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

Abstract

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-α and IL-1β 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 CCl 4 was significantly alleviated liver damage as indicated by improvement of the microscopic picture of liver and reduced hepatic iNOS, caspase-3, TNF-αand IL-1β expression compared to CCl 4 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.

The palliative effect of mulberry leaf and olive leaf ethanolic extracts on hepatic CYP2E1 and caspase-3 immunoexpression and oxidative damage induced by paracetamol in male rats

“…Compared to the PTL-administered group, pretreatment with OLE and silymarin reduced apoptotic events in the liver, as seen by lower hepatic CASP3 expression. Similar antiapoptotic effects of OLE and silymarin have been documented earlier (Osman and Tantawy 2017 , Teksoy et al 2020 ). Several bioactives in OLE and MLE have been known by their antiapoptotic activity.…”

Egyptian Olea europaea leaves bioactive extract: Antibacterial and wound healing activity in normal and diabetic rats

“… 27 reported that Olea europaea extract may lead to cell wall or cell membrane disruption to Gram-positive bacteria, which was more susceptible compared to Gram-negative bacteria. The antioxidant activity of Tanta LEM extract was 87.55% at concentration of 50 μg/ml which could be explained by Osman & Tantawy 28 who mentioned that olive leaves were considered as the highest scavenging activity radical of different parts of olive trees. The wound healing activity of Olea europaea can be explained by Rosa et al., 29 where olive oil administration proved to increase cell migration, TGF- β protein expression, and collagen deposition.…”