title: Protective effect of 3-methyl-1-phenyl-2-pyrazolin-5-one, a free radical scavenger, on acute toxicity of paraquat in mice.
abstract: Paraquat poisoning results in damages of multiple organs including liver, kidney and lung, and antioxidants have been proven to have protective effects. As a novel free radical scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), was introduced to clinical use recently, its protective effect was studied on acute toxicity of paraquat in male ddY mice. When paraquat (175 mg/kg) were given orally, the survival rate was only 8% on the 6th day of paraquat ingestion in Control Group mice. Protective effect of MCI-186 was most evident and the survival rate was 42% on the 6th day and 38% on the 14th day of paraquat ingestion, respectively, when mice were treated immediately. A delay of 30 min in treatment resulted in an abrupt reduction of the survival rate. These results suggested that MCI-186 used in acute phase of paraquat intoxication might serve as a clinically available antidote for attenuating paraquat toxicity.
authors.affiliation: First Department of Internal Medicine, Kochi Medical School, Nankoku 783-8505, Japan. saibarat@kochi-ms.ac.jp
authors.forename: Toshiji
authors.initials: T
authors.lastname: Saibara
authors.forename: Katsumi
authors.initials: K
authors.lastname: Toda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Wakatsuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ono
authors.forename: Saburo
authors.initials: S
authors.lastname: Onishi
mesh_terms: D000818:Animals; D000983:Antipyrine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000077553:Edaravone; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006540:Herbicides / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D008297:Male; D051379:Mice; D010269:Paraquat / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D016016:Proportional Hazards Models; D013534:Survival; D013997:Time Factors
chemical_list: D016166:Free Radical Scavengers; D006540:Herbicides; D010269:Paraquat; D000077553:Edaravone; D000983:Antipyrine