cytotoxic effect of cousinia verbascifolia bunge against ovcar-3 and ht-29 cancer cells

introduction: little information is available about phytochemical and biological properties of cousinia genus. in a primary study, seven cousinia species including c. verbascifolia showed cytotoxic activity ranged between 18.4 ± 0.59 to 87.9 ± 0.58 μg/ml. to the best of our knowledge, no other biological studies have been conducted on this plant. therefore, in this study the cytotoxic effect of cousinia verbascifolia bunge against ovcar-3 and ht-29 cancer cells was evaluated. methods: filtration and in vacuo concentration of methanol extract resulted in a green gum which was subjected on reverse column chromatography. semi polar fraction (41.3 g) eluted with water: methanol (20:80), was then subjected on a silica gel column chromatography using hexane/acetone and resulted in 11 fractions. finally, cytotoxic activities against ovarian and colon cancer cells were determined at a wavelength of 570 nm by matrix metalloproteinase protein (mtt) standard method. results: none of the fractions showed highly cytotoxic activity. based on nci, fractions fr. 1, fr. 2, fr. 4, fr. 5, fr. 6, fr. 8 and fr. 10 showed moderately cytotoxicity with ic50 values ranged between 119 to 190 μg/ml against ovcar-3 cells. fractions fr. 1, fr. 2, fr. 6, fr. 7 and fr. 8 showed moderately cytotoxic activity ranged between 118 to 194 μg/ml against ht-29 cells. fr. 10 and fr. 11 showed no cytotoxic activity. conclusion: due to the inhibitory properties of extract and its fractions on cancer cells, identification of responsible compounds possessing cytotoxic effects for generating possible new approach in medicinal chemistry are recommended.