Objective: To compare the effects of Yiqi Yangxue Tang containing Radix Astragali or Radix Hedyseri on the immune function of Senescence accelerated mouse P8(SAMP8) mice. Method: Ten Kunming mice were taken as normal group. 40 SAMP8 mice were randomly divided into normal saline group

thymosins group

Yiqi Yangxue Astragali Radix group and Yiqi Yangxue Hedyseri Radix group. The normal saline and thymosins were intragastrically administrated at 4.6 mg·kg-1 daily

and the mice in the Yiqi Yangxue Astragali Radix group and the Yiqi Yangxue Hedyseri Radix group received treatment at the dose of 6 g·kg-1 by ig

once a day for fifteen times. Eyeball was taken for blood 2 h after the last ig administration; then spleen was also taken. The contents of interleukins-2(IL-2) and γ-interferon (IFN-γ) in the serum were detected by ELISA; the expression levels of CD3

CD4

CD8

CD28 and CD152 on splenic lymphocyte surface were detected by using flow cytometry; mRNA and protein expression levels of p38MAPK were detected by Real-time PCR and Western blot respectively. Result: As compared with the normal group

the contents of IL-2 and IFN-γ were reduced; the expression of CD8 and CD28 molecules were decreased; CD4 molecule expression and CD28CD152 molecular double positive expression were increased; p38MAPK mRNA and protein expression levels were decreased in the normal saline group (P<0.05). As compared with the normal saline group

IL-2 and IFN-γ contents in the serum of SAMP8 mice were increased in thymosins group and Yiqi Yangxue groups; the contents in the thymosins group were higher than those in Yiqi Yangxue groups; the level of IL-2 in Hedyseri Radix group was higher than that in the Astragali Radix group; the expression level of CD28 was increased and the double positive expression level of CD28

CD152 was reduced in both thymosins group and Yiqi Yangxue groups; the double positive expression rate in the thymosins group and Astragali Radix group was lower than that in Hedyseri Radix group. Yiqi Yangxue groups increased the expression levels of CD8 molecules and the expression in Astragali Radix group was higher than that in Hedyseri Radix group. The expression level of CD4 was decreased in both thymosins group and Astragali Radix group. The p38MAPK mRNA expression level was increased in both thymosins group and Yiqi Yangxue groups

and the level in thymosins group was higher than that in Yiqi Yangxue groups; the level in Astragali Radix group was higher than that in Hedyseri Radix. p38MAPK protein content and protein positive rate were increased in both thymosins group and Yiqi Yangxue groups groups

and the effect in thymosins group was higher than that in Yiqi Yangxue groups (P<0.05). Conclusion: The Yiqi Yangxue Tang containing Astragali Radix or Hedyseri Radix could improve the immunosenescence performances of SAMP8 mice

which may be associated with up-regulating p38MAPK expression levels.