ABSTRACT
AIM: To investigate the immune mechanisms for Periplocin from Cortex Periplocae (CPP) in tumor-bearing mice. METHODS: H_(22) tumor-bearing model BALB/c mice were applied to evaluated in vivo immunoregulatory effect of CPP. The influence of different dose CPP (0.25, 0.50 and 1.00 mg/kg) on immune organs in tumorbearing mice were observed. T cell subsets of mice spleen were detected by flow cytometry. MTT assay was used to determine the influence of CPP on lymphocyte proliferation of mice spleen stimulated by ConA. The levels of TNF-α, IL-2 and IL-12 in serum from mice were detected by means of ELISA. RESULTS: Thymus index and spleen index of H_(22) tumor-bearing model control mice became less than that of normal mice (P < 0.05). Compared to both model and normal control groups, thymus index and spleen index of H_(22) tumor-bearing mice treated with CPP increased obviously (P < 0.05). CPP had no influence on the number of CD8~+ T cells, but up-regulated markedly the number of CD3~+, CD4~+ T cells and the ratio of CD4~+/CD8~+ in tumorbearing mice. In CPP-treated mice, the percentage of CD3~+, CD4~+ T cells were not different from normal mice (P<0.05), the ratio of CD4~+/CD8~+ was higher than that of normal mice (P < 0.05). CPP enhanced obviously lymphocyte proliferation of mice spleen induced by ConA, the SI scores were even higher than that of nornal mice. The levels of TNF-α, IL-2 and IL-12 in serum from CPP-treated mice, increased significantly compared to model control group (P<0.05) in a dose-dependent manner, were similar to or higher than that of normal mice. CONCLUSION: CPP protected immune organs of tumor-bearing mice, increased obviously the percentage of CD4~+ and CD4~+/ CD8~+ among the T cell line, and enhanced lymphocyte proliferation of mice spleen significantly, stimulated the production of TNF-α, IL-2 and IL-12. The results suggested that CPP possessed potent immunoregulatory effect.