Effects of Chaihu-Shugan-San and Shen-Ling-Bai-Zhu-San on p38 MAPK Pathway in Kupffer Cells of Nonalcoholic Steatohepatitis

Abstract

This study aimed to investigate the effects of Chaihu-Shugan-San (CSS), Shen-Ling-Bai-Zhu-San (SLBZS), and integrated recipe of the above two recipes on inflammatory markers and proteins involved in p38 MAPK pathway in Kupffer cells of NASH rats induced by high fat diet (HFD). Rats were administered at low or high dose of CSS, SLBZS, and integrated recipe except normal group and model group for 16 weeks. The levels of hepatic lipid, TNF-α, IL-1, and IL-6 in liver tissues were measured. Kupffer cells were isolated from livers to evaluate expressions of TLR4, p-p38 MAPK, and p38 MAPK by Western blotting. The results showed that the NASH model rats successfully reproduced typical pathogenetic and histopathological features. Levels of hepatic lipid and liver tissues inflammatory factors in high-dose SLBZS group and integrated recipe group were all lower than that of model group decreased observably. Expressions of TLR4, p-p38 MAPK, and p38 MAPK in Kupffer cells were decreased in all treatment groups, but there was no significant difference between treatment groups. The high-dose SLBZS group had the lowest expression levels of TLR4, and the most visible downtrend in the expression levels of p-p38 MAPK and p38 MAPK was found in the high-dose integrated recipe group. The ratio of p-p38 MAPK to total p38 MAPK protein was obviously increased in all treatment groups. Therefore, our study showed that the activation of p38 MAPK pathway in Kupffer cells might be related to the release of inflammatory factors such as TNF-α, IL-1, and IL-6 in NASH rats. High dose of SLBZS and integrated recipe might work as a significant anti-inflammatory effect in Kupffer cells of NASH rats induced by HFD through suppression of p38 MAPK pathway. It indicated that p38 MAPK pathway may be the possible effective target for the recipes.