title: Evaluation of antioxidant activity of Tetracarpidium conophorum (Müll. Arg) Hutch & Dalziel leaves.
abstract: This study evaluated the antioxidant activity as well as bioflavonoid content of the methanol and ethanol-water extracts of the fresh and dried leaves of Tetracarpidium conophorum. Antioxidant activity was determined by spectrophotometric methods using DPPH free radical, nitric oxide radical inhibition and ferric reducing antioxidant power assays. In addition, total phenolics, flavonoids and proanthocyanidin content were also determined. The ethanol: water extract of the dried leaves had the highest antioxidant activity with a 50% inhibition of DPPH at a concentration of 0.017 mg/mL compared to the standards, Vitamin C and Vitamin E with inhibition of 0.019 and 0.011 mg/mL, respectively. This extract also showed nitric oxide radical inhibition activity comparable to that of rutin, 54.45% and 55.03% for extract and rutin, respectively, at 0.1 mg/mL. Ferric reducing power was also comparable to that of ascorbic acid (281 and 287 μM Fe (11)/g, resp.) at a concentration of 1 mg/mL. The methanol extract of both the dried and the fresh leaves had higher phenolic, flavonoids and proanthocyanidin content than the ethanol:water extract. The study reveals that T. conophorum can be an interesting source of antioxidants with their potential use in different fields namely food, cosmetics and pharmaceuticals.
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Lagos, College of Medicine Campus, PMB 12003, Surulere, Lagos, Nigeria.
authors.forename: O U
authors.initials: OU
authors.lastname: Amaeze
authors.forename: G A
authors.initials: GA
authors.lastname: Ayoola
authors.forename: M O
authors.initials: MO
authors.lastname: Sofidiya
authors.forename: A A
authors.initials: AA
authors.lastname: Adepoju-Bello
authors.forename: A O
authors.initials: AO
authors.lastname: Adegoke
authors.forename: H A B
authors.initials: HA
authors.lastname: Coker
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D019665:Euphorbiaceae / Q000737:chemistry*; D010851:Picrates / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D014810:Vitamin E / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D014810:Vitamin E; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid