Comparative Evaluation of Antioxidant and Hepatoprotective Effects of Three Olive Leave Species Cultivated in Aljouf Region, Saudi Arabia

摘要

Aim of the work : the purpose of this study was to evaluate the antioxidant, anti-inflammatory and hepatoprotective effects of extract from 3 olive leave cultivars; K18, Nibali and Sorani growing in Aljouf region, Saudi Arabia. Methods : all plants were extracted with 80% methanol and the extracts were used to determine the total phenolic content, the total flavonoid content, the DPPH radical and anti-lipid peroxidation scavenging activities. In vivo hepatoprotective effect of these olive leaves extracts (OLEs) was evaluated in rabbit intoxicated with CCl4. Expression of iNOS, caspase-3, TNF- and IL-1 along with the histopathological findings of the examined liver were recorded to evaluate the extent of hepatoprotective of each extract. Results: methanolic extracts of all plants exhibited DPPH and peroxyl radicals scavenging activity that was well correlated with their total phenolic and flavonoid contents. The phenolic, flavonoid contents, DPPH, and peroxyl scavenging activities were in the following orders: Nibali K18 Sorani. Pretreatment with OLE (400 mg/kg) along with CCl4 was significantly alleviated liver damage as indicated by improvement of the microscopic picture of liver and reduced hepatic iNOS, caspase-3, TNF-and IL-1 expression compared to CCl4 intoxicated group. However, the hepatoprotective effects of Nibali and K18 OLEs were more prominent compared to those exerted by Sorani OLE. Conclusion : all OLEs had potent anti-inflammatory, antioxidant and antiapoptotic activities that preserved hepatic cells against CCl4-induced hepatic damage through attenuation of pro-inflammatory cytokines, oxidative stress and apoptotic pathways, however, these activities were probably species dependent.