Experimental Study of the Extract of Hedyotic Diffusa Willd on Induction of the Apoptosis of Leukemia U937 Cells.

Hedyotic Diffusa Willd (HDW) is a Chinese herbal medicine, it has the effect on heat-clearing and detoxicating, activating blood circulation to dissipate blood stasis, removing dampness and promoting diaresis and deturescence. It used for treating various kinds cancer generally for the past few years in china. According the different of solvent polarity, we had extracted the active components from HDW by various solvent (water, ethanol, acetidin, chloroform, alkane) and explored the effects of every active component from HDW on proliferation and apoptosis of leukemia U937 cells. It was found that ethanol extract showed the strongest antitumor effect. Exposured log phase growth U937 cells to different ethanol extract from HDW concentrations for different time respectively and then test the inhibitive effect by modified tertrozalium salt (MTT) assy. The apoptosis of HDW induced on U937 cells was detected by means of optics microscope, flow cytometry and gel electrophoresis of DNA. The antiproliferative effects were observed following exposure ethanol extract of HDW. It shows a very substantial differences in the dose and duration dependency of the observed antiproliferative and cytotoxic effects. The U937 cells treated by ethanol extract of HDW are observed apoptosis characteristic morphological changes such as complete cell membrane,nuclear fragmention apoposic bodies and found trapezoidal belt with DNA.When 0.5mg/ml, 1mg/ml, 2mg/ml, 4mg/ml ethanol extract of HDW treated U937 cells for 48 hours, the numbers of apoptotic cells were respectively 4.18%, 56.96%, 82.43%, 56.41%. These results indicate that Ethanol extract of HDW has the strongs antitumor and inhabited the proliferation and induced the apoptosis of U937 cells stignificantly.