In vitro inhibitory effect of diallyl sulfide on cell proliferation and vascular endothelial growth factor expression of human osteosarcoma MG-63 cells

Abstract

Objective To investigate the effect of diallyl sulfide (DAS) on the growth and vascular endothelial growth factor (VEGF) expression of human MG63 cells in vitro, and to explore the curative possibility of osteosarcoma with DAS. Methods The effect of DAS at the concentrations of 0, 10, 20, 40 g/L on growth and proliferation was assessed by methylthiazol tetrazolium (MTT) assay. The morphology of the cells was examined under the inverted phase contrast microscopy and Hoechst 33258 fluorescent staining. The apoptosis was detected by annexin-V/PI double-labeled cytometry after treated with DAS at different concentrations of 0, 10, 20, 40 g/L for 48 h. The effect of DAS on the cell cycle of MG63 cells was studied by flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to analyze the changes of VEGF mRNA and protein levels. Results Proliferation of MG63cells was significantly inhibited by DAS in a time- and dose-dependent fashion. As compared with the control group, the DAS over the concentration of 10 g/L significantly inhibited the proliferation of MG63 cells (P＜0.05). MG63 cells grew round and small obviously after being treated with DAS under the inverted microscopy. The apoptotic rate was(4.7±1.4)%, (18.6±0.7)%, (24.9±1.1)% after the cells were treated with DAS at the concentrations of 10, 20, 40 g/L for 48 h, respectively, which was significantly different from that in the control group (1.70±0.36)%, P＜0.05. Allicin reduced the secretion of VEGF and inhibited the level of VEGF mRNA expression in a dose-dependent manner. Conclusion DAS can inhibit the proliferation of MG63 cells in vitro. The antitumor effects of allicin may be related to down-regulation of the expression of VEGF mRNA. Key words: Osteosarcoma; DAS; Proliferation; VEGF