Purpose: Ecballium elaterium (L.) A. Rich (Cucurbitaceae), also known as the "squirting cucumber," is a wild medicinal plant found abundantly in Moghan, Ardabil province, Iran. This study was undertaken to examine possible cytotoxic effect of freeze-dried aqueous extract of E. elaterium fruit on cell lines of gastric and esophageal origin namely called AGS (human gastric carcinoma) and KYSE30 (human esophageal squamous cell carcinoma).
Methods: The aqueous extract of the fruits of E. elaterium was prepared and freeze-dried. AGS and KYSE30 cancer cell lines were treated by the extract and incubated for 24, 48, and 72 h. Cytotoxicity was examined by MTT assay. Ethidium bromide/acridine orange (EB/AO) staining was used for apoptotic cell detection. A DAPI staining method was used to analyze cell cycle by flow cytometry.
Results: The IC(50) values were 2.5, 0.7, and 0.7 μg/ml for AGS cell line after 24, 48, and 72 h, respectively. IC(50) values for KYSE30 cell line were 500, 150, and 125 μg/ml after 24, 48, and 72 h, respectively. The EB/AO staining showed an increase in apoptotic cells. Cell cycle analysis showed a significant increase in cell density at G2/M phase.
Conclusions: The results of the current study showed that the freeze-dried aqueous extract of E. elaterium fruit has a cytotoxic effect on gastric and esophageal cancer cell lines by means of apoptosis. The gastric cancer cells (AGS) showed a remarkably higher sensitivity. It seems that several compounds are possibly responsible for the cytotoxic effect of the extract.