Sappanone A, a potential natural inhibitor of PI3K, alleviates metabolic dysfunction-associated steatohepatitis in experimental models

Abstract

Metabolic dysfunction-associated steatohepatitis (MASH) affects a large proportion of the global population and is widely regarded as the fastest growing cause of hepatocellular carcinoma. Currently, approved therapeutic strategies for MASH are limited. Therefore, this study used the Connectivity Map (CMap) database to identify a candidate compound for MASH, evaluate its efficacy in experimental models, and explore its mechanism of action. Based on the gene expression profile of GSE126484, Sappanone A (SA) was screened using the CMap. In a palmitic acid-induced cell model, SA notably reduced the expression of fibrotic genes in LX-2 cells. In a methionine-choline-deficient (MCD) diet-induced MASH model, SA significantly attenuated liver injury, as evidenced by the reduction in serum alanine aminotransferase levels, alleviation of hepatic ballooning and inflammation. In a high-fat, methionine-restricted, choline-deficient (HFMRCD) diet-induced MASH model, SA remarkably improved lipid metabolism, ballooning, and inflammation. Importantly, SA markedly inhibited the progression of fibrosis. Network pharmacology results indicated that SA might alleviate MASH through the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/(Mechanistic target of rapamycin) mTOR signaling pathway. We performed molecular docking, cellular thermal shift assay, and western blotting to validate that SA bound to and inhibited PI3K activity, thereby reducing the downstream phosphorylation of AKT and mTOR. Notably, the PI3K activator Recilisib weakened the inhibitory effect of SA on PA-induced p-AKT and COL1a1 in LX-2 cells, further confirming the dependence of SA on PI3K activity. In conclusion, we identified SA as a potential natural PI3K inhibitor and promising compound for the treatment of MASH.