Danshen: a Chinese herb that can trigger apoptosis in Human Promyelocytic Leukemia cells

Department of Health Institute of Pathology, Yung Fung Shee, Kowloon, Hong Kong.

Danshen, isolated from the Chinese medicinal herb Salvia Miltiorrhiza Radix, has recently been shown to exhibit antitumor activity in human cancer cell lines in vitro; however, the underlying mechanisms are not yet well defined. By using a variety of flow cytometric methods such as DNA-flow cytometry (DNA-FCM); Annexin V assay; and bivariate Bcl-2/DNA flow cytometry, this study aimed to investigate the antineoplastic mechamsms of Danshen on Human Promyelocytic Leukemia HL-60 cells. Our data from DNA-FCM and Annexin V assay strongly indicated that treatment with Danshen triggered apoptotic death of HL60 cells. In addition to flow cytometric analysis, morphological changes in HL-60 cells and DNA ladder formation on gel electrophoresis were used to confirm the apoptosis induced by Danshen. Furthermore, the expression of the anti-apoptotic gene, Bcl-2, was downregulated in HL-60 cells by Danshen. We conclude that the exposure of HL60 cells to Danshen downregulated Bcl.2expression likely to be associated with increased apoptosis and decreased clonal growth. Together, these findings suggest that Induction of apoptosis may contribute to the mechanisms of antitumor activity of Danshen, which merit investigation as potential chemo-prevention agents in humans.