Immunotoxicity of carbaryl in chicken

Effect of methyl carbonate pesticide, carbonyl, was studied on macrophage functions, lymphocyte proliferation and delayed type hypersensitivity response. Sixteen adult chicken, vaccinated against Newcaslte disease, were procured and randomly divided in two experimental groups. Chicken of group I served as control, while group II birds were given carbaryl at 20 ppm (No observable effect level, NOEL) in feed for 3 months. To measure the functional activity of phagocytic cells, nitroblue tetrazolium (NBT) reduction test was performed on peripheral blood leucocytes. Concanvalin A (Con-A) and lipopolysaccharide stimulated proliferation of T and B lymphocytes was assessed using MTT dye method. At the end of experiment, the phagocytic capacities of macrophages were significantly reduced in carbaryl treated group. Lymphocyte proliferation responses to Con-A and LPS were (23 and 28%, respectively lower) in chicken fed with carbaryl. Delayed hypersensitivity reaction to tuberculin was reduced to 77% of control values indicating inhibition of cell mediated immune response. The present study suggested of immunosuppressive effect of (NOEL dose carbaryl) in chicken.