Antioxidant activity of selenium on bisphenol-induced apoptosis and testicular toxicity of Albino rats / Actividad antioxidante el selenio sobre la apoptosis inducid por bisfenol y toxicidad testicular en ratas albinas

SUMMARY: Bisphenol A (BPA) is an industrial chemical widely used to make polycarbonate plastics for packaging and epoxy resins. This study sought to examine how selenium (Se) affects BPA toxicity in terms of albino rats' histological structure, antioxidant enzymes and reproductive organs (seminiferous tubules). Twenty-four adult male rats were divided into four experimental groups: Group 1: Control; Group 2: Orally administered BPA; Group 3: Orally administered sodium selenite; Group 4: Treated daily with BPA followed by selenium (Se). All experiment done for 4 weeks. BPA exposure caused changes in the testicular histological structure, which consists apoptosis, and led to changes in several biochemical markers: Malondialdehyde, catalase, superoxide dismutase, and glutathione peroxidase. However, these BPA side effects may be ameliorated in rats treated with BPA-plus-Se. These protective effects of Se may attributable to its ability to remove potentially damaging oxidizing agents in living organisms. The results may confirm that Se countered the oxidant effects and increased the BPA-induced stress response in rats. So, Se promotes the healthy growth and development of mammals by protecting them from oxidative stress. As human are greatly exposed to BPA and it can accumulate in tissues, there is concern about human reproductive functions particularly for occupational workers exposed usually to greater levels of BPA. Thus, the use of BPA in multiple industries must be restricted and the inaccurate usage of plastic containers should be avoided to decrease the health hazards. Administration of Se may protect against the adverse effects of BPA on reproductive functions and structures.

RESUMEN: El bisfenol A (BPA) es un químico industrial ampliamente utilizado para fabricar plásticos de policarbonato para envases y resinas epoxi. Este estudio examinó el efecto de selenio (Se) en la toxicidad del BPA en términos de la estructura histológica, enzimas antioxidantes y los órganos reproductivos (túbulos seminíferos) de ratas albinas. Se dividieron veinticuatro ratas macho adultas en cuatro grupos experimentales: Grupo 1: control; Grupo 2: BPA administrado por vía oral; Grupo 3: BPA administrado por vía oral para; Grupo 4: tratado diariamente con BPA seguido de selenio (Se). El experimento se realizó durante cuatro semanas y se observó que la exposición al BPA provocó cambios en la estructura histológica testicular, incluyendo apoptosis, y alteraciones en varios marcadores bioquímicos:malondialdehído, catalasa, superóxido dismutasa y glutatión peroxidasa. Sin embargo, estos efectos secundarios del BPA pueden mejorar en ratas tratadas con BPA-plus-Se. Estos efectos protectores del Se pueden ser atribuidos a la capacidad de eliminar agentes oxidantes potencialmente dañinos en organismos vivos. Los resultados indicaron que se contrarrestaron los efectos oxidantes y aumentó la respuesta al estrés inducido por BPA en ratas, y favorece el crecimiento y desarrollo en los mamíferos al protegerlos del estrés oxidativo. Debido a la exposición al BPA en el ser humano, se puede acumular en los tejidos, por lo que existe una preocupación por el daño a las funciones reproductivas en particular de los trabajadores que generalmente están expuestos a niveles más altos de BPA. Por lo tanto, se debe restringir el uso de BPA en las industrias y evitar el uso incorrecto de envases de plástico para así disminuir los riesgos para la salud. La administración correcta de Se puede proteger contra los efectos adversos del BPA en las funciones y estructuras reproductivas.

Contaminação em larga escala por Bisfenol-A: estamos conscientes do risco e formas de exposição? / Large-scale contamination by Bisphenol A: are we aware of the risk and forms of exposure?

Resumo O Bisfenol-A (BFA) é uma substância amplamente empregada no cotidiano, principalmente nos materiais plásticos. Este estudo avaliou a exposição de universitários ao disruptor endócrino BFA, o conhecimento dos mesmos acerca dessa substância e dos seus danos à saúde humana. Trata-se de um estudo transversal descritivo realizado com 500 estudantes de uma Universidade de Curitiba. A amostra foi selecionada de forma proporcional as três grandes áreas do conhecimento, sendo que os cursos entrevistados foram sorteados. Aos estudantes aplicou-se um questionário objetivo composto por três partes: socioeconômica, avaliação da exposição e testes de conhecimento. Dos respondentes, 91,3% consomem alimentos armazenados em embalagens plásticas, 90,06% utilizam bebidas nesse tipo de recipiente e 84,8% consomem bebidas/alimentos enlatados. Entretanto, apenas 19,8% já ouviram falar em BFA e 97,2% não sabem sobre a relação entre a exposição ao BFA e alterações endócrinas. Observou-se uma alta taxa de exposição ao BFA e um baixo nível de conhecimento sobre o assunto. Essa desproporção evidencia a necessidade de pesquisas mais aprofundadas sobre o tema na população brasileira, além da ampliação de medidas informativas.

Abstract Bisphenol A (BPA) is a substance extensively used in daily life, mainly in plastic materials. This study assessed the exposure of university students to endocrine disruptor BPA, their knowledge about this substance and the damage it causes to human health. This is a cross-sectional descriptive study carried out with 500 students from a University in Curitiba. The sample was selected proportionally to the three major areas of knowledge, and the courses interviewed were drawn at random. Students were asked to fill out an objective questionnaire consisting of three parts: socioeconomic, assessment of exposure and knowledge tests. Of the respondents, 91.3% consume food stored in plastic packaging, 90.06% use drinks in this type of container and 84.8% consume canned food/drinks. However, only 19.8% have heard of BPA and 97.2% do not know about the relationship between exposure to BPA and endocrine changes. A high rate of exposure to BPA and a low level of knowledge on the subject was detected. This disproportion highlights the need for more in-depth research on the topic among the Brazilian population, in addition to broadening dissemination of information measures on the issue.

Challenges to regulate products containing bisphenol A: Implications for policy / Desafíos para regular los productos que contienen bisfenol A: implicaciones para la política

Abstract: Bisphenol A (BPA), found in plastics and epoxy resins, is one of the most studied chemicals. BPA is regarded as an endocrine disruptor and has been related to adverse health effects in humans. However, some regulatory agencies around the world have concluded that BPA is safe at current human exposure levels. As the scientific community attempts to settle the debate on BPA's health effects, regulatory agencies have been put into a challenging public health policy situation. The United States has implemented no regulatory actions due to safety concerns, while Europe has used the precautionary principle to guide its regulation in the face of scientific uncertainty. In this paper, we explore the debate surrounding BPA regulation and the possibility for countries to introduce guidelines, using Mexico as an example. Policy change determinants analysis suggest that countries can and should impose regulations on BPA.

Resumen: El bisfenol A (BPA), presente en plásticos y resinas epoxi, es uno de los químicos más estudiados. Se considera un disruptor endocrino y se ha relacionado con efectos adversos para la salud humana. Algunas agencias regulatorias en el mundo han concluido que el BPA es seguro a los niveles de exposición humana actuales. Mientas la comunidad científica intenta resolver el debate sobre dichos efectos, las agencias regulatorias enfrentan una difícil situación de política pública. Los Estados Unidos de América no han implementado acciones reglamentarias por razones precautorias, mientras que Europa ha utilizado el principio precautorio para guiar su regulación ante la incertidumbre científica. En este documento exploramos el debate que rodea la regulación del BPA y la posibilidad de que los países introduzcan directrices, usando a México como ejemplo. El análisis de los determinantes del cambio de políticas sugiere que los países pueden y deben regular el BPA.

Contribution of environmental pollutants to male infertily: A working model of germ cell apoptosis induced by plasticizers

Bisphenol A [2,2-bis(4-hydroxyphenyl)propane] (BPA), 4-nonylphenol (NP) and di(2-ethylhexyl)phthalate (DEHP), and its metabolite mono-2-ethylhexyl phthalate (MEHP) are chemicals found in plastics, which act as endocrine disruptors (EDs) in animals, including human. EDs act like hormones in the endocrine system, and disrupt the physiologic function of endogenous hormones. Most people are exposed to different endocrine disruptors and concern has been raised about their true effect on reproductive organs. In the testis, they seem to preferentially attack developing testis during puberty rather than adult organs. However, the lack of information about the molecular mechanism, and the apparently controversial effect observed in different models has hampered the understanding of their effects on mammalian spermatogenesis. In this review, we critically discuss the available information regarding the effect of BPA, NP and DEHP/ MEHP upon mammalian spermatogenesis, a major target of EDs. Germ cell sloughing, disruption of the blood-testis-barrier and germ cell apoptosis are the most common effects reported in the available literature. We propose a model at the molecular level to explain the effects at the cellular level, mainly focused on germ cell apoptosis.