Planta Med 2008; 74 - PA27
DOI: 10.1055/s-0028-1084025

Molecular cytotoxic mecanism of Dioscorealide B on human breast cancer cells

A Itharat 1, J Saekoo 2, C Dechsukum 3
  • 1Applied Thai Traditional Medicine Center, Faculty of Medicine, Thammasart University, Rungsit Campus, Klongluan, Pathumtani, 12120 Thailand
  • 2Department of Biomedical Sciences, Faculty of Medicine, Prince of Songkla University, Hadyai Songkla 90110 Thailand
  • 3Department of Pathology, Faculty of Medicine, Prince of Songkla University, Hadyai Songkla 90110 Thailand

Dioscorealide B is an active compound from the rhizome of Dioscorea membranacea Pierre which locally is known as „Hua-Khao-Yen“ [1]. This medicinal plant has long been used in the anticancer prescription of Thai traditional medicine. SRB (Sulphorhodamine B) assays [2] were used to assess the cytotoxic activity against MCF-7, human breast cancer cell lines.

It was demonstrated that Dioscorealide B inhibited proliferation of human breast adenocarcinoma cells (MCF-7) with IC50 =0.94µg/ml. MCF-7 cells treated with Dioscorealide B showed induction of apoptosis via the activation of caspase-7 in a dose- and time- dependent manner. In the present study, the mRNA level for p53 and Bax showed an increase while Bcl-2 was decreased after the treatment. The active compound also activated caspase-8 and caspase-9. These results showed that the mechanism of action of Dioscorealide B might be involved in both intrinsic and extrinsic pathways. In addition, our results demonstrated that the expression of p21, p27 and p57, the cyclin-kinase inhibitors, were regulated in mRNA level and Dioscorealide B might cause cell cycle arrest in breast cancer cells.

Acknowledgement: Prince of Songkhla University for the financial support.

References: 1. Itharat, A. et al. (2003) Org. Lett. 5:2879–2872. 2. Skehan, P. et al. (1990)J. Natl. Cancer Inst. 82: 1107–1112.