Chemotherapeutic Effect of Withaferin A in Human Oral Cancer Cells

Withaferin A (WA) is a bioactive compound derived from a medicinal plant Withania somnifera and has potential therapeutic effects against various types of cancers. The purpose of this study is to investigate an apoptotic effect of WA and identify its molecular target in HSC-3 and HSC-4 human oral cancer cell lines using Trypan blue exclusion assay, DAPI staining and western blotting. WA inhibited cell viability and induced apoptosis in a concentrationor time-dependent manner, as evidenced by induction of nuclear condensation and fragmentation, activation of caspase 3 and poly (ADP-ribose) polymerase (PARP) cleavage. WA-induced apoptosis was partly diminished by Z-VAD, a pancaspase inhibitor. WA also increased Bim and Bax protein in HSC-3 and HSC-4 cells, respectively. These results suggest that WA may be a potential chemotherapeutic drug candidate against human oral cancer.