Inhibition of tumor cells growth and stimulation of lymphocytes by Euphorbia species.

Plants have been shown to possess a number of beneficial anticancer and immunomodulatory properties. In this study the possible in vitro antitumor activity and immunomodulatory effects of five species of Euphorbia, an important genus of Euphorbiaceae, including E. petiolata, E. hebecarpa, E. osyridea, E. microciadia, and E. heteradenia were investigated using cytotoxicity and cell proliferation assays. Among different tumor cell lines, the most sensitive cell line to methanolic extracts of the plants was determined as follows. Hela cervical cancer cells to E. hebecarpa and E. microciadia, K562 leukemia cells to E. petiolata and E. heteradenia, and Fen bladder cancer cells to E. osyridea. The methanolic extracts were then fractionated into hexane, n-butanol, ethyl acetate, and water and the effect of these fractions was tested for cytotoxic activity on the selected cell lines. The results indicated the significant stronger antiproliferatory effect of the hexane factions in all the plants when compared with other ones. The methanolic extracts of the plants were also studied for their effects on the activation of the lymphocytes. All of the extracts showed stimulatory effects on the proliferation of the lymphocytes at lower concentrations. After further fractionation of the extracts, the butanolic and hexane fractions showed the highest activity on the lymphocyte activation. In conclusion, all the plants studied had the capacity to inhibit proliferation of tumor cells with beneficial immunomodulatory effects on the lymphocytes. This dual effect of the plants indicates their value for further investigations as antitumor agents.