Marchantinquinone, isolated from Reboulia hemisphaerica, as inhibitor of lipid peroxidation and as free radical scavenger.
The antioxidant effect of marchantinquinone was studied using various models. Marchantinquinone inhibited Fe(2+)-induced lipid peroxidation in rat brain homogenate in a concentration-dependent manner with an IC50 15.3 +/- 2.9 microM. Marchantinquinone was less effective than alpha-tocopherol and BHT in reducing the stable free radical diphenyl-2-picrylhydrazyl (DPPH). The IC0.200 were 37.5 +/- 2.5, 9.2 +/- 1.6 and 14.5 +/- 2.5 microM, respectively. Marchantinquinone also scavenged peroxyl radical derived from 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) in aqueous system with a stoichiometric factor of 0.9 +/- 0.1. Furthermore, it prevented conjugated-diene formation and apolipoprotein B (apo B) oxidation of LDL. However, marchantinquinone did not chelate Fe2+ or possess superoxide anion and hydroxyl radical scavenging activity. It also did not scavenge 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN)-derived peroxyl radical in hexane. These results indicate that marchantinquinone may be an effective antioxidant and can protect rat brain homogenate and LDL against oxidation.
Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.
F N
FN
Ko
C H
CH
Liao
C L
CL
Wu
D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification*; D001632:Bibenzyls / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D019068:Bryopsida / Q000737:chemistry*; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D003855:Deoxyribose / Q000378:metabolism; D004988:Ethers, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D016166:Free Radical Scavengers; D017665:Hydroxyl Radical / Q000378:metabolism; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D013481:Superoxides / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology
D000975:Antioxidants; D001632:Bibenzyls; D003574:Cytochrome c Group; D004988:Ethers, Cyclic; D016166:Free Radical Scavengers; D008077:Lipoproteins, LDL; D017392:Thiobarbituric Acid Reactive Substances; C097634:marchantinquinone; D013481:Superoxides; D014810:Vitamin E; D002084:Butylated Hydroxytoluene; D017665:Hydroxyl Radical; D003855:Deoxyribose