Abstract
AIM: To investigate the cytotoxic activity of extracts of trichosanthes root tubers (EOT) on HepA-H cells and HeLa cells compared with trichosanthin (TCS), and to explore the possible mechanism of growth inhibitory effect of EOT on HeLa cells. METHODS: Tumor cells were cultured in vitro, and then microculture tetrzoalium assay (MTT) was used to investigate drugs' cytotoxic activity. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe ultrastructural changes of cells, and electrophoresis was performed to detect changes of biochemical characteristics of intercellular DNA. RESULTS: TCS and EOT had no obvious effects on HepA-H cells (P>0.05), but had remarkable effects on HeLa cells in a time and dose dependent manner (r>0.864, P<0.05 or P<0.01). The inhibitory rate of EOT was much higher than that of TCS (P<0.01). Median inhibitory rates (IC50) of TCS and EOT on HeLa cells were 610.9 mg/L and 115.6 mg/L for 36 h, and 130.7 mg/L and 33.4 mg/L for 48 h respectively. Marked morphologic changes were observed including microvillus disappearance or reduction, cell membrane bledding, cell shrinkage, condensation of chromosomes and apoptotic bodies with complete membranes. Meanwhile, apoptosis of HeLa cells was confirmed by DNA ladder formation on gel electrophoresis. CONCLUSION: TCS and EOT have no obvious effects on HepA-H cells, but have significant inhibitory effects on HeLa cells, indicating that EOT is superior to TCS in anti-tumor activity.