title: Bioprospecting traditional Pakistani medicinal plants for potent antioxidants.
abstract: Antioxidant potential of four methanol extracts from three selected plant species, namely Salvia nubicola (Lamiaceae), Acer oblongifolium (Aceraceae) and Hedera nepalensis (Araliaceae) was measured using assays in aqueous and lipid systems. Antioxidant activities were investigated in aqueous systems by using DPPH radical-scavenging assay, ABTS radical-scavenging assay and DNA protection assay, while antioxidant activity in a lipid system was determined by using the thiobarbituric acid-reactive substances (TBARS) assay. Additionally, the Folin-Ciocalteu method was used to measure total phenolic content. Methanol extracts of leaves and flowers of S. nubicola showed the highest Trolox equivalent (TE) values in the case of the DPPH assay, 2484±4.9mmol TE/g extract, as well as total phenolic content, 139±0.2mg gallic acid equivalents/g extract. Three fractions (A-C) of the methanol extract of S. nubicola leaves and flowers were produced by semi-preparative HPLC. Fraction B was found to be the most active in the DPPH radical-scavenging assay and had the highest total phenol content. HPLC-DAD and LC-MS revealed rosmarinic acid in S. nubicola extracts and chlorogenic acid and rutin in H. nepalensis extracts as the main phenolic antioxidants.
authors.affiliation: Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Samia
authors.initials: S
authors.lastname: Inayatullah
authors.affiliation: School of Agricultural and Wine Sciences, E.H. Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2678, Australia. Electronic address: pprenzler@csu.edu.au.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Prenzler
authors.affiliation: School of Biomedical Sciences, E.H. Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2678, Australia.
authors.forename: Hassan K
authors.initials: HK
authors.lastname: Obied
authors.affiliation: Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga, NSW 2678, Australia.
authors.forename: Ata-Ur
authors.initials: AU
authors.lastname: Rehman
authors.affiliation: Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan. Electronic address: bushra_dr@yahoo.com.
authors.forename: Bushra
authors.initials: B
authors.lastname: Mirza
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D065132:Bioprospecting; D010084:Oxidation-Reduction; D010154:Pakistan; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; C011471:folin
keywords: Acer oblongifolium (Aceraceae); Antioxidant assays; Bioactivity-guided fractionation; Folin-Ciocalteau; Hedera nepalensis (Araliaceae); Salvia nubicola (Lamiaceae)