Antioxidant and pro-oxidant activities of p-hydroxybenzyl alcohol and vanillin: effects on free radicals, brain peroxidation and degradation of benzoate, deoxyribose, amino acids and DNA.
We examined the antioxidant and pro-oxidant activities of p-hydroxybenzyl alcohol (p-HBA), the major component of Gastrodia elata Bl. (GE), and compared them with those of vanillin, which is also a component of GE and a known antioxidant. Both p-HBA and vanillin are powerful scavengers of 1,1-diphenyl-2-picryl hydrozyl, superoxide and hydroxyl radicals. Like vanillin, p-HBA also inhibits iron-dependent lipid peroxidation in rat brain homogenate, microsomes and mitochondria. In addition, p-HBA and vanillin in a dose-dependent fashion inhibit Fe(II)-H2O2-induced damage to benzoate, deoxyribose, glutamic acid, 2-aminobutyric acid and methionine, as well as benzoate hydroxylation. Vanillin has a pro-oxidant effect on Fe(III)-superoxide-induced damage to benzoate, deoxyribose, amino acids and benzoate hydroxylation, whereas p-HBA shows no pro-oxidant activity in the system. Vanillin and p-HBA stimulate bleomycin-iron-dependent damage to DNA only at very high concentrations. These findings suggest that the antioxidant effect of GE extract in the rat brain may result from the antioxidant actions of p-HBA and other phenolic compounds such as vanillin at the cellular and molecular level in brain.
Liu
J
J
Department of Neuroscience, Okayama University Medical School, Japan.
Mori
A
A
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D001547:Benzaldehydes / Q000494:pharmacology*; D001565:Benzoates / Q000378:metabolism; D001592:Benzyl Alcohols / Q000494:pharmacology*; D001761:Bleomycin / Q000494:pharmacology; D001923:Brain Chemistry / Q000187:drug effects*; D004247:DNA / Q000378:metabolism; D003855:Deoxyribose / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D066298:In Vitro Techniques; D007501:Iron / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013481:Superoxides / Q000378:metabolism
D000596:Amino Acids; D000927:Anticonvulsants; D000975:Antioxidants; D001547:Benzaldehydes; D001565:Benzoates; D001592:Benzyl Alcohols; D005609:Free Radicals; D006993:Hypnotics and Sedatives; D016877:Oxidants; D001761:Bleomycin; D013481:Superoxides; C018966:4-hydroxybenzyl alcohol; D003855:Deoxyribose; D004247:DNA; C100058:vanillin; D007501:Iron