Four flavonoids from propolis ameliorate free fatty acids-induced non-alcoholic steatohepatitis in HepG2 cells: Involvement of enhanced AMPK activation, mTOR-NF-κBp65 interaction, and PTEN expression

Non-alcoholic steatohepatitis (NASH) is a prevalent chronic liver disease that lacks effective treatment. In this study, the anti-NASH effects of four flavonoids (pinocembrin, galangin, chrysin, and naringenin) rich in propolis were investigated in an in vitro NASH model established in free fatty acids (FFAs)-stimulated HepG2 cells. Using a co-treatment approach, our results showed that naringenin possessed the strongest anti-NASH efficacy by significantly counteracting FFAs-induced lipid accumulation, oxidative injuries, apoptosis, and secretion of pro-inflammatory IL-1β. Results from RNA-Seq revealed that co-treatment of naringenin significantly altered the expression profile of genes involved in lipid metabolism, apoptosis, and inflammatory responses in FFAs-stimulated HepG2 cells. The four flavonoids exerted their hepato-protective effects with the involvement of enhanced AMPK activation, mTOR-NF-κBp65 interaction, and PTEN expression. Moreover, molecular docking results showed that naringenin formed a stable complex with AMP-activated protein kinase (AMPK). Our results suggested that naringenin could be exploited as potential candidate for NASH treatment.