Effects Of Polysaccharide Of Atractylis Macroceohala Koidz On Immune Function Of Lingnan Yellow Chickens

Polysaccharide of Atractylis macroceohala koidz (PAM) is the main active constituentsof Rhizoma atractylodis macrocephalae, which has the effect to promote growth and enhanceimmune function. In recent years, PAM becomes an important development direction of greenfeed additive according to the characteristics of non-toxic, no residue and high biologicalactivity. The regulation effect of PAM on the immune function of Lingnan Yellow Chicken invitro and vivo were investigated in this study. In vivo study:150chickens (8day-old) wererandomly divided into5groups. The chickens were maintained either on diet added0,100,200,400or600mg·kg-1PAM. Detected the development status of immune organs andmRNA expression level of cytokines on14,21,28,35day-old.In vitro study:28-day-old chickens were used to isolate spleen lymphocytes,lymphocytes were incubated with100,50,25,12.5,6.25,3.13,1.57,0.78mg·L-1PAMrespectively. Lymphocyte proliferation rate was detected by MTS method. On this basis,lymphocytes were incubated with the best PAM dosage under37℃and47℃to researchthe proliferation and cytokine content (TNF-α, IL-4, IL-2and IFN-) of lymphocytes. Theresults showed as follows:1. It was showed in vivo study that different stages immune organ index of chicken with200mg·kg-1PAM rose significantly (P>0.05), structure of spleen, thymus and fabricius weremore compact, the number of lymphocytes increased, nucleoplasm full and cells arranged inneat.2. Real-time fluorescent quantitative PCR was used to detect the mRNA expression ofTNF-α, IL-4, IL-2and IFN-of spleen, thymus and fabricius. Results showed that theexpression of4cytokines were higher than control group, and best PAM dosages were100mg·kg-1and200mg·kg-1, it showed a dose-dependent pattern.3. It was showed in vitro study that lymphocytes had a highest proliferation rate with12.5mg·L-1PAM. A high concentration of PAM had certain inhibitory action to thelymphocyte proliferation.12.5mg·L-1PAM can increase the lymphocyte proliferation ratesignificantly, which improved38%compared to the heat stress control group, clearlydemonstrated PAM had the ability to anti-stress. Compared to the same conditions of controlgroups, the content of TNF-α, IL-4, IL-2and IFN-in culture supernatant with PAM had nosignificant difference (P>0.05), but the content increased, indicating PAM can promotelymphocytes secrete cytokines.In conclusion, PAM (100mg·kg-1-200mg·kg-1) can promote immune organ development; enhance the immune function in chicken. In vitro experiments confirmed that12.5mg·L-1PAM had the effect to increase the proliferation rate and cytokine secretion oflymphocytes, which also can alleviate heat stress.