Protective effect of compounds from the flowers of Citrus aurantium L. var. amara Engl against carbon tetrachloride-induced hepatocyte injury

5-Hydroxy-6,7,3′,4′-tetramethoxyflavone (HTF), limonexic acid (LA) are two compounds isolated from the flowers of Citrus aurantium L. var. amara Engl with various biological activities. This study was designed to investigate their protective effects against carbon tetrachloride (CCl4)-induced hepatocyte injury, using human hepatic cell line HL-7702 to determine the cell cytotoxicity, cell viability, levels of hepatic marker enzymes, malondialdehyde (MDA). Results showed that pretreatment with HTF, LA could significantly reverse CCl4-induced HL-7702 cell viability decrease, LA displayed a higher activity. HTF, LA also showed their capability of decreasing the CCl4-induced leakage of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), inhibiting the lipid peroxidation, HTF showed more significant activity. Given that HTF, LA were not toxic, it is concluded that HTF, LA could effectively protect hepatocyte against CCl4-induced injury.