title: Antioxidant activities of extracts from Barkleyanthus salicifolius (Asteraceae) and Penstemon gentianoides (Scrophulariaceae).
abstract: Various extracts of the aerial parts of Barkleyanthus salicifolius (Asteraceae) and Penstemon gentianoides (Scrophulariaceae) have been used in folk medicine to treat many ailments, particularly inflammation and migraine. Neither the bioactive components responsible nor the mechanisms involved have been evaluated. Here are reported antioxidant activities of their methanol, dichloromethane, and ethyl acetate extracts. Samples were evaluated for oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, and inhibition of the formation of thiobarbituric acid reactive species (TBARS), a measure of lipid peroxidation. Antioxidant activities were strongly correlated with total polyphenol content. The most active extracts from P. gentianoides in scavenging DPPH radicals and inhibiting TBARS formation were the methanol extract (A) and a further ethyl acetate extract of this (E). Partition E was further divided into eight fractions, and both E and the fractions were compared for activity against butylated hydroxytoluene, quercetin, and tocopherol. Partition E and the most active fractions, 5 and 6, were found to have I(50) values of 14.1, 38.6, and 41.8 ppm, respectively, against DPPH and 18.5, 26.0, and 12.7 ppm, respectively, against TBARS formation. Consistent with this finding, partition E and fractions 4-6 had the greatest ORAC and FRAP values. These results show that these plants could be useful antioxidant sources.
authors: Chemical Ecology Lab.2-C, Instituto de Quimica, Ciudad Universitaria, Coyoacán 04510, Mexico D.F., Mexico.
authors: Mariana
authors: M
authors: Domínguez
authors: Antonio
authors: A
authors: Nieto
authors: Juan C
authors: JC
authors: Marin
authors: Anna-Sigrid
authors: AS
authors: Keck
authors: Elizabeth
authors: E
authors: Jeffery
authors: Carlos L
authors: CL
authors: Céspedes
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D001713:Biphenyl Compounds; D005290:Ferric Compounds / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D010943:Plantago / Q000737:chemistry*; D059808:Polyphenols; D017382:Reactive Oxygen Species / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005290:Ferric Compounds; D005419:Flavonoids; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D059808:Polyphenols; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; C004931:1,1-diphenyl-2-picrylhydrazyl