Detection of apoptosis in citrinin, aflatoxin and their combined effects in broiler chicken

Immunomodulatory effects of citrinin (CTN) 5 ppm and aflatoxin (AF) 0.5 ppm in 3 week old broiler chicken were studied by their toxin induced apoptosis and necrosis in the spleen and thymus at 6, 12, 24 and 48h by flow cytometry and light and electron microscopic studies. In the spleen, by flow cytometry technique, peak induction of apoptosis was seen at 48h in the CTN group and 24h in the AF and CTN+AF groups. Peak induction of necrosis was noted at 48h post treatment in the spleen of CTN+AF when compared to the other groups. In thymus, the entire mycotoxin fed groups showed peak induction of apoptosis at 48h post treatment. The per cent necrosis of thymus increased significantly (P<0.05) in all the mycotoxin treated groups when compared to the control at 48h. Light and electron microscopic studies revealed apoptotic cells characterized by chromatin margination along the nuclear envelop shrinkage of cells with a clear halo formation around them and without any inflammatory reactions in the CTN, AF and CTN + AF birds. Lymphocytolysis in the spleen and thymus was also found in all mycotoxin fed groups. The changes in the CTN+AF mycotoxicoses were comparable to the individual toxicities. Combined toxicity effect was less than additive.