Ganoapplanilactone C from Ganoderma applanatum Ameliorates Metabolic Dysfunction-Associated Steatotic Liver Disease via AMPK/mTOR-Mediated Lipid Regulation in Zebrafish

A phytochemical study of <i>Ganoderma applanatum</i> identified four predominant triterpenoids, with ganoapplanilactone C (GATC) exhibiting the most significant lipid-reducing effects in high-fat diet-fed zebrafish, surpassing atorvastatin at 5 μM. Histopathological analysis confirmed GATC's protective effects on the liver against high-fat diet-induced damage. The Enzyme-Linked Immunosorbent Assay (ELISA) results showed a positive correlation between GATC treatment and liver health markers, as well as antioxidant enzymes, while they revealed a negative correlation with triglycerides and inflammatory cytokines. Metabolomic profiling demonstrates GATC's impact on metabolites such as amino acids, fatty acids, and the mechanistic Target of Rapamycin (mTOR) signaling pathway, suggesting its role in regulating multiple metabolic processes. The increase in Adenosine Monophosphate-activated protein kinase (AMPK) phosphorylation in the GATC-treated groups indicates the activation of the AMPK/mTOR pathway, a key mechanism in lipid metabolism and liver protection. Molecular docking studies highlighted the importance of GATC's spirocyclic ketone system and hydroxyl group in binding to target proteins. These findings underscore GATC's potential as a therapeutic agent for metabolic dysfunction-associated steatotic liver disease (MASLD), emphasizing its superior efficacy compared to other triterpenoids due to its unique C-23 spiro 5/7 system. This study provides valuable insights into the prevention and treatment of MASLD using <i>G. applanatum</i>-derived compounds.