Objective: To investigate the efficacy of Cigu Xiaozhi pill (, CGXZ) on non-alcoholic steatohepatitis (NASH)-associated lipoapoptosis through the stress-activated c-Jun N-terminal kinase (JNK)/ stress-activated protein kinase signalling pathway.
Methods: Sixty male Sprague-Dawley rats were randomly divided into the following groups (10rats each): blank control, model, low-dose CGXZ, medium-dose CGXZ, high-dose CGXZ, and positive control (treated with SP600125, a JNK inhibitor). The NASH model was established and the histomorphological characteristics of haematoxylin and eosin-stained liver tissues were examined under a light microscope. Cell apoptosis in liver tissues was assessed via terminal deoxynucleotidyl transferase dUTP nick-end labelling assay. In addition, the mRNA and protein expression levels of p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L were determined via fluorescence-based quantitative real-time PCR, immunohistochemical and Western blot assays.
Results: Histopathological examination of the liver showed that the model rats had moderate-to-severe steatosis with infiltration of inflammatory cells as well as significantly higher expression levels of the p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L proteins, compared with those in the blank control group (P < 0.01). Hepatic lobules of the rats in the treatment groups showed significantly reduced vacuolar degeneration and steatosis as well as alleviated inflammatory cell infiltration. The high and medium-dose CGXZ groups exhibited significantly lower mRNA and protein expression levels of p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L, compared with those in the model group (P < 0.05 or P < 0.01).
Conclusion: CGXZ pill inhibited the onset of hepatocyte apoptosis by regulating the expression of p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L, thereby exerting therapeutic effects against NASH.
Keywords: Cigu Xiaozhi pill; JNK mitogen-activated protein kinase; Non-alcoholic fatty liver disease; apoptosi; tress-activated signaling pathway.