The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species
Braz. j. med. biol. res
; 34(11): 1487-1494, Nov. 2001. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-303316
Biblioteca responsável:
BR1.1
ABSTRACT
Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (ÀOH, ÀO2-, H2O2, ¹O2) in phosphate buffer. Hydroxyl radicals were generated by the Fenton reaction, and the rate constants of scavenging were 1.6 x 10(9) M-1 s-1 for KA and 1.0 x 10(9) M-1 s-1 for PL, similar to that of ethanol (1.4 x 10(9) M-1 s-1). With superoxide anions generated by the xanthine/hypoxanthine system, KA and PL (0.2-1.0 mg/ml) inhibited ÀO2-dependent reduction of nitroblue tetrazolium by up to 30 and 31 percent, respectively. In the detection of ¹O2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43 percent relative to azide and KA by 36 percent. The present study demonstrates that PL showed an antioxidant effect, scavenging three of four reactive oxygen species tested here. Unlike KA, PL did not significantly scavenge hydrogen peroxide
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Pironas
/
Sequestradores de Radicais Livres
/
Espécies Reativas de Oxigênio
/
Antioxidantes
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2001
Tipo de documento:
Artigo
País de afiliação:
Brasil
/
Estados Unidos
Instituição/País de afiliação:
Harvard Medical School/US
/
Universidade de Säo Paulo/BR