Evaluation of protective effects of fish oil against oxidative damage in rats exposed to methylmercury.
The present study evaluates a possible protective effect of fish oil against oxidative damage promoted by methylmercury (MeHg) in sub-chronically exposed rats. Reduced glutathione peroxidase and catalase enzyme activity and reduced glutathione levels were observed in MeHg-exposed animals compared to controls. Methylmercury exposure was also associated with DNA damage. Administration of fish oil to the methylmercury-exposed animals did not ameliorate enzyme activity or glutathione levels. On the other hand, a significant DNA protective effect (about 30%) was observed with fish oil treatment. There were no differences in the total mercury concentration in rat liver, kidney, heart or brain after MeHg administration with or without fish oil co-administration. Histopathological analyses showed a significant leukocyte infiltration in rat tissues after MeHg exposure, but this effect was significantly reduced after co-administration of fish oil. Taken together, our findings demonstrate oxidative damage even after low-level MeHg exposure and the protective effect of fish oil. This protection seems not to be related to antioxidant defenses or mercury re-distribution in rat tissues. It is probably due to the anti-inflammatory effects of fish oil.
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas. Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, CEP.: 14040-903, Ribeirão Preto, São Paulo, Brazil.
Denise
D
Grotto
Juliana
J
Vicentini
José Pedro Friedmann
JP
Angeli
Elder Francisco
EF
Latorraca
Patrícia Alves Pontes
PA
Monteiro
Gustavo Rafael Mazzaron
GR
Barcelos
Sabrina
S
Somacal
Tatiana
T
Emanuelli
Fernando
F
Barbosa
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002374:Catalase / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D005395:Fish Oils / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008628:Mercury / Q000378:metabolism / Q000633:toxicity; D008767:Methylmercury Compounds / Q000633:toxicity*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D000975:Antioxidants; D005395:Fish Oils; D008767:Methylmercury Compounds; D002374:Catalase; D005979:Glutathione Peroxidase; D008628:Mercury