Abstract: AIM: To study the effect of triptolide on cell proliferation and apoptosis in A549 human lung cancer cell.METHODS: The effect of triptolide on cell viability in A549 cell was evaluated by MTT assay.Cell apoptosis was observed by flow cytometry and DNA ladder analysis.Activities of caspase-9 and caspase-3 were assayed with caspase colorimetric assay kit.RESULTS: Triptolide( eg., 0.5 -4.0 μg·ml^-1)inhibited cell growth and induced apoptosis in a dose-dependent way at 24 h in A549 cells.The activation of caspase-9 and caspase-3 was significantly increased at 24 h in A549 cells when exposed to triptolide ( eg., 0.5 -4.0 μg·ml^-1).CONCLUSION: Triptolide induces apoptosis in A549 cells partly through mitochondrial signal transduction pathway.

Key words: triptolide, lung cancer, apoptosis