Gamisoyo-san Ameliorates High-Fat Diet-Induced Metabolic Dysfunction-Associated Steatotic Liver Disease in Mice by Modulating the SIRT1–AMPK–NRF2 Pathway

Gamisoyo-san (GSS) is a traditional polyherbal formula derived from Soyo-san, a classic prescription used to treat liver disorders and metabolic imbalances, supplemented with Gardenia jasminoides Ellis and Paeonia × suffruticosa Andrews to enhance antioxidant and lipid-lowering effects. Although GSS is primarily prescribed in East Asia for gynecological conditions, its direct therapeutic efficacy in metabolic dysfunction-associated steatotic liver disease (MASLD) and underlying mechanisms remain to be fully elucidated. This study aimed to investigate the hepatoprotective effects of GSS in a high-fat diet (HFD)-induced MASLD model and to elucidate the mechanisms of action. Following oral administration of GSS for eight weeks, body weight gain was significantly inhibited, with a concomitant reduction in the weights of liver and adipose tissues. GSS treatment also improved serum markers for liver function (ALT, AST, and albumin), lipid profiles (triglycerides and total/LDL cholesterol), and glucose levels. Furthermore, it enhanced hepatic antioxidant defenses (glutathione, SOD, and catalase) while suppressing lipid peroxidation (MDA), pro-inflammatory cytokine production (TNF-α and IL-1β), and apoptosis (caspase-3). Mechanistically, GSS regulated hepatic lipid homeostasis by inhibiting lipogenesis and promoting β-oxidation, potentially through modulation of the SIRT1/AMPK/NRF2 signaling pathway. Histopathology and immunohistochemistry confirmed that GSS effectively ameliorated MASLD by regulating lipid metabolism and inhibiting oxidative stress, inflammation, and apoptosis. These findings provide scientific evidence validating the traditional use of GSS in metabolic liver disorders and suggest its potential as a natural, multi-target therapeutic candidate for MASLD management.