Jiangzhi Ligan Decoction Alleviated Nonalcoholic Fatty Liver Disease Induced by High-Fat-Diet in Rats via GSDMD-mediated Canonical/Non-canonical Pyroptosis Pathway

Abstract

Background Hepatoprotective effects of Chinese herbal formula Jiangzhi Ligan Decoction (JZLGD) against nonalcoholic fatty liver disease (NAFLD) have been demonstrated, but its mechanism is not clear. The aim of this study was to evaluate the protective effects of against high-fat diet (HFD) induced NAFLD in rat, and to further explore the potential molecular mechanism. Methods SD rats were assigned to five different groups: normal control group, NAFLD model group and JZLGD-treated NAFLD group (3 doses of JZLGD: 2.3, 4.6, 9.2 g/kg of body weight, respectively). All the rats were fed a HFD for 18 weeks except the normal control group(a normal diet). After 12 weeks, rats in JZLGD-treated NAFLD group were administered different doses of JZLGD by oral gavage once daily for another period of 6 weeks, and the rest were given the same dosage of normal saline. After the intervention, blood and liver from each sample were carefully removed and analyzed accordingly. Results We found that JZLGD significantly reduced the liver index, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum. Furthermore, pathological examinations showed that JZLGD markedly reduced liver lipid droplets and improved liver lipid accumulation, NAFLD activity score and ballooning pathology scoring were also decreased. The detection of cytokines showed that JZLGD could significantly reduced the levels of serum inflammatory factors IL-1β, IL-18, tumor necrosis factor α (TNF-α) and IL-6, protected HFD rats from inflammation. In addition, NAFLD treatment, exhibited significant reduction in serum triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL) and free fatty acid (FFA) when compared to NAFLD control rats. JZLGD intervention also reduced the level of serum lipopolysaccharide (LPS) and the expression of NOD-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, caspase-11, GSDMD, GSDMD N-terminus (GSDMD-N), IL-1β, IL-18 in the liver. Conclusion These results demonstrate the hepatoprotective effects of JZLGD in NAFLD mice, the effects may be mediated via downregulation of NLRP3 /caspase-1/GSDMD mediated canonical pyroptosis pathway and LPS /caspase-11/GSDMD mediated non-canonical pyroptosis pathway.