Protective effects of emodin and astragalus polysaccharides on chronic hepatic injury in rats

Background Chinese medicine plays an important role in hepatoprotective treatment. This study was conducted to investigate the protective effects of emodin and astragalus polysaccharides （APS） in a rat model of chronic hepatic injury. Methods Chronic hepatic injury was induced by hypodermic injection of an olive oil solution containing 40% carbon tetrachlodde （CCI4） twice a week, in addition to a diet of 79.5% maizena, 20% fat, 0.5% cholesterol, and 10% alcohol in the drinking water ad libitum for 12 weeks. Meanwhile, the rats were exposed to different concentrations of emodin （40 mg·kg^-1·d^-1）, APS （200 mg·kg^-1·d^-1）, combination drug （emodin 40 mg·kg^-1·d^-1 combined with APS 200 mg·kg^-1·d^-1） and colchicine （0.1 mg·kg^-1·d^-1） in parallel by oral gavage （once a day for 12 weeks）. At the end of 12 weeks, blood serum and liver tissue were taken. Serum was collected to determine the levels of total bilirubin （TBIL）, alanine transaminase （ALT）, aspartate transaminose （AST）, and albumin （ALB）. Liver and spleen indexes were assayed, followed by the measurements of the liver associated enzyme superoxide dismutase （SOD） and malondialdehyde （MDA）. Histopathological changes were studied using optical microscopy. Results Splenohepatomegalia was alleviated and serum levels of TBIL and ALT were reduced in the groups treated with emodin and APS when compared to the control group. In addition, the ALB level in the APS and combination groups was higher. Similarly, the SOD activity of liver homogenates was significantly higher in the groups treated with emodin and APS, while administration of the herbal derivatives prevented the elevation in MDA levels. Histological analysis showed that the APS and combination groups significantly ameliorated the hepatic injury. Conclusions Co-administration of emodin and APS demonstrated a synergistic action in reducing ALT and restoring ALB in the serum from a rat model of chronic hepatic injury. Emodin and APS may ameliorate the CCI4-induced hepatic injury in rats by elevating antioxidant-enzyme activities and reducing lipid peroxidation.