Heat stress can cause immune organ dysfunction and apoptosis. Polysaccharide of Atractylodes macrocephala Koidz may have protective effects on immune organs. In this study, we established chicken models of Polysaccharide of Atractylodes macrocephala Koidz-heat stress interaction and detected the oxidative index, activities of mitochondrial complexes and ATPases as well as the ultrastructure in chicken spleens. Expression levels of cytokines, mitochondrial dynamics- and apoptosis-related genes were also measured. In the result, heat stress increased the expression of interleukin 1 and tumour necrosis factor-alpha and decreased that of interleukin 2 and interferon gamma. The activities of mitochondrial complexes and ATPases were decreased and oxidative stress was induced by heat stress. Besides, expressions of the mitochondrial dynamics- and anti-apoptosis-related genes were decreased and those of pro-apoptosis-related genes were increased by heat stress. HS induced pathological changes of mitochondria and triggered apoptosis in chicken spleens. However, these adverse effects triggered by HS were remarkably alleviated in Polysaccharide of Atractylodes macrocephala Koidz + heat stress group. This study confirmed the protective effects of Polysaccharide of Atractylodes macrocephala Koidz on the chicken spleen against the heat stress and revealed its mechanism, which is that Polysaccharide of Atractylodes macrocephala Koidz could relieve the heat stress-induced immune dysfunction of chicken spleens via reducing oxidative stress, enhancing the mitochondria function and inhibiting apoptosis.
Keywords: apoptosis; chicken spleen; heat stress; immune function; polysaccharide of Atractylodes macrocephala koidz.