[Immune function regulation and tumor-suppressive effects of Shenqi Erpi Granules on S_(180) tumor-bearing mice]

This study aims to establish the S_(180) tumor-bearing mice model, and to investigate the influence of Shenqi Erpi Granules(SQEPG) on immune function, as well as the drug's tumor-suppressive effect and mechanism. SPF grade KM mice(half male and half female) were randomly divided into 6 groups: a control group, a model group, a cyclophosphamide group(50 mg·kg~(-1)), as well as SQEPG groups in low-, medium-, and high-dose(5.25, 10.5, 21 g·kg~(-1)). The control group and the model group were given distilled water, and the other 4 groups were given the corresponding drugs by gavage. The administration continued for 10 days before the mice were sacrificed. The antitumor and immune regulation effects of SQEPG were evaluated. The effect of SQEPG on delayed type hypersensitivity reaction(DTH), carbon clearance index, and serum hemolysin antibody level was observed to reflect the effect on the immune function of tumor-bearing mice. Tumor weight was recorded to calculate the tumor suppression rate and the immune organ index. Hematoxylin-eosin(HE) staining was used to detect morphological changes in tumor tissues. Flow cytometry was employed to detect the percentage of CD4~+ and CD8~+ T-cells in the spleen tissues and the tumor tissue apoptosis levels. Immunohistochemistry was conducted to detect the KI67 protein expression level of tumor tissues. ELISA resorted to the detection of the following expression levels in tumor tissues: tumor necrosis factor-α(TNF-α), interleukin-2(IL-2), interferon-γ(IFN-γ). Western blot was performed to detect the expression levels of caspase-3, B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), cyclin-dependent kinases 4(CDK4), G_1/S-specific cyclin D1(cyclin D1), and vascular endothelial growth factor A(VEGFA). The results showed that, compared with the model group, the SQEPG could increase the swelling of the auricle of the tumor-bearing mice; significantly increase the phagocytic index of carbon granule contour(P<0.05 or P<0.01), and the middle dose of SQEPG could significantly increase the antibody level of hemolysin(P<0.05); different doses of SQEPG significantly inhibit the growth of the tumor, and decrease the mass of the tumor tissues(P<0.05 or P<0.01); the low dose of SQEPG significantly decreased spleen index(P<0.05), low and high doses of SQEPG increased thymus index, while medium doses of SQEPG decreased thymus index. High doses of SQEPG significantly elevated the levels of CD4~+ and CD8~+ T-cells in the spleens of the homozygous mice(P<0.01 or P<0.001), and increased the apoptosis rate of the cells of the tumor tissues(P<0.05); Meanwhile, high-dose SQEPG elevated the levels of immunity factors such as IL-2, IFN-γ and TNF-α in the serum of tumor-bearing mice(P<0.01); medium-and high-dose SQEPG significantly lowered the rate of positive expression of KI67 protein in tumor tissues(P<0.01). Compared with the model group, high-dose SQEPG significantly up-regulated the expression of caspase-3 and Bax proteins in tumor tissues(P<0.05), and significantly down-regulated the expression of CDK4, cyclin D1, and VEGFA proteins(P<0.05 or P<0.01). In conclusion, SQEPG has the effect of improving immune function and inhibiting tumor growth in tumor-bearing mice. Its mechanism of tumor-suppressive effects may be related to apoptosis promotion, cell cycle progression block, and tumor cell proliferation inhibition.