Protective effect of Danning tablet on acute livery injury with cholestasis induced by α-naphthylisothiocyanate in rats

Ethnopharmacological relevance: Danning tablet, as a composite prescription of traditional Chinese medicine, has been used clinically to relieve liver and gallbladder diseases in China. However, the mechanisms involved are still unclear. Aim of the study: The present investigation was designed to assess the effects and possible mechanisms of Danning tablet on a-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis. Materials and methods: Danning tablet (3, 1.5 or 0.75 g/kg body weight/day) was intragastrically (i.g.) given to experimental rats for seven days before they were treated with ANIT (60 mg/kg daily via i.g.) which caused liver injury. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyltranspeptidase (gamma-GTP), total bilirubin (T-Bil), direct bilirubin (D-Bil), total bile acid (TBA) and bile flow were measured to evaluate the protective effect of Danning tablet at 48 h after ANIT treatment. Furthermore, protective mechanisms of Danning tablet against ANIT-induced liver injury were elucidated by assays of liver enzyme activities and component contents including myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase (CAT) and glutathione S-transferase (GST), as well as liver lipid peroxide (LPO) and glutathione (GSH). The biochemical observations were supplemented by histopathological examination. Phytochemical analysis of Danning tablet was performed by UPLC-MASS. Results: Obtained results demonstrated that high dose (3 g/kg) of Danning tablet significantly prevented ANIT-induced changes in bile flow (P < 0.01), and serum levels of ALT, AST, ALP, gamma-GTP, T-Bil, D-Bil (P < 0.01) and TBA (P < 0.05). In addition, ANIT-induced increases in hepatic MPO. GST activities and GSH, LPO contents were significantly (P < 0.01) reduced, while SOD, Gpx, CAT activities in the liver tissue which were suppressed by ANIT were significantly (P < 0.01) elevated in the groups pretreated with Danning tablet at the dose of 3 g/kg B.W. Histopathology of the liver tissue showed that pathological injuries were relieved after Danning tablet (3 g/kg) pretreatment. The results also showed that medium dose (1.5 g/kg) of Danning tablet exhibited partially protective effect on ANIT-induced liver injury with cholestasis by reversing part of biochemical parameters and histopathological changes. Low dose (0.75 g/kg) of Danning tablet did not show any protective effect on ANIT-induced liver injury with cholestasis. Phytochemical analyses revealed the presence of anthraquinones, flavonoids and stilbene in the Danning tablet. Conclusion: These findings indicate that Danning tablet exerts a dose-dependently protective effect on ANIT-induced liver injury with cholestasis in rats, and the possible mechanism of this activity is likely due to its attenuation of oxidative stress in the liver tissue and neutrophil infiltration. (C) 2011 Elsevier Ireland Ltd. All rights reserved.