RESUMEN
Objective To study the antitumor effects of three different extracts from Pedicellus Melo on the proliferation of cancer cells in vitro, and discuss the possible mechanism. Methods Pedicellus Melo was extracted by water, 75%ethanol and 95%ethanol, respectively. The anti-cancer activities in vitro were detected by MTT assay on five tumor cell lines SGC-7901, NCI-H460, SMMC-7721, K562 and L929 cells. Flow cytometry was used to detect the cell cycle and apoptosis of different cell groups. Results After 72-hour treatment with water, 75%ethanol and 95%ethanol extracts, inhibitory effects were found in five tumor cell lines, which showed dose-dependent manner on the proliferation of the cells. The IC50 values were significantly lower in the two ethanol extracts than those of water extract (P<0.05) . And the IC50 values of 95%ethanol extract on SGC-7901, SMMC-7721, K562 and L929 cells were significantly lower than those of 75% ethanol extract (P <0.05). All the extracts were sensitive to SGC-7901 cells. Apoptotic rates of SGC-7901 cells treated with 95%ethanol extract of the concentrations of 0.4, 0.6 and 0.8 mg/L for 48 hours were (8.32 ± 0.55)%, (11.06 ± 1.15)%and (12.25±1.51)%. The cell cycle was arrested in S and G2/M phases. Conclusion Results demonstrate that 95%ethanol extract of Pedicellus Melo has significant inhibitory effect on SGC-7901 cells in vitro, which may be related to the induced apoptosis and the inhibition of cell division.