Morphological evaluation of the effects of exercise on high-fat-diet-induced liver damage in rats

Abstract

Background/Aims: This study was aimed to investigate the protective effects of swimming on nonalcoholic fatty liver disease associated with high-fat-diet-induced obesity using microscopic and biochemical parameters. Materials and Methods: Sprague–Dawley male rats were fed either standard chow (STD group; 6% fat) or a high-fat diet (HFD group; 45% fat) for 18 weeks. The animals were divided into 4 groups: STD, STD+exercise (EXC), HFD, and HFD+EXC. The exercise groups were given swimming training for 5 days of week, 1 hour per day, during the last 6 weeks of the experiment. At the end of the experiment, the liver samples were evaluated morphologically and ultrastructurally, and malondialdehyde (MDA) and glutathione (GSH) levels were evaluated in the liver samples. Results: Normal morphology of the liver parenchyma with hepatocytes and sinusoids was observed in the STD and STD+EXC groups. Steatosis, lipid accumulation, ballooned hepatocytes, decrease of glycogen deposits, and fibrosis in the periportal area were observed in the HFD group. Liver MDA level was increased and GSH level was decreased in the HFD group. Exercise ameliorated these morphologic and oxidative changes in the HFD-induced liver damage. Conclusion: On the basis of morphologic and biochemical analysis, we could conclude that swimming ameliorated obesity-induced liver damage by regulating lipid accumulation and oxidative damage.