title: Extensive screening for edible herbal extracts with potent scavenging activity against superoxide anions.
abstract: To search for edible herbal extracts with potent antioxidant activity, we conducted a large scale screening based on the superoxide scavenging activity. That is, scavenging activity against superoxide anions were extensively screened from ethanol extracts of approximately 1,000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method. Among them we chose four edible herbal extracts with prominently potent ability to reduce the signal intensity of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OOH, a spin adduct formed by DMPO and superoxide anion. They are the extracts from Punica granatum (Peel), Syzygium aromaticum (Bud), Mangifera indica (Kernel), and Phyllanthus emblica (Fruit), and are allowed to be used as foodstuffs according to the Japanese legal regulation. The ESR-spin trapping method coupled with steady state kinetic analysis showed that all of the four extracts directly scavenge superoxide anions, and that the superoxide scavenging potential of any of the extracts was comparable to that of L-ascorbic acid. Furthermore, polyphenol determination indicates that the activity is at least in part attributable to polyphenols. These results with such large scale screening might give useful information when choosing a potent antioxidant as a foodstuff.
authors.affiliation: New Industry Creation Hatchery Center, Tohoku University, Aramaki, Sendai, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Saito
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kohno
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yoshizaki
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Niwano
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005419:Flavonoids / Q000378:metabolism; D016166:Free Radical Scavengers; D006801:Humans; D017665:Hydroxyl Radical; D010636:Phenols / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D059808:Polyphenols; D013113:Spin Labels; D013482:Superoxide Dismutase; D013481:Superoxides / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D013113:Spin Labels; D013481:Superoxides; D017665:Hydroxyl Radical; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D013482:Superoxide Dismutase