Protective effect of flavonoids from Cyclocarya paliurus leaves against carbon tetrachloride-induced acute liver injury in mice.

Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus), known locally as 'sweet tea tree', is commonly cultivated in China. Flavonoids from Cyclocarya paliurus (Batal.) Iljinskaja (FC) is reported to exhibit multiple biological effects, including anti-inflammatory, anti-oxidant and anti-diabetic activities. However, their influence on carbon tetrachloride (CCl4)-induced acute liver injury remains unclear. This study was designed to investigate the hepatoprotective effect of total flavonoids from C. paliurus leaves. Results revealed that flavonoids from C. paliurus significantly decreased CCl4-induced elevation of activities of aspartate transaminase (AST), alanine transaminase (ALT) and superoxide dismutase (SOD) as well as the level of malondialdehyde (MDA), and markedly increased the levels of SOD, total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) compared with the model group. Structures of mainly compounds were elucidated by nuclear magnetic resonance (NMR), mass spectrometry (MS) spectroscopic and chemical analyses. This study clearly shows that flavonoids from C. paliurus exert a potent protective effect against CCl4-induced acute liver injury in mice. Its hepatoprotective effect appears to be closely associated with its antioxidant activity. The results indicated that flavonoids from C. paliurus leaves could be considered as a potent food supplement in the prevention of acute liver injury.