LAUSR

Abstract In the present study, five root extracts of Onosma visianii Clem were investigated for their in vitro cytotoxic activity. On the basis of HPLC-PDA analysis, these extracts have proved to be a rich source of naphthoquinones as natural colourants for food and cosmetic industry. All investigated root extracts contain acetylshikonin, isobutyrylshikonin and α-methylbutyrylshikonin as major compounds. As the most abundant source of active compounds for antitumour therapy, acetone, chloroform and ethyl acetate extracts showed strong cytotoxic activity towards HCT-116 and MDA-MB-231 cancer cell lines. Also, these extracts induced apoptosis and cell cycle arrest in HCT-116 and MDA-MB-231 cancer cell lines.