Effect of aerobic exercise and rice bran ethanol extract on Akt/mTOR activity and oxidative stress in skeletal muscles in a rat model of high-fat diet-induced obesity

Introduction and Objective: Insulin resistance is a main complication associated to obesity. Rice bran and exercise seem effective for reducing obesity complications. Therefore, this study aimed to determine the effects of aerobic exercise (EX) and rice bran extract (RB) on the expression of Akt/mTOR genes and oxidative stress markers in the skeletal muscle of rats fed a high-fat diet (HFD). Methodology: Thirty female Wistar rats were randomly divided into five groups: control normal diet (ND-Con), control HFD (HFD-Con), HFD-aerobic exercise (EX), HFD-RB extract (RB), and HFD-EX-RB. EX-groups ran on a treadmill five times a week for four weeks and RB groups received 60 mg/kg/day of RB extract. At the end of the study, rats were sacrificed, and their quadriceps muscles were removed. Akt/mTOR gene expression and oxidative stress markers were determined. Results: HFD led to significant decrease in gene expression of Akt, mTOR, superoxide dismutase (SOD) and catalase activities, while increasing malondialdehyde (MDA) concentration. The EX-group showed significant increase in Akt/mTOR gene expression, while no noticeable effects were observed in RB. The Akt gene expression was significantly higher in EX-RB group than in HFD-CON group, with no effect in SOD. RB caused significant increase in SOD activity compared to HFD-Con group. Catalase activity in EX, RB, and EX-RB groups was significantly higher than in the HFD-Con group. The MDA concentration in the EX, RB, and EX-RB groups was significantly lower than in HFD-Con group. Conclusions: EX and RB can be suitable treatments for reducing HFD complications in skeletal muscle tissue.