Antioxidant activity of Hypericum androsaemum infusion: scavenging activity against superoxide radical, hydroxyl radical and hypochlorous acid.
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.
Valentão
Patricia
P
CEQUP/Laboratory of Pharmacognosy, Faculty of Pharmacy, Porto University, Portugal.
Fernandes
Eduarda
E
Carvalho
Félix
F
Andrade
Paula Branquinho
PB
Seabra
Rosa Maria
RM
de Lourdes Bastos
Maria
M
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*
D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D013481:Superoxides; D017665:Hydroxyl Radical; D006997:Hypochlorous Acid