Evaluation of the protective effect of Zhi-Zi-da-Huang decoction on acute liver injury with cholestasis induced by α-naphthylisothiocyanate in rats

Ethnopharmacological relevance: Zhi-Zi-Da-Huang decoction (ZZDHD), a classic traditional Chinese medicine (TCM) formula composed of four herbal medicines, has been widely used to treat various hepatobiliary disorders for a long time in China. However, the pharmacological effect of ZZDHD on liver injury with cholestasis is unrevealed. Aim of the study: To investigate the hepatoprotective effect of ZZDHD against alpha-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis in rats. Materials and methods: The rats were intragastrically (i.g.) given ZZDHD at doses of 1,2 and 4 g/kg (crude drug/body weight) once a day for seven days and treated with ANIT (75 mg/kg via i.g.) to cause liver injury at 12 h after the fifth administration. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyltranspeptidase (gamma-GTP), total bilirubin (TBIL), direct bilirubin (DBIL) and total bile acid (TBA), as well as bile flow were measured at 48 h after ANIT treatment to evaluate the protective effect of ZZDHD. Moreover, the possible protective mechanisms were elucidated by assays of liver enzyme activities and component contents including malondialdehyde (MDA), myeloperoxidase (MPO), lipid peroxide (LPG), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). The biochemical observations were supplemented by histopathological examination. Ultra fast liquid chromatography-mass spectrometry (UFLC-MS) was used for the phytochemical analysis of ZZDHD. Results: The high dose (4 g/kg) and middle dose (2 g/kg) of ZZDHD exhibited significant and dose-dependent protective effect on ANIT-induced liver injury with cholestasis by reversing the changes in bile flow, the serum and hepatic enzymes, and histopathology of the liver tissue. Meanwhile, it was found that the low dose (1 g/kg) of ZZDHD did not improve the biochemical indexes except serum TBIL, DBIL and TBA, which showed little protective effect. Phytochemical analysis revealed the presence of sixteen compounds in ZZDHD. Conclusions: This study indicates that ZZDHD exerted a hepatoprotective effect on ANIT-induced liver injury with cholestasis in rats, and the mechanism of this activity is possibly related to its antioxidant properties. (C) 2015 Elsevier Ireland Ltd. All rights reserved.