Pycnogenol Induces Nuclear Translocation of Apoptosis-inducing Factor and Caspase-independent Apoptosis in MC-3 Human Mucoepidermoid Carcinoma Cell Line

Abstract

Background:Pycnogenol is extracted from the pine bark of a tree known as Pinus pinasterthat has variety biological effects. However,its anticancer activity has not yet been completely studied. The aim of this study is to investigate anticancer effect of pycnogenol inMC-3 human mucoepidermoid carcinoma (MEC) cell line. Methods:We describe the effect of anti-cancer of pycnogenol in MC-3 human oral MEC cells using trypan blue exclusion assay,3-(4,5-dimethylthiazol-2-yl)-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium (MTS) assay, Western blot, preparation ofcytosolic and nuclear fractions, immunocytochemistry and reverse transcriptase polymerase chain reaction. Results:Pycnogenol significantly decreased cell viability and also induced caspase-independent apoptosis. We confirmed that pycnogenolinduced the translocation of apoptosis-inducing factor into nucleus and regulated apoptosis. Also, Bak protein stability was partly enhancedby pycnogenol to elevate the expression level of Bak protein. Conclusions:Overall, pycnogenol may be a fascinating therapeutic drug candidate for the treatment of MEC.