Neem, especially neem bark, is recognized for its immunomodulatory polysacharide compounds. These compounds appear to increase antibody production. Others compounds in neem enhance the immune system via a different mechanism; the cell-mediate immune response, the body first form of defense. Only when this system appears to be unable to stop an infectious unslaught is the more massive immune system involve.
Neem oil acts as a non-specific immunostimulant that activates the cell mediate immune response. This then creates an enhanced response to any future challenges by disease organisms. When neem oil was injected under the skin there was a significant increase in leukocytic cells and perioneal macrophages showed enhanced phagocytic activity and expression of MHC class II antigens. Production of gamma interferon was also induced by the injection. Spleen cells showed higher lymphocyte reaction to infection but did not augment anti-TT antibody response.
Water soluble neem leaf extracts, when taken orally, produced an increase in lymphomatic counts and both red and white blood cells as well as lymphocyte counts. In studies on the birth control effects of neem the major factor in that effect appear to be an increase tom the immune response where neem has been applied that causes the body to reject the fetus as a foreign body.
By enhancing the cellular immune response most pathogen can be eliminated before they cause the ill feeling associated with disease. This mechanism could also help in disease that involve the immune system, like AIDS. Taking neem leaf or bark powder every other day or drinking a mild neem tea will enhance antibody production and the body's cell-mediated immune response, helping to prevent infections.