Synergistic Effects of Aerobic Training and Capsaicin on Visceral Adipose Tissue SIRT1 Gene Expression and Insulin Resistance in Rat Fed a High-Fat Diet.

Metabolic dysregulation may cause tissue damage in obesity-related diseases. The effects of SIRT1 on metabolism may provide a therapeutic target for treating obesity-related diseases. This study aimed to investigate the effects of aerobic training and Capsaicin (Cap) on visceral adipose tissue SIRT1 gene expression and insulin resistance in rats fed a high-fat diet (HFD). 40 male Wistar rats were fed a normal diet (ND, n = 8) or HFD (n = 32) for 8 weeks. After 8 weeks, all rats were divided into five groups: ND, HFD, high-fat diet-training (HFDT), high-fat diet-capsaicin (HFDCap), and high-fat diet-training-capsaicin (HFDTCap). Training groups performed a progressive aerobic running program (at 15-25 m/min, 30-60 min/day, and 5 days/week) on a motor-driven treadmill for eight weeks. Capsaicin (4 mg/kg/day) was administered orally, by gavage, once a day. This study showed that SIRT1 expression decreased and HOMA-IR increased in the HFD group compared to the ND group. Also, the expression of SIRT1 in HFDT, HFDCap, and HFDTCap groups significantly increased compared to HFD. The expression of SIRT1 in HFDTCap also significantly increased compared to HFDT and HFDCap groups. There was a significant decrease in HOMA-IR levels in all experimental groups. Possibly, eight weeks of progressive training combined with capsaicin administration has an effect on the glucose homeostasis of HFD rats by increasing the expression of SIRT1 and decreasing HOMA-IR.