The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species
AUTOR(ES)
Gomes, A.J., Lunardi, C.N., Gonzalez, S., Tedesco, A.C.
FONTE
Brazilian Journal of Medical and Biological Research
DATA DE PUBLICAÇÃO
2001-11
RESUMO
Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (·OH, ·O2-, 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 ·O2-dependent reduction of nitroblue tetrazolium by up to 30 and 31%, respectively. In the detection of ¹O2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43% relative to azide and KA by 36%. 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.
Documentos Relacionados
- Polypodium leucotomos Extract Decreases UV-Induced Cox-2 Expression and Inflammation, Enhances DNA Repair, and Decreases Mutagenesis in Hairless Mice
- Production of aflatoxins and kojic acid by species of Aspergillus and Penicillium.
- Balancing the generation and elimination of reactive oxygen species
- Reactive oxygen species and sperm cells
- Antioxidant activity of natural compounds of Stachytarpheta cayennensis (Rich.) Vahl, Verbenaceae, by scavenger of mitochondrial reactive oxygen species