title: Phytic acid suppresses 1-methyl-4-phenylpyridinium ion-induced hydroxyl radical generation in rat striatum.
abstract: The present study examined the antioxidant effect of phytic acid on iron (II)-enhanced hydroxyl radical (*OH) generation induced by 1-methyl-4-phenylpyridinium ion (MPP(+)) in the extracellular fluid of rat striatum. Rats were anesthetized, and sodium salicylate in Ringer's solution (0.5 nmol/microl/min) was infused through a microdialysis probe to detect the generation of *OH as reflected by the non-enzymatic formation of 2,3-dihydroxybenzoic acid (DHBA) in the striatum. Phytic acid (100 microM) did not significantly decrease the levels of MPP(+)-induced *OH formation trapped as 2,3-DHBA. To confirm the generation of *OH by the Fenton-type reaction, iron (II) was infused through a microdialysis probe. Introduction of iron (II) (10 microM) enhanced MPP(+) induced *OH generation. However, phytic acid significantly suppressed iron (II)-enhanced *OH formation after MPP(+) treatment (n=6, P<0.05). These results suggest that the antiradical effect of phytic acid occurs by chelating iron required for the MPP(+)-enhanced *OH generation via the Fenton-type reaction.
authors.affiliation: Department of Pharmacology and Therapeutics, Oita Medical University, 1-1 Idaigaoka, Hasama, Oita 879-5593, Japan. tobata@oita-med.ac.jp
authors.forename: Toshio
authors.initials: T
authors.lastname: Obata
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000494:pharmacology*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004347:Drug Interactions; D005110:Extracellular Space; D006540:Herbicides / Q000494:pharmacology*; D062385:Hydroxybenzoates / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000494:pharmacology; D008297:Male; D017551:Microdialysis; D010833:Phytic Acid / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D006540:Herbicides; D062385:Hydroxybenzoates; D007502:Iron Chelating Agents; D017665:Hydroxyl Radical; D010833:Phytic Acid; D015655:1-Methyl-4-phenylpyridinium