Mechanism of Photodynamic Therapy Mediated by Hypericin in Inhibiting the Proliferation of Leukemia Cell Lines / 中国药学杂志

ABSTRACT

OBJECTIVE: To observe the effects of hypericin on proliferation, apoptosis of leukemia cells and its possible mechanism. METHODS: Subcellular localization of hypericin in leukemia cells by fluorescence microscopy. MTT(3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) test was adopted to observe the inhibitory effects of hypericin on the proliferation of leukemia cells and calculated its half maximal inhibitory concentration(IC50). The technology of flow cytometry, Annexin-V-FITC/PI double stained method were employed to measure the cell apoptosis of leukemia cells after hypericin treatment. RESULTS: The optimal time for hypericin to entry into cells was 16 h. Hypericin could inhibit the proliferation of leukemia cells in vitro, and the inhibition presented obvious dose-effect relationship(r=0.990 5, P<0.01). The apoptotic ratio of leukemia cells was gradually increased. The ratio of Bax/Bcl-2 was significantly increased, and the apoptotic protein caspase-3, 8, 9 is cleaved and activated. CONCLUSION: Hypericin could inhibit the growth of leukemia cells, induce the apoptosis through induction of caspase dependent apoptosis pathway.