Oleuropein, a phenolic component of Olea europaea L. ameliorates CCl4-induced liver injury in rats through the regulation of oxidative stress and inflammation.

OBJECTIVE: This study aimed to assess the hepatoprotective role of oleuropein (Olp), a phenolic compound found in olive, against carbon tetrachloride (CCl₄)-induced liver damage in rats. MATERIALS AND METHODS: The research involved male albino rats, which received intraperitoneal injections of 100 mg/kg b.w. of oleuropein for 8 consecutive weeks before being subjected to carbon tetrachloride (CCl₄) at a dosage of 1.0 ml/kg b.w. Changes induced by CCl₄ in antioxidant and inflammatory marker levels were assessed using ELISA assay kits. Moreover, CCl₄-induced liver tissue architecture alteration, fibrosis, and expression pattern of protein were evaluated by performing H&E, Sirius red, Masson trichrome, and immunohistochemistry staining. RESULTS: Increased serum transaminases and massive hepatic damage were observed by this liver toxicant. The hepatic injury was further evidenced by a significant decrease in antioxidant enzyme activity [superoxide dismutase (SOD), glutathione peroxidase (GPx), Glutathione (GSH) and Total Antioxidant Capacity (T-AOC)]. The administration of CCl₄ resulted in an increased inflammatory response, which was measured by C-reactive protein, interleukin-6, as well as tumor necrosis factor-alpha. Olp as a curative regimen led to significant attenuation in the inflammatory response and oxidative/nitrosative stress. This polyphenol treatment improved the hepatic tissue architecture and decreased fibrosis. In the CCl₄ treatment group, the expression pattern of IL-6 protein was high, whereas expression was decreased after Olp, as evidenced by immunohistochemistry staining. CONCLUSIONS: The study suggests that oleuropein treatment has the potential to reduce liver damage caused by CCl₄ induction by inhibiting oxidative stress and inflammation and maintaining liver tissue architecture. This could make it a promising treatment option for liver pathogenesis. [ABSTRACT FROM AUTHOR]