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Both cholinergic dysfunction and protein citrullination are the hallmarks of rheumatoid arthritis (RA), but the relationship between the two phenomena remains unclear. We explored whether and how cholinergic dysfunction accelerates protein citrullination and consequently drives the development of RA. Cholinergic function and protein citrullination levels in patients with RA and collagen-induced arthritis (CIA) mice were collected. In both neuron-macrophage coculture system and CIA mice, the effect of cholinergic dysfunction on protein citrullination and expression of peptidylarginine deiminases (PADs) was assessed by immunofluorescence. The key transcription factors for PAD4 expression were predicted and validated. Cholinergic dysfunction in the patients with RA and CIA mice negatively correlated with the degree of protein citrullination in synovial tissues. The cholinergic or alpha7 nicotinic acetylcholine receptor (α 7nAChR) deactivation and activation resulted in the promotion and reduction of protein citrullination in vitro and in vivo , respectively. Especially, the activation deficiency of α 7nAChR induced the earlier onset and aggravation of CIA. Furthermore, deactivation of α 7nAChR increased the expression of PAD4 and specificity protein-3 (SP3) in vitro and in vivo. Our results suggest that cholinergic dysfunction-induced deficient α 7nAChR activation, which induces the expression of SP3 and its downstream molecule PAD4, accelerating protein citrullination and the development of RA. The α 7nAChR agonists could be used as PAD4 inhibitors to prevent and treat rheumatoid arthritis. [Display omitted] [ABSTRACT FROM AUTHOR]

The martensite transformation (MT), magnetocaloric effect (MCE), and mechanical properties of the polycrystalline Ni 46 Mn 36 In 14 Co 4 (Co4) alloys with doping of 4 at.% Cu were examined. A large magnetization change (ΔM , 92 emu/g), large magnetic entropy change (ΔS M , 37.3 J kg−1K−1), high refrigerant capacity (RC , 261 J kg−1), relatively high sensitivity to magnetic fields (2.8 K/T), and two-way magnetic-field-induced MT were attained at approximately room temperature. Moreover, the compressive fracture strength and strain of the alloy reached 335 MPa and 7.4 %, respectively. Finally, the mechanism of the excellent combination properties of the Ni 42 Mn 36 In 14 Co 4 Cu 4 (Co4Cu4) alloy was discussed. This study can aid in the development of high-performance magnetic refrigeration and intelligent actuator materials. • A large magnetization change, a wide working temperature range, a large magnetic entropy change and large MCE were obtained. • The magnetic-field-induced transformation changed from one-way to two-way. • A kind of Ni-Mn-In based magnetic refrigerant material with excellent combination properties was obtained by co-doping. • The study has great purpose for the development of high-performance magnetic refrigerant and intelligent actuator materials. [ABSTRACT FROM AUTHOR]

• (1) This work proposes a new type of precast local high-performance concrete frame beam-column joint to enhance the seismic performance of the precast concrete frame structures. • (2) The load-bearing capacity, hysteresis characteristics, stiffness degradation, and energy dissipation capacity of the designed two joints were experimentally studied. • (3) A tri-linear skeleton curve model was established for joints using the experimental fitting method, which can better describe the stress and deformation characteristics of each stage. • (4) The Tri-linear restoring force model of the joint is established by the test fitting method, and it is in good agreement with the test results. To enhance the seismic performance of conventional precast concrete frame structures, this study introduces a novel precast high-performance concrete frame beam-column joint. We designed and conducted experiments on two full-scale precast concrete frame beam-column exterior joints, varying the presence of L-shaped steel reinforcement at the bottom of the beam-column joint. The findings reveal that the load-bearing capacity, hysteresis characteristics, stiffness degradation, and energy dissipation capacity of both joints significantly improve when using reactive powder concrete (RPC) poured into the joint connection area and L-shaped steel at the beam-column junction. A finite element model for these joints was further developed and validated based on the experimental data. Additionally, a parametric study was conducted to assess the impact of axial compression ratio and spacing of hoop bars in the joint area on joint behavior. Using an experimental fitting approach, a tri-linear skeleton curve model for the joints was established, offering a more precise representation of stress and deformation characteristics at each stage. The hysteretic curve generated from this restoring force model closely matches the experimental data, demonstrating the model's ability to accurately depict the hysteretic behavior of beam-column joints in precast RPC/RC composite frames. [ABSTRACT FROM AUTHOR]

This paper presents a study on the durability testing of a concrete facility located within the North Bay Port region, which has been in service for 200 months. Based on the results of 20 sets of concrete samples, an improved Kolmogorov-Smirnov (K-S) test method and gross error discrimination method are proposed to analyze the random distribution functions of the apparent chloride diffusion coefficient (D app) and the apparent surface chloride concentration (C s), and further explore the time-varying characteristics of chloride ion transmission in concrete. The research shows that the improved K-S method presented in this paper can effectively reduce the probability of type II errors by selecting a rational sample size, which can also improve detection efficiency. When the sample size does not exceed 10, the 2 σ criterion proposed in this paper can effectively identify and eliminate gross errors. In general, D app and C s follow the log-normal distribution, while the time factor (m) follows a normal distribution parameter. The value of C s basically stabilized after exposure to 80 months, whereas D app tended to stabilize after exposure to 100 months. The value of m obtained through fitting short-term experimental data is typically overestimated, and its value decreases as the exposure time prolongs. Therefore, m should also be considered a time-varying parameter that decreases with time. The tested RC structure will begin to experience rebar corrosion after 48.5–60 years of exposure to the marine environment based on the probabilistic assessment. • The 2 σ criterion was introduced to identify and rectify significant errors. • The improved K-S method was developed to minimize the likelihood of type II errors. • Chloride profiles were extracted from 200 months aged harbor concrete structures. • Both D app and C s demonstrated a good fit with the log-normal distribution. [ABSTRACT FROM AUTHOR]

The aryl hydrocarbon receptor (AhR), discovered 46 years ago, is a transcript factor member of the basic helix-loop-helix Per-ARNT-SIM (bHLH-PAS) family deeply implicated in health and diseases, and is traditionally associated with the metabolism of xenobiotic ligands. Recently, multiple and structurally diverse ingredients including amino acid metabolites, polyphenols, flavonoids, polyhydroxyalkanoates, polychlorinated biphenyls, and, triarylmethanes have been evaluated as AhR potential ligands, and there is increasing attention on AhR as an appealing target in various cancers, autoimmune disorders, inflammatory bowel diseases, rheumatoid arthritis and multiple sclerosis. Herein, this review focuses on the recent advances of AhR, covering articles published between 2002 and 2022. It summarizes the structure of AhR, regulation of the AhR pathway, physiological role, and AhR ligands, highlighting the vast opportunities and challenges for targeting drug development of AhR. [Display omitted] • Summarizing the latest research progress of diverse structures of AhR ligands and biological functions of AhR. • Summarizing the AhR ligands is of great importance to accelerate the discovery of novel pharmacotherapeutic agents. • Presenting the development potential of AhR and guide for future target drug modification and design. [ABSTRACT FROM AUTHOR]

Tripterygium wilfordii (TW) preparations have been utilized in China for treating rheumatoid arthritis and autoimmune diseases. However, their clinical use is limited due to reproductive toxicity, notably premature ovarian failure (POF). Our study aimed to investigate the effect and mechanism of bergenin in attenuating POF induced by triptolide in mice. POF was induced in female ICR mice via oral triptolide administration (50 μg/kg) for 60 days. Mice received bergenin (25, 50, 100 mg/kg, i.g.) or estradiol valerate (EV) (0.1 mg/kg, i.g.) daily, 1 h before triptolide treatment. In vitro , ovarian granulosa cells (OGCs) were exposed to triptolide (100 nM) and bergenin (1, 3, 10 μM). Antioxidant enzyme activity, protein expression, apoptosis rate, and reactive oxygen species (ROS) levels were assessed. The results showed that triptolide-treated mice exhibited evident atrophy, along with an increase in atretic follicles. Bergenin (50, 100 mg/kg) and EV (0.1 mg/kg), orally administered, exerted significant anti-POF effect. Bergenin and EV also decreased apoptosis in mouse ovaries. In vitro , bergenin (1, 3, 10 μM) attenuated triptolide-induced OGCs apoptosis by reducing levels of apoptosis-related proteins. Additionally, bergenin reduced oxidative stress through downregulation of antioxidant enzymes activity and overall ROS levels. Moreover, the combined use with Sh-Nrf2 resulted in a reduced protection of bergenin against triptolide-induced apoptosis of OGCs. Together, bergenin counteracts triptolide-caused POF in mice by inhibiting Nrf2-mediated oxidative stress and preventing OGC apoptosis. Combining bergenin with TW preparations may effectively reduce the risk of POF. [Display omitted] Bergenin can attenuate triptolide-induced premature ovarian failure in mice. Bergenin functions by inhibiting the apoptosis of ovarian granulosa cells (OGCs). Bergenin inhibits the apoptosis of OGCs through down-regulating oxidative stress. Bergenin down-regulates oxidative stress via activation of Nrf2. [ABSTRACT FROM AUTHOR]

Abstract: The present study determined the anti-inflammatory activity of scopoletin in gout air pouch model and revealed the underlying mechanisms by in vitro assays. Monosodium urate (MSU) crystal-induced inflammation in mouse air pouch model, an experimental model for acute gout, was used to assess the efficacy of scopoletin. The neutrophil and mononuclear phagocyte numbers and MPO levels were increased significantly six hours after MSU crystal injection into the air pouch, whereas these changes were inhibited substantially upon scopoletin (100 and 200mg/kg, i.p.) treatment. To get insight into the underlying mechanisms, the in vitro studies were performed to investigate the effects of scopoletin on activation of macrophages and resultant production of inflammatory mediators. The secretions of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO) were elevated in MSU crystal-stimulated RAW 264.7 cells, and scopoletin (30–300μM) suppressed the production of all mediators. Moreover, RT-PCR assay and western blot analysis indicated that scopoletin regulated the transcriptional level of these mediators via suppression of NF-κB activation and blockade of MAPK signal pathway. Thus, the results clearly indicated that scopoletin inhibited the monosodium urate crystal-induced inflammation both in vivo and in vitro. In combination with our previous findings that scopoletin shows hypouricemic, anti-angiogenesis and pro-apoptotic activities, this compound may be a potential agent for gout therapy and could serve as a structural base for developing new drugs. [Copyright &y& Elsevier]

• Orifice flow noise appears in two reverse flows of vortex areas of the pipe. • The SPL of orifice flow noise increases over velocity logarithmically. • Smaller orifice leads to higher SPL, while orifice thickness causes faint influence. Based on the previous measurements data, the standard orifice flowmeters is one of the main noise sources in nature gas metering stations. In this paper, a theoretical method that combines the Large Eddy Simulations (LES) with the Ffowcs Williams Hawkings (FW-H) acoustic analogy theory has been used to analysis the Sound Pressure Level (SPL) distribution in standard orifice flowmeter. And then, a series of numerical simulations have been performed over a range of conditions, including medium velocity, aperture size, and orifice thickness. At last, a correlation formula of the maximum SPL and medium velocity has been presented by fitting the numerical results. It shows that the SPL increases over velocity logarithmically, and the maximum SPL is present at the upstream wall of orifice and in two reverse flows of vortex areas of the downstream pipe. Meanwhile, a smaller aperture size leads to higher SPL, while orifice thickness brings about faint influence. The SPL increases by about 8 dB by the decreasing of aperture per 20 mm. Finally, the data obtained from the fitting are verified by field data and is approved by the staff. The results provide effective guidance for practical operation of orifice flowmeter noise prevention and control. [ABSTRACT FROM AUTHOR]

Arctigenin, the major active constituent of Fructus Arctii, has been reported to inhibit the growth of various tumors and alleviate colitis. This study aimed to prove the protective effect of arctigenin on colitis-associated cancer (CAC) and explore its mechanisms. Orally administered arctigenin prevented the progression of colitis and protected against colon carcinogenesis in azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced CAC mice. Arctigenin downregulated NLRP3 inflammasome activation and fatty acid oxidation (FAO) metabolism in macrophages, as determined by untargeted metabolomics. Arctigenin also inhibited the expression of carnitine palmitoyltransferase 1 (CPT1), reduced the acetylation of α-tubulin, and disrupted NLRP3 complex formation, which in turn inactivated the NLRP3 inflammasome. Downregulation of the CPT1-FAO-acetyl-coenzyme A (acetyl-CoA)-acetylated α-tubulin pathway was observed to inhibit the effect of arctigenin on NLRP3 inflammasome assembly, as confirmed by CPT1 overexpression. Lastly, arctigenin was shown to inhibit NLRP3 inflammasome activation and improve CAC in mice, and the effect was significantly diminished by the overexpression of adeno-associated virus (AAV)9-CPT1. Taken together, these results show that the inhibition of NLRP3 inflammasome assembly in macrophages due to FAO downregulation contributes to the preventative effect of arctigenin against CAC. Our findings highlight the potential value of arctigenin to reduce the risk of CAC in patients with colitis. [ABSTRACT FROM AUTHOR]

Bergenin, a plant polyphenol, has been reported to lower the blood glucose level and ameliorate kidney function in streptozotocin (STZ)-induced diabetic rats. Herein, its protective effect on diabetic nephropathy (DN) was explored in view of extracellular matrix (ECM) generation in glomerular mesangial cells. Glomerular mesangial cells were treated with high glucose, and Q-PCR as well as western blot were used to determine the expression of ECM. To establish the participation and role of mammalian target of rapamycin (mTOR) and nuclear factor erythroid-derived 2-related factor 2 (Nrf2) in ECM generation, a combination of l -leucine (activator of mTOR) and Nrf2 shRNA transfection were performed, respectively. Moreover, a DN model was established in mice using high-glucose/high-fat diet and STZ. Bergenin impeded the generation of TGF-β1 and ECM, decreased the levels of intracellular superoxide anion and hydrogen peroxide, and increased the activity of antioxidant enzymes in the glomerular mesangial cells (HBZY-1 and HRMC cells) treated with high glucose. The inhibition of ECM generation by bergenin was dependent on the down-regulation of oxidative stress as confirmed via a superoxide overexpression system. The activation of Nrf2 was required for bergenin to inhibit the oxidative stress and ECM generation. Moreover, bergenin was found to inhibit the phosphorylation of mTOR, which is located at the upstream of Nrf2. Bergenin did not interfere with the expression of Nrf2 mRNA and Keap1 (the classic degradation control factor of Nrf2), but markedly inhibited the protein expression of the β-TrcP, an effect which could be abolished by l -leucine. In DN model mice, l -leucine diminished the ability of bergenin to reduce the levels of superoxide anion, hydrogen peroxide and ECM, which contributed to the eradication of the ameliorative effect of bergenin on nephropathy. Bergenin can inhibit glucose-induced ECM production in glomerular mesangial cells through the down-regulation of oxidative stress via the mTOR/β-TrcP/Nrf2 pathway, and it might be a candidate drug for the prevention and treatment of DN. Image 1 • Bergenin impedes ECM generation in GMCs dependent on the inhibition of oxidative stress. • mTOR is located upstream of Nrf2 in high glucose-stimulated GMCs. • Bergenin impedes ECM generation and ameliorates DN via the mTOR/β-TrcP/Nrf2 pathway. • The anti-DN potency of bergenin is nearly equivalent to that of the same dose of metformin. [ABSTRACT FROM AUTHOR]

Abstract Aims Sinomenine, an anti-rheumatoid arthritis drug used in China for decades, is usually co-administered with cardiovascular (CV) drugs to reduce arthritis-related risk of cardiovascular diseases. This study was to investigate whether and how CV drugs affect the pharmacokinetic profile of sinomenine. Main methods In rat liver microsomes (RLMs), the key metabolic enzymes of sinomenine were identified by using specific inhibitors. The influences of CV drugs, including propranolol, verapamil, warfarin, atorvastatin, simvastatin, and lovastatin, on the metabolism of sinomenine were examined. Cocktail probe, RT-qPCR, and western blotting were performed to unveil the underlying mechanism of the drug-drug interaction. Key findings The key metabolic enzymes of sinomenine were identified to be CYP3A1/2 and CYP2D1 in RLMs. Among the CV drugs screened, simvastatin and lovastatin were shown to inhibit the liver metabolism of sinomenine with Ki values of 13.00 and 25.83 μM, respectively. Single administration of simvastatin or lovastatin in rats increased the AUC value of sinomenine to 1.40- or 1.50-fold, and decreased the CLz/F value to 68.19% or 65.44%, respectively. In contrast, multiple administrations of simvastatin, but not lovastatin, increased the CLz/F value of sinomenine to 1.38-fold and decreased the AUC value to 71.59%. Further studies showed that the long-term administration of simvastatin could up-regulate the expression of CYP3A1/2 to account for the effect. Significance This study demonstrated the potential effect of simvastatin and lovastatin on the metabolism of sinomenine for the first time. The findings provide guidelines for the co-administration of sinomenine with simvastatin or lovastatin in clinic. [ABSTRACT FROM AUTHOR]

F-box protein 11 (FBXO11) has both the E3 ubiquitin ligase activity and the methyltrasferase activity, and regulates metastasis, apoptosis and chemosensitivity in human cancer. However, the clinical significance and biological function of FBXO11 in gastric cancer (GC) are rarely known. Here, we demonstrated up-regulated expression of FBXO11 in GC tissues in comparison with that in tumor-adjacent tissues. Clinical analysis based on our specimens and the TCGA database revealed that FBXO11 overexpression was associated with large tumor size, lymph node metastasis and advanced TNM stage. Notably, GC patients with high FBXO11 expression showed a significant shorter overall survival. Cell proliferation and mobility were measured by CCK-8 and Transwell assays. FBXO11 silencing by transfection with two specific shRNAs attenuated proliferation, migration and invasion of MGC-803 cells. In accordance, FBXO11 overexpression promoted these cellular processes in SGC-7901 cells. Mechanistically, FBXO11 obviously facilitated epithelial-mesenchymal transition (EMT) process as suggested by immunoblotting and immunofluorescence data. Moreover, we found that FBXO11 promoted the activation of AKT pathway with increased phosphorylated AKT level in SGC-7901 cells. LY294002 and Wortmannin, phosphotidylinsitol-3-kinase (PI3K) inhibitors, blocked FBXO11 induced EMT, proliferation, migration and invasion of SGC-7901 cells. Phosphatase and tensin homolog (PTEN), which played a crucial role in regulating PI3K/AKT pathway, was negatively modulated by FBXO11 in GC cells. Taken together, our findings contribute to current understanding of the functions of FBXO11 and suggest a mechanism by which FBXO11 plays an oncogenic role in the development of GC possibly by inhibiting PTEN and subsequently promoting PI3K/AKT pathway activation. [ABSTRACT FROM AUTHOR]

Butyrate, given by oral administration or in drinking water, has been shown to improve experimental pulmonary fibrosis (PF) in mice despite of very low bioavailability. The pharmacokinetic-pharmacodynamics disconnection attracts us to explore its anti-PF mechanism in view of the intestinal expression of anti-PF factors. In bleomycin-induced PF in mice, rectal administration of butyrate (500 mg/kg) exhibited a significant anti-PF effect, with a maximum plasma concentration largely lower than the minimum effective concentration (1 mM) at which butyrate inhibited the expression of pro-inflammatory factors by lung epithelial cells and the production of extracellular matrix by lung fibroblasts. The rectal administration of butyrate significantly upregulated the mRNA expression of hepatocyte growth factor (HGF) in the colons of PF mice, but showed no significant effect on the mRNA expression of HGF in the small intestines, lungs and livers. In colon epithelial cells, the monocarboxylate transporter inhibitor α-cyano-4-hydroxycinnamic acid (CHC) abrogated butyrate-induced expression of HGF, indicating that butyrate functions through entering into cells. Butyrate showed no significant effect on the histone acetylation in the promoter region of HGF, suggesting that it promotes HGF expression not by directly affecting the histone deacetylation of HGF but by other pathways. GW9662, the inhibitor of PPARγ, significantly attenuated the effect of butyrate to promote the mRNA expression of HGF. Butyrate was able to enhance the acetylation of PPARγ, and a targeted mutation of lysine at the position 240 (K240) of PPARγ markedly diminished the induction of butyrate on HGF expression, suggesting that butyrate promoted HGF expression in colon epithelial cells by upregulating PPARγ K240 acetylation. In summary, rectal administration of butyrate promotes the expression of HGF in colonic epithelial cells through upregulating PPARγ acetylation via inhibition of HDAC activity. The findings of the present study provide a reasonable explanation for the anti-PF action mode of butyrate based on the 'lung-gut axis', and found that intestine-derived butyrate and HGF may be involved in the modulation of the occurrence and progression of PF. [ABSTRACT FROM AUTHOR]

Objective Norisoboldine (NOR), an isoquinoline alkaloid with very poor oral bioavailability, was previously proven to have a unique anti-arthritis activity in rats by inducing intestinal Treg cells. Herein, we explored its underlying mechanism in view of aryl hydrocarbon receptor (AhR). Methods The differentiation of regulatory T cells (Treg cells) and IL-17-producing T cells (Th17 cells) from naïve T cells was analyzed in vitro . The key role of AhR was ascertained using siRNA transfection. AhR agonistic effect was verified based on the activation of downstream signaling pathway and target genes. The correlation between AhR activation and Treg cell induction as well as pathological changes of joints was confirmed in collagen-induced arthritis (CIA) mouse model. Results NOR promoted intestinal Treg cell differentiation and function in an AhR-dependent manner. It acted as an AhR agonist, as evidenced by induction of CYP1A1 expression and activity, promotion of AhR/Hsp90 dissociation and AhR nuclear translocation, induction of XRE reporter activity, and facilitation of AhR/XRE binding. In CIA mice, NOR exerted substantial anti-arthritic effect through enhancing AhR activation in intestinal tissues and inducing intestinal Treg cell generation, which could be largely abolished by resveratrol (a antagonist of AhR). An adoptive transfer of Treg cells from NOR-treated mice could successfully alleviate arthritis symptoms in CIA mice. Conclusion Oral NOR induces the generation of intestinal Treg cells by the activation of AhR, and thereby exerts anti-arthritic effect. [ABSTRACT FROM AUTHOR]

Endotoxin can stimulate inflammatory cytokine release from monocytes/macrophages and result in septic shock. Glycyrrhetinic acid (GA), the main bioactive component of licorice, possesses substantial anti-inflammatory activity. Here, we explored effect of 11-deoxy-18α-glycyrrhetinic acid-30-ethyl ester (DGAEE), a newly synthesized derivative of GA, on septic shock. DGAEE and its main metabolite 11-deoxy-18α-glycyrrhetinic acid (DGA) significantly alleviated septic shock as evidenced by improvements of survival rates, lung histopathological changes and wet/dry ratio in lipopolysaccharide (LPS)/D-galactosamine-stimulated mice, and decreased blood pressure in LPS/D-galactosamine-stimulated rats. The two compounds decreased serum levels of NO, TNF-α, IL-6, IL-1β, and increased the level of IL-10 more potently in mice. In LPS-stimulated RAW 264.7 cells, DGA but not DGAEE showed marked regulation of NO, TNF-α, IL-6 and IL-10 levels, suggesting that DGAEE display anti-shock effect by DGA rather than itself. Moreover, the neutralizing antibody against IL-10 markedly prohibited the inhibitory effect of DGA on the production of cytokines from RAW 264.7 cells, and AS101 (an inhibitor of IL-10 biosynthesis) almost completely reversed the anti-shock effect of DGA in mice. In addition, DGA did not affect activation of NF-κB-p65 and p38 MAPK as well as IκBα degradation, but moderately reduced activation of ERK and JNK, and markedly increased phosphorylation of GSK3β in LPS-stimulated RAW 264.7 cells. LY294002 (an inhibitor of GSK3β phosphorylation) and LiCl (an inhibitor of GSK3β activity) diminished and potentiated increase of IL-10 levels by DGA, respectively. In conclusion, DGAEE alleviates septic shock through DGA in an IL-10-dependent manner, and the mechanism is related to inactivation of GSK3β. [ABSTRACT FROM AUTHOR]

[Display omitted] Madecassic acid (MA), a triterpene compound isolated from Centella Asiatica herbs, has previously been shown to attenuate colitis induced by DSS in mice. In the present study, we address whether and how MA ameliorates colitis-associated colorectal cancer (CAC), which accounts for a considerable proportion of colorectal cancer. CAC was induced by AOM/DSS in mice, and MA was administered orally once a day. To identify the source cells of IL-17 and the target cells for MA reducing the expression of IL-17 in the colons of CAC mice, single-cell suspensions were prepared from the colons of CAC mice and analyzed by flow cytometry. An adoptive transfer experiment was performed to verify the importance of the decreasing γδT17 cell population in the anti-CAC effect of MA. Oral administration of MA reduced the burden and incidence of tumors in the CAC mice. MA decreased the number of MDSCs in the colon tissues of CAC mice and ameliorated anti-tumor immune responses. MA could prevent the migration of MDSCs by inhibiting the activation of γδT17 cells and the expression of chemokines. The population of activated-γδT17 cells in the tumor microenvironment of CAC mice positively correlated with the number of MDSCs and tumors as well as tumor load. Moreover, the anti-CAC effect of MA was significantly counteracted by the adoptive transfer of γδT17 cells. MA alleviates CAC by blocking the recruitment of MDSCs to increase the population of anti-tumor immune cells in tumor microenvironment via inhibition of the activation of γδT17 cells. [ABSTRACT FROM AUTHOR]

Arctigenin, the main effective constituent of Arctium lappa L. fruit, has previously been proven to dramatically attenuate dextran sulfate sodium (DSS)-induced colitis in mice, a frequently used animal model of inflammatory bowel disease (IBD). As Th1 and Th17 cells play a crucial role in the pathogenesis of IBD, the present study addressed whether and how arctigenin exerted anti-colitis efficacy by interfering with the differentiation and activation of Th1/Th17 cells. In vitro , arctigenin was shown to markedly inhibit the differentiation of Th17 cells from naïve T cells, and moderately inhibit the differentiation of Th1 cells, which was accompanied by lowered phosphorylation of STAT3 and STAT4, respectively. In contrast, arctigenin was lack of marked effect on the differentiation of either Th2 or regulatory T cells. Furthermore, arctigenin was shown to suppress the mammalian target of rapamycin complex 1 (mTORC1) pathway in T cells as demonstrated by down-regulated phosphorylation of the downstream target genes p70S6K and RPS6, and it functioned independent of two well-known upstream kinases PI3K/AKT and ERK. Arctigenin was also able to inhibit the activity of mTORC1 by dissociating raptor from mTOR. Interestingly, the inhibitory effect of arctigenin on T cell differentiation disappeared under a status of mTORC1 overactivation via knockdown of tuberous sclerosis complex 2 (TSC2, a negative regulator of mTORC1) or pretreatment of leucine (an agonist of mTOR). In DSS-induced mice, the inhibition of Th1/Th17 responses and anti-colitis effect of arctigenin were abrogated by leucine treatment. In conclusion, arctigenin ameliorates colitis through down-regulating the differentiation of Th1 and Th17 cells via mTORC1 pathway. [ABSTRACT FROM AUTHOR]

(E)-3-(4-chlorophenyl)-N-(7-hydroxy-6-methoxy-2-oxo-2H-chromen-3-yl) acrylamide (SC-III3), a newly synthesized derivative of scopoletin, was previously shown to reduce the viability of HepG2 cells and tumor growth of HepG2 xenograft mouse model. It induces the death of HepG2 cells by a way irrelevant to apoptosis and necrosis. To shed light on the cytotoxic mechanisms of SC-III3, the present study addresses whether and how it can induce autophagic cell death. When HepG2 cells were incubated with various concentrations of SC-III3, autophagic vacuoles could be observed by transmission electron microscopy and monodansylcadaverine staining. Increased expressions of LC3-II to LC3-I and Beclin-1, required for autophagosome formation, were accompanied. These characteristics integrally indicated that SC-III3 could initiate autophagy in HepG2 cells. N-acetyl- l -cysteine (NAC), a ROS scavenger, could reverse SC-III3-caused ROS accumulation, but it did not affect SC-III3-induced autophagy, suggesting that ROS was not involved in SC-III3-mediated autophagy in HepG2 cells. SC-III3 significantly depressed mitochondrial function, as evidenced by disruption of mitochondrial transmembrane potential and loss of the mitochondrial cristae structure, as well as decrease of Cox-I, Cox-III, Cox-IV, and ATP levels. The autophagy and activation of AMPK–TSC2–mTOR–p70s6k pathways induced by SC-III3 in HepG2 cells could be efficiently blocked by pre-treatments of compound C (an inhibitor of AMPK). Moreover, addition of extracellular ATP to the cell culture media could reverse SC-III3-caused activation of AMPK–TSC2–mTOR–p70s6k pathway, autophagy and cell viability decrease in HepG2 cells. Collectively, SC-III3 leads to autophagy through inducing mitochondrial dysfunction, depleting ATP, and activating AMPK–mTOR pathway, which thus reflects the cytotoxic effect of SC-III3 in HepG2 cells. [ABSTRACT FROM AUTHOR]

Sinomenine (SIN) has long been used as a therapeutic agent of rheumatoid arthritis (RA) in China. However, the discrepancy between low oral bioavailability and higher minimal effective concentration made its action mode mysterious. The present study aimed to gain insight into the mechanisms by which SIN suppressed collagen-induced arthritis (CIA) in rats in view of Th17 and regulatory T (Treg) cell balance. SIN was orally administered, and the clinical symptoms of CIA rats were monitored; inflammatory cytokines levels in serum were measured by ELISA; pharmacokinetic studies were performed in normal and CIA rats; Th17 and Treg cell frequencies were analyzed by flow cytometry. The data showed that SIN treatment resulted in a dramatic decrease of arthritis scores and paw volume of CIA rats, which was accompanied by down-regulation of IL-17A and up-regulation of IL-10 in rat serum. The frequency of Treg cells was increased and the frequency of Th17 cells was decreased in the gut lymphoid tissues of SIN-treated rats. Immunohistochemistry assay demonstrated that more α4β7-positive cells were detained in joint tissues after SIN treatment. Moreover, the anti-arthritis efficacy of SIN disappeared when it was given by intraperitoneal injection, further confirming the action of SIN was gut-dependent. In conclusion, SIN exerts anti-RA action probably through modulating the frequencies of Treg cells and Th17 cells in intestinal lymph nodes and yielding a trafficking of lymphocytes (especially Treg cells) from gut to joint. [ABSTRACT FROM AUTHOR]

A series of hybrids of scopoletin and substituted cinnamic acid were designed, synthesized and evaluated in vitro and in vivo against five human tumor cell lines [MCF-7, MDA-MB-231, A549, HCT-116, and HeLa] with doxorubicin as the positive control. Compounds 17a , 17b , 17c and 17g exhibited potent cytotoxic activity. Especially, compound 17b displayed broad spectrum activity with IC 50 values ranging from 0.249 μM to 0.684 μM. Moreover, in a preliminary pharmacological study, 17b not only remarkably induced cellular apoptosis, but also clearly induced A549 cells cycle arrest at S phase. In vivo study showed that 17b significantly suppressed tumor growth in a dose-dependent manner without causing the loss of the mean body weight of mice, which was superior to doxorubicin. These preliminary results indicate that 17b is an optimal anti-cancer leading compound and merit further structural modification. [ABSTRACT FROM AUTHOR]

Madecassoside, a triterpenoid saponin present in Centella asiatica herbs with extremely low bioavailability, possesses excellent anti-rheumatoid arthritis property after oral administration. Such a disconnection between poor pharmacokinetic property and undoubted bioactivity also exists in many other herbal medicines. However, there is no reasonable explanation for this phenomenon to date. Here we showed that orally administered madecassoside displayed marked therapeutic effect on collagen-induced arthritis (CIA) in rats, which was accompanied by a systemic downregulation of inflammatory cytokines and an upregulation of anti-inflammatory cytokine IL-10. In vitro assays demonstrated that neither madecassoside nor its main metabolite madecassic acid could directly interfere with the secretion of inflammatory cytokines and IL-10. Intraperitoneal injection of madecassoside or madecassic acid was absent of significant effects on CIA progression, which further excluded the possibility of systemic action and highlighted the indispensable role of intestinal tracts. Notably, madecassoside could dramatically enhance the secretion of IL-10 from the small intestine of CIA rats probably through increasing the number of Foxp3 + T lymphocytes in the lamina propria. In conclusion, madecassoside displays anti-arthritis property not by absorption into blood or by its metabolite, but through an intestine-dependent manner. The action can be mediated by, at least partially, the mobilization of IL-10 that originates from small intestines. [ABSTRACT FROM AUTHOR]

The crude powder of the fruit of Arctium lappa L. (ALF) has previously been reported to attenuate experimental colitis in mice. But, its main effective ingredient and underlying mechanisms remain to be identified. In this study, ALF was extracted with ethanol, and then successively fractionated into petroleum ether, ethyl acetate, n -butanol and water fraction. Experimental colitis was induced by dextran sulfate sodium (DSS) in mice. Among the four fractions of ALF, the ethyl acetate fraction showed the most significant inhibition of DSS-induced colitis in mice. The comparative studies of arctigenin and arctiin (the two main ingredients of ethyl acetate fraction) indicated that arctigenin rather than arctiin could reduce the loss of body weight, disease activity index and histological damage in the colon. Arctigenin markedly recovered the loss of intestinal epithelial cells (E-cadherin-positive cells) and decreased the infiltration of neutrophils (MPO-positive cells) and macrophages (CD68-positive cells). Arctigenin could down-regulate the expressions of TNF-α, IL-6, MIP-2, MCP-1, MAdCAM-1, ICAM-1 and VCAM-1 at both protein and mRNA levels in colonic tissues. Also, it markedly decreased the MDA level, but increased SOD activity and the GSH level. Of note, the efficacy of arctigenin was comparable or even superior to that of the positive control mesalazine. Moreover, it significantly suppressed the phosphorylation of MAPKs and the activation of NF-κB, including phosphorylation of IκBα and p65, p65 translocation and DNA binding activity. In conclusion, arctigenin but not arctiin is the main active ingredient of ALF for attenuating colitis via down-regulating the activation of MAPK and NF-κB pathways. [ABSTRACT FROM AUTHOR]

[Display omitted] • Neuropeptide CST can inhibit Th17 cell differentiation by attenuating glycolysis. • CST inhibits glycolysis of Th17 cells by down-regulating the expression of HK2. • CST attenuates glycolysis and inhibits Th17 cell differentiation by activating GHSR1 receptor. The neuropeptide cortistatin (CST) has been reported to attenuate Th17 cell response in multiple disease models, but the mechanism of action remains obscure. Here, we show that either overexpression or exogenous addition of CST obviously restricts Th17 cell differentiation. As metabolic reprogramming plays an important role in Th17 cell development, we explore whether CST inhibits Th17 cell differentiation by regulating glycolysis. The results show that CST substantially attenuates the glycolysis during Th17 differentiation and down-regulates the mRNA expression of myelocytomatosis oncogene (Myc) and hexokinase 2 (HK2), the glycolysis rate-limiting enzyme. Following the overexpression of Myc and HK2, the inhibitory effect of CST on Th17 differentiation nearly disappears, suggesting that Myc-HK2 pathway is deeply involved. Furthermore, growth hormone secretagogue receptor 1 (GHSR1) is identified as the key receptor subtype for CST attenuating glycolysis and Th17 cell differentiation by the combined uses of CST with various receptor subtype blockers. The knockdown of GHSR1 abrogates the inhibition of CST on Th17 differentiation and glycolysis. Finally, in the colitis mice induced by dextran sulfate sodium, an intraperitoneal injection of CST markedly inhibits Th17 cell response and down-regulates the expression of HK2 in the Th17 cells, which is reversed by the combined use of GHSR1 antagonist. These findings suggest that inhibition of glycolysis is the key pathway for CST attenuating Th17 cell response, and GHSR1, Myc and HK2 are potential therapeutic targets of Th17 cell-related diseases. [ABSTRACT FROM AUTHOR]

Abstract: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by pronounced synovial inflammation and hyperplasia, in which there may be an imbalance between the growth and death of fibroblast-like synoviocytes (FLS). Norisoboldine (NOR), the main active constituent in the alkaloid fraction isolated from Radix Linderae, was previously demonstrated to alleviate arthritis severity in experimental RA. This study aimed to evaluate the effects of NOR on proliferation and apoptosis of FLS from adjuvant-induced arthritis (AIA) rats to elucidate the mechanism of its inhibitory effect on inflammatory synovial hyperplasia in RA. Our results indicated that NOR exhibited a pro-apoptotic effect on AIA FLS but only slightly affected cell proliferation and the cell cycle. Following treatment with NOR for 24h, the activation of caspase 3 and caspase 9 and the cleavage of poly (ADP-ribose) polymerase (PARP) in AIA FLS were observed; however, caspase 8 remained unaffected. Meanwhile, a flow cytometric assay revealed that NOR significantly increased the percentage of apoptotic cells, causing the loss of the depolarized mitochondrial membrane potential and the release of cytochrome C. The expression of Bax and Bcl-2 was also regulated by NOR treatment. Additionally, the expression of p53 protein was up-regulated by NOR, and pretreatment with PFT-α, a p53 specific inhibitor, reversed the increase in FLS apoptosis caused by NOR. These findings indicated that NOR-induced apoptosis in AIA FLS is achieved via a mitochondrial-dependent pathway, which may be mediated by promoting the release of cytochrome C and by regulating the expression of Bax and Bcl-2 proteins, and p53 might also be required for NOR-induced apoptosis in AIA FLS. [Copyright &y& Elsevier]

Abstract: Scopoletin, a coumarin compound naturally occurring in many medicinal plants, has previously been demonstrated to ameliorate synovial inflammation and destruction of cartilage and bone in adjuvant arthritis (AA) rats. As interleukin (IL)-6 is critically involved in the initiation and development of rheumatoid arthritis (RA), the present study was performed to investigate the effect of scopoletin on IL-6 production from fibroblast-like synoviocytes (FLS) to get insight into its anti-RA mechanisms. FLS were isolated from synovial membrane tissues of AA rats, and stimulated with IL-1β (10ng/mL). Scopoletin, at concentrations of 15, 30, and 60μM, was shown to only moderately inhibit FLS proliferation, but dramatically reduce IL-6 production at both mRNA and protein levels. It also inhibited the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), protein kinase C (PKC) and cAMP response element binding protein (CREB). These findings suggest that scopoletin exerts anti-RA action probably through suppressing IL-6 production from FLS via MAPK/PKC/CREB pathways. [Copyright &y& Elsevier]

Abstract: Angiogenesis has become an attractive target for the treatment of certain diseases such as cancer and rheumatoid arthritis. Our previous studies demonstrated that the saponin fraction from Gleditsia sinensis fruits had anti-angiogenic potential, and Gleditsiosides B (GB) was probably the main active constituent. In the present study, we assessed the effect of GB on endothelial cell migration, a crucial event in angiogenesis, and explored the underlying mechanisms. The migration of endothelial cells was assessed by transwell. The expressions of MMP-2/-9 and TIMP-1/-2 were analyzed by Western blotting, and the activities of MMP-2/-9 were detected by gelatin zymography assay. Moreover, migration-related proteins and signaling pathways, including FAK, MAPKs and PI3K/AKT, were analyzed by Western blotting. It was shown that GB, at a concentration of 10μM without significant cytotoxicity, could effectively abrogate the migration of human umbilical vein endothelial cells (HUVECs) induced by bFGF. GB also inhibited the expression and activity of MMP-2, elevated the expression of TIMP-1, and restrained the phosphorylations of FAK, ERK, PI3K and AKT in a concentration-dependent manner. The findings suggest that GB was able to abrogate the migration of endothelial cells through down-regulating the activation of MMP-2 and FAK via preventing ERK and PI3K/AKT signaling pathways. [Copyright &y& Elsevier]

Abstract: Keloid is a specific skin scar that expands beyond the boundaries of the original injury as it heals. The invasive nature of keloid and notable migratory activity of fibroblasts are a hallmark, which distinguishes keloids from other common scars. Madecassoside, a triterpenoid saponin occurring in Centella asiatica herbs, possesses unique pharmacological properties to enhance wound-healing and diminish keloid formation. However, the effects of madecassoside on the formation of keloid scars have been poorly understood. Here, we focused on the potential of madecassoside on the migration of keloid-derived fibroblasts (KFs) and its mechanism. Primary KF, originating from human earlobe keloids, were purified and cultured, and then treated with madecassoside (10, 30, and 100μM). In both transwell migration assays and scratch-wound-closure assays, KF migration was considerably suppressed by madecassoside pretreatment. Furthermore, KFs treated with madecassoside showed decreased F-actin filaments, as revealed by fluorescein isothiocyanate (FITC)-phalloidin staining and confocal microscopy. By Western blot analysis, madecassoside was shown to remarkably attenuate the phosphorylation of cofilin, p38 MAPK and phosphatidylinositol-3-kinase (PI3K)/AKT signaling, but only exhibited a minor effect on MMP-13 and little effect on ERK1/2 phosphorylation. It was concluded that madecassoside could be of great use in the treatment and/or prevention of hypertrophic scars and keloids. [Copyright &y& Elsevier]

Abstract: Previous work in our laboratory has shown that scopoletin, one of the main bioactive constituents of Erycibe obtusifolia Benth stems, exerts anti-arthritic activity in vivo partly by preventing synovial angiogenesis. The present study was performed to further investigate the anti-angiogenic potential of scopoletin, focusing on the mechanisms of action in vitro. In the aortic ring sprouting assay, scopoletin (10, 30 and 100μM) significantly inhibited the growth of endothelial sprouts in a concentration-dependent manner. As to human umbilical vein endothelial cells (HUVECs), scopoletin could inhibit their proliferation, migration and tubule formation induced by FGF-2, especially the proliferation. It also remarkably decreased the expression of VEGF at mRNA and protein levels, and the phosphorylations of IKKα and IκB but not Akt, as well as the degradation of IκB caused by FGF-2 in HUVECs. These findings suggest that scopoletin is substantially able to attenuate FGF-2-induced angiogenesis, and it might act by directly preventing the stimulation action of FGF-2 and by indirectly decreasing the production of VEGF. Scopoletin down-regulated the VEGF expression through NF-κB rather than PI-3K/Akt signaling pathway. [Copyright &y& Elsevier]

Abstract: Despite scopolin is a main coumarin constituent in the stems of Erycibe obtusifolia Benth, a herb drug that has long been utilized in traditional Chinese medicine for the treatment of rheumatoid arthritis, little information is available about the pharmacological activities of this compound. The present study was performed to investigate the anti-rheumatic effects of scopolin in adjuvant-induced arthritis (AIA) in rats, and explore the underlying mechanisms of action in views of anti-inflammatory and anti-angiogenic properties in the synovial tissues. Scopolin (50, 100 mg/kg), injected intraperitoneally for 10 days from the onset of secondary response, significantly inhibited both inoculated and non-inoculated paw swelling as well as articular index scores in AIA. Meanwhile, the mean body weight of rats treated with scopolin was higher than that of model group. Rats treated with high dose of scopolin (100 mg/kg) preserved a nearly normal histological architecture of the joints and showed a significant reduction of the new blood vessels in the synovial tissues. Additionally, scopolin could reduce IL-6, VEGF and FGF-2 expressions in rat synovial tissues. In conclusion, scopolin can reduce the clinical symptoms of rat AIA by inhibiting inflammation and angiogenesis, and this compound may be a potent agent for angiogenesis related diseases and can serve as a structural base for screening more potent synthetic analogs. [Copyright &y& Elsevier]

Norisoboldine (NOR), an isoquinoline alkaloid, has previously been shown to ameliorate collagen-induced arthritis (CIA) by modulating the function of multiple cells such as T lymphocytes and fibroblast-like synoviocytes. To further study its anti-arthritis mechanism, the effect of NOR on the systemic metabolism regulation was investigated using an NMR-based untargeted metabolomics approach. CIA model rats were orally administered with NOR (30 mg/kg) for 14 consecutive days. The alterations of endogenous metabolites in the urine samples were quantified by 1H NMR. While NOR significantly mitigated CIA in rats as evidenced by the reduced clinical scores and histopathological changes, the results indicated that the treatment restored the levels of 22 metabolites that were significantly changed by arthritis, and most of which were related to lipid metabolism. Further studies demonstrated that NOR up-regulated the expression of carnitine palmitoyltransferase 1 (CPT-1) and down-regulated the expression of fatty acid synthase (FASN) in the spleens and the synovial tissues of CIA rats. Together these results revealed a strong association between RA and the system in metabolic disorders. The differential metabolites and their related pathways may also serve as novel therapeutic targets for RA. [Display omitted] • NMR-based untargeted metabolomic analysis of the urine reveals the systemic metabolic abnormalities of CIA rats. • A total of 22 altered metabolites might contribute to the therapeutic effect of norisoboldine on rheumatoid arthritis. • Anti-arthritis effect of norisoboldine involves the regulation of systemic metabolism, especially lipid metabolism. [ABSTRACT FROM AUTHOR]

Abstract: Madecassoside is the highest amount of triterpene constituent in Centella asiatica herbs, a frequently prescribed crude drug in southeastern Asian and China for wound healing and scar management. The present study aimed to investigate the therapeutic potential and underlying mechanisms of madecassoside on collagen II (CII)-induced arthritis (CIA) in mice. Madecassoside (10, 20 and 40mg/kg), orally administered from the day of the antigen challenge for twenty consecutive days, dose-dependently alleviated the severity of the disease based on the reduced clinical scores, and elevated the body weights of mice. Histopathological examination indicated that madecassoside alleviated infiltration of inflammatory cells and synovial hyperplasia as well as protected joint destruction. Moreover, madecassoside reduced the serum level of anti-CII IgG, suppressed the delayed type hypersensitivity against CII in ears, and moderately suppress CII-stimulated proliferation of lymphocytes from popliteal lymph nodes in CIA mice. In vitro, madecassoside was ineffective in the activation of macrophages caused by lipopolysaccharide. It was concluded that madecassoside substantially prevented mouse CIA, and might be the major active constituent of C. asiatica herbs responsible for clinical uses for rheumatoid arthritis. The underlying mechanisms of action may be mainly through regulating the abnormal humoral and cellular immunity as well as protecting joint destruction. [Copyright &y& Elsevier]

[Display omitted] In this study, we used chemical modification to improve the pharmacological activity of norisoboldine (NOR). A new NOR-benzoic acid derivative, named DC-01, showed more potent induction of Treg cell differentiation than NOR. The in vitro effective concentration of DC-01 (1 μM) is about an order of magnitude lower than that of NOR (10 μM). DC-01 (28, 56 mg/kg) showed better amelioration of dextran sodium sulfate-induced colitis in mice than NOR (20, 40 mg/kg), and DC-01 (28 mg/kg) increased the number of Treg cells slightly better than NOR (20 mg/kg). In summary, DC-01 exerts more potent induction of Treg cell generation, which might be a candidate drug for the treatment of inflammation- and immune-related diseases. [ABSTRACT FROM AUTHOR]

• The ileum is the main action site of madecassoside by oral administration. • Madecassoside exerts anti-arthritis effect in a gut microbiota-dependent manner. • Madecassoside up-regulates the production of SCFAs and induce Treg cell differentiation. Previously, we reported that oral administration of madecassoside, the main active triterpene in Centella asiatica L., exerted anti-arthritis effect by inducing the generation of regulatory T (Treg) cells in small intestine. This study investigates the action site and mechanism of madecassoside to induce Treg cells. In collagen-induced arthritis (CIA) of rats, oral administration of madecassoside significantly alleviated arthritis symptoms, but its main metabolite madecassic acid did not, suggesting that madecassoside functions in the parent form. Madecassoside was shown to increase the number of Treg cells and promote the expression of Foxp3 and IL-10 in rat ileum rather than duodenum and jejunum, as detected using the immunohistochemistry assay and quantitative PCR assay, respectively. Unexpectedly, madecassoside was absent of significant effect on in vitro Treg cell differentiation and the expression of Foxp3 and IL-10. A combined use of broad-spectrum antibiotics resulted in significant reduction of the anti-arthritis effect of madecassoside in CIA rats. The 16S rRNA gene sequence showed that madecassoside could reverse the changes of gut microbiota under arthritis condition, and enrich several bacteria such as Lachnospiraceae, Butyricicoccus, Faecalibacterium, Butyricicoccus pullicaecorum and so on. GC-MS assay showed that madecassoside elevated the levels of acetic acid and butyric acid, but not other short chain fatty acids (SCFAs) in the cecum contents of CIA rats. Butyric acid rather than acetic acid could induce the in vitro differentiation of Treg cells and the expression of Foxp3 and IL-10. Accordingly, when madecassoside was co-administered with heptanoyl CoA, the competitive inhibitor of butyrate synthase, its effect on butyric acid production, Treg cell proportion and arthritis nearly disappeared. These findings indicate that oral madecassoside induces the generation of Treg cells and therefore displays anti-arthritis effect in the parent form but not metabolites, and the ileum is the main action site. The mechanism of madecassoside can be summarized as: expansion of the richness of butyrate-producing bacteria-up-regulation of intestinal butyrate level-induction of Treg cell differentiation and IL-10 expression. [ABSTRACT FROM AUTHOR]

Our previous studies demonstrated that oral administration of madecassoside could markedly attenuate collagen-induced arthritis in rats, a rodent model of rheumatoid arthritis. As the autonomic nervous system is critically involved in the modulation of peripheral inflammation and immune response, the present study aims to explore the possible involvement of adrenergic and cholinergic nerves in the effect of madecassoside on rheumatoid arthritis. Arthritis was induced by chicken collagen in rats, and madecassoside was orally administered daily for two weeks from day 14 after the primary immunization. The antagonists of adrenoceptor and cholinergic receptors were co-administered with madecassoside, respectively. Unilateral cervical vagotomy was performed four days before the arthritis induction. The results showed that madecassoside (30 mg/kg) treatment markedly ameliorated arthritis symptoms in rats, mainly evidenced by the reduction of paw swelling and arthritis index scores. Co-administration of madecassoside with atropine (an antagonist of the muscarinic acetylcholine receptor) or hexamethonium (an antagonist of the nicotinic acetylcholine receptor) markedly diminished the therapeutic effects of madecassoside in arthritis. However, co-administration with phentolamine (an antagonist of the α-adrenoceptor) or propranolol (an antagonist of the β-adrenoceptor) did not alter the effect of madecassoside on arthritis. Furthermore, unilateral cervical vagotomy significantly reduced the anti-arthritis efficacy of madecassoside, including the amelioration of clinical symptoms, as well as the inhibition of the production of pro-inflammatory cytokines except T lymphocytes-related cytokines. These findings suggest that madecassoside exerts inhibitory effects on collagen-induced arthritis through, at least partially, the peripheral cholinergic system. • Madecassoside ameliorates collagen-induced arthritis through peripheral cholinergic system rather than adrenergic system. • Madecassoside exerts anti-arthritis efficacy dependent on the vagus nerve integrity. • Madecassoside-induced anti-inflammatory but not immunomodulatory effect requires vagus nerve. [ABSTRACT FROM AUTHOR]