Effect of diet and omega-3 fatty acids in NAFLD

Nonalcoholic fatty liver disease (NAFLD) ranges from simple hepatic steatosis to steatohepatitis (NASH) and cirrhosis. The aim of this study is to test beneficial effects of omega-3 fatty acids (DHA 130 mg, EPA 25 mg) treatment in NAFLD, in a mouse model of non-alcoholic fatty liver disease. As pretreatment, 50 mice were fed for one month with a high-fat diet to induce NAFLD. Then, the mice were divided in different groups according to diet (normo- or hypercaloric), with and without treatment with omega-3 fatty acids, for another month, forming the post-treatment group. The liver and blood samples were collected for biochemical and histopathological analysis. Biochemical parameters including: glycemia, total cholesterol, triglycerides, uric acid, albumin, total plasma antioxidant capacity (TEAC) was measured in serum. Glutathione (GSH), total thiols and malonyldialdehyde (MDA) were determined in mouse liver homogenates. Mice from post-treatment group, on hypercaloric diet with or without omega-3 fatty acids treatment, had medium hepatopathy (granular and vacuolar degeneration of the hepatocytes) and hypertriglyceridemia. Omega-3 fatty acid treatment lowered the rise of triglycerides (p<0.03), glycemia (p<0.01) and cholesterol (p<0.02) in serum and MDA level of the liver (p<0.05). Mice from post-treatment group, on normocaloric diet with or without omega-3 fatty acid had different histopathological and biochemical results. Those with normocaloric/normolipidic diet and omega-3 fatty acids treatment had reversed liver histopathological results from NASH to normal aspect and had the best metabolic parameters results. In conclusion, omega-3 fatty acids treatment associated with a normocaloric/normolipidic diet has hepatoprotective action in nonalcoholic fatty liver disease.