title: Antioxidant activity of Hypericum androsaemum infusion: scavenging activity against superoxide radical, hydroxyl radical and hypochlorous acid.
abstract: Hypericum androsaemum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Since polyphenolic compounds have high antioxidant potential, the ability of H. androsaemum infusion to act as a scavenger of reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid) was investigated. Superoxide radical was generated by the xanthine/xanthine oxidase and phenazine methosulphate/NADH systems. The infusion-mediated prevention of nitroblue tetrazolium reduction by the superoxide radical was used as the measured endpoint. Hydroxyl radical was generated by the Fe3+-EDTA/ascorbate Fenton system, and assayed by evaluating deoxyribose degradation using the thiobarbituric acid method. Hypochlorous acid scavenging activity was tested by measuring the inhibition of hypochlorous acid-induced 5-thio-2-nitrobenzoic acid oxidation to 5,5'-dithiobis(2-nitrobenzoic acid). The tested infusion mainly exhibited a potent scavenging effect on superoxide radicals (although a noncompetitive inhibitory effect on xanthine oxidase was also observed). The infusion also acted as a moderate scavenger of hydroxyl radicals and hypochlorous acid. A phytochemical study of the infusion was also undertaken, and nine phenolic compounds were identified.
authors.affiliation: CEQUP/Laboratory of Pharmacognosy, Faculty of Pharmacy, Porto University, Portugal.
authors.forename: Patricia
authors.initials: P
authors.lastname: Valentão
authors.forename: Eduarda
authors.initials: E
authors.lastname: Fernandes
authors.forename: Félix
authors.initials: F
authors.lastname: Carvalho
authors.forename: Paula Branquinho
authors.initials: PB
authors.lastname: Andrade
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Seabra
authors.forename: Maria
authors.initials: M
authors.lastname: de Lourdes Bastos
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000378:metabolism*; D020902:Hypericum; D006997:Hypochlorous Acid / Q000378:metabolism*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves; D013481:Superoxides / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D013481:Superoxides; D017665:Hydroxyl Radical; D006997:Hypochlorous Acid