The Mechanism Of "Zhong Liu Xiao" Decoction Induces Apoptosis In Tumor Cells

Tumor has become a major killer in human life and threat to people’s health. Lung canceris the most common malignancy in the world at present, it is the main cause of cancer-relateddeaths. At the same time, the morbidity and mortality of animal tumor diseases are also rise.such as Marek’s disease (MD) which has highly pathogenic and contagious infectious causedserious damage to livestock production. The cancer treatment by Chinese medicine has manyadvantages. The plant-originated antitumor drugs have been gradually dominated in thecancer treatment and research. Qinling Taibai Mountain is one of the three drugs hill in ourcountry which has rich herbal resources. There are149kinds of Taibai "Qi drug". The "ZhongLiu Xiao" decoction composed of six plants from Taibai "Qi drug". The action andmechanism of "Zhong Liu Xiao" decoction induce tumor cell apoptosis were tested usinghuman lung adenocarcinoma A549cells and Marek’s lymphoma MDCC-MSBl cells as theprimary tumor cells model in vitro. The purpose of this research is to provide a theoreticalbasis in clinical screening for anticancer drugs. On the other hand, it can provide a scientificand rational guidance for people to exploit herbal resources in Taibai Mountain.(1)"Zhong Liu Xiao" decoction have anti-tumor activity to many tumor cells. Theanti-tumor activity of "Zhong Liu Xiao" decoction was detected by MTT assay. Resultsshowed that the "Zhong Liu Xiao" significantly inhibited the proliferation of MDCC-MSBl,A549, C6, SP2/0and HeLa cells, but not normal293A cells.(2)"Zhong Liu Xiao" decoction have obvious effects of induce apoptosis in tumor cells.The A549cells apoptosis induced by "Zhong Liu Xiao" decoction were detected by cellmorphology and Hoechst332580staining. Both methods proved that "Zhong Liu Xiao"decoction has the effect of induced apoptosis in A549cells. The MDCC-MSBl cells apoptosisinduced by "Zhong Liu Xiao" decoction were detected by DNA fragmentation analysis andthe potential of mitochondrial membrane potential assay. Both methods proved that "ZhongLiu Xiao" decoction has the effect of induced apoptosis in MDCC-MSBl cells. Using AnnexinV/PI double staining and flow cytometry to analysis the rate of tumor cells apoptosis inducedby "Zhong Liu Xiao" decoction. The results confirm that the rate of apoptosis of tumor cellssignificantly increased by "Zhong Liu Xiao" decoction. (3) Under the joint action of death receptor pathway and mitochondrial pathway,activation of p38MAPK signaling pathway in "Zhong Liu Xiao" decoction induces apoptosisin lung adenocarcinoma A549cells is needed. We further to study the apoptosis signalingpathways and the expression levels of apoptotic proteins in A549cells by western blotingassay. The results detected by Western blotting showed that "Zhong Liu Xiao" induced A549cells apoptosis involves the persistent activation of p38MAPK and the subsequent activationof death receptors(TNF-R1and DR5), and further activation of caspase8, thus initiate theapoptotic death receptor pathway. On the other hand, the expression level of p53gene wasincreased in A549cells, and further upregulates the level of protein expression of Bax,meanwhile downregulates the protein expression of anti-apoptotic gene Bcl-2. Potential ofmitochondrial membrane potential was declined under the condition of co-regulation of Bcl-2and Bax, and cytochrome c translocated from mitochondria to the cytoplasm, which resultedin the activation of caspase9, Thereby activating the endogenous mitochondrial apoptoticpathway. Both death receptor pathway and mitochondrial pathway were led to the activationof caspase3and to induce A549cells apoptosis.