RESUMO
In recent decades, glyphosate and glyphosate-based herbicides (GBH) have been extensively used in agriculture all over the world. Initially, they were considered safe, but rising evidence suggests that these molecules reach the central nervous system producing metabolic, functional, and permanent alterations that impact cognition and behavior. This theoretical and non-systematic review involved searching, integrating, and analyzing preclinical evidence regarding the effects of acute, sub-chronic, and chronic exposure to glyphosate and GBH on cognition, behavior, neural activity, and development in adult and juvenile rodents following perinatal exposition. In addition, this review gathers the mechanisms underlying the neurotoxicity of glyphosate mediating cognitive and behavioral alterations. Furthermore, clinical evidence of the effects of exposition to GBH on human health and its possible link with several neurological disorders was revised.
Assuntos
Herbicidas , Síndromes Neurotóxicas , Adulto , Humanos , Feminino , Gravidez , Glifosato , Cognição , Síndromes Neurotóxicas/etiologia , Herbicidas/toxicidade , AgriculturaRESUMO
The significant increase in glyphosate-based herbicide (GBH) use raises concerns about residues in the environment and food, potentially jeopardizing human health. The involvement of GBHs in the increased incidence of thyroid disorders is speculated, since glyphosate has been linked to an increased risk of thyroid disease in farmers. In this sense, this study aims to investigate the potential effects of low levels of GBH exposure (0, 0.5 or 5 mg/kg) from weaning (postnatal day PND23) to adult life (PND60 and PND90) in male Wistar rats on hypothalamic-pituitary-thyroid (HPT) axis function. The serum levels of T4 were increased. The hypothalamus showed reduced expression of Dio2, Thra1, and Thra2. The pituitary showed reduced expression of Mct8 and Dio2 and increased expression of Thra1. The thyroid showed increased expression of Tshr and Thra1. The heart showed increased expression of Mct8 and Myh6. The liver showed reduced expression of Mct8 and Thra2 and increased expression of Thra1. In thyroid morphometry, a decrease in both follicular diameter and area and decreased follicular and colloid diameters and areas were observed. These results suggested that GBH may affect several steps of HPT axis regulation at the transcriptional level in an age-dependent manner and alter the morphometric parameters of the thyroid gland and TH synthesis, with potential repercussions in the TH-target organs.
Assuntos
Herbicidas , Glândula Tireoide , Ratos , Humanos , Animais , Masculino , Herbicidas/metabolismo , Ratos Wistar , Hipófise , GlifosatoRESUMO
The aim of the present study was to evaluate whether early postnatal exposure to a glyphosate-based herbicide (GBH) alters pre-pubertal mammary development in Friesian lambs. To this end, from postnatal day 1-14, ewe lambs were exposed subcutaneously or orally to GBH (2 mg/kg bw/day) or vehicle (control) and mammary gland biopsies were obtained at 45 days of age. GBH-exposed lambs exhibited larger mammary ducts and less area occupied by terminal duct lobular units than controls, accompanied by an increase in the area of adipocytes in the mammary stroma. Lambs subcutaneously exposed to GBH showed increased protein expression of estrogen receptor alpha; however, both GBH-exposed groups had decreased mRNA expression of this receptor. Control lambs showed nuclear progesterone receptor (PR) protein expression, whereas GBH-exposed animals showed cytoplasmic PR expression; both GBH-exposed groups exhibited decreased mRNA expression of PR. GBH-exposed lambs also had decreased epithelial cell proliferation. Regarding insulin-like growth factors, both groups showed similar IGF-1 mRNA and protein expression but decreased expression of its receptor, and increased IGFBP5 expression. In addition, phosphorylated AKT was only observed in the mammary gland of control lambs. Our results show that early postnatal exposure to GBH, regardless of the exposure route, affects the IGF-1 system and the AKT/protein kinase B pathway, interfering with steroid hormone receptor expression and cell proliferation. This consequently modifies the growth and development of the pre-pubertal mammary gland of Frisian lambs.
Assuntos
Herbicidas , Fator de Crescimento Insulin-Like I , Animais , Feminino , Ratos , Proliferação de Células , Herbicidas/toxicidade , Fator de Crescimento Insulin-Like I/genética , Progesterona , Proteínas Proto-Oncogênicas c-akt , Ratos Wistar , Receptores de Progesterona , RNA Mensageiro , Ovinos , Glândulas Mamárias Animais/metabolismo , GlifosatoRESUMO
Agrochemicals became a public health concern due to increased human exposure and possible endocrine disruption effects in several organs, including the brain. Thyroid hormones controls neurodevelopment, which turn them sensitive to endocrine disruptors (EDs). In this work, we evaluated the effect of glyphosate-based herbicides (GBH) as an intergenerational endocrine disrupter on thyroid homeostasis in cerebellar cells. Female pregnant Wistar rats were exposed to Roundup Transorb® solution at 5 and 50 mg/kg/day, from gestation day 18 to post-natal day 5 (P5). Cerebellum of male offspring was used to evaluate gene expression. The mRNA levels of thyroid hormone receptors, hormonal conversion enzymes, hormone transporters, as well as, de novo epigenetic regulators were altered, with some of these genes presenting a non-monotonic dose response. Furthermore, metabolomic profile correlation with tested dose demonstrated altered metabolic profile, in agreement with cerebellar gene alterations. Moreover, cerebellar primary cultures exposed to non-toxic GBH concentration presented a decrease level in glial fibrillary acidic protein, a protein regulated by endocrine signals. In conclusion, our results indicate that animals exposed to non-toxic GBH doses during perinatal phase carry intergenerational alterations in key regulators of cellular thyroid hormone homeostasis and epigenetic controllers in adulthood, indicating the possible ED effect of GBH based on epigenetic alterations.
Assuntos
Herbicidas , Animais , Cerebelo , Feminino , Glicina/análogos & derivados , Herbicidas/toxicidade , Homeostase , Masculino , Ratos , Ratos Wistar , Glândula Tireoide , Hormônios Tireóideos , GlifosatoRESUMO
Gills represent one of the major sites of gas exchange of fish, consequently they are in continuous close contact with the aquatic environment and its pollutants. In the present study the effects on gills of pejerrey fish, Odontesthes bonariensis, under glyphosate-based herbicide subchronic exposure were analyzed. Adult animals were exposed to sublethal concentrations of a glyphosate-based commercial formulation (1 and 10 PMG mg L-1, PMG: glyphosate active ingredient) for 15 days, while control group was maintained in rearing water. Ultrastructural changes in gills were observed by scanning electron microscopy (SEM). The composition of the surface epithelium and specific surface area were determined by energy dispersive spectroscopy (EDS) and N2 (g) adsorption-desorption isotherms, respectively. The herbicide exposure induced severe alterations in gill ultrastructure, as shown in the SEM micrographs. Accordingly, an increase in surface area of the gills of exposed animals was determined. These results support that gills parameters of freshwater fish are sensitive morphological biomarkers for glyphosate exposure.
Assuntos
Peixes/fisiologia , Herbicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Água Doce , Brânquias/efeitos dos fármacos , Glicina/análogos & derivados , Testes de Toxicidade Subcrônica , GlifosatoRESUMO
We previously reported that exposure during gestation and lactation to a low dose of glyphosate-based herbicide (GBH) reduced the area and perimeter of male offspring mammary gland at postnatal day 60 (PND60), whereas a higher dose increased the longitudinal growth of the gland. Here, our aim was to assess whether perinatal exposure to GBH exhibits endocrine disruptive action in male mammary gland at an early time point (pre-puberty), which could be related to the changes observed after puberty. We also wanted to explore whether an early evaluation of the male rat mammary gland is appropriate to assess exposure to potential endocrine disrupting chemicals (EDCs). Pregnant rats were orally exposed, through the diet, to vehicle (saline solution), 3.5 or 350 mg/kg/day of GBH from gestational day 9 until weaning. At PND21, the male offspring were euthanized, and mammary gland samples were collected. The histology and proliferation index of the mammary glands were evaluated, and the mRNA expression of estrogen (ESR1) and androgen (AR) receptors, cyclin D1 (Ccnd1), amphiregulin (Areg), insulin-like growth factor 1 (IGF1), epidermal growth factor receptor (EGFR) and IGF1 receptor (IGF1R) were assessed. Moreover, the phosphorylated-Erk1/2 (p-ERK1/2) protein expression was determined. No differences were observed in mammary epithelial structures and AR expression between experimental groups; however, the proliferation index was reduced in GBH3.5-exposed males. This result was associated with decreased ESR1, Ccnd1, Areg, IGF1, EGFR and IGF1R mRNA expressions, as well as reduced p-Erk1/2 protein expression in these animals. ESR1, Ccnd1, IGF1R and EGFR expressions were also reduced in GBH350-exposed males. In conclusion, the mammary gland development of pre-pubertal male rats is affected by perinatal exposure to GBH. Although further studies are still needed to understand the molecular mechanisms involved in GBH350 exposure, the present results may explain the alterations observed in mammary gland growth of post-pubertal males exposed to low doses of GBH. Our results also suggest that early evaluation of the male rat mammary gland is useful in assessing exposure to potential EDCs. However, analysis of EDCs effects at later time points should not be excluded.
Assuntos
Disruptores Endócrinos/toxicidade , Glicina/análogos & derivados , Herbicidas/toxicidade , Glândulas Mamárias Animais/crescimento & desenvolvimento , Actinas/metabolismo , Animais , Feminino , Glicina/toxicidade , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Glândulas Mamárias Animais/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos Wistar , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/genética , Receptores de Fatores de Crescimento/biossíntese , Receptores de Esteroides/biossíntese , GlifosatoRESUMO
Several investigators demonstrated that glyphosate formulations produce neurotoxicity associated with oxidative stress, alterations in glutamatergic system, inhibition of acetylcholinesterase activity and mitochondrial dysfunction. However, the underlying molecular mechanisms following exposure to this herbicide on astrocytes are unclear. Thus, the aim of the present study was to determine the activity of enzymes related to energy metabolism, in addition to oxidative stress parameters, mitochondrial mass, nuclear area, and autophagy in astrocytes treated with a glyphosate-based herbicide. Our results showed that 24 h exposure to a glyphosate-based herbicide decreased (1) cell viability, (2) activities of mitochondrial respiratory chain enzymes and creatine kinase (CK), (3) mitochondrial mass, and (4) nuclear area in rat astroglioma cell line (C6 cells). However, non-protein thiol (NPSH) levels were increased but catalase activity was not changed in cells exposed to the herbicide at non-cytotoxic concentrations. Low glyphosate concentrations elevated content of cells positive to autophagy-related proteins. Nuclear factor erythroid 2-related factor (Nrf2), NAD(P)H dehydrogenase [quinone] 1 (NQO1) and PTEN-induced kinase 1 (PINK1) labeling were not markedly altered in cells exposed to glyphosate at the same concentrations that an increase in NPSH levels and positive cells to autophagy were found. It is conceivable that mitochondria and CK may be glyphosate-based herbicides targets. Further, autophagy induction and NPSH increase may be mechanisms initiated to avoid oxidative stress and cell death. However, more studies are needed to clarify the role of autophagy in astrocytes exposed to the herbicide and which components of the formulation might be triggering the effects observed here.
Assuntos
Autofagia/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular , Glicina/toxicidade , Humanos , Espécies Reativas de Oxigênio , GlifosatoRESUMO
Glyphosate (GLY)-dicamba (DIC) and GLY-flurochloridone (FLC) are herbicide mixtures which are widely used for treating fallow containing glyphosate resistant weeds. The aim of this study was to evaluate the acute toxic effects and the prevailing interactions on stage 36 tadpoles of the anuran species Rhinella arenarum when exposed to equitoxic and non-equitoxic combinations of these herbicide combinations. Experiments were realized using the following combinations of commercial formulations: 48% GLY-based Credit® + 57.71% DIC-based Banvel® and 48% GLY-based Credit® + 25% FLC-based Twin Pack Gold®. GLY-DIC and GLY-FLC equitoxic mixtures were assayed mixing each constituent with an equivalent individual toxicity able to induce the same lethality effect. After 96 h of exposure, GLY-DIC and GLY-FLC equitoxic mixtures presented toxic unit 50 values (TU50 96h) of 1.74 (confidence interval: 1.58-1.92) and 1.54 (confidence interval: 1.46-1.62) respectively, indicating the presence of a weak antagonistic interaction as TU values were greater than 1. For their part, most non-equitoxic combinations of GLY-DIC and GLY-FLC tested did not significantly differ from additivity, the only exception being when DIC and FLC were fixed at 0.33 TUs, where a weak antagonism was observed. Overall, results indicate that the toxicity of both GLY-DIC and GLY-FLC mixtures to R. arenarum tadpoles vary from additive to slightly antagonistic, depending on the proportion of constituting herbicide formulations present in the mixture.
Assuntos
Bufonidae , Dicamba/toxicidade , Glicina/análogos & derivados , Herbicidas/toxicidade , Larva/efeitos dos fármacos , Animais , Anuros , Misturas Complexas/toxicidade , Antagonismo de Drogas , Glicina/toxicidade , Pirrolidinonas/toxicidade , GlifosatoRESUMO
Postnatal treatment with glyphosate-based herbicides (GBHs) induces endocrine-disrupting effects on the male rat mammary gland. In this study, the effects of developmental exposure to GBH on mammary gland growth and development, and the possible molecular mechanisms involved, were evaluated in pre- and post-pubertal male rats. To this end, pregnant rats were orally exposed through the food to 0, 3.5 or 350â¯mg GBH/kg bw/day from gestational day 9 until weaning. Mammary gland development and estradiol (E2) and testosterone (T) serum levels of male offspring were evaluated on postnatal day (PND)21 and PND60. Besides, prolactin (PRL) serum levels, proliferation index, androgen (AR) and estrogen receptor alpha (ESR1) expression, ESR1 alternative transcript mRNA levels, and DNA methylation status of ESR1 promoters were assessed on PND60. No differences between groups were observed in mammary gland development at PND21 or in E2 and T levels on both PNDs studied. On PND60, GBH3.5-exposed animals presented similar mammary gland histology but higher AR protein expression than controls, whereas GBH350-exposed males presented a less developed mammary gland, accompanied by a lower proliferation index, similar AR levels, and slightly increased PRL serum levels than controls. In both exposed groups, ESR1 expression was lower than in control rats, being lower in GBH350-exposed rats. GBH also altered the abundance of ESR1 transcript variants by hypermethylation of ESR1 promoters. GHB3.5 decreased only ESR1-OS expression, whereas GBH350 affected ESR1-O, OT and E1 expression. Our results show that developmental exposure to GBH induces epigenetic changes in ESR1, which could be responsible for the altered male mammary gland development observed in GBH350-exposed animals.
Assuntos
Metilação de DNA/efeitos dos fármacos , Receptor alfa de Estrogênio/genética , Glicina/análogos & derivados , Glândulas Mamárias Animais/crescimento & desenvolvimento , Efeitos Tardios da Exposição Pré-Natal/genética , Administração Oral , Animais , Relação Dose-Resposta a Droga , Estradiol/sangue , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Glicina/administração & dosagem , Glicina/efeitos adversos , Masculino , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/sangue , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Prolactina/sangue , Regiões Promotoras Genéticas/efeitos dos fármacos , Ratos Wistar , Testosterona/sangue , GlifosatoRESUMO
Previously, we have shown that perinatal exposure to a glyphosate-based herbicide (GBH) induces implantation failures in rats. Estrogen receptor alpha (ERα) is critical for successful implantation. ERα transcription is under the control of five promoters (E1, OT, O, ON, and OS), which yield different transcripts. Here, we studied whether perinatal exposure to a GBH alters uterine ERα gene expression and prompts epigenetic modifications in its regulatory regions during the preimplantation period. Pregnant rats (F0) were orally treated with 350â¯mg glyphosate/kg bw/day through food from gestational day (GD) 9 until weaning. F1 females were bred, and uterine samples were collected on GD5 (preimplantation period). ERα mRNA levels and its transcript variants were evaluated by RT-qPCR. Enzyme-specific restriction sites and predicted transcription factors were searched in silico in the ERα promoter regions to assess the methylation status using the methylation-sensitive restriction enzymes-PCR technique. Post-translational modifications of histones were studied by the chromatin immunoprecipitation assay. GBH upregulated the expression of total ERα mRNA by increasing the abundance of the ERα-O transcript variant. In addition, different epigenetic changes were detected in the O promoter. A decrease in DNA methylation was observed in one of the three sites evaluated in the O promoter. Moreover, histone H4 acetylation and histone H3 lysine 9 trimethylation (H3K9me3) were enriched in the O promoter in GBH-exposed rats, whereas H3K27me3 was decreased. All these alterations could account for the increase in ERα gene expression. Our findings show that perinatal exposure to a GBH causes long-term epigenetic disruption of the uterine ERα gene, which could be associated with the GBH-induced implantation failures.
Assuntos
Implantação do Embrião/genética , Epigênese Genética , Receptor alfa de Estrogênio/genética , Glicina/análogos & derivados , Herbicidas/toxicidade , Útero/metabolismo , Animais , Sítios de Ligação , Simulação por Computador , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Implantação do Embrião/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Genoma , Glicina/toxicidade , Histonas/metabolismo , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos , Útero/efeitos dos fármacos , GlifosatoRESUMO
Glyphosate-based herbicides (GBHs) are the most globally used herbicides raising the risk of environmental exposition. Here, we investigated whether perinatal exposure to low doses of a GBH alters the female reproductive performance, and/or induced second-generation effects related to congenital anomalies or growth alterations. Pregnant rats (F0) received a GBH through food, in a dose of 2 mg (GBH-LD: GBH-low dose group) or 200 mg (GBH-HD: GBH-high dose group) of glyphosate/kg bw/day from gestational day (GD) 9 until weaning. Body weight gain and vaginal canal-opening of F1 females were recorded. Sexually mature F1 females were mated to evaluate their reproductive performance by assessing the pregnancy rate, and on GD19, the number of corpora lutea, the implantation sites (IS) and resorption sites. To analyze second-generation effects on F2 offspring, we analyzed the fetal morphology on GD19, and assessed the fetal length and weight, and the placental weight. GBH exposure neither altered the body weight gain of F1 females, nor vaginal opening onset. Although all GBH-exposed F1 rats became pregnant, a lower number of IS was detected. F2 offspring from both GBH groups showed delayed growth, evidenced by lower fetal weight and length, associated with a higher incidence of small for gestational age fetuses. In addition, higher placental weight and placental index were found in F2 offspring from GBH-HD dams. Surprisingly, structural congenital anomalies (conjoined fetuses and abnormally developed limbs) were detected in the F2 offspring from GBH-HD group. In conclusion, perinatal exposure to low doses of a GBH impaired female reproductive performance and induced fetal growth retardation and structural congenital anomalies in F2 offspring.
Assuntos
Glicina/análogos & derivados , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Reprodução/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Retardo do Crescimento Fetal/induzido quimicamente , Glicina/administração & dosagem , Glicina/toxicidade , Herbicidas/toxicidade , Isoxazóis/sangue , Lactação , Masculino , Placenta/efeitos dos fármacos , Placenta/patologia , Gravidez , Taxa de Gravidez , Puberdade/efeitos dos fármacos , Puberdade/fisiologia , Ratos Wistar , Reprodução/fisiologia , Tetrazóis/sangue , GlifosatoRESUMO
Our aim was to evaluate whether postnatal exposure to a glyphosate-based herbicide (GBH) modifies mammary gland development in pre- and post-pubertal male rats. From postnatal day 1 (PND1) to PND7, male rats were injected subcutaneously every 48â¯h with either saline solution (vehicle) or 2â¯mg GBH/kg·bw. On PND21 and PND60, mammary gland and blood samples were collected. Estradiol (E2) and testosterone (T) serum levels, mammary gland histology, collagen fiber organization, mast cell infiltration, proliferation index, and estrogen (ESR1) and androgen receptor (AR) expression levels were evaluated. At PND21, GBH-exposed male rats exhibited greater development of the mammary gland with increased stromal collagen organization and terminal end buds (TEBs) compared to control rats. At PND60, the number of TEBs remained high and was accompanied by an increase in mast cell infiltration, proliferation and ESR1 expression in GBH-exposed male rats. In contrast, no effects were observed in E2 and T serum levels and AR expression in both days studied. Our results showed that a postnatal subacute treatment with GBH induces endocrine-disrupting effects in the male mammary gland in vivo, altering its normal development.
Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Glândulas Mamárias Animais/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Proliferação de Células , Estradiol/sangue , Receptor alfa de Estrogênio/metabolismo , Feminino , Glicina/toxicidade , Masculino , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/crescimento & desenvolvimento , Glândulas Mamárias Animais/metabolismo , Mastócitos/citologia , Ratos Wistar , Receptores Androgênicos/metabolismo , Maturidade Sexual , Testosterona/sangue , Testes de Toxicidade Subaguda , GlifosatoRESUMO
We investigated whether defective modulation of uterine signaling may cause decidualization failure in rats neonatally exposed to a glyphosate-based herbicide (GBH). Female pups received vehicle or 2mg/kg of GBH from postnatal day (PND) 1 to PND7. On PND8 and PND21, Wnt5a and ß-catenin expression was evaluated in uterine samples. On gestational day (GD) 9, Wnt5a, Wnt7a and ß-catenin expression and Dkk1 and sFRP4 mRNA were evaluated on implantation sites. On PND8, GBH-exposed rats showed increased Wnt5a and ß-catenin expression in luminal epithelium (LE), whereas on PND21, they showed increased Wnt5a and ß-catenin expression in subepithelial stroma but decreased ß-catenin expression in glandular epithelium. On GD9, GBH-exposed rats showed decreased Wnt5a and Wnt7a expression in the antimesometrial zone and LE respectively, without changes in ß-catenin expression, while Dkk1 and sFRP4 were up- and down-regulated respectively. We concluded that neonatal GBH exposure may lead to embryo losses by disturbing uterine signaling.
Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Útero/efeitos dos fármacos , Animais , Feminino , Glicina/toxicidade , Peptídeos e Proteínas de Sinalização Intercelular/genética , Troca Materno-Fetal , Gravidez , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Ratos Wistar , Proteínas Ribossômicas/genética , Transdução de Sinais/efeitos dos fármacos , Útero/metabolismo , Proteínas Wnt/metabolismo , Proteína Wnt-5a/metabolismo , beta Catenina/metabolismo , GlifosatoRESUMO
We have previously demonstrated that maternal exposure to glyphosate-based herbicide (GBH) leads to glutamate excitotoxicity in 15-day-old rat hippocampus. The present study was conducted in order to investigate the effects of subchronic exposure to GBH on some neurochemical and behavioral parameters in immature and adult offspring. Rats were exposed to 1% GBH in drinking water (corresponding to 0.36% of glyphosate) from gestational day 5 until postnatal day (PND)-15 or PND60. Results showed that GBH exposure during both prenatal and postnatal periods causes oxidative stress, affects cholinergic and glutamatergic neurotransmission in offspring hippocampus from immature and adult rats. The subchronic exposure to the pesticide decreased L-[14C]-glutamate uptake and increased 45Ca2+ influx in 60-day-old rat hippocampus, suggesting a persistent glutamate excitotoxicity from developmental period (PND15) to adulthood (PND60). Moreover, GBH exposure alters the serum levels of the astrocytic protein S100B. The effects of GBH exposure were associated with oxidative stress and depressive-like behavior in offspring on PND60, as demonstrated by the prolonged immobility time and decreased time of climbing observed in forced swimming test. The mechanisms underlying the GBH-induced neurotoxicity involve the NMDA receptor activation, impairment of cholinergic transmission, astrocyte dysfunction, ERK1/2 overactivation, decreased p65 NF-κB phosphorylation, which are associated with oxidative stress and glutamate excitotoxicity. These neurochemical events may contribute, at least in part, to the depressive-like behavior observed in adult offspring.
Assuntos
Comportamento Animal/efeitos dos fármacos , Depressão/induzido quimicamente , Ácido Glutâmico/metabolismo , Glicina/análogos & derivados , Herbicidas/toxicidade , Hipocampo/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Estresse Oxidativo/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Acetilcolinesterase/metabolismo , Fatores Etários , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Sítios de Ligação , Fibras Colinérgicas/efeitos dos fármacos , Fibras Colinérgicas/metabolismo , Depressão/metabolismo , Depressão/fisiopatologia , Depressão/psicologia , Feminino , Proteínas Ligadas por GPI/metabolismo , Idade Gestacional , Ácido Glutâmico/química , Glicina/química , Glicina/metabolismo , Glicina/toxicidade , Herbicidas/química , Herbicidas/metabolismo , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Masculino , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , NF-kappa B/metabolismo , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/fisiopatologia , Síndromes Neurotóxicas/psicologia , Gravidez , Ligação Proteica , Ratos Wistar , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/metabolismo , Subunidade beta da Proteína Ligante de Cálcio S100/metabolismo , Relação Estrutura-Atividade , Transmissão Sináptica/efeitos dos fármacos , GlifosatoRESUMO
Glyphosate-based herbicides (GBHs) are widely used in agriculture. Recently, several animal and epidemiological studies have been conducted to understand the effects of these chemicals as an endocrine disruptor for the gonadal system. The aim of the present study was to determine whether GBHs could also disrupt the hypothalamic-pituitary-thyroid (HPT) axis. Female pregnant Wistar rats were exposed to a solution containing GBH Roundup®Transorb (Monsanto). The animals were divided into three groups (control, 5mg/kg/day or 50mg/kg/day) and exposed from gestation day 18 (GD18) to post-natal day 5 (PND5). Male offspring were euthanized at PND 90, and blood and tissues samples from the hypothalamus, pituitary, liver and heart were collected for hormonal evaluation (TSH-Thyroid stimulating hormone, T3-triiodothyronine and T4-thyroxine), metabolomic and mRNA analyses of genes related to thyroid hormone metabolism and function. The hormonal profiles showed decreased concentrations of TSH in the exposed groups, with no variation in the levels of the thyroid hormones (THs) T3 and T4 between the groups. Hypothalamus gene expression analysis of the exposed groups revealed a reduction in the expression of genes encoding deiodinases 2 (Dio2) and 3 (Dio3) and TH transporters Slco1c1 (former Oatp1c1) and Slc16a2 (former Mct8). In the pituitary, Dio2, thyroid hormone receptor genes (Thra1 and Thrb1), and Slc16a2 showed higher expression levels in the exposed groups than in the control group. Interestingly, Tshb gene expression did not show any difference in expression profile between the control and exposed groups. Liver Thra1 and Thrb1 showed increased mRNA expression in both GBH-exposed groups, and in the heart, Dio2, Mb, Myh6 (former Mhca) and Slc2a4 (former Glut4) showed higher mRNA expression in the exposed groups. Additionally, correlation analysis between gene expression and metabolomic data showed similar alterations as detected in hypothyroid rats. Perinatal exposure to GBH in male rats modified the HPT set point, with lower levels of TSH likely reflecting post-translational events. Several genes regulated by TH or involved in TH metabolism and transport presented varying degrees of gene expression alteration that were probably programmed during intrauterine exposure to GBHs and reflects in peripheral metabolism. In conclusion, the role of GBH exposure in HPT axis disruption should be considered in populations exposed to this herbicide.
Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Sistema Hipotálamo-Hipofisário/metabolismo , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Glândula Tireoide/metabolismo , Hormônios Tireóideos/metabolismo , Animais , Feminino , Glicina/toxicidade , Homeostase/efeitos dos fármacos , Homeostase/fisiologia , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Masculino , Metabolômica/métodos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , Ratos Wistar , Glândula Tireoide/efeitos dos fármacos , GlifosatoRESUMO
Glyphosate is the active ingredient of several herbicide formulations. Different reports suggest that glyphosate-based herbicides (GBHs) may act as endocrine disruptors. We evaluated the potential estrogenic effects of a GBH formulation using the uterotrophic assay. Adult ovariectomized rats were sc injected for 3 consecutive days with: saline solution (vehicle control), 2.10-5 g E2 /kg/day (uterotrophic dose; UE2 ), 2.10-7 g E2 /kg/day (nonuterotrophic dose; NUE2 ), or 0.5, 5, or 50 mg GBH/kg/day of the. Twenty-four hours after the last injection, the uterus was removed and weighed and processed for histopathology and mRNA extraction. Epithelial cell proliferation and height and expression of estrogen-responsive genes were evaluated (estrogen receptors, ERα and ERß; progesterone receptor, PR; complement 3, C3). Uterine weight and epithelial proliferation were not affected by GBH. However, the luminal epithelial cell height increased at GBH0.5. ERα mRNA was downregulated by all GBH doses and E2 groups, whereas PR and C3 mRNA were diminished by GBH0.5. GBH5-, GBH50-, and UE2 -treated rats showed downregulated ERα protein expression in luminal epithelial cells, while the receptor was upregulated in the stroma. GBH upregulated ERß (GBH0.5-50) and PR (GBH5) expressions in glandular epithelial cells, similar effect to that of NUE2 group. These results indicate that, although the uterine weight was not affected, GBH modulates the expression of estrogen-sensitive genes. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1191-1201, 2017.
Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Útero/efeitos dos fármacos , Animais , Animais Endogâmicos , Estradiol/fisiologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Glicina/toxicidade , Tamanho do Órgão/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Wistar , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Útero/metabolismo , Útero/patologia , GlifosatoRESUMO
Glyphosate-based herbicides (GBHs) are extensively used to control weeds on both cropland and non-cropland areas. No reports are available regarding the effects of GBHs exposure on uterine development. We evaluated if neonatal exposure to a GBH affects uterine morphology, proliferation and expression of proteins that regulate uterine organogenetic differentiation in rats. Female Wistar pups received saline solution (control, C) or a commercial formulation of glyphosate (GBH, 2mg/kg) by sc injection every 48h from postnatal day (PND) 1 to PND7. Rats were sacrificed on PND8 (neonatal period) and PND21 (prepubertal period) to evaluate acute and short-term effects, respectively. The uterine morphology was evaluated in hematoxylin and eosin stained sections. The epithelial and stromal immunophenotypes were established by assessing the expression of luminal epithelial protein (cytokeratin 8; CK8), basal epithelial proteins (p63 and pan cytokeratin CK1, 5, 10 and 14); and vimentin by immunohistochemistry (IHC). To investigate changes on proteins that regulate uterine organogenetic differentiation we evaluated the expression of estrogen receptor alpha (ERα), progesterone receptor (PR), Hoxa10 and Wnt7a by IHC. The GBH-exposed uteri showed morphological changes, characterized by an increase in the incidence of luminal epithelial hyperplasia (LEH) and an increase in the stromal and myometrial thickness. The epithelial cells showed a positive immunostaining for CK8, while the stromal cells for vimentin. GBH treatment increased cell proliferation in the luminal and stromal compartment on PND8, without changes on PND21. GBH treatment also altered the expression of proteins involved in uterine organogenetic differentiation. PR and Hoxa10 were deregulated both immediately and two weeks after the exposure. ERα was induced in the stromal compartment on PND8, and was downregulated in the luminal epithelial cells of gyphosate-exposed animals on PND21. GBH treatment also increased the expression of Wnt7a in the stromal and glandular epithelial cells on PND21. Neonatal exposure to GBH disrupts the postnatal uterine development at the neonatal and prepubertal period. All these changes may alter the functional differentiation of the uterus, affecting the female fertility and/or promoting the development of neoplasias.
Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Útero/efeitos dos fármacos , Útero/crescimento & desenvolvimento , Animais , Animais Recém-Nascidos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Feminino , Glicina/toxicidade , Gravidez , Distribuição Aleatória , Ratos , Ratos Wistar , Útero/metabolismo , GlifosatoRESUMO
Glyphosate-based herbicides (GF) are extensively used for weed control. Thus, it is important to investigate their putative toxic effects. We have reported that GF at subagriculture concentrations inhibits proliferation and differentiation to adipocytes of 3T3-L1 fibroblasts. In this investigation, we evaluated the effect of GF on genes upregulated during adipogenesis. GF was able to inhibit the induction of PPAR gamma, the master gene in adipogenesis but not C/EBP beta, which precedes PPAR gamma activation. GF also inhibited differentiation and proliferation of another model of preadipocyte: mouse embryonic fibroblasts. In exponentially growing 3T3-L1 cells, GF increased lipid peroxidation and the activity of the antioxidant enzyme, superoxide dismutase. We also found that proliferation was inhibited with lower concentrations of GF when time of exposure was extended. Thus, GF was able to inhibit proliferation and differentiation of preadipocytes and to induce oxidative stress, which is indicative of its ability to alter cellular physiology.