Diosgenin alleviates lipid accumulation in NAFLD through the pathways of ferroptosis defensive and executive system

The most prevalent liver condition globally is non-alcoholic fatty liver disease (NAFLD), for which no approved therapies currently exist. Diosgenin, an important component in plants from the Leguminosae, Dioscoreaceae, and Solanaceae families, has demonstrated considerable anti-inflammatory and antioxidant effects. Nonetheless, the specific mechanism by which it may act in managing NAFLD remains unclear. Our research aims to explore the effects and molecular mechanisms of DG on NAFLD by utilizing both in vivo and in vitro experimental approaches. To investigate the effect of DG on hepatic steatosis, we used Sprague-Dawley rats induced by a high-fat diet (HFD) and HepG2 cells exposed to free fatty acids. Oil red O staining and hematoxylin-eosin (H&E) staining were used to explore lipid accumulation and hepatic degeneration. ROS staining, SOD, MDA, and Fe²⁺kits were used to detect the indexes related to oxidative stress in ferroptosis in hepatic tissues and cells. IFSP1 and pcDNA3.1-ACSL4 plasmid were used to knock down Ferroptosis suppressor protein1 (FSP1) and promote the expression of acyl-CoA synthetase long-chain family member 4 (ACSL4) in HepG2 cells. DG improved lipid metabolism disorders and liver damage induced by a high-fat diet in rats with NAFLD. Furthermore, the administration of DG notably decreased oxidative stress levels and liver Fe²⁺ concentrations in rats. Additionally, in vitro experiments demonstrated that DG treatment markedly attenuated ferroptosis and ROS accumulation in HepG2 cells induced by FFAs. Moreover, overexpression of hepatic ACSL4 expression by pcDNA3.1-ACSL4 plasmid promoted the regulatory effects of DG on LPCAT3 and ALOX15. Our research shows that DG can alleviate NAFLD by regulating the FSP1/COQ10 pathway of the ferroptosis defense system and the ACSL4/LPCAT3/ALOX15 pathway of the ferroptosis execution system. Therefore, DG may serve as a novel inhibitor of ferroptosis for the treatment of NAFLD.