Abstract: In this paper, we aimed to study the protective effect and mechanism of flavonoids from millet bran (FMB) on H2O2-induced oxidative damage in HepG2 cells by determining cell proliferation rate, intracellular reactive oxygen species (ROS) level, antioxidant enzymes activities and the expression of apoptosis-related proteins. The experiment was divided into normal group, oxidative stress model group, and low-, medium- and high-dose FMB treatment groups. The results showed that FMB significantly alleviated cell growth inhibition induced by H2O2 in HepG2 cells, decreased the levels of intracellular ROS and malondialdehyde (MDA), and increased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), as well as down-regulated the expression of bax, p53, and caspase-3 (P < 0.05). Consequently, FMB could protect HepG2 cells against H2O2-induced oxidative damage, and its underlying mechanism may be related to inhibiting the expression of apoptosis-related proteins, regulating the cellular redox system, scavenging intracellular ROS, and increasing the activities of intracellular antioxidant enzymes.

Key words: flavonoids from millet bran, oxidative stress, antioxidant enzyme system, apoptotic pathways