Cytotoxic effect and its mechanism of dioscorealide B from Dioscorea membranacea against breast cancer cells.

BACKGROUND

Dioscorealide B is an active compound from the rhizome of Dioscorea membranacea Pierre which locally known as "Hua-Khao-Yen". This medicinal plant has long been used in the anticancer prescription of Thai traditional medicine.

OBJECTIVE

To examine the cytotoxic effect and mechanism of Dioscorealide B in human breast carcinoma cells.

METHODS

Dioscorealide B was isolated from the rhizome of Hua KhaoYen (Dioscorea membranacea).The cytotoxicity of Dioscorealide B was evaluated in two human breast cancer cell lines, MCF-7 and MDA-MB 468 by Sulphorhodamine B (SRB) assay. RT-PCR and Caspase-Glo assay were used to further elucidate its cytotoxic mechanism.

RESULTS

Dioscorealide B showed cytotoxic effect on MCF-7 (IC50 = 2.76 microM) and MDA-MB 468 (IC50 = 9.93 microM). The mRNA level for p53, p21 and Bax were increased while Bcl-2 was decreased after the treatment. MCF-7 treated with Dioscorealide B showed the induction of apoptosis via the activation of caspase-9 and -7.

CONCLUSIONS

The results suggested that the mechanisms of Dioscorealide B might be involved in p53 and the intrinsic apoptotic pathway.