Killing Effects And Preliminary Mechanisms Of Natural Plant Antimicrobial Solution In Anti-Cancer

Cancer is a fatal disease to human health.The finding of efficient medicine or method for cancer therapy is of greatly needed.The advantages of Chinese folk medicine may open a new and promising way for the therapy of cancers.The natural plant antimicrobial solution(PAMs)was the ethanol extract of the complex Chinese natural and folk medicinal plants including carthamus tinctorius L.,lithospermum erythrorhizon,Solanum indicum L.,Cymbopogon distans(nees)wats.provided by the Institute of Yunnan folk medicine Co.Ltd.Previous studies revealed that PAMs could strongly inhibit the growth of all tested tumor cell lines in vitro including hepatic carcinoma,and breast cancer cells,which showed its great potential and advantage in anticancer drug development as a kind of modern Chinese medicine product.However,theanticancer mechanism of PAMs was still unknown due to its complicated constituents.Here in this study,the leukemia K562 cell line and murine melanoma B16 cells were taken as models to elucidate the anticancer effects and preliminary mechanisms of PAMs.MTT assay concluded that PAMs could cause cytotoxicities to K562 cells in a dose-and time-dependent manner.AO-EB,Annexin-FITC/PI staining showed that the killing effects of PAMs to K562 cells were related to apoptosis,which was further confirmed by the following molecular and enzymatic assay.The mRNA levels of pro-apoptotic genes caspase-3,caspase-9 and bax were remarkably increased while the anti-apoptotic gene bcl-2 was significantly decreased by Fluorescent quantitative PCR.Western blotting disclosed that PAMs could up-regulate the Caspase-3 and down-regulate the anti-apoptotic Survivin protein expression.The latter was also consistent with the results that PAMs could increase the enzymatic activities of both Caspase-3 and Caspase-9.All these results suggested that PAMs could effectively inhibit the proliferation of K562 cells and the mechanisms may be closely related to apoptosis induction.B16 melanoma cell lines were tested in vitro for cytotoxicity by MTT assay,for apoptosis by AO/EB staining and Flow cytometry.The results showed that the inhibition of PAMs on B16 cell proliferation was dose-and time-dependence.Apoptosis and nonapopotosis were the main pathway of cell death for B16 after treated with PAMs.Wound healing and Transwell chamebers assay showed that PAMs could effectively inhibite the migrations of B16 cells.Also,the B16 transplanted C57/BL mice model was established and treated with PAMs.After three weeks,the mice of each group were killed and the influences of PAMs on growth speed,size,weight of tumor,spleen index,thymus index and the levels of vascular endothelial cell growth factor(VEGF)and IL-12 in serum were detected In contrast to normal control group,the inhibition rate of the PAMs group and the CTX group were 47.5%? 77.6%(**P<0.01)respectively.The spleen index and thymus index of the CTX group were decreased significantly(**P<0.01),however,there was no statistical significance in the PAMs group as compared to the normal control group.The content of VEGF in the serum of PAMs group was also decreased remarkably(**p<0.01)and the IL-12 was increased(**P<0.01).Conclusion:PAMs had a strong killing effect on K562 cells,whose main mechanism was associated with the induction of apoptosis in K562 cells and the expressions of a variety of molecules such as Caspase,bax,Bcl-2,Survivin and so on.PAMs also could inhibit the growth of B16 cells in vivo and in vitro through apoptosis and nonapoptosis manner.Its main mechanisms were related to inhibiting cells migration through reducing the level of VEGF and incesase IL-12.Further study of more mechanisms were still in progress.