Purification of Cucurbitacins D, E, and I from Ecballium Elaterium (L.) A. Rich Fruits and Study of Their Cytotoxic Effects on the AGS Cell Line.

Background: The plant Ecballium elaterium (L.) A. Rich, belongs to the Cucurbitaceae family which occupies an important position in traditional medicine prescriptions. It has been reported that a freeze-dried aqueous extract of E. elaterium fruits has cytotoxic effects on the AGS human stomach adenocarcinoma cell line. We here focused on anticancer effects of the main chemicals purified from E. elaterium fruits. Materials and Methods: We isolated cucurbitacins D, E, and I from chloroform, and ethyl acetate fractions of a methanolic extract of E. elaterium fruits and assessed their cytotoxic effects on the AGS cell line by MTT assay. The methanolic extract was fractionated to petroleum ether, chloroform, and ethyl acetate fractions. The compounds isolated by column chromatography were identified by NMR spectroscopy. Results: After 24 h of incubation with AGS cells, the IC50 values were 0.3, 0.1, and 0.5 μg/ml for cucurbitacins D, E, and I respectively. Conclusions: This finding suggests that because of its cucurbitacins, E. elaterium fruit may have some cytotoxic effects on gastric cancer cells. Also, compared with D and I, cucurbitacin E showed greater potency in this regard.