title: Antioxidant and antimicrobial activities of Withania frutescens.
abstract: In the present study, we report for the first time the antioxidant and antimicrobial activities of Withania frutescens (L.) Pauquy roots and leaves. Total phenolic content was determined using the Folin-Ciocalteu method and antioxidant activity was evaluated by the DPPH free radical scavenging and reducing power methods. Antimicrobial activity tests were carried out against ten bacterial species involved in nosocomial infections and two opportunistic clinical yeast isolates. The ethyl acetate and n-butanol leaf fractions exhibited the highest DPPH radical scavenging activity with IC50 = 4.53 +/- 0.12 and 8.49 +/- 0.46 microg/mL, respectively. The n-butanol root fraction showed the greatest reducing power comparable with that of quercetin at 0.4 mg/mL. The dichloromethane leaf fraction exhibited the highest antibacterial activity against both Gram-positive and Gram-negative bacteria with MIC values ranging between 50 and 400 microg/mL, depending on the tested bacteria. However, none of the examined extracts exhibited anticandidal activity. The polyphenol and glycowithanolide constituents appeared to be responsible for the antioxidant capacity of W. frutescens, whereas the observed antimicrobial activity may be due to the presence of withanolides.
authors.affiliation: Laboratory of Biotechnology, Protection and Valorisation of Plant Resources, URAC-35 Research Unit Associated to the CNRST, Phytochemistry and Pharmacology of Aromatic and Medicinal Plant Unit, Faculty of Science Semlalia, University Cadi Ayyad, B.P.2390, 40000, Marrakech, Morocco.
authors.forename: Laila
authors.initials: L
authors.lastname: El Bouzidi
authors.forename: Mustapha
authors.initials: M
authors.lastname: Larhsini
authors.forename: Mohamed
authors.initials: M
authors.lastname: Markouk
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Abbad
authors.forename: Lahcen
authors.initials: L
authors.lastname: Hassani
authors.forename: Khalid
authors.initials: K
authors.lastname: Bekkouche
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001713:Biphenyl Compounds / Q000737:chemistry; D024901:Drug Resistance, Multiple, Bacterial; D010851:Picrates / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D032341:Withania / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl