Anti-adipogenic effects of fermented Poncirus trifoliata fruit ethanol extract using Lactobacillus rhamnosus GG

This study improved the biofunctional properties of Poncirus trifoliata fruit ethanol extract (PFEP) via fermentation with Lactobacillus rhamnosus GG (LGG). The fermentation endpoint was determined on day 8 (FP), with peak acidity (2.83%) and viable LGG cells (6.42 log CFU/mL). FP reduced lipid accumulation and leptin secretion by 69.56 and 96.1%, respectively, at a 1/100 dilution in 3T3-L1 cells. The expressions of sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor gamma (PPAR-γ) decreased by 82.79 and 98.33%, respectively. In HepG2 cells, lipid accumulation and total cholesterol levels were reduced by 33.01 and 24.92%, respectively, accompanied by downregulation of SREBP-1c, fatty acid synthase (FAS), SREBP-2, and HMG-CoA reductase (HMGCR). UPLC-QTOF-MS analysis revealed increased levels of flavonoids and six new metabolite peaks in FP. LGG fermentation effectively enhanced the anti-obesity and lipid-lowering activities of PFEP, suggesting its potential as a functional food ingredient.