Cytotoxic and apoptotic effects of root extract and tanshinones isolated from Perovskia abrotanoides Kar

Abstract

<strong><em>Objective(s)</em></strong>:<em>Perovskia abrotanoides </em>Kar., from family Lamiaceae, is a little known medicinal plant growing in various regions of Iran. In the present study, cryptotanshinone (CT), tanshinone 2A (Tan2A), and hydroxycryptotanshinone (HCT) were isolated and purified from the roots of <em>P. abrotanoides</em>. In addition, cytotoxic and apoptotic effects of total root extract (TE) and three purified tanshinones were investigated in human cervical carcinoma (HeLa) and human breast cancer (MCF-7) cell lines. <br /> <strong><em>Materials and Methods:</em></strong> Alamar Blue^® assay was used to determine cell viability. Cell apoptotic rate was detected using propidium iodide staining of DNA fragmentation by flow cytometry (sub-G1 peak). The PARP cleavage, as the sign of apoptosis, was investigated by Western blotting.<br /> <strong><em>Results:</em></strong> The results revealed that CT, Tan2A, HCT, and TE exhibited significant cytotoxicity in cancer cell lines. All of these compounds caused apoptosis in treated cells and induced sub-G1 peak in the related flow cytometry histograms. HCT was found to have the highest anti-proliferative activity on cancer cells. Western blotting analysis showed cleavage of PARP protein in MCF-7 cells treated with purified tanshinones and TE after 48 hr contact with cells.<br /> <strong><em>Conclusion:</em></strong> The findings suggest that root extract of <em>P. abrotanoides</em> and purified tanshinones especially Tan2A and HCT have cytotoxic and apoptotic effects against cancer cell lines. So, they may serve as potential cytotoxic agents for future investigations.