Background and Objective: Liver fibrosis is one of the most common chronic diseases worldwide. The current medical therapy of hepatic disorders is ineffective and till now there is no any therapy has successfully prevented the liver diseases and disorders. The present study aimed to investigate the effect of basil leaves extract on liver fibrosis induced by thioacetamide (TAA) in male rats. Materials and Methods: About 40 rats were randomly divided into four experimental groups. Rats of group 1 were served as controls. Rats of group 2 were given 300 mg kgG1 body weight of TAA by intraperitoneal injection, twice weekly. Rats of group 3 were orally supplemented with basil leaves extract at a dose of 300 mg kgG1 body weight/day. Moreover, they were intraperitoneally injected with TAA at the same dose given to group 2. Rats of group 4 were orally supplemented with basil leaves extract at same dose given to group 3. After 6 weeks of treatment, the blood samples and liver tissues were subjected to biochemical and histopathological evaluations. Results: Group 2 showed significantly increases of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transferase and total bilirubin. Significant decreases in the levels of liver glutathione and superoxide dismutase were observed in rats treated with TAA and basil leaves extract plus TAA. Noticeably decrease of liver catalase was observed in TAA treated rats. Malondialdehyde levels in liver were significantly increased in TAA and basil leaves extract plus TAA treated rats compared with control rats. In rats exposed to only TAA, liver sections showed an abnormal morphology characterized by noticeable fibrosis with extracellular matrix collagen contents and damage of liver cells structure. Administration of basil leaves extract to rats exposed to TAA led to inhibition of biochemical and histopathological alterations. Conclusion: These results confirmed that the protective role of basil leaves extract attributed to its antioxidant effects. Additionally, the obtained results clarify that the basil leaves extract is a potential protective natural therapy against liver fibrosis induced by exposure to TAA.

Key words: Liver fibrosis, liver diseases, basil leaves, thioacetamide, Ocimum basilicum, hepatic disorders, liver cells structure