xie-Xin-Tang, which was widely used in traditional Chinese medicine for the treatment of gastritis, hypertension, gastric bleeding and peptic ulcers, etc. Aim of the study: Based on the extensive phase II conjugation reactions of polyphenols (Rh and BG) in vivo, the aims of the present study were to investigate the effects of combination (Rh, BG and Be) on the system exposures of total Rh and BG involving the phase II conjugates metabolites and its possible mechanism. Materials and methods: A 3×3 Latin square single heavy design was used to investigate the pharmacokinetics influence of total Rh and BG after combination of Be by treating plasma samples with β-glucuronidase/sulfatase both in beagle dogs and Wistar rats. In vitro and in situ experiment models including in situ rat intestinal perfusion, Caco-2 cell monolayer transport and small intestinal flora incubation system were used to discuss the possible mechanism. Results: The results of pharmacokinetic interactions showed that combination significantly reduced the system exposures of total Rh and BG. Compared with Rh or BG alone, the mean area under concentration-time curves (AUC0–t ) of total Rh and BG reduced by 31% and 77% in beagle dog experiment. In Wistar rat experiment, the AUC0–t of total Rh and BG reduced by 22% and 21%. Subsequently, the results of in situ rat intestinal perfusion and small intestinal flora incubation system tests revealed that combination may decrease the absorption and metabolism of BG. However, combination could not affect the transport profile of BG across the Caco-2 cell. Moreover, combination did not affect the absorption or metabolism profile of Rh in all three in situ/in vitro experiments. Conclusions: It was deduced that the possible mechanism of the reduction of the system exposures of total Rh and BG was related to that combination decreased the metabolism of BG to B or the phase II conjugates of Rh/BG excreted from liver/bile duct to their free aglycones in vivo by inhibiting intestinal flora. The potent effects of combination on the phase II conjugates of Rh and B in pharmacokinetics, shown in this paper, indicated that more attention should be paid to the phase II conjugates metabolites of these polyphenols (undergo extensive phase II conjugation reactions in vivo) when applied herbal products composed of these coexist compounds. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Angelicae Dahurica (Hoffm.)Benth.& Hook.f.ex Franch.&Sav combined with Pueraria labota (Willd.)Ohwi has been widely used as herb-pairs in traditional Chinese medicine (TCM) for utilization of antipyretic analgesic and anti-inflammatory drugs, and modern pharmacological studies have shown that application compatibility of the two drugs has the effects of cardiovascular disease treatment. The previous study has proved that Radix Angelicae Dahuricae extract could enhance the intestinal absorption of puerarin in Pueraria. But the underlying compatibility mechanism of the two herbs remains unknown. In this study we tried to further evaluate the improvement of Radix Angelicae Dahuricae extract on the puerarin using the Caco-2 cell model and explore the transport properties of puerarin through the above research to discuss the possible effect mechanism of Radix Angelicae Dahuricae extract on the transport of puerarin and the underlying compatibility mechanism of the two herbs. Aim of study: The aim of this work was to study the transport properties of puerarin in Radix Pueraria across Caco-2 cell membrane and to explore how the Radix Angelicae Dahuricae extract affected the transport of puerarin using the well-characterized, human-based intestinal Caco-2 cell model as a platform. Materials and methods: The bidirectional transport, and the effects of time, drug concentration, pH, P-gp inhibitors (Verapamil, Cyclosporin A), MRP inhibitor (MK-571) and EDTA-Na2 (tight junction modulator) on the absorption of puerarin were observed. Then the influence of extract of Radix Angelicae Dahuricae on the transport of puerarin was studied. Drug concentration was measured by HPLC and the apparent permeability coefficients (Papp) and apparent permeability ratio (PDR) were calculated. Results and conclusions: The results showed that the transport (Papp) of puerarin in Caco-2 cell monolayer model had time and concentration dependence, and the transport showed saturation characteristics with the time and concentration of puerarin to a certain degree. The Papp of puerarin transported on Caco-2 cell monolayer model was significantly changed when the specified inhibitors of P-gp were added to the model and the PDR decreased from 1.74 to 0.43. The absorption of puerarin was improved when combined with Radix Angelicae Dahuricae. The intestinal absorption of puerarin is by passive diffusion as the dominating process and active transportation was mediated by P-gp and MRP transporter in Caco-2 cell monolayer model, and Radix Angelicae Dahuricae could enhance the intestinal absorption of puerarin. [Copyright &y& Elsevier]

Abstract: Aims of the study: This study was to investigate the gastrokinetic activity of Morinda citrifolia aqueous fruit extract (AFE) in human subjects by examining the GI absorption of ranitidine, a putative indicator of GI motility and to elucidate its possible gastrokinetic mechanism of action in rats. Materials and methods: The single-dose, randomized, open-label and 2-period crossover study was performed on 20 Thai healthy volunteers with a washout period of 14 day between the doses. AFE or drinking water was administered orally 30min prior to a single oral administration of ranitidine (300mg). Blood samples were collected over a 12h period after drug administration and the pharmacokinetic parameters of ranitidine were calculated. The gastrokinetic mechanism of action of AFE was elucidated by measurement of its contractile response on the isolated rat gastric fundus strip. Results: The area under the plasma ranitidine concentration–time curve and the maximal plasma ranitidine concentration were significantly increased after pretreatment with AFE (p=0.001). The plasma ranitidine concentrations were significantly greater at 30–120min after its administration. AFE produced a definite contractile response of a rat gastric fundus strip with a dose dependency. Scopoletin at the same equivalent dose present in AFE elicited a concentration-dependent contraction that amounted to 45% of the maximal response to AFE. The contractile response of both AFE and scopoletin was mediated through the 5-HT4 receptor. Conclusion: AFE has a unique gastrokinetic activity in enhancement of the rate and the extent of ranitidine absorption. The underlying mechanism can be attributed, at least in part, to the ability of its active component: scopoletin to stimulate the 5-HT4 receptor. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Geniposide is derived from Gardenia jasminoides Ellis (Rubiaceae). Its anti-inflammatory, antithrombotic effects as well as its preventive effect against ischemic stroke have been reported. Radix notoginseng (Chinese name tienchi or sanqi) is the dried root of Panax notoginseng (Burk.) F.H. Chen, an herb noted for its promotion of blood circulation, blood stasis removal and pain alleviation, and has been widely utilized for the prevention and treatment of microcirculatory disturbances in China and other Asian countries for many years. Notoginsenoside R1 is an effective and structurally representative bioactive constituent of R. notoginseng. In our preliminary study, notoginsenoside R1 was able significantly to improve the bioavailability of geniposide in beagle dogs, but the underlying mechanisms remain unknown. Materials and Methods: The present study aimed to investigate the intestinal kinetic absorptive characteristics of geniposide as well as the absorptive behavior influenced by the co-administration of notoginsenoside R1 using an in vitro everted rat gut sac model. Results: The results showed good linear correlation between the geniposide absorption in sac contents and the incubation time from 0 to 120min. The concentration dependence showed a non-linear correlation between the geniposide absorption and the concentrations 0.356–1.424mg/mL, the absorption was saturated about 1.424mg/mL. Notoginsenoside R1 at 0.1 and 0.2mg/mL concentrations was able significantly to enhance the absorption of geniposide (1.424mg/mL) by 1.7- and 1.4-fold. Moreover, verapamil, a well-known P-glycoprotein inhibitor, was able significantly to elevate the absorption of geniposide 2.4-fold. Notoginsenoside R1 influenced geniposide''s absorption in a way similar to that of a P-glycoprotein inhibitor. Conclusions: In conclusion, notoginsenoside R1 significantly enhances the intestinal absorption of geniposide. As for the mechanism underlying the improvement of geniposide''s bioavailability, it is proposed that notoginsenoside R1 was able to decrease the efflux transport of geniposide by P-glycoproteins. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Baicalein (B), a bioactive flavone isolated from the root of a traditional Chinese medicinal herb Scutellaria baicalensis Georgi, was found to undergo extensive intestinal Phase II metabolism during its absorption process. Compounds sharing the same metabolic pathways with B or being inhibitors of enzymes UGT and SULT are expected to interfere with the metabolism of B leading to alteration of the absorption of B. The present study aims to identify potential intestinal absorption and metabolism interactions between B and four selected compounds, namely acetaminophen (APAP), (−)-epicatechin (EC), piperine (PIP) and curcumin (CUR) using in vitro and in situ models. Materials and methods: Three in vitro and one in situ methods were employed to investigate the effect of selected compounds on the metabolism and absorption on B. Incubation studies using rat intestinal s9 and Caco-2 cell lysate were used to study the effect of selected compounds on glucuronidation and sulfation of B. Sigmoidal dose–response curves were plotted and IC50 values were estimated. Apical to basolateral absorption study using Caco-2 cell monolayer model was also employed to study the effect of selected compounds on absorption of B. The most potent inhibitor identified was selected to further investigate its potential herb–drug interaction with B using in situ rat intestinal perfusion model. LC/MS/MS was used for the analysis of B and its metabolites in collected samples. Results: It was found that all the four selected compounds could produce a dose-dependent inhibition on the glucuronidation and sulfation of B. Moreover, the presence of CUR and high-dose EC demonstrated a subsequent increase in the absorption of B. In general, the order of potency on glucuronidation inhibition is: CUR>PIP>EC>APAP; while the potency order on sulfation inhibition is: CUR>EC>PIP>APAP. CUR was selected to further study its in vivo effect on B using in situ rat intestinal perfusion model. It was found that CUR could significantly increase the absorption of B via the inhibition on formation of its metabolites. Conclusions: Our findings indicated that the intestinal metabolism of B could be inhibited by all the selected compounds with CUR being the most potent inhibitor, which could result in subsequent increase of absorption of B. The current study had significant implications for further investigation on the in vivo evaluations of the herb–drug and herb–herb interactions between B and selected compounds, especially CUR. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Angelicae Dahurica(Hoffm.)Benth.&Hook.f.ex Franch.&Sav combined with Scutellaria baicalensis Georgi. has been widely used as herb-pairs in traditional Chinese medicine (TCM) to treat migraine headache and cataract, but the underlying compatibility mechanism of the two herbs remains unknown. Aim of study: In the present work, we investigated the additive or synergistic effects of absorption behavior of Radix Angelicae dahuricae extracts on baicalin, and the absorption-enhancing mechanism of Radix Angelicae dahuricae extracts on baicalin. Materials and methods: Total coumarins (Cou) and volatile oil (VO), as the two main components of Radix Angelicae dahuricae, were extracted by supercritical fluid extraction (SFE) further treated with liquid–liquid separation method. The absorption behavior was investigated by applying the everted gut sac technique and in situ single-pass intestinal perfusion method. Results and conclusions: The results showed that both the Cou and the VO could improve the intestinal absorption of baicalin in vivo, and had synergistic action the enhanced absorption of baicalin. Since verapamil did not affect the P app and K a of baicalin significantly, we concluded that the absorption of Baicalin could not be an active transportation in dependent of P-glycoprotein-Mediated efflux systems. Based on intestinal absorption of drug studying was one of the efficacious methods to clarify the compatibility of principles of herb-pairs. The everted gut sac technique and in situ single-pass intestinal perfusion technique model were the effective methods to study the absorption of drug, the application of the animal model to investigating the absorption of herb–drug interactions or other relevant research purposes is envisioned. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: Cinnabar (Cin), a naturally occurring mercuric sulfide (HgS), is a mineral widely used in traditional Chinese medicine throughout history. As for the toxicity of cinnabar, one important assumption is that cinnabar may be transformed into highly toxic methylmercury by gastrointestinal flora. There is no evidence in humans to support this assumption. Aim of the study: To investigate the biotransformation of cinnabar (HgS) in the human intestinal bacteria with modern analytical techniques. Materials and methods: A gas chromatograph, equipped with electron capture detection (GC-ECD) and mass spectrometry (GC–MS), were used to detect the formation of methylmercury after incubation of cinnabar with human intestinal bacteria. The content of soluble mercury in the bacteria media was determined by cold vapor-atomic absorption spectrometry (CV-AAS). In addition, X-ray absorption near-edge structure spectroscopy (XANES) was used to confirm the possible transformation of cinnabar in the bacteria media, and under mimetic intestinal condition by measuring the species of sulfur and mercury in the reaction extraction of cinnabar and Na2S mixture. Results: No methylmercury was detected by both GC-ECD and GC–MS, which suggest that cinnabar (HgS) is not methylated in the human intestine. A small amount of soluble mercury was found to be released in the flora medium of HgS or cinnabar by CV-AAS. The XANES analyses revealed that polysulfides exist in the flora medium, and the simulated results showed that the products by incubating cinnabar with Na2S were mercuric polysulfides. Conclusion: These results showed that under gut flora conditions cinnabar would be transformed into mercuric polysulfides rather than methylmercury. Our work provides evidences of nontoxic transformation of cinnabar in the human intestinal bacteria. [Copyright &y& Elsevier]

Background: Type II diabetes and obesity are major health problems worldwide and aboriginal peoples are particularly at risk. To address this problem in Canadian native populations who find modern pharmaceuticals culturally inappropriate, our team is testing the traditional pharmacopeia of the James Bay Cree for anti-diabetic and anti-obesity activities. More specifically, the aim of the present study was to define the effects of traditional plants on intestinal glucose absorption, an under-appreciated anti-hyperglycaemic and anti-obesity activity. Methods: Crude ethanol extracts of 17 Boreal forest medicinal plants were tested in vitro using the Caco-2 human enterocytic cell line and in vivo using an oral glucose tolerance test. Results: Thirteen of seventeen extracts were observed to significantly inhibit uptake when administered simultaneously with 3H-deoxyglucose. Inhibition was dose-dependent and, in a few cases, even surpassed that induced by a combination of the positive controls. To validate these effects in vivo, four plant extracts were administered by intragastric gavage at 250mg/kg to normal rats simultaneously with a 3g/kg bolus of glucose. This resulted in a decrease in peak glycaemia by approximately 40% for two of them. Similarly, only 2 extracts reduced glucose transport after long term incubation and this could be related to reductions in the expression of SGLT-1 or GLUT-2 proteins. Conclusions: These findings indicate that competitive inhibition of intestinal glucose uptake can be achieved by crude extracts of medicinal plants. Such extracts could be taken with meals to control postprandial glycaemia and reduce caloric intake in high risk populations that are positively inclined towards traditional medicine. [Copyright &y& Elsevier]

Aim of the study: Luteolin is a major flavonoid constituent and a primary candidate that might contribute to the claimed in vivo protective effects of Artemisia afra (Jacq. Ex. Willd). However, an exhaustive search yielded no literature evidence on the absorption, metabolism and fate of this flavonoid from the traditional plant preparation. The purpose of this study was to investigate the effect of the plant matrix on the uptake of luteolin derivatives from Artemisia afra aqueous extract in human intestinal epithelial Caco-2 cells. Materials and methods: Cell monolayers were incubated with 5, 10 and 20μg/ml doses of luteolin aglycone, luteolin-7-0-glucoside, un-hydrolyzed or acid-hydrolyzed Artemisia afra extracts, and samples of 150μl each were collected from both apical and basolateral sides of cells at 30, 60 and 120min for HPLC and LC–MS analyses. Results: After 1-h exposure, the uptake of luteolin aglycone and luteolin-7-0-glucoside from the un-hydrolyzed and acid-hydrolyzed extracts was significantly faster and quantitatively higher (i.e. >77% vs. <25% of the initial doses over the first 30min, p <0.05) than that from non-plant solutions. Apical to basolateral permeability coefficients for luteolin and its-7-0-glucoside in the extracts were 1.6- to 2-fold higher than that for the non-plant solutions. Glucuronidation was an important pathway of metabolism for luteolin in both non-plant and plant extract forms. Conclusions: Luteolin in Artemisia afra aqueous extract, regardless of its form (i.e. whether aglycone and 7-0-glucoside), is taken up better and more efficiently metabolized than the aglycone and 7-0-glucoside forms administered as pure solutions in Caco-2 cells. Flavonoid actives from Artemisia afra plant extracts and especially traditionally prepared dosage forms may thus have better bioavailability, and consequently greater in vivo potency, than that predicted from studies done using the pure solutions. [Copyright &y& Elsevier]

Abstract: Aim of study: The purpose of the present study was to examine the effects of daily administration of an aqueous extract of the dried, immature fruit of Poncirus trifoliata Raf. (Rutaceae) (PF-W) on body weight in rats. Materials and methods: PF-W was used in following experiments: 10-week-long measurement of body weight and food intake, in vitro pancreatic lipase activity assay, in vivo triglyceride concentration study, and measurement of intestinal transit rate. Results: A high dose of PF-W (200mg/2mL/animal/day, in aqueous solution) was administered intragastrically to rats for 10 weeks. PF-W suppressed body weight gain by 6%. However, administration of PF-W at a lower dose (20mg/animal/day) did not reduce weight gain. Administration of low- or high-dose PF-W had no effect on food intake throughout the experimental period. Additional experiments revealed that the suppressive effect of PF-W on body weight gain was not related to pancreatic lipase activity. Moreover, co-administration of PF-W with a lipid emulsion did not reduce plasma triglyceride concentration. Of interest, the high dose of PF-W significantly increased the rate of intestinal transit, whereas oral administration of the lower dose did not. Control and PF-W-treated groups did not differ in hematological and serum biochemical parameters, or in relative organ weights after 10 weeks of high-dose PF-W administration. Conclusion: PF-W does not suppress body weight gain by interfering with fat absorption in a pancreatic lipase-dependent manner. The suppressive effect of PF-W on weight gain is likely due to the increased rate of intestinal transit, and the consequent reduction in nutrient absorption. Moreover, it appears that PF-W is relatively safe for long-term use. Taken together, the results of the present study suggest that long-term, daily administration of PF-W successfully suppressed body weight gain—apparently due to accelerated intestinal transit and not to interference with pancreatic lipase activity. Due to its apparent long-term safety, PF-W is a potential therapeutic agent for reduction of body weight in humans. [Copyright &y& Elsevier]

Abstract: Aim of the study: Aged animals as well as elderly humans commonly exhibit calcium (Ca) shortage because of increased Ca excretion into urine and decreased intestinal Ca absorption, which induce elevation of serum PTH levels to maintain serum Ca levels between a normal physiological range. The most important organ that regulates this Ca homeostasis is the kidney. Hachimijiogan (HJG), a traditional herbal medicine in Japan and China, has been used for treating clinical diseases associated with kidney dysfunctions in elderly humans. However, the mechanisms of its pharmacological actions remain to be understood poorly. The present study was designed to examine whether HJG improves age-related unbalance of Ca metabolism at the systemic level using aged rats. Materials and methods: HJG was administered to 21-month-old aged rats for 3 months, and several parameters associated with Ca metabolism in serum and urine were measured. Results: Although HJG as well as aging itself did not affect serum Ca levels compared to young (11-week-old) rats, HJG improved increase in urinary Ca excretion and elevation of serum parathyroid hormone (PTH) levels in aged rats. However, HJG did not improve marked reduction of intestinal Ca absorption in aged rats. Conclusion: HJG showed regulating action for age-related unbalance of Ca metabolism at the systemic level. This finding would provide useful information for treating age-related several disorders associated with Ca unbalance. [Copyright &y& Elsevier]

The Dang-Gui-Si-Ni (DGSN) decoction as a classic prescription has been widely used for thousands of years in the clinical practice of traditional Chinese medicine (TCM). Especially in recent years, the potential efficacy of TCM for the treatment of Raynaud's syndrome has attracted great attention as there are still no specific remedies for this disease. However, the active constituents and underlying mechanisms responsible for the therapeutic benefits are not well understood, which makes it difficult to ensure quality control or to design research and drug development strategies. To identify the potential pharmacodynamic ingredients (PPIs) of TCM will help to achieve suitable process control procedures for industrial production and large-scale manufacturing. In the present study, we propose a multi-dimensional qualitative analysis method combining water-decoction spectra, in-vitro intestinal absorption spectra, in-vivo plasma spectra, and molecular docking of components to quickly identify the PPIs for the DGSN decoction of TCM. Water-based decoctions of DGSN were prepared in accordance with the clinical use registered in ancient books. Ultra-high-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q/TOF-MS) coupled with computerized modelling activity screening was used to quickly identify the PPIs of the DGSN decoction. Bioactive compounds absorbed in vitro were identified using the everted intestinal sac model from rats and compounds absorbed in vivo were confirmed in portal vein blood samples obtained following oral administration in rats. Molecular docking validation experiments were adopted to predict the binding activity to coagulation factors I, II, VII, X, and IX. The active components were further confirmed by pharmacodynamics analysis. The anticoagulant activity of the DGSN decoction was verified using rat models. Thirty-one compounds were identified in the DGSN decoction. According to the in vivo experiments, 22 compounds that could be absorbed in vivo were detected by the everted intestinal sac model in rats. This model greatly reduces the scope of PPIs and is easy to perform. Ten compounds were detected in the portal vein blood in rats. The compounds detected in plasma provide stronger evidence supporting the PPIs. Molecular docking in vitro experiments indicated that 7 compounds exhibited better binding activity with coagulation factors I, II, VII, X, and IX. The animal experiments confirmed that the DGSN decoction could improve the microcirculation, providing indirect proof of anticoagulant activity suggested by the molecular docking studies. Finally, based on the multi-dimensional methods, 9 potential compounds present in the DGSN decoction were identified as PPIs (i.e., ferulic acid, paeoniflorin, albiflorin, chlorogenic acid, cryptochlorogenic acid, liquiritin, liquiritin apioside, cinnamaldehyde and glycyrrhizic acid). Overall, this study combined the water-decoction spectra, intestinal absorption spectra in vitro , plasma spectra in vivo, and molecular docking studies to establish a multi-dimensional qualitative analysis method of the DGSN decoction. Meanwhile, 9 compounds in DGSN decoction were identified as PPIs using this method, and are proposed for application as quality standards for complex TCM prescriptions. [Display omitted] [ABSTRACT FROM AUTHOR]

Shengmai San (SMS) has been commonly used as a traditional Chinese medicine for the treatment of cardiovascular disorders, of which drug interactions need to be assessed for the safety concern. There is little evidence for the alterations of hepatic and intestinal drug-metabolizing enzymes after repeated SMS treatments to assess drug interactions. The studies aim to illustrate the effects of repeated treatments with SMS on cytochrome P450s (CYPs), reduced nicotinamide adenine dinucleotide (phosphate)-quinone oxidoreductase (NQO), uridine diphosphate-glucuronosyltransferase (UGT), and glutathione S-transferase (GST) using in vivo rat model. The SMS was prepared using Schisandrae Fructus, Ginseng Radix, and Ophiopogonis Radix (OR) (1:2:2). Chromatographic analyses of decoctions were performed using ultra-performance liquid chromatography (UPLC) and LC-mass spectrometry. Sprague-Dawley rats were orally treated with the SMS and its component herbal decoctions for 2 or 3 weeks. Hepatic and intestinal enzyme activities were determined. CYP3A expression and the kinetics of intestinal nifedipine oxidation (NFO, a CYP3A marker reaction) were determined. Schisandrol A, schisandrin B, ginsenoside Rb1 and ophiopogonin D were identified in SMS. SMS selectively suppressed intestinal, but not hepatic, NFO activity in a dose- and time-dependent manner. Hepatic and intestinal UGT, NQO and GST activities were not affected. A 3-week SMS treatment decreased the maximal velocity of intestinal NFO by 50%, while the CYP3A protein level remained unchanged. Among SMS component herbs, the decoction of OR decreased intestinal NFO activity. These findings demonstrate that 3-week treatment with SMS and OR suppress intestinal, but not hepatic CYP3A function. It suggested that the potential interactions of SMS with CYP 3A drug substrates should be noticed, especially the drugs whose bioavailability depends heavily on intestinal CYP3A. Image 1 • The 3-week Shengmai San (SMS) treatment decreased intestinal nifedipine oxidation. • SMS treatment decreased the maximal velocity of intestinal nifedipine oxidation. • SMS had no effects on activities of NQO, UGT and GST, and the expression of CYP3A. • The 3-week Ophiopogonis Radix treatment reduced intestinal nifedipine oxidation. [ABSTRACT FROM AUTHOR]

The Scutellariae Radix (SR) and Coptidis Rhizoma (CR) herb couple is widely used in traditional Chinese medicine prescriptions for the treatment of diabetes mellitus due to its interaction and synergistic effect compared to either herb alone, but the underlying mechanism of interaction between these herbs is unclear. This study aimed to investigate the effects of CR on the metabolism and absorption of SR. After rats were treated with normal saline (NS group) or the CR extract (CR-treated group) for seven consecutive days, the intestinal flora was extracted from rat faeces for a co-incubation with the SR extract to investigate the metabolism of SR flavonoids, and a non-everted gut sac was prepared in vitro to evaluate the intestinal absorption of the SR extract. The components of the SR extract, the metabolites of the SR extract that was co-incubated with intestinal flora, and the dialysate acquired from non-everted gut sacs were identified and determined by an HPLC-MS/MS method. The absorption rate constant (K a) and the apparent permeability (P app) of each compound were calculated, and the effects of CR on the metabolism and absorption of flavonoids in SR were evaluated, by comparison the K a and P app between two groups using Student's t -test. Twenty-nine flavonoids were detected and identified in the SR extract, including 16 glycosides and 13 aglycones. In the co-incubation with the intestinal flora, differences in metabolite classes were not observed between the NS group and CR-treated group; however, the metabolic rates of 17 flavonoids in the CR-treated group were significantly higher than the NS group. The P app of 11 compounds (4 glycosides and 7 aglycones) across the gut sac were greater than 2 × 10−5 cm/s in both groups, while the P app values of 7 compounds including wogonoside (WG) and other aglycones were significantly decreased in the CR-treated group. Based on these results, CR decreased the metabolism and absorption of SR flavonoids, and exerted much greater inhibitory effects on aglycones than glycosides, which may be one of the potential mechanisms underlying the therapeutic effects of the combination of SR and CR on diabetes mellitus. Image 1 • Sixteen glycosides and 13 aglycones were identified and determined in Scutellariae Radix (SR) extract by an HPLC-MS/MS. • Coptidis Rhizoma (CR) reduced the rates of metabolism of 17 flavonoids by the intestinal flora. • CR inhibited the decrease of glycosides and the increase of aglycones in the co-incubated system. • CR showed a greater inhibitory effect on the absorption of flavonoid aglycones than that of glycosides. • These inhibitory effects may be one of the potential mechanisms of the combination of SR and CR on diabetes treatment. [ABSTRACT FROM AUTHOR]

Chiang-Da, Gymnema inodorum (Lour.) Decne. (GI), is an ethnomedicinal plant that has been used for diabetic treatment since ancient times. One of the anti-diabetic mechanisms is possibly related to the actions of triterpene glycoside, (3β, 16β)-16,28-dihydroxyolean-12-en-3-yl-O-β-D-glucopyranosyl-β-D-glucopyranosiduronic acid (GIA1) in decreasing carbohydrate digestive enzymes and intestinal glucose absorption in the gut system. To observe the amount of GIA1 in GI leaf extracts obtained from different ethanol concentrations and to investigate the anti-hyperglycemic mechanisms of the extracts and GIA1. The crude extracts were prepared using 50%v/v to 95%v/v ethanol solutions and used for GIA1 isolation. The anti-hyperglycemic models included in our study examined the inhibitory activities of α-amylase/α-glucosidase and intestinal glucose absorption related to sodium glucose cotransporter type 1 (SGLT1) using Caco-2 cells. GIA1 was found about 8%w/w to 18%w/w in the GI extract depending on ethanol concentrations. The GI extracts and GIA1 showed less inhibitory activities on α-amylase. The extracts from 75%v/v and 95%v/v ethanol and GIA1 significantly delayed the glycemic absorption by lowering α-glucosidase activity and glucose transportation of SGLT1. However, the 50%v/v ethanolic extract markedly decreased the α-glucosidase activity than the SGLT1 function. Differences in the GIA1 contents and anti-glycemic properties of the GI leaf extract was dependent on ethanol concentrations. Furthermore, the inhibitory effects of the 75%v/v and 95%v/v ethanolic extracts on α-glucosidase and SGLT1 were relevant to GIA1 content. Image 1 [ABSTRACT FROM AUTHOR]

Sea buckthorn is popularly used as a herbal medicine and food additive in the world. Sea buckthorn flavonoids (SF) is reported to have an ameliorative effect on obesity and hyperlipidemia (HLP). To identify the major bioactive compounds and the lipid-lowering mechanism of SF. We used network pharmacology analysis and in vitro experiments to identify the major bioactive compounds and the lipid-lowering mechanism of SF. A total of 12 bioactive compounds, 60 targets related to SF and HLP were identified, and a component-target-disease network was constructed. The KEGG analysis revealed that SF regulated cholesterol metabolism, fat digestion and absorption, and PPAR signaling pathways in HLP. The experimental validation indicated that sea buckthorn flavonoids extract (SFE) and 4 bioactive compounds reduced lipid droplet accumulation, up-regulated the mRNA expression of PPAR-γ , PPAR-α , ABCA1 and CPT1A , etc , down-regulated SREBP-2 and its target gene LDLR , which are closely related to cholesterol conversion into bile acids, de novo synthesis and fatty acids oxidation. The major bioactive flavonoid isorhamnetin (ISOR) also increased the protein expression of PPAR-γ, LXRα and CYP7A1. SF might promote cholesterol transformation into bile acids and cholesterol efflux, inhibit cholesterol de novo synthesis and accelerate fatty acids oxidation for ameliorating HLP. Image 1 • 12 active component, 60 targets related to SF and HLP were enriched. • C-T-D, PPI, T-P and C-T-P network, and KEGG analysis were constructed. • SF promote cholesterol efflux, conversion and fatty acid oxidation, inhibit cholesterol de novo synthesis. [ABSTRACT FROM AUTHOR]

The modern study of the traditional Chinese medicine (TCM) compound recipes is a complex issue because of the large number of components in the recipes that would produce several metabolites after entering the body. The TCM compound recipes are known to have the advantage of synergistic treatment by multiple targets due to diverse components. Therefore, a research method that can reflect the overall effect of compounds with multi-components is essential. The pharmacological studies of the classic TCM compound recipes mainly use the sero-pharmacological method. It is a semi- in vivo study method, and the drug to be tested in the in vitro experiment is the drug-containing serum from the model animals (the drug to be tested is a mixed drug system containing the prototype drugs in animal bodies that have pharmacodynamic effects and the metabolites). Herein, a safe and effective external TCM recipe was used to develop another semi- in vivo experimental method to reflect the overall effects of TCM. To observe the effects of in-vitro intestinal absorption liquid of aqueous extracts of the TCM compound recipe—Guangtongxiao foam aerosol (Guangtongxiao)—on the tension of isolated rectal rings of mouse and investigate the underlying mechanisms of antispasmodic and amelioration of muscular spasm-induced pain. Intestinal absorption liquid of the Guangtongxiao aqueous extract at the five time points (30, 45, 75, 105, and 120 min) was prepared using a non-everted gut sac method. The isolated rectal rings of mice were prepared by pre-contraction using potassium chloride (KCl) or acetylcholine chloride (ACh) to make steady contraction. The intestinal absorption liquid were added cumulatively to the sink with the constricted rectal rings. The effects of the five groups of the intestinal absorption liquid with different drug concentration were observed on the tension of the isolated rectal rings. Then the ex vivo perfusion of the mouse rectal ring was performed as same as Guangtongxiao intestinal absorption liquid experiments, and the effects of two major components of Guangtongxiao, paeoniflorin (Pae) and tetrahydropalmatine (THP), on the rectal ring pre-treated with high concentration of KCl and ACh to induce contraction were studied. The relaxation rate of the five groups of the intestinal canals increased significantly with 3200 μL cumulative sample volume as compared to the blank group (P < 0.01). It suggested that the relaxation activity of the intestinal absorption liquid enhanced significantly with the prolongation of the interaction between isolated rectal rings and intestinal absorption liquid in a time-dependent manner. Also, significant differences were detected while comparing between the 120-min intestinal absorption liquid group and the blank group with respect to various cumulative sampling volumes (P < 0.01). In addition, the intestinal relaxation rate elevated gradually with the increase in sampling volume, indicating that the concentrations of active substances in the intestinal absorption liquid prepared by the non-everted gut sac model increased and the intestinal relaxation activity was enhanced with the prolongation of the absorption time in a dose-dependent manner. And Pae and THP in a concentration-dependent manner caused relaxation of the rectal ring, which is pretreated with high K+(KCl) and ACh to induce contraction. The EC 50 of Pae and THP was 8.67 × 10−5 M (6.68 × 10−5-1.13 × 10−4) and 1.41 × 10−4 M (1.24 × 10−4-1.61 × 10−4) in the contraction model induced by KCl, and was 6.15 × 10−5 M (4.47 × 10−5-8.45 × 10−5), and 1.31 × 10−4 M(1.22 × 10−4-1.42 × 10−4) in the model induced by ACh, respectively. The intestinal absorption liquid of Guangtongxiao exerted a remarkable relaxation activity for the rectal rings, and relaxation of the smooth muscle tension might be one of the antispasmodic mechanisms of Guangtongxiao compound recipe. Also, adopting a semi-in-vivo experimental method to study the efficacy of topical external TCM recipe medicine is optimal. Image 1 [ABSTRACT FROM AUTHOR]

Pyrrolizidine alkaloids (PAs) are a group of phytotoxins widely present in about 3% of flowering plants. Many PA-containing herbal plants can cause liver injury. Our previous studies demonstrated that PA N -oxides are also hepatotoxic, with toxic potency much lower than the corresponding PAs, due to significant differences in their toxicokinetic fates. This study aimed to investigate the oral absorption of PAs and PA N -oxides for better understanding of their significant differences in toxicokinetics and toxic potency. The oral absorption of PAs and PA N -oxides in rats and in rat in situ single pass intestine perfusion model was investigated. The intestinal permeability and absorption mechanisms of five pairs of PAs and PA N -oxides were evaluated by using Caco-2 monolayer model. The plasma concentrations of total PAs and PA N -oxides within 0–60 min were significantly lower in rats orally treated with a PA N -oxide-containing herbal alkaloid extract than with a PA-containing herbal alkaloid extract at the same dose, indicating that the absorption of PA N -oxides was lower than that of PAs. Using the rat in situ single pass intestine perfusion model, less cumulative amounts of retrorsine N -oxide in mesenteric blood were observed compared to that of retrorsine. In Caco-2 monolayer model, all five PAs showed absorption with P app AtoB values [(1.43–16.26) × 10−6 cm/s] higher than those of corresponding N -oxides with P app AtoB values lower than 1.35 × 10−6 cm/s. A further mechanistic study demonstrated that except for senecionine N- oxide, retrorsine N- oxide, and lycopsamine N- oxide, all PAs and PA N -oxides investigated were absorbed via passive diffusion. While, for these 3 PA N- oxides, in addition to passive diffusion as their primary transportation, efflux transporter-mediated active transportation was also involved but to a less extent with the efflux ratio of 2.31–3.41. Furthermore, a good correlation between lipophilicity and permeability of retronecine-type PAs and their N -oxides with absorption via passive diffusion was observed, demonstrating that PAs have a better oral absorbability than that of the corresponding PA N -oxides. We discovered that among many contributors, the lower intestinal absorption of PA N -oxides was the initiating contributor that caused differences in toxicokinetics and toxic potency between PAs and PA N -oxides. Image 1 [ABSTRACT FROM AUTHOR]

Because the toxicity and efficacy of arsenic is closely related to its chemical species, we conducted examinations of arsenic species accumulation and distribution in the rat body after one-time and 30-day realgar administration and then elucidated the probable roles of different arsenic species in the short-term toxicity of realgar. According to ICH M3 guidelines for non-clinical repeated dose toxicity studies and OECD Test guideline TG407 "Repeated Dose 28-Day oral Toxicity Study in Rodents, the doses of realgar set were 10.6 mg/kg, 40.5 mg/kg and 170 mg/kg. Rats were orally administered with realgar for one-tme and 30 days, respectively. Thereafter, biological samples (plasma, urine, liver, kidney, and brain) were obtained from rats and analyzed using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) to determine realgar metabolism, arsenic species accumulation and distribution. Additionally, the toxicity of realgar in rats was evaluated. The absorption, distribution and elimination half-life of total arsenic species in realgar were 3.33 hs, 16.08 hs and 24.65 hs, respectively. After 30 days of oral administration of realgar in rats, no significant drug-related toxicity occurred in the rats. Dimethylarsenic acid (DMA) is the most abundant arsenic species. The DMA contents of the liver and kidney of the high-dose realgar group were approximately 40-fold and 50-fold higher than those in the corresponding tissues of the control group, respectively. The arsenic species (III) was mainly detected in the liver and its content was about 40-fold higher than that of the control group. MMA was mainly detected in rat kidney, and the MMA content of the realgar treatment group was more than 2000 times higher than that of the control group. Arsenic is rapidly absorbed and distributed over the liver, kidneys and brain, and the distribution and elimination of arsenic in the blood is slow. The realgar doses corresponded to human equivalent doses (HED) of 1.7, 6.4 and 27.2 mg/kg, respectively. Considering that humans are 10 times more sensitive than animals, the realgar dose is equivalent to 0.17, 0.64 and 2.7 mg/kg HED. It can be considered that if patients take no more than 2.7 mg/kg realgar for 2 weeks, there will be no adverse reactions. [ABSTRACT FROM AUTHOR]

Origanum majorana L. (Lamiaceae) is commonly used in Moroccan folk medicine to treat infantile colic, abdominal discomfort and diarrhea. Liquid stools and abdominal discomfort observed in acute infectious diarrhea are the consequences of imbalance between intestinal water secretion and absorption in the lumen, and relaxation of smooth muscle surrounding the intestinal mucosa. The objective of our study was to see if aqueous extract of Origanum majorana L. (AEOM) may exhibit an effect on those deleterious mechanisms. The effect of AEOM on electrogenic Cl- secretion and Na+ absorption, the two main mechanisms underlying water movement in the intestine, was assessed on intestinal pieces of mice intestine mounted, in vitro, in Ussing chambers. AEOM effect on muscle relaxation was measured on rat intestinal smooth muscle mounted in an isotonic transducer. 1) AEOM placed on the serosal (i.e. blood) side of the piece of jejunum entirely inhibited in a concentration-dependent manner the Forskolin-induced electrogenic chloride secretion, with an IC 50 = 654 ± 8 µg/mL. 2) AEOM placed on the mucosal (i.e. luminal) side stimulated in a concentration-dependent manner an electrogenic Na+ absorption, with an IC 50 = 476.9 ± 1 µg/mL. 3) AEOM (1 mg/mL) inhibition of Forskolin-induced electrogenic secretion was almost entirely prevented by prior exposure to Ca++ channels or neurotransmitters inhibitors. 4) AEOM (1 mg/mL) proabsorptive effect was greater in the ileum and progressively declined in the jejunum, distal colon and proximal colon (minimal). 5) AEOM inhibited in a concentration-dependent manner smooth muscle Carbachol or KCl induced contraction, with an IC 50 = 1.64 ± 0.2 mg/mL or 1.92 ± 0.8 mg/mL, respectively. the present results indicate that aqueous extract of Origanum majorana L. exhibit positive cooperative effects on the main mechanisms that are involved in acute infectious diarrhea. fx1 [ABSTRACT FROM AUTHOR]