Environmental Effects of Endocrine-Disrupting Chemicals: A Special Focus on Phthalates and Bisphenol A

Several environmental chemicals are classified as endocrine-disrupting chemicals (EDCs). Many of them have an impact on reproductive functions and sex hormones because of their estrogenic and/or antiandrogenic properties. Phthalates and bisphenol A (BPA) are two well-known EDCs. They are abundant in the environment. Phthalates are usually classified as antiandrogens, whereas BPA is considered as estrogen-like EDC and xenoestrogen. Other than their endocrine-disrupting effects, these two chemicals are also known to have genotoxic and epigenetic effects. Besides, they are hepatotoxic and have substantial effects on other organs/systems (thyroid, kidney, neuroendocrine system, immune system, etc.). In this chapter, we will mainly focus on the toxic effects of different phthalate esters and BPA by discussing their availability in the environment, mechanism and mode of actions, their biotransformation and reproductive effects, and their effects on other systems (hepatic, renal, etc.). Besides, we discuss epidemiological studies that are conducted to reveal their effects on the reproductive and endocrine systems. This chapter provides the readers a compact piece of knowledge on these abundant substances and helps them to understand the action of these substances at the molecular and cellular levels

Antioksidansi i spojevi selenija inhibiraju toksično djelovanje 3,5-dimetilaminofenola na epitelne bubrežne stanice u ljudi

Exposure to alkyl anilines may lead to bladder cancer, which is the second most frequent cancer of the urogenital tract. 3,5-dimethylaniline is highly used in industry. Studies on its primary metabolite 3,5-dimethylaminophenol (3,5-DMAP) showed that this compound causes oxidative stress, changes antioxidant enzyme activities, and leads to death of different mammalian cells. However, there is no in vitro study to show the direct effects of 3,5-DMAP on human bladder and urothelial cells. Selenocompounds are suggested to decrease oxidative stress caused by some chemicals, and selenium supplementation was shown to reduce the risk of bladder cancer. The main aim of this study was to investigate whether selenocompounds organic selenomethionine (SM, 10 μmol/L) or inorganic sodium selenite (SS, 30 nmol/L) could reduce oxidative stress, DNA damage, and apoptosis in UROtsa cells exposed to 3,5-DMAP. 3,5-DMAP caused a dose-dependent increase in intracellular generation of reactive oxygen species, and its dose of 50 μmol/L caused lipid peroxidation, protein oxidation, and changes in antioxidant enzyme activities in different cellular fractions. The comet assay also showed single-strand DNA breaks induced by the 3,5-DMAP dose of 50 μmol/L, but no changes in double-strand DNA breaks. Apoptosis was also triggered. Both selenocompounds provided partial protection against the cellular toxicity of 3,5-DMAP. Low selenium status along with exposure to alkyl anilines can be a major factor in the development of bladder cancer. More mechanistic studies are needed to specify the role of selenium in bladder cancer.Izloženost alkilnim anilinima može uzrokovati rak mokraćnoga mjehura, koji je drugi po redu po učestalosti raka mokraćnospolnog sustava. 3,5-dimetilanilin često se rabi u industrijskoj proizvodnji, a istraživanja njegova primarnog metabolita, 3,5-dimetilaminofenola (3,5-DMAP), pokazuju da on uzrokuje oksidacijski stres i promjene u aktivnosti antioksidacijskih enzima te u konačnici dovodi do smrti raznih stanica u sisavaca. Dosad, međutim, nije provedeno nijedno istraživanje njegovih izravnih učinaka na epitelne stanice mokraćnoga mjehura i bubrega u ljudi. Za spojeve selenija smatra se da smanjuju oksidacijski stres različitih kemikalija te da dopuna prehrane selenijem smanjuje rizik od raka mokraćnoga mjehura. Primarni je cilj ovoga istraživanja bio utvrditi može li organski spoj selenija selenometionin (SM, 10 μmol/L), odnosno anorganski spoj natrijev selenit (SS, 30 nmol/L], smanjiti oksidacijski stres, oštećenje DNA i apoptozu u UROtsa stanicama izloženima 3,5-dimetilaminofenolu. Jednosatna izloženost stanica 3,5-DMAP-u dovela je do povećanja razina reaktivnih kisikovih spojeva (ROS), lipidne peroksidacije, oksidacije bjelančevina te do promjena u aktivnosti antioksidacijskih enzima u staničnoj citoplazmi i jezgri, ovisno o primijenjenoj dozi. Osim toga, komet-testom su utvrđeni jednolančani, ali ne i dvolančani lomovi DNA. Također, 3,5-DMAP uzrokovao je apoptozu stanica. Oba su spoja selenija pružila djelomičnu zaštitu od njegova toksičnoga djelovanja. Nedostatak selenija pri izloženosti alkilnim anilinskim spojevima stoga može odigrati značajnu ulogu u nastanku raka mokraćnog mjehura. Potrebna su daljnja istraživanja mehanizama djelovanja selenija u njegovu sprječavanju

Nutritional Deficiency

Intake of a sufficient diet will provide an individual to live a healthy and functional life. However, poor intake of different nutritional components, such as proteins, vitamins, minerals, and trace elements, may lead to health problems that can cause morbidity and finally mortality. Assessment of nutritional status involves physical examination, comprehensive evaluation of biochemical tests, body composition, and organ functions. Both high and low intake of nutritional elements may lead to significant health impairment. The main aim of the book Nutritional Deficiency is to determine the relationships between nutritional status and general health. The authors, who are contributing to the book, particularly focused on iron, vitamin D, and zinc deficiencies, which are global health problems. Besides, some chapters mention the impact of different nutritional deficiencies in susceptible periods of life, such as pregnancy and elderly. Besides, as a result of these deficiencies, different health conditions, such as depression, anemia, loss of neuronal plasticity, and cancer, are widely scrutinized in the book. One chapter mainly focuses on the effects of disasters on nutrition and disaster-caused malnutrition in underdeveloped countries. This book will widen the knowledge store of the readers on the effects of nutrition on general health, how nutritional deficiencies arise when there is a health problem, and how the nutritional status affects susceptible populations

Glutathione in Health and Disease

Reduced glutathione (GSH) is the most important thiol in living organisms. It is the key component of antioxidant system and serves as a free radical scavenger. There is a cycle of GSH in biological systems and this cycle provides higher intracellular levels of GSH. GSH depletion and apparent oxidative stress may cause toxicity and can affect the general well-being of the organism. GSH was shown to be preventive against aging, cancer, heart disease, infections and dementia. This book is mainly focused on GSH in health and disease. The readers will gain qualified scientific knowledge on the diverse functions of GSH, the importance of GSH status against oxidative stress and the interaction between GSH and nervous system-related infections from this book

Bisphenol A Exposure and Health Risks

Bisphenol A (BPA) is a synthetic compound for hardening and clearing polycarbonate plastics. BPA is mainly classified as an estrogen-like endocrine-disrupting chemical. In the last decade, attention has arisen in scientific communities that it is not safe to use this chemical in mainly polycarbonate plastics. Exposure to BPA starts in prenatal period, which is the critical period for its toxic effects on different organs. Throughout this book, the readers will obtain information on the effects of BPA on different systems. They will also get information on the prenatal and postnatal effects of BPA. We believe that readers will get qualified scientific knowledge and a general overview of the toxic effects of BPA exposure and its consequences from this book

Selenyum, Selenoproteinler ve Hashimoto Tiroiditi

selenium is a trace element that has important functions within the body. it is suggested that there is a link between selenium levels and thyroid functions since the enzymes involved in the synthesis of thyroid hormones are selenoenzymes. selenium is also required for the normal functioning of antioxidant defense mechanisms and the reduction of oxidative stress caused by Hashimoto's thyroiditis. Although studies on selenium supplementation in autoimmune thyroid diseases are limited, the data suggest that selenium treatment may have beneficial effects. in this review the roles of selenium, an important trace element which is essential for many vital functions particularly on the oxidant/ antioxidant balance, on vital functions in the organism, effects on thyroid functions and its use as an alternative treatment or supplement in Hashimoto's thyroiditis will be emphasize

Evaluation of skin irritation potentials of different cosmetic products in Turkish market by reconstructed human epidermis model.

Human skin is a protective barrier against the toxic effects of cosmetics. Marketing of cosmetic products with ingredients tested on animals was prohibited in 2013. Since then, safety evaluation of cosmetic products is performed by using alternative in vitro toxicity tests. In vitro 3-D reconstructed human epidermis (RhE) tissue models are now used to define skin irritation/corrosion potentials of cosmetic ingredients and end-products. The main aim of this study was to evaluate skin irritation potentials of topically used cosmetic end-products which were marketed in Turkey during 2015-2017, by using the EpiDerm in vitro 3D-human skin model. Sixty widely used cosmetic products were collected from different markets/cosmetic shops. Among hair care products, only one shampoo was found to be strong/severe skin irritant/possible corrosive while 22 shampoos were moderate skin irritant and 11 shampoos were moderate to mild skin irritant. Among 6 skin care products, one was found to be moderate to mild skin irritant. We can suggest that alternative in vitro tests should continuously be used to test both the ingredients and the final cosmetic formulations

The Effects of Fenvalerate on Hepatic and Cerebral Xenobiotic Metabolizing Enzymes in Selenium and/or Iodine Deficient Rats

Objective(s): Particularly in developing countries, selenium and/or iodine deficiencies are encountered and use of pesticides in agriculture are not well-controlled. Fenvalerate is a pyrethroid insectide used in agriculture and has applications against a wide range of pests. This study was designed to evaluate the effects of fenvalerate on hepatic and cerebral xenobiotic metabolizing enzyme activities in the presence of iodine and/or selenium deficiency on a rat model. Materials and Methods: Iodine and/or selenium deficiency was induced by feeding three-week-old Wistar rats with a diet containing <0.005 mg selenium kg-1, and/or administering 1% sodium perchlorate in drinking water for 7 weeks. Test groups received fenvalerate (100 mg kg-1 BW IP) for the last 7 days. Hepatic and cerebral microsomal aniline hydroxylase (CYP2E1) and cytosolic glutathione S-transferase (GST) activities were determined. Besides, hepatic NADPH-cytochrome P450 reductase (P450R), ethoxyresorufin O-deethylase (EROD, CYP1A1/1A2) and penthoxyresorufin O-depenthylase (PROD, CYP2B1/2B2), activities were also measured. Results: Fenvalerate had a general inductive effect on the hepatic and cerebral xenobiotic metabolizing enzyme activities. Moreover, enzyme activities were also altered by iodine and/or selenium deficiency, but the effects seemed to be enzyme- and tissue-specific. Conclusion: The inductive effect of fenvalerate, particularly in high dose exposures, may change the metabolism of several xenobiotics, including drugs, as well as endogenous substrates. The effects may vary depending on the selenium and/or iodine status of individual.PubMedWo

Evaluation of skin irritation potentials of different cosmetic products in Turkish market by reconstructed human epidermis model

Human skin is a protective barrier against the toxic effects of cosmetics. Marketing of cosmetic products with ingredients tested on animals was prohibited in 2013. Since then, safety evaluation of cosmetic products is performed by using alternative in vitro toxicity tests. In vitro 3-D reconstructed human epidermis (RhE) tissue models are now used to define skin irritation/corrosion potentials of cosmetic ingredients and end-products. The main aim of this study was to evaluate skin irritation potentials of topically used cosmetic end-products which were marketed in Turkey during 2015-2017, by using the EpiDerm in vitro 3D-human skin model. Sixty widely used cosmetic products were collected from different markets/cosmetic shops. Among hair care products, only one shampoo was found to be strong/severe skin irritant/possible corrosive while 22 shampoos were moderate skin irritant and 11 shampoos were moderate to mild skin irritant. Among 6 skin care products, one was found to be moderate to mild skin irritant. We can suggest that alternative in vitro tests should continuously be used to test both the ingredients and the final cosmetic formulations