Effect of dietary ghee - the anhydrous milk fat on lymphocytes in rats

Lymphocytes are important components of the immune system. Dietary lipids a ffect the functioning of the immune system. Changes in the lipid compositio n of the lymphocyte membrane is a case in point. Membrane structural change s are reflected in the altered function of the cell. Lymphocyte proliferati on and lymphocyte rosetting are membrane associated phenomena. Ghee, is a c larified butter product, commonly used in the Indian diet. It is rich in sa turated fatty acids and also contain oxysterols which are generated on prol onged heating of ghee. Male weanling rats were fed 2.5% (of the total fat l evels) of fresh or thermally oxidized ghee for a period of 8 weeks. The con trol rats were fed groundnut oil. Lipid composition of lymphocytes in ghee fed rats showed changes. In vitro lipid peroxidation of lymphocyte membrane s increased by 26% in oxidized ghee fed rats. Na+K+ ATPase activity was dec reased in oxidized ghee fed rats (18%). Lymphocyte proliferation was reduce d in ghee fed rats (32%), compared to the controls, irrespective of the mit ogens used (Con-A or PHA), or the tissue (splenocytes or peripheral blood l ymphocytes). Oxysterols present in oxidized ghee are the likely agents inhi biting lymphoproliferation. Rosetting of lymphocytes decreased in the fresh ghee fed rats by 16% and in oxidized ghee fed rats by 25%. Membrane fluidi ty declined in the oxidized ghee fed rats. It is concluded that feeding ghe e results in decreased proliferation of lymphocytes. Also, feeding oxidised ghee results in decreased proliferation of lymphocytes through alterations in the structure of the lymphocyte membranes in the rat.