Free radical scavenging reactions and antioxidant activity of embelin: biochemical and pulse radiolytic studies.
Embelin (from Embelia ribes) is a component of herbal drugs and possess wide range of medicinal properties. These properties may be, in part, due to scavenging of oxidizing free radicals. In this context, free radical scavenging reactions and antioxidant activity of embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone) have been studied. It has been found to scavenge DPPH radical and inhibit hydroxyl radical induced deoxyribose degradation. It has been also found to inhibit lipid peroxidation and restore impaired Mn-superoxide dismutase in rat liver mitochondria. Further, kinetics and mechanism of the reactions of embelin with hydroxyl, one-electron oxidizing, organo-haloperoxyl and thiyl radicals have been studied using nanosecond pulse radiolysis technique. Its redox potential has been also evaluated with cyclic voltammetry. These studies suggest that embelin can act as a competitive antioxidant in physiological conditions.
Joshi
Ravi
R
Radiation and Photochemistry Division, Chemistry Group, Bhabha Atomic Research Center, Mumbai 400085, India. rjudrin@yahoo.com
Kamat
J P
JP
Mukherjee
Tulsi
T
D000578:Amidines / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D016227:Benzoquinones / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D004347:Drug Interactions; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006834:Hydrazines / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D010084:Oxidation-Reduction; D010851:Picrates; D011199:Potentiometry; D011675:Pulse Radiolysis; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000578:Amidines; D000975:Antioxidants; D016227:Benzoquinones; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006834:Hydrazines; D010851:Picrates; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D017665:Hydroxyl Radical; C046728:2,2'-azobis(2-amidinopropane); C004931:1,1-diphenyl-2-picrylhydrazyl; D013482:Superoxide Dismutase; C010945:embelin