title: Inhibition of peroxynitrite-mediated reactions by vanillin.
abstract: Several neurodegenerative diseases such as Alzeimer's and Parkinson's as well as septic shock and inflammation involve formation of reactive oxygen and nitrogen species that include peroxynitrite (PON). PON can also react with endogenous antioxidants. Therefore, dietary supplementation with antioxidants may help in these diseases. An exogenous antioxidant, vanillin (4-hydroxy-3-methoxybenzaldehyde), used widely as a food flavoring agent, was evaluated for its ability to scavenge PON and inhibit PON-mediated reactions. Nitration of tyrosine by PON was assessed by high-performance liquid chromatography (HPLC). This reaction was inhibited by vanillin. The oxidation of dihydrorhodamine 123 to fluorescent rhodamine 123 was also inhibited by vanillin. The kinetics of reaction between PON and vanillin was studied by stopped-flow technique. The products of this reaction were analyzed by HPLC, and hydroxyvanillin was identified as one of the five products with absorption at 350 nm. These data demonstrate that vanillin effectively scavenges PON in cell-free systems.
authors.affiliation: Radiation Biology and Health Sciences Division, Bioscience Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
authors.forename: S Santosh
authors.initials: SS
authors.lastname: Kumar
authors.forename: K Indira
authors.initials: KI
authors.lastname: Priyadarsini
authors.forename: Krishna B
authors.initials: KB
authors.lastname: Sainis
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001547:Benzaldehydes / Q000737:chemistry / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements; D005421:Flavoring Agents; D016166:Free Radical Scavengers; D006900:Hydroxylation; D007700:Kinetics; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry; D013053:Spectrophotometry
chemical_list: D000975:Antioxidants; D001547:Benzaldehydes; D005421:Flavoring Agents; D016166:Free Radical Scavengers; D012235:Rhodamines; C058319:dihydrorhodamine 123; D030421:Peroxynitrous Acid; C100058:vanillin