Effects Of Soy Isoflavones On Immunity Indexes In Lymphocyte Of Lymph Nodes And Splenocytes Of Dairy Cow

Soy isoflavones are a group of plant-derived biologically active substances with a chemical structure that resembles that of17β-estradiol(E2).As the presence of estrogen receptors(ER)has been identified in several immune cells, soy isoflavones may also have a great impact on the immune system. This paper aims to research the in vitro effects of soy isoflavones on the proliferation and activation and the production of cytokines by stimulated lymphocyte of lymph nodes and splenocytes from dairy cow, investigate to improve the mechanism of immune of cows, to provide a theoretical basis of the soy isoflavones developed into a functional feed additive.first, The experiments were assigned into7groups [0.00(control),0.05,0.25,1.00,5.00,25.00and100.00μg/mL] soy isoflavones and incubated with lymphocyte to48h or60h, respectively. The plates were read at570nm. The results showed that:First, for the lymphocyte of lymph nodes, all over the concentrates of soy isoflavones ranging from0.05μg/ml to25.00μg/mL had promoted effect to the lymphocyte proliferation, while the most promotion concentrates was5.00μg/mL it reach the most promotion effect. But when the addition concentrations of soy isoflavones enhanced reach to100.00μg/mL, the inhibition suppressed effect of lymphocyte proliferation was significantly. Second, in lymphocyte of splenocytes, the lymphocyte proliferation at higher concentrations (25.00and100.00μg/ml soy isoflavones group) had a significantly suppressed effect on the proliferation of lymphocyte in the spleen of the cow (P<0.01).(P<0.01) comparing with the control. However, at lower concentrations (1μg/ml) the lymphocyte proliferation could be significantly stimulated (P<0.05). The other groups had the same inhibition suppressed effect, but the difference was not significant.Second,This paper aims to investigate the effects of soy isoflavones on proliferation, activation and production of cytokines in lymphocytes of spleen and intestinal lymph nodes of dairy cows in vitro. A single factor design was used, and lymphocytes were incubated with different levels of soy isoflavones [0.00(control)、0.25、1.00、5.00、25.00and100.00μg/mL] at37℃in5%CO2FOR4,24and48h,respectively. Concentrations of interferon γ, interleukin2, interleukin4in culture supernatants were determined by doubleantibody sandwich enzyme-linked immunosorbent assay,and expression lebel of estrogen receptors β mRNA in lymphocytes of spleen and intestinal lymph nodes was determined by real-time PCR. The results showed as follows:1) afer incubated with soy isoflavones (0.25and1.00μg/mL) for a while, concentrations of interferon γ and interleukin2in culture supernatants of lymphocytes of spleen were increased at different lebels (P<0.05or P<0.01),and48h later,5.00and25.00μg/mL soy isoflavones reduced interferon γ and interleukin2concentrations significantly (P<0.05);2) In lymphocytes of intestinal lymph nodes, after incrbated with soy isoflavones (1.00and5.00μg/mL) for a while, concentrations of interferon y and interleukin2wer increased at different lebels (P<0.05or P<0.01); the concentrations tended to e increased by0.25μg/mL soy isoflavones (P>0.05);48h later, concentrations of interferon γ(P<0.05) and interleukin2(P<0.01) wer significantly decreased.3) Compared with that in the control group, interleukin4concentrations in lymphocytes of spleen in experimental groups were not change significantly (P>0.05), and the concentrations in lymph nodes of intestinal lymph nodes in experimental groups was significantly reduced (P<0.05or P<0.01).4) Rantios of interferon y and interleukin4in lymphocytes of spleen tended to be increased, but that of intestinal lymph nodes tended to be opposite.5) Expression lebels of estrogen receptors mRNA in lymphocytes of spleen and intestinal lymph nodes were significantly increased (P<0.05or P<0.01), and there was positive correlation between lebels of estrogen receptors β mRNA expression and soy isoflavones. In conclusion, soy isoflavones can increase concentrations of interferon γ and interleukin2, ratio of interferon γ and interleukin2, as well as expression level of estrogen receptors β mRNA, but can decrease interleukin4concentrations; Low dose (0.25to5.00μg/mL) soy isoflavones can get better effects on immunity promotion, but high dose (25.00to100.00μg/mL) can stimulate expression of estrogen receptors β mRNA.