Ameliorating Effects of Fermented Rice Bran Extract on Oxidative Stress Induced by High Glucose and Hydrogen Peroxide in 3T3-L1 Adipocytes

In this study, we investigated whether fermented rice bran (FRB) can ameliorate the oxidative stress induced by high glucose and hydrogen peroxide (H ₂O ₂) in 3T3-L1 adipocytes by analyzing reactive oxygen species (ROS), oil red O staining, as well as the expression of mRNAs related to glucose homeostasis and adipogenesis. It was first confirmed that rice bran fermented by Issatchenkia orientalis MFST1 extract increased free phenolic content compared to non-fermented rice bran. The FRB extract strongly inhibited ROS generation and upregulated the expression of PPAR-γ and adiponectin. Moreover, FRB upregulated GLUT4 related to glucose transportation and insulin sensitivity. Taken together, FRB extract ameliorated oxidative stress-induced insulin resistance by neutralizing free radicals and upregulating adiponectin in adipocytes. Our results provide information toward understanding the beneficial effects of FRB on oxidative stress.