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
Article
in English
| LILACS
| ID: lil-303316
Responsible library:
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
Full text:
Available
Collection:
International databases
Database:
LILACS
Main subject:
Pyrones
/
Free Radical Scavengers
/
Reactive Oxygen Species
/
Antioxidants
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2001
Document type:
Article
Affiliation country:
Brazil
/
United States
Institution/Affiliation country:
Harvard Medical School/US
/
Universidade de Säo Paulo/BR