Investigating the cytotoxic and apoptosis inducing effects of monoterpenoid stylosin in vitro Fatemeh Behnam Rassouli a , Maryam M. Matin a,b, ⁎, Mehrdad Iranshahi c , Ahmad Reza Bahrami a,b a Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran b Cell and Molecular Research Group, Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran c Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran article info abstract Article history: Received 8 January 2011 Accepted in revised form 13 March 2011 Available online 31 March 2011 The aim of this study was to investigate the cytotoxic and anticancer activities of stylosin, a monoterpene extracted from an edible plant, Ferula ovina, on 5637 and HFF3 cells using MTT and comet assays and DAPI staining. To assess stylosin effects, cells were cultured in the presence of various concentrations of stylosin during three days; the IC 50 of stylosin on cancerous 5637 cells was less than its value on HFF3 normal cells, indicating that it might have anticancer properties. Investigating the mechanism of stylosin action revealed that it quickly induced DNA lesions and increased the number of apoptotic cells. © 2011 Elsevier B.V. All rights reserved. Keywords: Ferula ovina Monoterpene Stylosin Cytotoxicity Anticancer 1. Introduction Transitional cell carcinoma (TCC) is a superficial tumour arising from the transitional epithelium lining of the urinary bladder. TCC accounts for approximately 90% of all bladder cancers with more incidence in men [1]. The combination of vinblastine, methotrexate, doxorubicin and cisplatin is the best-studied chemotherapy regimen for TCCs [2]. However, due to resistance of TCC cells to a wide range of chemother- apeutic agents, complete responses have been obtained only in a small proportion of patients [3]. Monoterpenes are naturally occurring hydrocarbons, which have shown antitumour activities on a wide variety of experimental tumours [4–9] and different human cancer- ous cell lines [7,9–14]. The genus Ferula (Apiaceae) has a wide distribution throughout Mediterranean and Middle East area, especially in countries such as Iran. Ferula species are well documented as a source of biologically active compounds that are found in different parts of the plants, and due to their diverse and effective pharmaceutical properties, they are widely used as edible plants in several Asian countries. For instance, since Ferula species possess stimulant, expectorant and vulnerary effects, they have been traditionally used for the treatment of a number of respiratory and digestive system disorders including asthma, influenza, stomachache, flatulence and intestinal parasites [15–17]. Furthermore, in Iranian tradi- tional medicine, the fresh leaves and yellow concrete gummy-resinous juice of the stems, which is called sagape- num, are edible parts of Ferula species that have been widely used for their antiepileptic, antiflatulent, antispasmodic and also anticonvulsant effects [18]. We have previously shown that terpenoid derivatives from Ferula species have antileishmanial [19] and cancer chemopreventive [20,21] activities and can reverse multidrug resistance of cancer cells [22–25]. In present study, monoterpenoid stylosin was isolated from the roots of Ferula ovina for the first time (Fig. 1), and evaluated for its possible cytotoxic and apoptosis inducing effects. The investigations were carried out on two different human cell lines; 5637 cells (a TCC subline) and HFF3 cells (human fetal fibroblast). To study the cytotoxic activity of Fitoterapia 82 (2011) 742–749 ⁎ Corresponding author at: Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran. Tel./fax: +98 5118762227. E-mail address: Matin@um.ac.ir (M.M. Matin). 0367-326X/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.fitote.2011.03.005 Contents lists available at ScienceDirect Fitoterapia journal homepage: www.elsevier.com/locate/fitote