Background: Berberine is an active compound in Coptidis Rhizoma (Huanglian) with multiple pharmacological activities including antimicrobial, antiviral, anti-inflammatory, cholesterol-lowering and anticancer effects. The present study aims to determine the hepatoprotective effects of berberine on serum and tissue superoxide dismutase (SOD) levels, the histology in tetrachloride (CCl)-induced liver injury.Methods: Sprague-Dawley rats aged seven weeks were injected intraperitoneally with 50% CClin olive oil. Berberine was orally administered before or after CCltreatment in various groups. Twenty-four hours after CClinjection, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, serum and liver superoxide dismutase (SOD) activities were measured. Histological changes of liver were examined with microscopy.Results: Serum ALT and AST activities significantly decreased in a dose-dependent manner in both pre-treatment and post-treatment groups with berberine. Berberine increased the SOD activity in liver. Histological examination showed lowered liver damage in berberine-treated groups.Conclusion: The present study demonstrates that berberine possesses hepatoprotective effects against CCl-induced hepatotoxicity and that the effects are both preventive and curative. Berberine should have potential for developing a new drug to treat liver toxicity. © 2010 Feng et al; licensee BioMed Central Ltd.