Genistein shows beneficial effects on hepatic lipid metabolism in an in vitro hepatic steatosis model

Non-alcoholic fatty liver disease (NAFLD) is a pervasive disease leading to durable morphologic and biochemical changes, including steatosis, inflammation, fibrosis and cirrhosis. Epidemiologic studies suggest that Genistein (GEN) improves hepatic lipid levels. Our aim was to apply an in vitro steatosis model on primary human hepatocytes to investigate the effects of GEN on lipid metabolism. Primary human hepatocytes (PHH) were isolated from human liver resectates using a two step collagenase perfusion technique. PHH were treated with oleic acid and palmitate for 24h. GEN was then applied for 24h in concentrations up to 100µM. Lipid content was measured photometrically by Oil Red O and SRB staining. Toxicity of FFA and GEN was evaluated by AST, LDH and XTT assay and Urea formation. Cytosolic and nuclear protein of the transcription factors PPARalpha and SREBP1c were measured using Western blot analysis. The in vitro hepatic steatosis model showed a significant increase in number and size of lipid particles compared to control PHH. XTT assay as well as AST and LDH levels revealed a slightly negative impact of FFA in steatotic PHH whereas Urea levels were unchanged. GEN did not significantly decrease lipid content in this setting. Cytotoxicity was observed only at 100µM GEN in control and steatotic PHH. Western blot analysis revealed that GEN elevated nuclear PPARalpha level and significantly decreased cleaved SREBP1c, both in a concentration dependent manner.The in vitro steatosis model showed an increased lipid content and a slight lipotoxicity, similar to in vivo conditions. GEN did not significantly lower hepatic lipid content. However, GEN altered hepatic lipid pathways by increasing PPARalpha and decreasing active SREBP1c, implying an increased catabolic and impaired anabolic lipid metabolism. Further investigation is needed to elucidate the entire effects of GEN and its potential to lower lipid content in the in vitro steatosis model.

genistein - hepatic steatosis - lipid metablism - ppar alpha - srebp1c