Seyed Ebrahim Sajjadi
Mustafa Ghanadian
Mehrangiz Haghighi
Leili Mouhebat

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 ۱۸.۴ ± ۰.۵۹ to ۸۷.۹ ± ۰.۵۸ 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-۳ and HT-۲۹ 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 (۴۱.۳ g) eluted with water: methanol (۲۰:۸۰), was then subjected on a silica gel column chromatography using hexane/acetone and resulted in ۱۱ fractions. Finally, cytotoxic activities against ovarian and colon cancer cells were determined at a wavelength of ۵۷۰ nm by Matrix metalloproteinase protein (MTT) standard method. Results: None of the fractions showed highly cytotoxic activity. Based on NCI, fractions Fr. ۱, Fr. ۲, Fr. ۴, Fr. ۵, Fr. ۶, Fr. ۸ and Fr. ۱۰ showed moderately cytotoxicity with IC۵۰ values ranged between ۱۱۹ to ۱۹۰ μg/mL against OVCAR-۳ cells. Fractions Fr. ۱, Fr. ۲, Fr. ۶, Fr. ۷ and Fr. ۸ showed moderately cytotoxic activity ranged between ۱۱۸ to ۱۹۴ μg/mL against HT-۲۹ cells. Fr. ۱۰ and Fr. ۱۱ 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.