RESUMO
The endocrine system is highly sensitive to endocrine-disrupting chemicals (EDC) which interfere with metabolism, growth and reproduction throughout different periods of life, especially in the embryonic and pubertal stages, in which gene reprogramming may be associated with impaired development and control of tissues/organs even in adulthood. Acrylamide is considered a potential EDC and its main source comes from fried, baked and roasted foods that are widely consumed by children, teenagers and adults around the world. This review aimed to present some aspects regarding the acrylamide formation, its toxicokinetics, the occurrence of acrylamide in foods, the recent findings about its effects on different systems and the consequences for the human healthy. The challenges to characterize the molecular mechanisms triggered by acrylamide and to establish safe levels of consumption and/or exposure are also discussed in the present review.
Assuntos
Acrilamida/toxicidade , Disruptores Endócrinos/toxicidade , Sistema Nervoso/efeitos dos fármacos , Acrilamida/química , Acrilamida/farmacocinética , Animais , Criança , Disruptores Endócrinos/química , Disruptores Endócrinos/farmacocinética , Humanos , Sistema Nervoso/crescimento & desenvolvimento , Sistema Nervoso/metabolismo , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Reprodução/efeitos dos fármacos , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismoRESUMO
Environmental chemicals originating from human activities, such as persistent organic pollutants (POPs), may interfere with the endocrine system of aquatic organisms. The effect of these chemicals on biota and human populations is of high public concern but remains poorly understood, especially in aquatic environments of South America. The aim of this study was to investigate the bioavailability of POPs and the related effects in caged male tilapia (Oreochromis niloticus) in four cascading reservoirs of the Iguaçu River, Southern Brazil. POPs including organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in the reservoir water and tissue samples of tilapia after two months of exposure. The PCB levels in water (14.7â¯ngâ¯L-1) were 14 times higher than the limits permitted by the Brazilian legislation in the Salto Santiago (SS) reservoir. Similarly, concentrations of aldrin and its metabolites (6.05â¯ngâ¯L-1) detected in the water sample of the Salto Osório (SO) reservoir were also above the permitted limits. RT-qPCR analysis revealed different transcript levels of cytochrome P450 enzymes (CYP1A and CYP3A) in the liver among the four groups, with induced activity in tilapia from the SS reservoir. Quantification of the CYP3A mRNA expression and catalytic activity showed higher values for fish caged at the SS reservoir. The fish from this site also had a higher number of eosinophils observed in the testes. Although overt measurements of endocrine disruption were not observed in caged fish, alteration of CYP enzymes with co-occurrence of organochlorine contaminants in water may suggest bioavailability of contaminants from agricultural sources to biota. Additional studies with feral or caged animals for a longer duration may be necessary to evaluate the risks of the waterways to humans and wildlife.
Assuntos
Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP3A/metabolismo , Disruptores Endócrinos/farmacocinética , Fígado/metabolismo , Praguicidas/farmacocinética , Tilápia/metabolismo , Poluentes Químicos da Água/farmacocinética , Animais , Disponibilidade Biológica , Brasil , Disruptores Endócrinos/análise , Peixes , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/farmacocinética , Humanos , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/farmacocinética , Masculino , Praguicidas/análise , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Rios/química , Poluentes Químicos da Água/análiseRESUMO
Organotins (OTs) are environmental contaminants used as biocides in antifouling paints that have been shown to be endocrine disrupters. However, studies evaluating the effects of OTs accumulated in seafood (LNI) on reproductive health are particularly sparse. This study demonstrates that LNI leads to impairment in the reproductive tract of female rats, as the estrous cycle development, as well as for ovary and uterus morphology. Rats were treated with LNI, and their reproductive morphophysiology was assessed. Morphophysiological abnormalities, such as irregular estrous cycles, abnormal ovarian follicular development and ovarian collagen deposition, were observed in LNI rats. An increase in luminal epithelia and ERα expression was observed in the LNI uteri. Together, these data provide in vivo evidence that LNI are toxic for reproductive morphophysiology, which may be associated with risks to reproductive function.
Assuntos
Disruptores Endócrinos/toxicidade , Compostos Orgânicos de Estanho/toxicidade , Ovário/efeitos dos fármacos , Alimentos Marinhos/efeitos adversos , Útero/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Colágeno/metabolismo , Disruptores Endócrinos/sangue , Disruptores Endócrinos/farmacocinética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Ciclo Estral/efeitos dos fármacos , Feminino , Contaminação de Alimentos , Gastrópodes , Compostos Orgânicos de Estanho/sangue , Compostos Orgânicos de Estanho/farmacocinética , Ovário/metabolismo , Ovário/patologia , Ratos Wistar , Útero/metabolismo , Útero/patologia , Poluentes Químicos da Água/sangue , Poluentes Químicos da Água/farmacocinéticaRESUMO
The goal of the present study was to evaluate the role of Tamoxifen (TAM), in the distribution and/or elimination kinetics of o,p'-DDT, in male tilapias. A non-compartmental analysis was chosen to describe the time course of o,p'-DDT plasma concentrations. Mean plasma concentration of o,p'-DDT following IP administration indicates a very complex kinetic profile. Tamoxifen decreased the o,p'-DDT mean half-life (t½) from 20.38 to 16.11 days, the Mean Residence Time (MRT) from 28.7 to 23.23 days, and clearance (CL) from 0.0031 to 0.001 mL/min. The distribution pattern of o,p'-DDT in tissues and the clearance in plasma suggest that storage points mediated through the membrane-receptor lipophilicity can be involved.
Assuntos
Ciclídeos/sangue , DDT/farmacocinética , Disruptores Endócrinos/farmacocinética , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Animais , DDT/sangue , DDT/toxicidade , Disruptores Endócrinos/sangue , Disruptores Endócrinos/toxicidade , Meia-Vida , Masculino , Taxa de Depuração Metabólica , Distribuição TecidualRESUMO
Nuclear receptors (NRs) constitute a superfamily of transcriptional factors that participate in homeostasis and development through the binding of endogenous compounds. Despite this constitutive activity, some xenobiotics can also bind to NRs and disturb some signaling pathways, giving rise to the concept that NR activity can be modulated by antagonists or competitive agonists. Some NRs, such as the Pregnane X receptor (PXR), Peroxisome Proliferator Activated Receptors (PPARs) and Constitutive Androstane Receptor (CAR) have received particular attention because after binding to xenobiotics, they activate the expression of genes involved in Phases I, II and III of biotransformation pathways. Another important protein involved in the signaling of toxic compounds is the aromatic hydrocarbon receptor (AhR), a member of the basic helix loop-helix (bHLH) PER-ARNT-SIM (PAS) family of nuclear transcription factors. AhR modulates an important panel of cognate genes and is remarkably prone to protein-protein interactions interfering with transcription factors and NRs. Several observations have been made associating the exposure to chemicals with adverse effects on reproduction of aquatic organisms, termed endocrine disrupting compounds (EDC). NRs are believed to play an essential role in the adverse effects elicited by EDC and some mechanisms are addressed in this review.
Assuntos
Receptores Citoplasmáticos e Nucleares/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Biotransformação , Disruptores Endócrinos/farmacocinética , Disruptores Endócrinos/toxicidade , Receptores Citoplasmáticos e Nucleares/metabolismo , Poluentes Químicos da Água/farmacocinéticaRESUMO
Organochlorine compounds (OCCs), such as pesticides and polychlorinated biphenyls (PCBs), are persistent lipophilic chemicals identified as endocrine disruptors, mainly with estrogen-like effects. Northeastern Argentina, near the Paraná River, is characterized by intensive farming and agricultural activities and industrial development, and is therefore prone to high incidences of environmental and dietary exposure to OCCs. Hence, we conducted a study to (1) estimate the organochlorine residues present in mammary fat tissue in a population of women from this littoral region and (2) identify potential sources of exposure to OCCs. Our subjects were 76 women (residing in and around Santa Fe city and not occupationally exposed to organochlorines) who underwent excision biopsy of a breast lesion or had plastic surgery. Both frequency of occurrence and levels of organochlorine residues were high in breast adipose tissue of all the participants. The organochlorine residues most frequently found were p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in all the subjects analyzed, hexachlorobenzene (HCB) in 86.8%, and beta-hexachlorocyclohexane (beta-HCH) in 75.0%. The incidence of PCB congeners was very low. p,p'-DDE and beta-HCH residues reached the highest levels, 4794 and 1780 ppb, respectively. The diet was a relevant source of exposure, consumption of animal fat and freshwater fish playing a significant role. Bioaccumulation was evidenced by the significant positive association between organochlorine levels and body mass index (p = 0.0003) and the age of the patient (p = 0.0002). The frequency and levels of OCCs found in our study population raise concerns regarding Argentinean exposure to these endocrine disruptors.