Immune dysfunction and increased oxidative stress state in diet-induced obese mice are reverted by nutritional supplementation with monounsaturated and n-3 polyunsaturated fatty acids

Obesity is associated with impaired immune defences and chronic low levels of inflammation and oxidation. In addition, this condition may lead to premature aging. The aim of the study was to evaluate the effects of a nutritional supplementation with monounsaturated and n-3 polyunsaturated fatty acids on several functions and oxidative stress parameters in peritoneal immune cells of obese mice, as well as on the life span of these animals. Obesity was induced in adult female ICR/CD1 by the administration of a high-fat diet (HFD) for 14 weeks. During the last 6 weeks of HFD feeding, one group of obese mice received the same HFD, supplemented with 1500 mg of 2-hydroxyoleic acid (2-OHOA) and another with 3000 mg of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Several functions and oxidative stress parameters of peritoneal leukocytes were evaluated. The groups of obese mice treated with 2-OHOA or with EPA and DHA showed a significant improvement in several functions such as chemotaxis, phagocytosis, digestion capacity, Natural killer activity and lymphoproliferation in response to mitogens. All of these functions, which were decreased in obese mice, increased reaching similar levels to those found in non-obese controls. Both treatments also improved oxidative stress parameters such as xanthine oxidase activity, which decreased, catalase activity and glutathione levels, which increased. These data suggest that dietary supplementation with monounsaturated and n-3 polyunsaturated fatty acids could be an effective nutritional intervention to restore the immune response and oxidative stress state, which are impaired in obese mice.