ObjectiveTo investigate the protective effect of hesperdin (HDN) on acetaminophen (APAP)-induced acute liver injury in mice. MethodsForty-eight male BALB/c mice were randomly divided into six groups:normal group, model group, HDN (the doses respectively were 500, 250 and 125 mg/kg) group and bifendate group. The HDN group was separately intragastrically given different doses of hesperidin for ten days. The bifendate group was given bifendate. Acute liver injury was induced by injecting APAP (150 mg/kg) in all mice except those in the normal group. After 16 hours, all mice were sacrificed. Serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. The contents of glutathione (GSH) and malondialdehyde (MDA) in liver homogenates were determined. Pathological changes in hepatic tissue were observed under an optical microscope. The expression of high mobility group protein B1 (HMGB1) in hepatic tissue was measured by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. ResultsHDN could significantly reduce serum ALT, AST, liver homogenate MDA levels, improve liver tissue GSH activity and the liver injury was lightened. By RT-PCR and immunohistochemistry, it showed that HDN could inhibit the releasing and expression of HMGB1. ConclusionHDN protects mice from acetaminophen-induced liver injury possibly via mechanisms related to inhibition of the expression and releasing of HMGB1.