Induction of apoptosis by Tryptanthrin on K562 cells

Aim To study the effect of Tryptanthrin(Try) on proliferation and apoptosis of erythroleukemia K562 cells.Methods The cell proliferation effect of Try(1.56～50 mg·L-1) on K562 cells was assessed by MTT assay.The morphologic change was observed by Hoechst 33258 fluore-scent stain.The flow cytometer was used to detect cell apoptosis and cell cycle.Results MTT showed that in the range of 3.12～50 mg·L-1 Try obviously inhibited the proliferation of K562 cells in a dose and time-dependent manner.Typical apoptosis changes were observed in K562 cells treated with Try for 48 h by flourescence inverted microscope.With Annexin V-FITC and PI double staining,folw cytometer result showed that the apoptosis state was obvious in K562 cells treated with 25,50 mg·L-1 Try for 48 h.The cell cycle distribution of K562 was changed.The G0/G1 phase was blocked and the DNA synthesis was inhibited,accompanied with subdiploid apoptotic peak.Conclusion Try has an effect on inhibiting the cell proliferation and inducing the apoptosis of K562.