Hepatoprotective effects of olive leaf extract against carbon tetrachloride-induced oxidative stress: in vivo and in-silico insights into the Nrf2-NFκB pathway

Abstract

Olive Leaves Extract (OLE) holds therapeutic potential, traditionally used to treat hepatic ailments, though its molecular mechanisms remain unclear. This study evaluated the efficacy of ethanolic OLE against Carbon Tetrachloride (CCl₄)-induced oxidative stress in a rat model. Phytochemical analysis was performed using High Performance Liquid Chromatography (HPLC). For this porous, thirty rats were divided into six groups (n = 5): Group 1 (negative control) received a standard diet, while Groups 2–6 were subjected to CCl₄-induced toxicity. Group 2 served as the disease control, and Group 3 was treated with silymarin (100 mg/kg). Groups 4, 5, and 6 received OLE at 100 mg/kg, 200 mg/kg, and 300 mg/kg, respectively, for 21 days. OLE significantly modulated hepatic biomarkers (ALT, AST, ALP), increased Total Antioxidant Capacity (TAC), decreased Total Oxidation Capacity (TOC), and restored levels of SOD, GSH, and CAT compared to the CCl₄ group. Malondialdehyde (MDA) levels, elevated in the disease group, however downregulated by OLE, particularly at 300 mg/kg. Histological examination revealed normal liver integrity in the OLE-treated groups. Additionally, OLE modulated the mRNA expression of IL-1β, IL-6, TNF-α, NF-kB, Bcl2, and p-53. Apoptotic markers such as Nrf2, HO-1, Cytochrome c, caspase 3, caspase 7, and Bax were normalized with OLE treatment. The inhibition of KEAP1-NRF2 protein-protein interaction showed OLE’s superior efficacy compared to silymarin, with a better docking score. These findings suggest that OLE exerts significant hepatoprotective effects against CCl₄-induced oxidative stress and inflammation via the Nrf2-NFκB pathway.