【Abstract】 The cytotoxic effect of Pingyangmycin (PYM) (Bleomycin A5) on the laryngeal cancer Hep 2 line in vitro was observed with two experimental methods of MTT colorimetric assay and living cell count.Results:(1) The PYM value of IC50 (index of light density of PYM inhibited Hep 2 cell line) was 35μg/ml by MTT colorime tric assay.It showed that the proliferation activity of Hep 2 cell was inhibited strongly when the concentration of PYM increased.(2) The assay of living cell count showed that the livability of the Hep 2 was 46% when the concetration of the PYM in 30μg/ml.In our study,it was found that the PYM could induce the apoptosis effect of the Hep 2 cell in a certain range.更多还原