title: Protective effects of Polygala paniculata extract against methylmercury-induced neurotoxicity in mice.
abstract: We have examined the possible protective effects of Polygala paniculata extract against methylmercury (MeHg)-induced neurotoxicity in adult mice. MeHg was diluted in drinking water (40 mg L(-1), freely available) and the hydroalcoholic Polygala extract was diluted in a 150 mM NaCl solution and administered by gavage (100 mg kg(-1) b.w., twice a day). After a two-week treatment, MeHg exposure significantly inhibited glutathione peroxidase and increased glutathione reductase activity, while the levels of thiobarbituric acid reactive substances were increased in the cerebral cortex and cerebellum. These alterations were prevented by administration of Polygala extract, except for glutathione reductase activity, which remained elevated in the cerebral cortex. Behavioural interference in the MeHg-exposed animals was evident through a marked deficit in the motor performance in the rotarod task, which was completely recovered to control levels by Polygala extract co-administration. This study has shown, for the first time, the in-vivo protective effects of Polygala extract against MeHg-induced neurotoxicity. In addition, our findings encourage studies concerning the beneficial effects of P. paniculata on neurological conditions related to excitotoxicity and oxidative stress.
authors.affiliation: Departamento de Bioquímica, Centro de Cieências Biológicas, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil. marcelofarina@zipmail.com.br
authors.forename: Marcelo
authors.initials: M
authors.lastname: Farina
authors.forename: Jeferson Luis
authors.initials: JL
authors.lastname: Franco
authors.forename: Camila Mafalda
authors.initials: CM
authors.lastname: Ribas
authors.forename: Flávia Carla
authors.initials: FC
authors.lastname: Meotti
authors.forename: Fabiana Cristina
authors.initials: FC
authors.lastname: Missau
authors.forename: Moacir G
authors.initials: MG
authors.lastname: Pizzolatti
authors.forename: Alcir Luiz
authors.initials: AL
authors.lastname: Dafre
authors.forename: Adair R S
authors.initials: AR
authors.lastname: Santos
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D008297:Male; D020262:Mercury Poisoning, Nervous System / Q000209:etiology / Q000517:prevention & control*; D008767:Methylmercury Compounds; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D018696:Neuroprotective Agents / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D031801:Polygala / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances
chemical_list: D000975:Antioxidants; D008767:Methylmercury Compounds; D018696:Neuroprotective Agents; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase