The effect of eight weeks of high-intensity intermittent swimming training on tumor necrosis factor alpha and transforming growth factor beta ۱ in the liver tissue of rats fed with high-fat diet

On average, patients suffering from non-alcoholic steatohepatitis after about seven years, their disease turns into fibrosis and reversibility at this stage becomes very difficult because this disease is an irreversible stage of the disease. Fatty liver is non-alcoholic (۲). Researches have come to the conclusion that liver inflammation and insulin resistance decrease and insulin sensitivity increases with sports activity (۳). TNF-α has a high inflammatory effect; So that different agents and species of this family and their receptors play a role in NASH disease and liver fibrosis (۵). However, exercise increases prostaglandins and cAMP. The mentioned hormones inhibit the function of TNF-α (۶). On the other hand, anti-inflammatory cytokines increase due to exercise and inhibit the increase of TNF-α. With the increase in production and secretion of TNF-α, other inflammatory factors such as TGF-β۱ signaling are activated and fibrosis signaling will start in liver cells (۵). TGF-β۱ (Transforming growth factor beta ۱) is one of the members of the large family of transforming growth factors beta (TGF-β) and a key cytokine in obesity and insulin resistance (۷). In a research, during ۴۸ weeks of applying a high-fat diet to rats, they found that steatosis occurs in the liver of rats from the eighth week onwards, and the amount of TGF-β۱ in them increased significantly. In the end, they came to the conclusion that this factor can be one of the main characteristics of determining the degree of liver fibrosis in patients with NASH (۱۰). High-intensity interval training (HIIT) is one of the new training models whose positive effects have been identified in a variety of metabolic diseases (۱۳). On the other hand, there are very few researches about the effect of aquatic environment and swimming on the improvement of metabolism and inflammation in NASH patients. Based on the results of a systematic review in ۲۰۱۸, it was shown that endurance exercise in water improved systemic inflammation and weight control (۱۸). Despite the conflicting results in this field and the beneficial effects of exercise in water and also human's innate interest in water, the effect of high-intensity interval exercise in water in patients with non-alcoholic steatohepatitis has not been observed by the researchers of this study. Therefore, the effect of eight weeks of high-intensity interval training in water on inflammatory factors in patients with non-alcoholic steatohepatitis was investigated.