Mulberry leaf phenolics ameliorate hyperglycemia-induced oxidative stress and stabilize mitochondrial membrane potential in HepG2 cells

摘要

To investigate the effect of phenolics in mulberry leaves (mulberry leaf phenolics; MLP) on hyperglycemia-induced oxidative stress and mitochondrial membrane potential (Delta Psi m) in HepG2 cells; we treated HepG2 with glucose [5.5 (N-Glc) or 50 mmol/L (Hi-Glc)] with or without MLP at 10 or 100 mmol/L gallic acid equivalents and assessed level of reactive oxidant species (ROS), Delta Psi m, malondialdehyde (MDA) and nuclear factor-kappaB (NF-kappa B) activation. Hi-Glc-induced oxidative damage was demonstrated by a series of increase in superoxides (560%, 0.5 h), MDA (400%, 24 h), NF-kappa B activation (474%, 4 h) and a wild fluctuation of Delta Psi m relative to the control cells (p <= 0.05). MLP treatments ameliorate Hi-Glc-induced negative effects by a 40% reduction in ROS production, 34-44% reduction in MDA production, over 35% inhibition of NF-kappa B activation, as well as exert protective effect on HepG2 cells from change in Delta Psi m. Our data show that MLP in vitro can protect hepatoctyes from hyperglycemia-induced oxidative damages.