Paeoniflorin Alleviates Metabolic Dysfunction-Associated Fatty Liver Disease by Targeting STING-Mediated Pyroptosis via Inhibiting the NLRP3 Inflammasome

Paeoniflorin (PF) is a key active ingredient with anti-inflammatory and antioxidant properties extracted from the root of Paeonia lactiflora. Non-alcoholic fatty liver disease (NAFLD), recently referred to as metabolic dysfunction-related fatty liver disease (MAFLD), is the leading cause of chronic liver disease worldwide. However, the potential mechanisms and targets of paeoniflorin's anti-inflammatory and antioxidant therapy for MAFLD remain to be thoroughly investigated. Thus, in cellular experiments, we added free fatty acids (P/O) to AML-12 cells and cultured them for 24 h. In animal experiments, mice were administered a high-fat diet (HFD) for a duration of 16 weeks in order to create an animal model of fatty liver disease. Our study confirmed that PF significantly reduced steatosis and alleviated oxidative stress and inflammation levels in P/O-induced AML-12 hepatocytes and mouse livers with HFD. Cellular experiments showed that PF-attenuated Phosphoric acid/Oleic acid (P/O) induced lipid deposition in AML-12 cells, indicators related to cellular focal death were downregulated, and mitochondrial oxidative damage was alleviated. In animal experiments, ALT, AST, TG, TC and the hepatic index were elevated in the model group, and lipid deposition and cell infiltration were shown by HE, Oil Red O staining. These were significantly reduced in the PF groups. Network pharmacology studies indicated PF may target the Stimulator of interferon genes (STING) as a crucial molecule for the treatment of MAFLD, and the validation of C-176 (STING inhibitor) and DXMAA (STING promoter) further supported that PF could target STING to regulate hepatocyte cellular pyroptosis.