Phytochemical profiling, antioxidant potential and protective effect of leaves extract of tunisian Vitis vinifera autochthonous accessions against acute CCl4-injured hepatotoxicity in mice.

Vitis vinifera leaves (VVL) are agro-industrial waste. In the current study, the phytochemical profile of V. vinifera leaves extracts (VVLE) of two Tunisian autochthonous accessions was determined via LC-UV-ESI/MS, and their antioxidant and hepatoprotective properties were also assessed. Mice were pretreated orally with VVLE (7.5, 15 and 30 mg/kg) for 7 days, and then received acutely and by i.p. a solution CCl4 at 12% in sunflower oil (v/v). Serum levels of hepatic markers, oxidative stress indicators in liver tissue and histological changes were assessed. LC-UV-ESI/MS analysis revealed four phenolic compounds identified in both extracts with quercetin-3-O-glucuronide being the dominant constituent (23.32 ± 1.06 vs. 10.24 ± 0.12 mg/g DM, p < 0.05 for wild and cultivated accessions, respectively). The Antioxidant activity revealed a significant difference between the genotypes. Moreover, the VVLE of the wild "Nefza-I" ecotype was the most active based on antioxidant assays. Furthermore, the results showed that pre-treatment, especially with VVLE, of the wild ecotype "Nefza-I", attenuated CCl4-induced acute liver injury in a dose-dependent manner, as demonstrated by the decrease in the activities of hepatic serum function markers. This was also evidenced by a decrease in the levels of lipoperoxidation and histological damage in the liver, as well as a restoration of antioxidant enzyme activities (SOD and catalase) and an increase in the hepatic glutathione content. Our results demonstrate that VVLE possesses protective effects on CCl4-induced liver injury. Overall, the wild ecotype "Nefza-I" extract could serve as an effective protector against CCl4-induced hepatocellular oxidative stress.

Essential oils from Artemisia species inhibit biofilm formation and the virulence of Escherichia coli EPEC 2348/69.

Enteropathogenic Escherichia coli E2346/69 (EPEC) has caused foodborne outbreaks worldwide and the bacterium forms antimicrobial-tolerant biofilms. The anti-biofilm formation of various components of essential oils extracted from selected medicinal plants were investigated and tested on EPEC and wild strains of E. coli. Oils extracted from the family Asteraceae and their major common constituents at 0.031 and 0.062% (V/v) were found to significantly inhibit biofilm formation without affecting the growth of planktonic cells. In addition, three plants belonging to this family (Artemisia herba alba, Artemisia campestris and Artemisia absinthium) played important roles in the antimicrobial activity. Interestingly, their essential oils reduced the ability of E. coli (the EPEC and K12 strains) to form a biofilm. The crystal violet reduction assay showed that the plant extracts tested reduced biofilm formation with the inhibition of bacterial attachment up to 45% for EPEC and 70% for E. coli K-12 after 24 h treatment at 0.62 mg ml-1, demonstrating that Artemisia oils had a high anti-biofilm activity on the bacteria tested. The results indicate that the locus of enterocyte effacement (LEE) acquired by horizontal transfer promotes the formation of the attaching and effacing (A/E) lesion and increases the capacity of the photogen strain (EPEC) to form a biofilm. The chemical composition of the volatile compounds was obtained by gas chromatography-mass spectrometry analysis, which showed that the essential oils consisted of thirty-four compounds. Chamazulene (39.21%), ß-pinene (32.07%), and α-thujone (29.39%) were the main constituents of the essential oils of A. herba alba, A. absinthium and A. campestris, respectively.

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'.