High-intensity interval training and royal jelly synergistically attenuate insulin resistance and renal inflammatory markers (TNF-α and NF-κB) in experimental diabetes

Exercise and the use of anti-inflammatory supplements are effective in controlling inflammation and tissue damage in diabetes. Therefore, the aim of the present study was to investigate the effect of 8 weeks of interval training and royal jelly on the expression of renal inflammatory genes and insulin resistance in diabetic rats. Thirty-two male Wistar rats were used in this study. Diabetes was induced by a high-fat diet for 20 weeks followed by intraperitoneal injection of freshly prepared STZ solution in saline (25 mg/kg). Then the rats were randomly divided into 4 groups: Diabetes (DI), DI+ HIIT, DI+ royal jelly (RJ), and DI+ HIIT+ RJ. Royal jelly groups were given royal jelly at a dose of 100 mg/kg diluted in distilled water and gavage 5 days a week. The exercise program consisted of eight weeks of HIIT training, five sessions per week with a gradual increase in intensity intervals from 22 to 38 meters per minute (80 to 90% of Vo2max) and rest intervals at a speed of 16 to 22 meters per minute (50 to 56% of Vo2max). At the end of the research, rats were euthanized and kidney tissue was removed to measure the expression of TNF-α and NF-κB genes. The DI+HIIT (p=0.0006), DI+RJ (p=0.0011) and DI+HIIT+RJ (p<0.0001) groups showed a significant decrease in HOMA-IR compared to the diabetes control group. The DI+HIIT, DI+RJ and DI+HIIT+RJ groups showed a significant decrease in TNF-α and NF-κB gene expression in kidney tissue compared to the diabetes control group. In conclusion, 8 weeks of HIIT and/or royal jelly supplementation significantly ameliorated insulin resistance and suppressed renal pro-inflammatory gene expression (TNF-α, NF-κB) in diabetic rats, with the combined approach showing the greatest efficacy.