title: Cytotoxic withanolides from the leaves of Moroccan Withania frutescens.
abstract: BACKGROUND
  Withania species are a rich source of interesting phytochemical substances (withanolides) which have shown several biological properties.
  
  
  OBJECTIVE
  To investigate the cytotoxic potential of Withania frutescens (L.) Pauquy (Solanaceae) leaf extracts and isolated active compounds against cultured tumor cell lines.
  
  
  METHODS
  The crude methanol extract of W. frutescens leaves was partitioned with dichloromethane, ethyl acetate and n-butanol. MeOH extract and its fractions were tested for their cytotoxic activity against cancer cell lines (HepG2 and HT29) using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Bioassay-guided fractionation was performed for the active CH₂Cl₂ fraction employing column chromatography and preparative high-performance liquid chromatography. Structural elucidation of the isolated active compounds was carried out mainly by 1D and 2D NMR and mass spectrometry. The compounds were then tested for their cytotoxic activity.
  
  
  RESULTS
  The CH₂Cl₂ fraction was the most active against HT29 cell line. The fractionation procedure resulted in the isolation of 4β,17α,27-trihydroxy-1-oxo-22-R-witha-2,5,24-trienolide (1), 5β,6β-epoxy-4β,17α,27-trihydroxy-1-oxowitha-2,24-dienolide (2) and 2,3-dihydroxywithaferin A-3β-O-sulfate (3). The latter exhibited the strongest cytotoxic activity against HT29 cancer cell lines (IC₅₀ of 1.78 ± 0.09 µM) which was comparable to that of 5-fluorouracil (5-FU) used as the positive antimitotic control.
  
  
  CONCLUSIONS
  Compounds 2 and 3 were isolated from W. frutescens for the first time. Data obtained suggest that the sulfated steroidal lactone (3) can be considered as a compound with potential application in the new anticancer drugs development field.
authors.affiliation: Laboratory of Biotechnology, Protection and Valorisation of Plant Resources, Phytochemistry and Pharmacology of Aromatic and Medicinal Plant Unit, Faculty of Sciences Semlalia, University Cadi Ayyad, Marrakech, Morocco.
authors.forename: Laila
authors.initials: L
authors.lastname: El Bouzidi
authors.forename: Valérie
authors.initials: V
authors.lastname: Mahiou-Leddet
authors.forename: Sok-Siya
authors.initials: SS
authors.lastname: Bun
authors.forename: Mustapha
authors.initials: M
authors.lastname: Larhsini
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Abbad
authors.forename: Mohammed
authors.initials: M
authors.lastname: Markouk
authors.forename: Mabrouki
authors.initials: M
authors.lastname: Fathi
authors.forename: Michèle
authors.initials: M
authors.lastname: Boudon
authors.forename: Evelyne
authors.initials: E
authors.lastname: Ollivier
authors.forename: Khalid
authors.initials: K
authors.lastname: Bekkouche
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000473:pathology; D002851:Chromatography, High Pressure Liquid; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology; D005472:Fluorouracil / Q000494:pharmacology; D019073:HT29 Cells; D056945:Hep G2 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D008113:Liver Neoplasms / Q000188:drug therapy / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009018:Morocco; D018515:Plant Leaves; D012997:Solvents / Q000737:chemistry; D032341:Withania / Q000737:chemistry*; D054358:Withanolides / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D012997:Solvents; D054358:Withanolides; D005472:Fluorouracil