title: In vitro antioxidant and radical scavenging of Guinean kinkeliba leaf (Combretum micranthum G. Don) extracts.
abstract: The antioxidant properties of the water and ethanol leaf extracts of kinkeliba (Combretum micranthum) were investigated, including scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (IC₅₀ values: 8.02 ± 0.34 for the ethanol extract [KE] and 9.1 ± 0.28 for the water extract [KW]), the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical (IC(50) values: 7.4 ± 0.14 for KE and 11.8 ± 0.01 for KW) and the hydroxyl radical (58.1% for KE and 61.1% for KW). The ferric thiocyanate method, reducing power, metal chelating activity, an assay of protein oxidation and the β-carotene-linoleic bleaching assay were also used. Butylated hydroxytoluene and ascorbic acid were used as the reference antioxidant compounds. At 20 mg mL⁻¹ concentration, KW and KE provided 36.8% and 75.1% inhibition of lipid peroxidation of linoleic acid emulsion, respectively. The IC₅₀ values of the ethanol extract in ABTS and DPPH tests were significantly lower than those from the water extract. Furthermore, crude polyphenols were extracted from kinkeliba leaf with 90% ethanol solution using a water bath treatment and then purified by a macroporous resin, AB-8. The polyphenols from kinkeliba leaf were subjected to analyses by RP-HPLC and ESI-MS. The dominant polyphenols in kinkeliba leaf were identified as gallic acid, rutin trihydrate, (+)-catechin and benzoic acid.
authors.affiliation: State Key Laboratory of the School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, P.R. China.
authors.forename: Alhassane
authors.initials: A
authors.lastname: Touré
authors.forename: Xueming
authors.initials: X
authors.lastname: Xu
authors.forename: T
authors.initials: T
authors.lastname: Michel
authors.forename: M
authors.initials: M
authors.lastname: Bangoura
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D019817:Benzoic Acid / Q000737:chemistry / Q000494:pharmacology; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D029765:Combretum / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry / Q000494:pharmacology; D012431:Rutin / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D059808:Polyphenols; D012431:Rutin; D002392:Catechin; D019817:Benzoic Acid