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Evidence-Based Complementary and Alternative Medicine
Volume 2012 (2012), Article ID 134512, 11 pages
http://dx.doi.org/10.1155/2012/134512
Research Article

Autophagy Inhibition Enhances Apoptosis Induced by Dioscin in Huh7 Cells

1School of Medical Laboratory and Biotechnology, Chung Shan Medical University, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan
2Institute of Medicine, Chung Shan Medical University, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan
3Department of Medical Research, Chung Shan Medical University Hospital, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan
4Department of Biochemistry and Institute of Biochemistry and Biotechnology, Chung Shan Medical University, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan
5Department of Internal Medicine, Chung Shan Medical University Hospital, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan
6Department of Internal Medicine, School of Medicine, Chung Shan Medical University, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan
7Department of Clinical Laboratory, Chung Shan Medical University Hospital, 110, Section 1, Chien-Kuo N. Road, Taichung 402, Taiwan

Received 9 August 2012; Accepted 2 October 2012

Academic Editor: William CS Cho

Copyright © 2012 Ming-Ju Hsieh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Extensive research results support the application of herbal medicine or natural food as an augment during therapy for various cancers. However, the effect of dioscin on tumor cells autophagy has not been clearly clarified. In this study, the unique effects of dioscin on autophagy of hepatoma cells were investigated. Results found that dioscin induced caspase-3- and -9-dependent cell apoptosis in a dose-dependent manner. Moreover, inhibition of ERK1/2 phosphorylation significantly abolished the dioscin-induced apoptosis. In addition, dioscin triggered cell autophagy in early stages. With autophagy inhibitors to hinder the autophagy process, dioscin-induced cell apoptosis was significantly enhanced. An inhibition of caspase activation did not affect the dioscin-induced LC3-II protein expression. Based on the results, we believed that while apoptosis was blocked, dioscin-induced autophagy process also diminished in Huh7 cells. In conclusion, this study indicates that dioscin causes autophagy in Huh7 cells and suggests that dioscin has a cytoprotective effect.