Research: role of antioxidant vitamins in immune function in leprosy

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. (Hansen, 1875) affecting mainly the immune system. Oxidation-mediated tissue injury is a particular hazard to the immune system, since phagocytic cells produce reactive oxygen species as part of the body's defense against infection. Adequate amounts of neutralizing antioxidants are required, therefore, to prevent damage to the immune cells themselves. Vitamin E, C, and beta-carotene (provitamin A) are essential nutrients that the human organism cannot synthesize and which act as antioxidants by stabilizing highly reactive and potentially harmful molecules, as are the free radicals. To assess the severity of oxidation stress, all subjects and controls were studied for plasma lipid peroxide levels. The plasma levels of vitamin C, vitamin E and β carotene were measured to know the status of antioxidant vitamins. The estimation of lipid peroxide levels gave an idea about the possibility of oxidation mediated tissue damage while the levels of antioxidant vitamins indicated that these vitamins have an unfavorable action in cell and humoral immune responses and therefore produce immunosuppression due to increase in the peroxide level.