Study On The Anti-tumor Effects And Immunomodulatory Function Of Periplaneta Americana Peptide

ObjectiveTumor is a severe disease that seriously endangers human health,and every year millions of people die of tumors.Tumor treatments have surgery,chemotherapy and radiotherapy.However,these treatments have poor targets.They are not only to kill tumor cells,but also to damage the normal cells to make that the patients can not tolerate treatment.Therefore,one of the tasks of the current research work is to find efficient,low toxicity anti-tumor drugs from the natural products.Periplaneta americana is a kind of traditional animal medicine with anti-inflammatory,antitumor and so on.But its antitumor mechanism is not clear.In this study,we used Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 on L1210 tumor-bearing mice to explore their anti-tumor effect and the influencing immune organs,immune cells,and immune factors,and to understand the effects of Periplaneta americana and HFDT1 on tumor inhibition and immune function in L1210 tumor-bearing mice.MethodsThe L1210 tumor-bearing BALB/c mice were established.The mice randomly divided into tumor control group,cyclophosphamide(CTX)group,CⅡ-3 high and low dose group and HFDT1 group.The blank control group also was set.The mice were gave continuous administration for 10 days(blank control group and tumor control group,normal saline,20 m L / kg,1 time / day;CⅡ-3 high and low dose group,20mL/kg,1 times/ day,by gavage;HFDT1 group,7.8mg/m L intraperitoneal injection,10mL/kg,1 times/ day;CTX group 45 mg / kg intraperitoneal injection,10 m L/kg,1 times/every other day).The weights of the mice were observed during the feeding.The mice were weighed and killed in the next day after the last administration.The tumor weight,tumor inhibition rate and thymus index and spleen index were measured in each group.The numbers of peripheral blood immune cells in the L1210 tumor-bearing mice were measured through hematology analyzer.The levels of serum IgG,IgM and IgA in L1210 tumor-bearing mice were detected by double antibody sandwich ELISA.The peritoneal macrophage phagocytosis of the mice was tested.It was also studied that the effects of CⅡ-3 and HFDT1 to L1210 tumor-(NK cells,DC cells),T cells and their subgroups,B cells and their subgroups in L1210 tumorbearing mice by flow cytometry.The proliferation of splenic T and B lymphocytes were studied in L1210 tumor-bearing mice by CFSE labeled method.Th1/Th2 reactions were analyzed by flow cytometry.It is detected that included the levels of TNF-α secreted by peritoneal macrophages,IFN-γ and IL-4 secreted by tumorassociated lymphocytes and IL-2,IL-4,IL-10,IL-17,IFN-γ secreted by spleen lymphocytes in L1210 tumor-bearing mice by ELISA.Results1.Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 had a strong inhibitory effect on L1210 cells in vivo.The inhibitory rates of CTX,CⅡ-3 high dose and low dose of CⅡ-3 and short peptide HFDT1 were 59.57% 55.32%,65.32%,61.70%,respectively.Compared with CTX group,the body weight of CⅡ-3 and HFDT1 groups’ mice increased(P<0.05).2.Compared with model group and CTX group,the effects of CⅡ-3 and HFDT1 on the thymus index and spleen index were increased(P<0.05).3.Compared with CTX group,CⅡ-3 and HFDT1 could increase the numbers of leukocytes,lymphocytes,monocytes and granulocytes in peripheral blood of tumorbearing mice.4.Compared with CTX group,the levels of serum IgA,IgG and IgM increased by CⅡ-3 and HFDT1(P<0.05).5.Compared with the model group and CTX group,CⅡ-3 and HFDT1 could increase the number of macrophages in the spleen.Compared with the model group,CⅡ-3 and HFDT1 increased the phagocytic index and phagocytic rate of peritoneal macrophages(P<0.05).The levels of TNF-α secreted by peritoneal macrophages in CⅡ-3 and HFDT1 groups’ mice were increased(P<0.05).CⅡ-3 and HFDT1 could increase the numbers of NK and DC cells in the spleen.Compared with model group and CTX group,CⅡ-3 and HFDT1 down-regulated Th17 cells in tumor tissue,and up-regulated it in spleen.6.CⅡ-3 and HFDT1 were able to maintain the number of spleen lymphocytes,up-regulated T cells,and down-regulated B cells.Compared with model group,CD4/CD8 T cells were changed,and CD4+ T cells were up-regulated and CD8+ T(CTL)cells were up-regulated.CD4+ T cells in CⅡ-3 low dose group mice were significantly decreased and CD8+ T cells were significantly increased.Compared with CTX group,CⅡ-3 and HFDT1 could decrease Treg cells and CD45RA+ cells.The Treg cells of CⅡ-3 low dose group mice decreased significantly and CD45RA+ cells in HFTD1 group mice were significantly decreased.7.The Th1/Th2 responses in tumor tissue were similar with spleen.Compared with model group and CTX group,CⅡ-3 and HFDT1 could regulate Th1/Th2 response,and up-regulated Th1 cells,and down-regulated Th2 cells.CⅡ-3 and HFDT1 could increase IFN-γ secretion and decrease IL-4 secration in tumor tissue.IFN-γ secratiob in HFDT1 group mice was significantly higher than that of model group mice.Compared with CTX group,the levels of IFN-γ and IL-2 in splenic cells increased,and the secretion of IL-4 and IL-10 decreased in CⅡ-3 and HFDT1 group splenic cells.8.CⅡ-3 low dose and HFDT1 increased the number of mature B cells(IgM-IgDhi)and activated B cells(CD45RA-).Compared with model group and CTX group,CⅡ-3 and HFDT1 could promote B lymphocyte proliferation.Conclusions1.Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 could inhibited the growth of tumor in L1210 tumor-bearing mice,and they did not decrease the weight of the mice.2.Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 could enhanced the immune organs function of tumor-bearing mice,and increased the numbers of immune cells in peripheral blood and the level of immunoglobulin.3.Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 could up-regulated NK cells,macrophages,DC cells,Th1 cells,CTL cells,and inhibited negative regulatied cells of anti-tumor such as Th2 cells,Treg cells,and Th17 cells.4.Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 could regulate Th1/Th2 response,enhanced the secretion of anti-tumor cytokines TNF-α,IFN-γ,IL-2 and promoted lymphocyte proliferation.In conclusion,Periplaneta americana extract CⅡ-3 and related synthetic peptide HFDT1 may through regulated the immune function of the body to achieve anti-tumor efect.