Hepatoprotective and antioxidant activity of anthocyanins in black rice bran on carbon tetrachloride-induced liver injury in mice

The benefits of anthocyanin-rich black rice bran extract (ARBE) on the liver of carbon tetrachloride (CCl4)-intoxicated mice was investigated. Based on the in vivo experiment, the effect of cyanidin-3-glucoside (Cy-3-G) and peonidin-3-glucoside (Pn-3-G), the predominant anthocyanins in ARBE, on CCl4 insulted hepatocytes L-02 was further evaluated. Mice treated with ARBE for 7 weeks by oral administration showed reduced aminotransferase activities in serum, accompanied by enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, while tiobarbituric acid reactive substances (TBARS), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels were significantly decreased compared to CCl4-intoxicated model group. Histopathological observation showed ARBE administration alleviated the pathological changes in livers of CCl4-intoxicated mice. Similarly, preincubation of L-02 cells with Cy-3-G or Pn-3-G significantly alleviated CCl4-induced injury dose-dependently, exhibited higher cell viability, decreased aminotransferase activity and enhanced cellular antioxidant status. Furthermore, Cy-3-G showed much stronger hepatoprotective activity than Pn-3-G at the same concentration. HPLC analysis showed that Cy-3-G accounted for more than 88% of total anthocyanins in ARBE. These results indicate that ARBE is significantly beneficial to liver health, and that Cy-3-G is the predominant anthocyanin in ARBE exerting this effect. The antioxidant activity of anthocyanins is an important mechanism by which ARBE exerts hepatic health benefit.