Efeito do fipronil na fertilidade em ratos: efeitos oxidantes e proteção pela vitamina E
Carregando...
Arquivos
Data
2017-02-21
Autores
Mazzo, Meiriele [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Fipronil é um inseticida de amplo-espectro de ação, utilizado para o controle de pragas nas lavouras e de ectoparasitas na medicina veterinária. O objetivo do trabalho foi avaliar os efeitos tóxicos do fipronil sobre a fertilidade de ratos machos por meio da avaliação da produção de espermatozoides e de danos oxidativos causados no homogenato de testículos, além de avaliar a ação protetora da vitamina E. Ratos Wistar machos pesando aproximadamente 200 g foram divididos em três grupos (n = 6): controle: DMSO (60%) mais salina (40%) por via intraperitoneal (i.p.); fipronil 5: fipronil dissolvido em DMSO (60%) mais salina (40%) (5 mg/kg de peso corporal i.p.); fipronil 5 + vitamina E: fipronil dissolvido em DMSO (60%) mais salina (40%) (5 mg/kg de peso corporal i.p.) e vitamina E (100 mg/kg de peso vivo via oral).Durante 14 dias os animais foram pesados e cada grupo recebeu seu respectivo tratamento conforme citado, sendo que no 15º dia os animais foram eutanasiados e os testículos e epidídimos foram isolados para realização das seguintes análises: concentração de espermatozoides nos epidídimos, atividade das enzimas glutationa peroxidase (GPx) e catalase (CAT), determinação das concentrações de glutationa reduzida (GSH), grupos tióis de proteínas e malondialdeído (MDA) no homogenato dos testículos. Os dados foram analisados por ANOVA seguido pelo teste de Tukey. O fipronil reduziu significantemente a produção de espermatozoides (P < 0,01) e a vitamina E apresentou efeito protetor sobre esse parâmetro. A atividade da enzima GPx aumentou e a da CAT foi significantemente reduzida pelo fipronil (P < 0,001 e P < 0,05, respectivamente) e a vitamina E reestabeleceu as atividades das enzimas para níveis similares aos do grupo controle. Observou-se uma redução significante na concentração de GSH nos testículos dos ratos tratados com fipronil (P < 0,001) em relação ao grupo controle e a vitamina E apresentou uma proteção parcial deste efeito. Não houve alteração na concentração de grupos tióis de proteínas. Houve um aumento significante na concentração de MDA (P < 0,05), indicador de lipoperoxidação, nos animais tratados com fipronil e esse efeito foi diminuído pela vitamina E. Conclui-se que o fipronil afetou a produção de espermatozoides em ratos por apresentar atividade oxidante e que este efeito foi revertido pela vitamina E.
Fipronil is an insecticide with a broad-spectrum of action, used largely in both agricultural crops and veterinary medicine to control pests and ectoparasites. The objective of this study was to evaluate the toxic effects of fipronil on the fertility of male rats by evaluating sperm production and oxidative damage caused in the testis homogenate, as well as the protective action of vitamin E. Male Wistar rats weighing approximately 200 g were divided into three groups (n = 6): control: corn oil orally and DMSO (60%) plus saline (40%) intraperitoneally (i.p.); fipronil 5: fipronil dissolved in DMSO (60%) plus saline (40%) (5 mg/kg body weight i.p.); fipronil 5 + vitamin E: fipronil dissolved in DMSO (60%) plus saline (40%) (5 mg/kg body weight i.p.) and vitamin E dissolved in corn oil (100 mg/kg body weight orally). During 14 days the animals were weighed and each group received its respective treatment as mentioned, and on the 15th day the animals were euthanized and the testicles and epididymis were isolated for the following analysis: sperm concentration in the epididymis, activity of the glutathione peroxidase (GPx) and catalase (CAT) enzymes, concentrations of reduced glutathione (GSH), protein thiol groups and malondialdehyde (MDA) in the homogenate of testicles. Data were analyzed by ANOVA followed by the Tukey test. Fipronil significantly reduced sperm production (P < 0.01) and vitamin E had a protective effect on this parameter. The activity of the GPx enzyme increased and that of CAT was significantly reduced by fipronil (P < 0.001 and P < 0.05, respectively) but the vitamin E reestablished the enzyme activities to levels similar to those of the control group. A significant reduction in GSH concentration was observed in the testis of rats treated with fipronil (P < 0.001) compared to the control group and vitamin E showed partial protection against this effect. There was no change in the concentration of thiol groups of proteins. There was a significant increase in the concentration of MDA (P < 0.05), indicative of lipoperoxidation, in the animals treated with fipronil and this effect was reduced by vitamin E. It was concluded that fipronil declined the sperm production of the rats because its oxidant activity and that this effect was reversed by vitamin E.
Fipronil is an insecticide with a broad-spectrum of action, used largely in both agricultural crops and veterinary medicine to control pests and ectoparasites. The objective of this study was to evaluate the toxic effects of fipronil on the fertility of male rats by evaluating sperm production and oxidative damage caused in the testis homogenate, as well as the protective action of vitamin E. Male Wistar rats weighing approximately 200 g were divided into three groups (n = 6): control: corn oil orally and DMSO (60%) plus saline (40%) intraperitoneally (i.p.); fipronil 5: fipronil dissolved in DMSO (60%) plus saline (40%) (5 mg/kg body weight i.p.); fipronil 5 + vitamin E: fipronil dissolved in DMSO (60%) plus saline (40%) (5 mg/kg body weight i.p.) and vitamin E dissolved in corn oil (100 mg/kg body weight orally). During 14 days the animals were weighed and each group received its respective treatment as mentioned, and on the 15th day the animals were euthanized and the testicles and epididymis were isolated for the following analysis: sperm concentration in the epididymis, activity of the glutathione peroxidase (GPx) and catalase (CAT) enzymes, concentrations of reduced glutathione (GSH), protein thiol groups and malondialdehyde (MDA) in the homogenate of testicles. Data were analyzed by ANOVA followed by the Tukey test. Fipronil significantly reduced sperm production (P < 0.01) and vitamin E had a protective effect on this parameter. The activity of the GPx enzyme increased and that of CAT was significantly reduced by fipronil (P < 0.001 and P < 0.05, respectively) but the vitamin E reestablished the enzyme activities to levels similar to those of the control group. A significant reduction in GSH concentration was observed in the testis of rats treated with fipronil (P < 0.001) compared to the control group and vitamin E showed partial protection against this effect. There was no change in the concentration of thiol groups of proteins. There was a significant increase in the concentration of MDA (P < 0.05), indicative of lipoperoxidation, in the animals treated with fipronil and this effect was reduced by vitamin E. It was concluded that fipronil declined the sperm production of the rats because its oxidant activity and that this effect was reversed by vitamin E.
Descrição
Palavras-chave
Enzimas antioxidantes, Estresse oxidativo, Espermatozoide, Inseticidas, Testículo