Search

Jaboticaba is a fruit from a native tree to Brazil,Plinia peruviana. Jaboticaba peels are an important source of antioxidant molecules such as phenolic compounds. This study aimed to evaluatein vitrothe activity of a hydroalcoholic extract of jaboticaba fruit peels (HEJFP) in wound healing processes and antioxidant activity in murine fibroblasts (L929 cell line). HEJFP concentrations (0.5, 1, 5, 10, 25, 50, 100, and 200 µg/mL) were tested in MTT assay and cell proliferation was verified at 100 µg/mL after 24 h and at 25, 50, and 100 µg/mL after 48 h of extract exposure. Evaluation of antioxidant activity was performed at 0.5, 5, 25, 50, and 100 µg/mL HEJFP concentrations. Cell treatment with HEJFP at 25, 50, and 100 µg/mL for 24 h followed by H2O2exposure for 3 h showed a strong cytoprotective effect.In vitroscratch wound healing assay indicated that none of tested HEJFP concentrations (0.5, 5, 25, 50, and 100 µg/mL) were capable of increasing migration rate after 12 h of incubation. These results demonstrate a positive effect of HEJFP on the wound healing process on L929 fibroblasts cell line, probably due to the antioxidant activity exhibited by phytochemicals in the extract.

OBJECTIVE The aim of this work is to develop and characterize nanoemulsions containing jaboticaba extract (Plinia peruviana) aiming pharmaceutical and cosmetic applications. METHODS Nanoemulsions were prepared by high-pressure homogenization method using different concentrations of components (oil, surfactant, and extract) and homogenization pressures, in order to optimize the preparation conditions. Both unloaded and extract-loaded nanoemulsions were characterized according to their size, polydispersity, zeta potential, pH, morphology, and physical stability. Total phenolic and flavonoid contents in free jaboticaba extract and jaboticaba-loaded nanoemulsions were determined spectrophotometrically, while ellagic acid content was determined by high-performance liquid chromatography (HPLC) analysis. In vitro antioxidant activity was investigated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. RESULTS Colloidal dispersions exhibited a mean particle size around 200 nm, with monodisperse size distribution (PdI

The present study describes the chemical composition and the antioxidant activity of spent coffee grounds and coffee husks extracts, obtained by supercritical fluid extraction (SFE) with CO(2) and with CO(2) and co-solvent. In order to evaluate the high pressure method in terms of process yield, extract composition and antioxidant activity, low pressure methods, such as ultrasound (UE) and soxhlet (SOX) with different organic solvents, were also applied to obtain the extracts. The conditions for the SFE were: temperatures of 313.15K, 323.15K and 333.15K and pressures from 100 bar to 300 bar. The SFE kinetics and the mathematical modeling of the overall extraction curves (OEC) were also investigated. The extracts obtained by LPE (low pressure extraction) with ethanol showed the best results for the global extraction yield (X(0)) when compared to SFE results. The best extraction yield was 15±2% for spent coffee grounds with ethanol and 3.1±04% for coffee husks. The antioxidant potential was evaluated by DPPH method, ABTS method and Folin-Ciocalteau method. The best antioxidant activity was showed by coffee husk extracts obtained by LPE. The quantification and the identification of the extracts were accomplished using HPLC analysis. The main compounds identified were caffeine and chlorogenic acid for the supercritical extracts from coffee husks.

The present study investigated the antioxidant properties of Cyathea phalerata Mart. (Cyatheaceae) using in vitro and in vivo assays. The in vitro antioxidant potential of the crude extract (CE), precipitate (PPT), aqueous fraction (AQF), n-butanolic fraction (BUF) and ethyl acetate fraction (EAF) from C. phalerata was evaluated through the scavenging of diphenyl-1-picryl-hydrazyl-hydrate (DPPH), superoxide anion (O 2 • − ) (nitroblue tetrazolium assay) and hydroxyl radicals (OH • ) (deoxyribose assay), and lipid peroxidation in rat liver homogenate. In these assays, it was observed that EAF had marked antioxidant potential, especially as a scavenger of the OH • radical and in inhibiting lipid peroxidation. The in vivo evaluation of oxidative stress (DNA fragmentation, membrane lipoperoxidation and carbonyl protein formation) and the antioxidant defenses (concentration of reduced glutathione, as well as catalase and glutathione S-transferase activities) were measured in mice pre-treated with EAF (10, 30 or 100 mg/kg, orally) and later exposed to carbon tetrachloride (CCl 4 ). The EAF decreased thiobarbituric acid reactive substances levels, DNA damage and carbonyl protein contents, and increased catalase and glutathione S-transferase activities. Based on these results, it is concluded that the EAF from C. phalerata protects liver from oxidative stress induced by CCl 4 in mice and these effects are probably related to the antioxidant activity associated with the free radical scavenging property of this fraction. Cyathea phalerata Mart. (Cyatheaceae) is a tree fern that grows in the tropical and subtropical areas of Brazil and is commonly known as 'xaxim'. In folk medicine, its stem pith is used to treat several inflammatory diseases and the alco- hol extract of the pith is used for the treatment of varicose veins and hemorrhoids. In phytochemical studies of Cyathea genus, several classes of compounds were identified such as fernene, filicene and hopane triterpenes (1,2), phenolic acids (coumaric and caffeic), protocatechuic acids and flavonoids, mainly kaempferol glycosides (3-5). In a recent study, Pizzolatti et al . (6) isolated the cyathenosin A, a spiropyranosil derivative of protocatechuic acid, from the stem pith of C. phalerata . Studies on the pharmacological effects of C. phalerata are still limited. However, recently, Cazarolli et al . (7) demonstrated that the flavonoid, kaempferol-3- neohesperidoside, isolated from C. phalerata , has a hypogly- caemic effect in diabetes induced by alloxan in rats. Flavonoids exhibit a wide range of biological effects, includ- ing antibacterial, anti-inflammatory, anti-allergic, hepato- protective, antithrombotic, antiviral, anticarcinogenic and vasodilatory actions; many of these biological functions have been attributed to the free radical scavenging and antioxidant activity of these compounds (8-10). Oxidative stress plays an important role in the pathogenesis of several human pathologies, including ischaemia and reperfusion injury, atherosclerosis, neurodegenerative diseases and cancer (11). The excess of reactive oxygen species (ROS) can damage cellular lipids, proteins or DNA, thereby inhibiting their normal function (12). Thus, oxidative stress has been implicated in a number of human diseases as well as in the ageing process (11). Owing to the relative inefficiency of our endogenous defence systems and the existence of some pathophysiological situations (cigarette smoke, air pollutants, ultraviolet radiation, inflammation, ischaemia/ reperfusion, etc.) in which ROS are produced in excess and at the wrong time and place, dietary antioxidants are needed to diminish the cumulative effects of oxidative damage over the life span (13). In this regard, there has been a great deal of interest in the screening and characterization of novel, potentially therapeutic herbal products. Therefore, the aim of the present study was to investigate the antioxidant activity ( in vitro and in vivo ) of the crude extract and fractions obtained from C. phalerata .

In a previous study, we demonstrated the antinociceptive effect of 63SF, a proanthocyanidin-rich fraction obtained from Croton celtidifolius barks, in chemical and thermal behavioural models of pain in mice. The current study now investigate the possible mechanisms underlying the antinociceptive activity of 63SF in the formalin test, by using drugs which interfere with systems that are implicated in descending control of nociception. The antinociceptive effect of 63SF (11 mg/kg, i.p., given 30 min prior to 2.5% formalin) was not altered by pre-treatment of animals 45-50 min beforehand with either prazosin (alpha(1)-adrenergic antagonist; 0.15 mg/kg, i.p.), yohimbine (alpha(2)-adrenergic antagonist; 0.15 mg/kg, i.p.), ketanserin (5-HT(2A)-receptor antagonist; 1.0 mg/kg, i.p.), or l-arginine (substrate for NO synthase, 600 mg/kg, i.p.). On the other hand, treatment with sulpiride, an antagonist of dopaminergic D(2)-receptors (1.0 mg/kg, i.p., 45 min of pre-treatment), reversed the antinociceptive activity of 63SF. Pre-treatment of animals with reserpine (5 mg/kg, i.p., 24 h beforehand) did not alter the antinociceptive effect of 63SF. The current results support the view that the 63SF exerts antinociceptive effects by enhancing the activity of descending control, possibly by direct stimulation of dopaminergic D(2) receptors.

A number of studies suggest that moderate consumption of red wine may be more effective than other alcoholic beverages in decreasing the risk of coronary heart disease (CAD). In this study, we investigated the effect of a crude extract (CE), as well as an ethyl acetate fraction (EAF) obtained from a Brazilian red wine in the mesenteric arterial bed (MAB) from rats. Our results showed that after the tonus of MAB was increased with phenylephrine (PE), increasing concentrations of CE induced a concentration-dependent relaxation; moreover, EAF was more potent in relaxing the MAB when compared with CE. In vessels depolarized with KCl (80 mM) or treated with the Na(+)/K(+)-ATPase pump inhibitor, ouabain (OUA; 100 microM), or with the K(+) channel blockers: barium (BaCl(2), 100 microM) and tetraethylammonium (TEA; 500 microM), the effect of EAF was significantly reduced. However, this effect was not altered by the ATP-dependent K(+) (K(ATP)) channel blocker, glibenclamide (GLI; 100 microM) as well as Charybdotoxin (ChTx 10 nM), a nonselective inhibitor of K(Ca) channels of large and intermediate conductance plus Apamin (Apamin 100 nM), a specific inhibitor of K(Ca) channels of small conductance. The residual vasodilator effect of EAF observed in vessels pretreated with L-NOARG (100 microM), 1H-[1,2,4,] oxadiazolo[4,3-alfa]quinoxalin, ODQ (10 microM) or KCl (80 mM), given separately, was reduced by the administration of KCl (40 mM) plus L-NOARG (100 microM). The present study demonstrates that the vasodilator effect of EAF is partially dependent upon membrane hyperpolarization in combination with nitric oxide (NO) release.

Wilbrandia ebracteata is a medicinal plant from South America used in folk medicine for the treatment of chronic rheumatic diseases. We have shown that the high performance liquid chromatography-characterized (HPLC) dichloromethane fraction isolated from Wilbrandia ebracteata (WEDC) inhibits the parameters observed in experimental models of inflammation in vivo and in vitro. In the present study, we extend our previous observations on the analgesic effects of WEDC by investigating its actions using the hot plate test and zymosan-induced writhing test in mice, as well as zymosan-induced arthritis in rats evaluating articular inflammatory pain, cell migration and determination of NO release into the joint exudate. The effect of WEDC on the activity of COX-1 and COX-2 in vitro and its ulcerogenic capacity in vivo were also investigated. The oral treatment of the animals with WEDC (1-10 mg/kg) produced a significant, dose-dependent reduction of articular incapacitation and abdominal contortions in the writhing test. The same effect was not observed in the hot plate and rota-rod tests. WEDC also reduced nitrite release into the zymosan-inflamed joints. In the evaluation of COX activity, we observed that WEDC was able to selectively inhibit COX-2 but not COX-1 activity in COS-7 cells. Moreover, WEDC treatment did not show gastrointestinal toxicity. Our data confirm the anti-nociceptive activities of the WEDC and indicate that this effect could be associated with inhibition of cyclooxygenase-2 (COX-2) and nitric oxide release. The effects could be attributed to cucurbitacins since several of these were isolated from the WEDC.

Croton celtidifolius Baill commonly known as "sangue-de-adave" is a tree found in the Atlantic Forest of south of Brazil, mainly in Santa Catarina. The bark and leaf infusions of this medicinal plant have been popularly used for the treatment of inflammatory diseases. In this study we evaluated the anti-inflammatory and antioxidant properties of crude extract (CE), aqueous fraction (AqF), ethyl acetate fraction (EAF), butanolic fraction (BuF) and catechin, gallocatechin and sub-fractions, 19SF, 35SF and 63SF that contained a mixture of proanthocyanidins and were derived from the EAF fraction. The CE, AqF, EAF, BuF, catechin and sub-fractions 35SF and 63SF reduced paw edema induced by carrageenan. The CE, fractions, sub-fractions and isolated compounds showed antioxidant properties in vitro, all were able to scavenge superoxide anions at a concentration of 100 microg ml(-1). The EAF, catechin and gallocatechin were most effective in the deoxyribose assay, IC50 0.69 (0.44-1.06), 0.20 (0.11-0.39), 0.55 (0.28-1.08) microg x ml(-1) respectively. The CE and other fractions and sub-fractions inhibited deoxyribose degradation up to 1 microg x ml(-1). In the hydrophobic system only AqF did not show lipid peroxidation inhibition. The CE, other fractions, sub-fractions and isolated compounds inhibited lipidid peroxidation only at a concentration of 100 microg x ml(-1). In summary, this study demonstrates that Croton celtidifolius bark has significant anti-inflammatory and antioxidant activity.

Wilbrandia ebracteata Cogn. (Cucurbitaceae) is commonly known in Brazil as “Taiuia”. The roots are employed in folk medicine for the treatment of several diseases, such as rheumatic disease. This study has evaluated the anti-inflammatory action of dicloromethane fraction (F-DCM), purified fraction (PFIII) and Cucurbitacin B extracted from crude extract of W. ebracteata in experimental models in vivo . The F-DCM (0.3 to 10 mg.kg −1 , i.p. or 3 to 30 mg.kg −1 p.o.) produced significant but not dose-dependent inhibition of the carrageenan-induced cell influx and exsudate leakage in the pleural cavity of mice. The F-DCM 0.01 to 10 mg.kg −1 , i.p. or 0.1 to 10 mg.kg −1 p.o.) decreased the levels of PGE 2 in the exsudate leakage induced by carrageenan in the pleural cavity after 4 h with a calculated ID 50 of 0.01 (0.002–0.09, i.p.) and 0.29 (0.05–1.45, p.o.) mg.kg −1 . The PFIII (3 mg.kg −1 , i.p.) inhibited 80% of cell migration (1.50 ± 0.09 × 10 6 cells/cavity) and exsudate leakage by about 50% (3.09 ± 0.71 μg ml ) in relation to the control group. Cucurbitacin B (0.1 mg.kg −1 , i.p.), the main compound of PFIII, reduced significantly the levels of PGE 2 in the exsudate leakage by 40.7% (10.41 ± 2.67 ng.ml −1 ). These data show that the active principle(s) present in the F-DCM of W. ebracteata elicited pronounced anti-inflammatory effects when assessed by i.p. or p.o. routes, as well as PFIII. The F-DCM was also able to prevent PGE 2 formation in exsudate leakage induced by carrageenan, as well as Cucurbitacin B, its active principle. These results indicate that the anti-inflammatory activity of Wilbrandia ebracteata can be related with the inhibition of the production of PGE 2 .

Objectives In this study, we evaluated the effect of the proanthocyanidins-rich fraction (PRF) obtained from Croton celtidifolius bark in an experimental animal model of spinal cord injury and cell death induced by glutamate. Methods Experiments were conducted using adult male Wistar rats (10 weeks old and weighing 270–300g). Experimental groups were randomly allocated into the following groups: spinal cord injury (SCI) + vehicle group: rats were subjected to SCI plus intraperitoneal administration of vehicle (saline 10 ml/kg); SCI + PRF: rats were subjected to SCI plus intraperitoneal administration of PRF (10 mg/kg) at 1 and 6 h after injury and sham operated. Key findings The treatment with the proanthocyanidin-rich fraction significantly improved not only motor recovery and grip force but also H2O2 or glutamate-induced cell death and reactive oxygen species generation induced by glutamate in dorsal root ganglion cells. In this study we demonstrate that the neuroprotective effect triggered by the proanthocyanidins-rich fraction appears to be mediated in part by the inhibition of N-methyl-D-aspartate-type glutamate receptors. Conclusions Taken together, our results demonstrate that PRF treatment ameliorates spinal cord injury and glutamatergic excitotoxicity and could have a potential therapeutic use.

Objectives This paper aims to evaluate the anti-tumour properties of elatol, a compound (sesquiterpene) isolated from algae Laurencia microcladia. Methods In-vitro and in-vivo anti-tumour properties of elatol were investigated using: MTT assays to assess the cytotoxic effects; flow cytometry analysis to examine the cell cycle and apoptosis; Western blot analysis for determination of the expression of cell cycle and apoptosis proteins; and study of in-vivo tumour growth in mice (C57Bl6 mice bearing B16F10 cells). Key findings Elatol exhibited a cytotoxic effect, at least in part, by inducing cell cycle arrest in the G1 and the sub-G1 phases, leading cells to apoptosis. Western blot analysis demonstrated that elatol reduced the expression of cyclin-D1, cyclin-E, cyclin-dependent kinase (cdk)2 and cdk4. A decrease in bcl-xl and an increase in bak, caspase-9 and p53 expression was also observed. In the in-vivo experiment, treatment with elatol was able to reduce tumour growth in C57Bl6 mice. Conclusions Elatol promotes a delay in the cell cycle, probably in the G1/S transition, activating the apoptotic process and this could be responsible, at least in part, for the in-vivo effects observed. Taken together, the in-vitro and in-vivo experiments suggested that elatol has anti-tumour properties. Further studies should be conducted to clarify the mechanism of action.

The aim of this study was to evaluate the effects of green tea extract (GTE) administration on vascular reactivity and atherosclerosis progression in low-density lipoprotein receptor knockout mice. We hypothesized that GTE intake may ameliorate atherosclerosis by improving endothelial dysfunction. Animals (n = 12 per group) were fed a hypercholesterolemic diet and received either water or GTE at a dose of 50, 100, or 300 mg/kg once a day by gavage (100 μL/10 g weight). After 4 weeks, atherosclerosis extension and vascular reactivity were evaluated in the aorta, and the levels of lipids, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor α were measured in the plasma. Administration of GTE at a dose of 50 mg/kg significantly decreased the area of atherosclerotic lesions by 35%, improved the vascular reactivity in the isolated thoracic aorta, and lowered the plasma levels of both MCP-1 and triglycerides. Delivery of 100 mg/kg of GTE only promoted vasocontraction and vasorelaxation (P.05), whereas a dose of 300 mg/kg was ineffective. Maximum contraction and relaxation negatively correlated with the lesion area (r = -0.755 and -0.767, respectively), whereas the plasma levels of MCP-1 and triglycerides positively correlated with plaque size (r = 0.549 and 0.421, respectively). In summary, our results supported the hypothesis that administration of GTE at low doses may contribute to a decrease in atherosclerosis progression by reversing endothelial dysfunction.

Objectives The aim of the present study was to evaluate the possible neurobehavioural effects in rats of the proanthocyanidin-rich fraction (PRF) isolated from the bark of Croton celtidifolius (Euphorbiaceae). Methods Adult Wistar rats were treated with the PRF (0.3–30 mg/kg) and evaluated in different behavioural paradigms classically used for the screening of drugs with psychoactive effects. Key findings Acute intraperitoneal (i.p.) administration of PRF decreased spontaneous locomotor activity (open field arena and activity cage), enhanced the duration of ethyl ether-induced hypnosis, increased the latency to the first convulsion induced by pentylenetetrazole (60 mg/kg, i.p.) and attenuated apomorphine-induced (0.5 mg/kg, i.p.) stereotyped behaviour. In lower doses, PRF (0.3 or 3 mg/kg, i.p.) increased the frequency of open arm entries in the elevated plus-maze test. Conclusions The present findings suggest that the systemic administration of PRF induces a wide spectrum of behavioural alterations in rats, consistent with the putative existence of hypnosedative, anticonvulsant and anxiolytic compounds.

We have recently demonstrated that rodents treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) suffered impairments in olfactory, cognitive and motor functions associated with time-dependent disruption of dopaminergic neurotransmission in different brain structures conceivably analogous to those observed during different stages of Parkinson’s disease (PD). On the other hand, the proanthocyanidin-rich fraction (PRF) obtained from the bark of Croton celtidifolius Baill (Euphorbiaceae), a tree frequently found in the Atlantic forest in south Brazil, has been described to have several neurobiological activities including antioxidant and anti-inflammatory properties, which may be of interest in the treatment of PD. The present data indicated that the pretreatment with PRF (10 mg/kg, i.p.) during five consecutive days was able to prevent mitochondrial complex-I inhibition in the striatum and olfactory bulb, as well as a decrease of the enzyme tyrosine hydroxylase expression in the olfactory bulb and substantia nigra of rats infused with a single intranasal administration of MPTP (1 mg/nostril). Moreover, pretreatment with PRF was found to attenuate the short-term social memory deficits, depressive-like behavior and reduction of locomotor activity observed at different periods after intranasal MPTP administration in rats. Altogether, the present findings provide strong evidence that PRF from C. celtidifolius may represent a promising therapeutic tool in PD, thus being able to prevent both motor and non-motor early symptoms of PD, together with its neuroprotective potential.

Elephantopus scaber has been used in Brazil as a traditional remedy to cause diuresis, antipyresis and to eliminate bladder stones. In the current study, aqueous and hydroalcoholic extracts of whole plants were tested for acute toxicity, analgesic, antipyretic, antiinflammatory, cardiovascular, diuretic and constipating activities. Both extracts (0.3–6 g/kg i.p.) induced writhing, loss of muscle tone, ataxia, prostration and death in mice. No analgesic effects of these extracts were detected using mouse hot-plate and acetic acidinduced writhing tests. Both extracts failed to modify diuresis or carrageenan-induced rat paw edema. In contrast, given intraperitoneally, both reduced brewer's yeast-induced hyperthermia in rats, but when given orally did not affect it. Moreover, the aqueous extract decreased the intestinal transit time in mice while the hydroalcoholic extract increased it. Finally, these extracts, given intravenously, reduced blood pressure and heart rate in rats; these effects could be blocked by atropine but not by co-administration of pyrilamine and cimetidine.

Croton celtidifolius Bailon, commonly known as Sangue-de-Adave or Pau-Andrade, is a tree found in the Atlantic forest of southern Brazil. It has been popularly used for the treatment of inflammatory and ulcerative disorders. Phytochemical analysis demonstrated the presence of flavonoids and proanthocyanidins in an ethyl acetate fraction (EAF) from C. celtidifolius Bailon. In this study, we have evaluated the effects of EAF and its sub-fractions (35 and 63, catechin) on inflammatory (cell migration and plasma extravasation) and oxidative (lipid peroxidation, superoxide dismutase (SOD) activity and superoxide anion production) parameters in carrageenan-induced pleurisy in rats. NO production was also measured by nitrite/nitrate levels. EAF and sub-fraction 63 (63SF) showed anti-inflammatory activity, as indicated by a reduction in plasma extravasation and cell migration (mainly polymorphonuclear leukocytes) to the pleural cavity. Furthermore, EAF treatment decreased the production of superoxide radical anion by cells isolated from the pleural cavity, while it did not affect the nitrite/nitrate levels in exudates. The results show that C. celtidifolius contains substances with antioxidant and anti-inflammatory activity that, at least in part, act by a modulation of oxidative stress by phenolic compounds.

The chemical composition of the chromatography 63 subfraction (63SF) from the ethyl acetate soluble fraction of the crude extract of Croton celtidifolius bark presented a high content of total proanthocyanidins (75.0 ± 2.3%). HPLC analysis of 63SF revealed a dimeric profile (e.g. catechin-(4α → 8)-catechin and gallocatechin-(4α → 8)-catechin) and polymeric proanthocyanidins. In pharmacological investigations, 63SF administered intraperitoneally exhibited dose-dependent antinociceptive activity against several chemical stimuli, including the intraperitoneal injection of acetic acid (ID50 (the dose of 63SF which was able to reduce the nociceptive response by 50% relative to the control value) = 0.9 (0.5–1.6)) and the intraplantar injection of capsaicin (ID50 = 13.0 (10.0–17.0)), glutamate (ID50 = 4.0 (2.0–7.0)) and formalin (ID50 first phase = 36.0 (24.0–53.0) and late phase = 11.0 (8.0–14.0)). 63SF administered orally exhibited an antinociceptive effect in the formalin test (ID50 first phase = 125.0 (89.0–177.0) and late phase = 65.0 (33.0–95.0)). In the same test, 63SF was effective when given soon after the first phase, as well as exhibiting therapeutic activity. Furthermore, 63SF was effective in models of thermal nociception including tail-flick and hot-plate tests. When the mice were treated in the neonatal period with capsaicin, the antinociceptive effect of 63SF in the first phase of the formalin test was abolished, but pretreatment with naltrexone did not change the antinociceptive effect of 63SF. Together, these results provide evidence that 63SF exerted a pronounced systemic antinociception against chemical (acetic acid, formalin, glutamate and capsaicin tests) and thermal (hot-plate and tail-flick tests) nociceptive models of pain in mice at a dose that did not interfere with the locomotor activity. The mechanism by which this sub-fraction produced antinociception remains unclear, but it is unlikely to involve the activation of the opioid system. However, unmyelinated C-fibres sensitive to treatment with capsaicin are likely to participate in antinociception caused by 63SF.

This study investigated the superoxide anion and hydroxyl radical scavenger properties, as well as the inhibition of lipid peroxidation by the crude hydroalcoholic extract (CE) and the butanolic (BF) and ethyl acetate (EAF) fractions of Cuphea carthagenensis leaves. In a enzymatic system of O 2 − production (xanthine/xanthine oxidase system) the CE, EAF and BF (0.1–100 μg ml −1 ) were effective at inhibiting both uric acid formation and NBT reduction by O 2 −1 . In the non-enzymatic system of O 2 − generation, the CE and fractions were effective only at the concentration of 100 μg ml −1 . The CE, EAF and BF were also evaluated for their ability to scavenge hydroxyl radicals and/or to chelate iron. The results showed that CE, BF and EAF from C. carthagenensis (0.1–100 μg ml −1 ) were able to inhibit deoxyribose degradation in a concentration-dependent manner. CE was more potent than the fractions. In a hydrophobic system, increasing concentrations of CE, EAF and BF (0.1–100 μg ml −1 ) caused graded inhibition of lipid peroxidation of rat liver homogenate. The EAF displayed the lowest median inhibitory concentration. The present study suggests that an extract (CE) and fractions (EAF and BF) from C. carthagenensis leaves are significant sources of phenolic compounds with antioxidant activity in vitro and may have important health effects, for example, in cardiovascular disease.

Croton celtidifolius Baill (Euphorbiaceae) is a tree found in the Atlantic forest of southern Brazil. This plant is used in folk medicine for the treatment of several inflammatory diseases, leukaemia, ulcers and other pathologies. Previous studies demonstrated anti-inflammatory and antioxidant activities and the objective of this work was to investigate a possible antinociceptive action of ethanolic extract of Croton celtidifolius bark (EE) and ethyl acetate fraction (EAF), n-butanol fraction (FBuOH), and aqueous fraction (FAq) obtained from EE. Two standard rodent models of pain were employed for this investigation, the writhing test and the formalin test. In the writhing test, the pre-treatment with EE significantly reduced the writhing induced by 0.6% acetic acid injection and its effect persisted for 4 h. In the formalin test, the pre-treatment with EAF caused marked and dose-related inhibition of formalin-induced licking in mice in the first phase, while pre-treatment with EAF, FBuOH and FAq had a similar effect in the second phase, when given by intraperitoneal (i.p.) and orally (p.o.) route. However, given by i.p. route, the effect of fractions was about three to five-fold more potent in inhibiting licking than when administered by p.o. route. EE presented an antinociceptive effect only in the second phase, when given by i.p. or p.o. route. The oedema caused by formalin was significantly reduced in animals treated i.p. with EAF, FBuOH and FAq. Under the same experimental conditions, in animals treated with sub-fractions derived from EAF only the 63 sub-fraction significantly reduced nociception in both phases and oedema caused by formalin. The results obtained suggest that Croton celtidifolius possesses antinociceptive properties since the EE, fractions and a sub-fraction significantly reduced the writhing induced by acetic acid and the nociception in both phases of the formalin test.

This study evaluated the vasorelaxant properties of the crude hydroalcoholic extract (CE) of Cuphea carthagenensis, as well as its butanolic (BF) and ethyl acetate (EA) fractions, in rings of rat thoracic aorta. In endothelium-intact rings contracted with phenylephrine (30-100 nM), cumulative additions of increasing concentrations of CE, BF, and EA of C. carthagenensis (0.1 microg/ml-3 mg/ml) caused graded relaxations, with BF displaying the lowest median inhibitory concentration (IC5; mean, 6.8 microg/ml; 95% confidence limits, 3.3-14.2). BF-induced relaxations of endothelium-intact rings were virtually abolished by prior incubation with the NO-synthase inhibitor N(omega)-nitro-L-arginine (L-NOARG; 10 or 30 microM), and were markedly reduced after guanylate cyclase inhibition with either methylene blue (10 microM) or ODQ (1 microM; 1H[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one). The inhibition of BF-induced relaxation by L-NOARG was prevented to a large extent by simultaneous incubation with L-arginine (1 mM). In endothelium-denuded rings contracted with phenylephrine, CE and BF caused graded relaxations only at doses >100 microg/ml, whereas the NO-donors SNAP (S-nitroso-N-acetyl-penicillamine) and SIN-1 (3-morpholino-sydnonimine) induced full relaxation at 1 microM. BF (100 microg/ml), which caused little relaxation per se of endothelium-denuded rings, potentiated the relaxant effects of SNAP and even more so of SIN-1 (which, unlike SNAP, also releases superoxide anion O2- in addition to NO), in a manner qualitatively similar to that seen with SOD (superoxide dismutase) against SIN-1. These data indicate that the BF of C. carthagenensis induces relaxation of the rat thoracic aorta by two mechanisms: (a) an endothelium-dependent component of action, which clearly depends on the NO/cyclic guanosine monophosphate (cGMP) pathway and can be attributed, at least in part, to free radical-scavenging properties; and (b) an endothelium-independent component of action, which becomes evident at higher doses (> or = 100 microg/ml) and remains to be further characterized. These results suggest that this native South American plant might be beneficial in cardiovascular disease.

This study has evaluated the possible role played by the l-arginine-nitric oxide pathway in the vasorelaxant action of the hydroalcoholic extract from Eugenia uniflora, and fractions from the extract, in rings of rat thoracic aorta. The addition of an increasing cumulative concentration of hydroalcoholic extract from E. uniflora (1–300 μg mL−1) caused a concentration-dependent relaxation response in intact endothelium-thoracic aorta rings pre-contracted with noradrenaline (30–100 nm). The IC50 value, with its respective confidence limit, and the maximum relaxation (Rmax) were 7.02 (4.77–10.00) μg mL−1 and 83.94 ± 3.04%, respectively. The removal of the endothelium completely abolished these responses. The nitric oxide synthase inhibitors Nω-nitro-l-arginine (l-NOARG, 30 μm) and Nω-nitro-l-arginine methyl ester (l-NAME, 30 μm), inhibited the relaxation (Rmax) to −10.43 ± 7.81% and −3.69 ± 2.62%, respectively. In addition, l-arginine (1 mm), but not d-arginine (1 mm), completely reversed inhibition by l-NOARG. Methylene blue (30 μm), a soluble guanylate cyclase inhibitor, reduced the relaxation induced by the extract to 14.60 ± 7.40%. These data indicate that in the rat thoracic aorta the hydroalcoholic extract, and its fractions, from the leaves of E. uniflora have graded and endothelium-dependent vasorelaxant effects.

Portulaca pilosa has been used in Brazil as a traditional remedy to cause diuresis, antipyresis and analgesia. Achyrocline satureioides has been used in folk medicine as antiinflammatory, hypoglycemic, sedative and to treat gastrointestinal disorders such as diarrhea and dysentery suggesting that it may affect salt and water reabsorption by the gastrointestinal tract. In the current study, hydroalcoholic extracts of both plants were investigated in order to examine their renal effects. The results support the claim that extracts of P. pilosa present renal effects but not the popular belief that it affects diuresis. It has also been proved that, in rats, it causes an increase in K excretion without a concomitant change in water diuresis or Na excretion. Our findings also support the popular belief that A. satureioides does not apparently have renal effects and it might change renal ion transport based on observations that it affects gastrointestinal reabsorption.

Antidiabetic activity of crude extract of leaves of Talauma ovata St. Hil. (Magnoliaceae) was analysed as part of a general pharmacological screening of this plant. Chemical analysis demonstrated the presence of phytosteroids, saponins, alkaloids and tannins in the crude extract. Pharmacological studies failed to demonstrate hypoglycemic effect of this plant in normoglycemic, hyperglycemic or alloxan-diabetic rats. The low LD50 obtained for this plant strongly suggests that its consumption by the population may be hazardous.