Shahrekord University of Medical Sciences Journal of Herbmed Pharmacology 2345-5004 4 2 2015 04 01 Cytotoxic activities of Euphorbia kopetdaghi against OVCAR-3 and EJ-138 cell lines 49 52 EN Mahmoud Aghaei Mustafa Ghanadian Farough Faez Ebrahim Esfandiary Journal Article Introduction: Over the centuries, the genus Euphorbia was known to be toxic to humans and animals. Recently, in a primary study significant suppressive activity against phytohemagglutinin activated T-cell proliferation has been reported from this plant. Therefore, this study was designed to evaluate the cytotoxic effects of different parts of E. kopetdaghi against cancer cell lines. Methods: Filtration and in vacuo concentration resulted in a green gum which was subjected on silica gel CC (hexane/Acetone, 0 →50) to several fractions: F1-F8. The inhibitory effects of obtained fractions with 5, 50, and 500 μg/ml concentrations were evaluated on proliferation and viability of cancer cells (OVCAR and EJ-138) in 48 hours treatment. Finally, cell viability was determined at a wavelength of 570 by 3-4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. Results: Based on studies of microscopic observation and viability testing, F1, F2, F4, F5, F6, and F7 showed significant cytotoxic effect at concentration of 50 and 500 μg/ml against EJ-138 and OVCAR-3 cell lines. These fractions inhibited growth of EJ-138 and OVCAR-3 cells in a concentration-dependent manner. Fraction of F8 induced tumor promotion significantly in EJ-138 and OVCAR-3 cells, respectively. Conclusion: Due to the inhibitory properties of E. kopetdaghi extract and its fractions on cancer cells of OVCAR3 and EJ-13, isolation, purification and identification of compounds presented in the fractions possessing cytotoxic effects are recommended which were the area of our future research.