Effects of Continuous Exercise and Silymarin Supplementation on Tumor Necrosis Factor-alpha (TNF-a) and Liver Leptin in Male Wistar Rats with Fatty Liver Disease

Leptin is associated with metabolic disorders and promotes the development of liver steatosis to steatohepatitis. It selectively increases the secretion of Tumor-necrosis factor-α (TNF-a) in response to saturated fatty acid. The general purpose of this research was to determine the effects of eight weeks of continuous training and silymarin supplementation on the serum levels of TNF-α and leptin in Wistar rats with fatty liver disease.

In this experimental study, 40 male Wistar rats aged three weeks and weighting 159±3 grams were randomly divided into five groups: normal diet/saline, high-fat diet/saline (control), high-fat diet/supplemented, high-fat diet/exercise/saline, and high-fat diet/exercise/supplement. The rats were fed 10 grams per 100 grams of body weight (standard diet 13% fat and high-fat diet 41% fat) for eight weeks, and silymarin (140 mg per kilogram body weight) were given by gavage for 2 weeks. The continuous aerobic exercise protocol consisted 30 minutes of treadmill running at 70-75% of VO2max for eight weeks, five days a week. After sacrificing the animals, samples were taken and sent to the laboratory for histological analysis. The expression of leptin and TNF-α in the liver was measured using commercial ELISA kits.

The findings showed a greater decrease in hepatic leptin concentration in the high-fat diet + continuous exercise + supplement group (P<0.05) compared to the high-fat diet + continuous exercise + saline group (P<0.05). Tukey's post hoc test showed a greater decrease in the concentration of hepatic TNF-α in the high-fat diet + saline group (compared to the high-fat diet + supplement group) (P<0.05), and the high-fat + exercise + saline group (P<0.05). The weight of the rats in the normal diet + saline group differed significantly from other groups (P<0.05).

The results indicated that the combination of continuous training with silymarin supplementation can help reduce leptin and TNF-α in rats with a high-fat diet, an effect not observed by silymarin supplementation alone. Therefore, the combination of continuous aerobic exercises and silymarin supplementation can further oxidize fat and reduce inflammation in the body.