Paris polyphylla Smith Extract Induces Apoptosis and Activates Cancer Suppressor Gene Connexin26 Expression

Background: The inhibition of tumor cell growth without toxicity to normal cells is an important target incancer therapy. One possible way to increase the efficacy of anticancer drugs and to decrease toxicity or side effectsis to develop traditional natural products, especially from medicinal plants. Paris polyphylla Smith has shownanti-tumour effects by inhibition of tumor promotion and inducement of tumor cell apoptosis, but mechanismsare still not well understood. The present study was to explore the effect of Paris polyphylla Smith extract (PPSE)on connexin26 and growth control in human esophageal cancer ECA109 cells.
Methods: The effects of PPSE onConnexin26 were examined by RT-PCR, western blot and immunofluorescence; cell growth and proliferationwere examined by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay.
Results:PPSE inhibited the growth and proliferation on esophageal cancer ECA109 cells, while increasing the expressionof connexin26 mRNA and protein; conversely, PPSE decreased Bcl-2 and increased Bad.
Conclusion: This studyfirstly shows that PPSE can increase connexin26 expression at mRNA and protein level, exerting anti-tumoureffects on esophageal cacner ECA109 cells via inhibiting cell proliferation and inducing cell apoptosis.