Gastroprotective effect of leaf extract of two varieties grapevine (Vitis vinifera L.) native wild and cultivar grown in North of Tunisia against the oxidative stress induced by ethanol in rats.

Context: Vitis vinifera leaves are traditionally used in Tunisian folk medicine to treat digestive pathologies.Objective: We aimed to compare the gastroprotective effects of hydromethanolic leaves extracts of wild and cultivated grapes accessions native of Tunisia.Materials and methods: The phytochemical analysis of grapevine leaves extracts was performed. The gastroprotective activity was evaluated by ethanol-induced gastric-ulcer in rats pre-treated with increased doses of the extracts or with the standard omeprazole. Index of gastric secretions (volume, pH and gastric mucus production), stomach wall histology and biochemical parameters were estimated for assessment of anti-secretory and gastroprotective effects of the extracts.Results: Pre-treatment with grapevine leaves extracts decreased significantly gastric volume, gastric mucosal damage and increased significantly gastric juice pH compared with the negative control group. The extracts prevented ethanol-induced decrease of the activity of antioxidant enzymes while the levels of malondialdehyde and of reduced glutathione were decreased significantly. Moreover, the most marked effect was observed at low doses of wild ecotype 'Nefza-I' extracts.Conclusion: The leaves of Vitis species might be suitable as a functional food for therapeutic purpose and demonstrates gastroprotective action in gastric lesions model. Both accessions exhibited gastroprotective effects, but wild 'Nefza-I' ecotype was more effective than cultivar 'Marsaoui'.

Gastroprotective effect of carob (Ceratonia siliqua L.) against ethanol-induced oxidative stress in rat.

BACKGROUND: We aimed in the present study, at investigating the gastroprotective effect of carob pods aqueous extract (CPAE) against ethanol-induced oxidative stress in rats as well as the mechanism implicated. METHODS: Adult male wistar rats were used and divided into six groups of ten each: control, EtOH (80% v/v, 4 g/kg b.w.), EtOH 80% + various doses of CPAE (500, 1000 and 2000 mg/kg, b.w.) and EtOH + Famotidine (10 mg/kg, p.o.) Animals were perorally (p.o.) pre-treated with CPAE during 15 days and intoxicated with a single oral administration of EtOH (4 g/kg b.w.) for two hours. RESULTS: The colorimetric analysis demonstrated that the CPAE exhibited an importance in vitro antioxidant activity against ABTS and DPPH radicals. We found that CPAE pretreatment in vivo, protected against EtOH-induced macroscopic and histological changes induced in stomach mucosa. Carob extract administration also protected against alcohol-induced volume gastric juice decrease. More importantly, We showed that CPAE counteracted EtOH-induced gastric lipoperoxidation, reversed the decrease of sulfhydryl groups (-SH) an hydrogen peroxide (H2O2) levels, and prevented the depletion of antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). CONCLUSIONS: These findings suggest that CPAE exerted a potential gastro-protective effect against EtOH-induced oxidative stress in rats, due in part, to its antioxidants properties.

Inhibitory Effects of Two Varieties of Tunisian Pomegranate (Punica granatum L.) Extracts on Gastrointestinal Transit in Rat.

The present study was undertaken to determine whether total and methanol juice extracts of two Tunisian Pomegranate (Punica granatum L.) varieties (Garsi and Gabsi) protect against diarrhea as well as their effects on gastrointestinal transit (GIT) in healthy rats. In this respect, male Wistar rats were used and divided into control- and pomegranate-treated groups. The antidiarrheal activity was evaluated using the castor oil-induced diarrhea method and the GIT was assessed using charcoal meal. Our results showed that total and methanol P. granatum juice extracts produced a significant dose-dependent protection against castor oil-induced diarrhea. Pomegranate extracts and juice also decreased the GIT significantly and dose dependently. Importantly, the Garsi variety appeared to be more effective than the Gabsi variety on these two parameters. These findings suggest that pomegranate extracts have a potent antidiarrheal property in rats confirming their efficiency in the Tunisian traditional medicine.

Chemical composition, antioxidant properties and hepatoprotective effects of chamomile (Matricaria recutita L.) decoction extract against alcohol-induced oxidative stress in rat.

The present study assessed the chemical composition, antioxidant properties, and hepatoprotective effects of subacute pre-treatment with chamomile (Matricaria recutita L.) decoction extract (CDE) against ethanol (EtOH)-induced oxidative stress in rats. The colorimetric analysis demonstrated that the CDE is rich in total polyphenols, total flavonoids and condensed tannins, and exhibited an important in vitro antioxidant activity. The use of LC/MS technique allowed us to identify 10 phenolic compounds in CDE. We found that CDE pretreatment, in vivo, protected against EtOH-induced liver injury evident by plasma transaminases activity and preservation of the hepatic tissue structure. The CDE counteracted EtOH-induced liver lipoperoxidation, preserved thiol -SH groups and prevented the depletion of antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). We also showed that acute alcohol administration increased tissue and plasma hydrogen peroxide (H(2)O(2)), calcium and free iron levels. More importantly, CDE pre-treatment reversed all EtOH-induced disturbances in intracellular mediators. In conclusion, our data suggest that CDE exerted a potential hepatoprotective effect against EtOH-induced oxidative stress in rat, at least in part, by negatively regulating Fenton reaction components such as H(2)O(2) and free iron, which are known to lead to cytotoxicity mediated by intracellular calcium deregulation.

Antidiarrheal and antioxidant activities of chamomile (Matricaria recutita L.) decoction extract in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Matricaria recutita L. (Chamomile) has been widely used in the Tunisian traditional medicine for the treatment of digestive system disorders. The present work aims to investigate the protective effects of chamomile decoction extract (CDE) against castor oil-induced diarrhea and oxidative stress in rats. METHODS: The antidiarrheal activity was evaluated using castor oil-induced diarrhea method. In this respect, rats were divided into six groups: Control, Castor oil, Castor oil+Loperamide (LOP) and Castor oil+various doses of CDE. Animals were per orally (p.o.) pre-treated with CDE during 1h and intoxicated for 2 or 4h by acute oral administration of castor oil. RESULTS: Our results showed that CDE produced a significant dose-dependent protection against castor oil-induced diarrhea and intestinal fluid accumulation. On the other hand, we showed that diarrhea was accompagned by an oxidative stress status assessed by an increase of malondialdehyde (MDA) level and depletion of antioxidant enzyme activities as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Castor oil also increased gastric and intestinal mucosa hydrogen peroxide (H2O2) and free iron levels. Importantly, we showed that chamomile pre-treatment abrogated all these biochemical alterations. CONCLUSION: These findings suggested that chamomile extract had a potent antidiarrheal and antioxidant properties in rats confirming their use in traditional medicine.