Killing two birds with one stone: Pregnancy is a sensitive window for endocrine effects on both the mother and the fetus

Pregnancy is a complex process requiring tremendous physiological changes in the mother in order to fulfill the needs of the growing fetus, and to give birth, expel the placenta and nurse the newborn. These physiological modifications are accompanied with psychological changes, as well as with variations in habits and behaviors. As a result, this period of life is considered as a sensitive window as impaired functional and physiological changes in the mother can have short- and long-term impacts on her health. In addition, dysregulation of the placenta and of mechanisms governing placentation have been linked to chronic diseases later-on in life for the fetus, in a concept known as the Developmental Origin of Health and Diseases (DOHaD). This concept stipulates that any change in the environment during the pre-conception and perinatal (in utero life and neonatal) period to puberty, can be "imprinted" in the organism, thereby impacting the health and risk of chronic diseases later in life. Pregnancy is a succession of events that is regulated, in large part, by hormones and growth factors. Therefore, small changes in hormonal balance can have important effects on both the mother and the developing fetus. An increasing number of studies demonstrate that exposure to endocrine disrupting compounds (EDCs) affect both the mother and the fetus giving rise to growing concerns surrounding these exposures. This review will give an overview of changes that happen during pregnancy with respect to the mother, the placenta, and the fetus, and of the current literature regarding the effects of EDCs during this specific sensitive window of exposure.

Bottom-up approach synthesis of core-shell nanoscale zerovalent iron (CS-nZVI): Physicochemical and spectroscopic characterization with Cu(II) ions adsorption application

Single pot system in chemical reduction via bottom-up approach was used for the synthesis of core shell nanoscale zerovalent iron (CS-nZVI). CS-nZVI was characterized by a combination of physicochemical and spectroscopic techniques. Data obtained showed BET surface area 20.8643 m2/g, t-Plot micropore volume 0.001895 cm3/g, BJH volume pores 0.115083 cm3/g, average pore width 186.9268 Å, average pore diameter 240.753 Å, PZC 5.24, and pH 6.80. Surface plasmon Resonance from UV-Vis spectrophotometer was observed at 340 nm. Surface morphology from SEM and TEM revealed a spherical cluster and chain-like nanostructure of size range 15.425 nm -97.566 nm. Energy Dispersive XRF revealed an elemental abundance of 96.05% core shell indicating the dominance of nZVI. EDX showed an intense peak of nZVI at 6.2 keV. FTIR data revealed the surface functional groups of Fe-O with characteristics peaks at 686.68 cm-1, 569.02 cm-1 and 434 cm-1. In a batch technique, effective adsorption of endocrine disruptive Cu(II) ions was operational parameters dependent. Isotherm and kinetics studies were validated by statistical models. The study revealed unique characteristics of CS-nZVI and its efficacy in waste water treatment.

Assessment of agonistic and antagonistic properties of widely used oral care antimicrobial substances toward steroid estrogenic and androgenic receptors

Personal care product consumption has increased in the last decades. A typical representative ingredient, i.e., triclosan, was identified in the scientific literature as an endocrine disruptor, and its use is restricted in several applications. Oral hygiene formulations contain various compounds, including synthetic phenol derivatives, quaternary ammonium compounds (QACs), various amides and amines, or natural essential oils containing terpenes. The aim of this paper was to explore possible endocrine-disrupting effects of these most-used compounds. For this purpose, two different assays based on recombinant yeast (BMAEREluc/ERα; BMAEREluc/AR) and human cell lines (T47D; AIZ-AR) were employed to investigate the agonistic and antagonistic properties of these compounds on human estrogen and androgen receptors. The results showed that none of the compounds were indicated as agonists of the steroid receptors. However, octenidine (OCT, QAC-like) and hexadecylpyridinium (HDP, QAC) were able to completely inhibit both androgenic (IC₅₀ OCT = 0.84 μM; IC₅₀ HDP = 1.66 μM) and estrogenic (IC₅₀ OCT = 0.50 μM; IC₅₀ HDP = 1.64 μM) signaling pathways in a dose-dependent manner. Additionally, chlorhexidine was found to inhibit the 17β-estradiol response, with a similar IC₅₀ (2.9 μM). In contrast, the natural terpenes thymol and menthol were found to be competitive antagonists of the receptors; however, their IC₅₀ values were higher (by orders of magnitude). We tried to estimate the risk associated with the presence of these compounds in environmental matrices by calculating hazard quotients (HQs), and the calculated HQs were found to be close to or greater than 1 only when predicted environmental concentrations were used for surface waters.

Endocrine effects after ozonation of tamoxifen

Ozonation is used as additional wastewater treatment option to remove recalcitrant micropollutants. It also removes the estrogenic activity found in wastewater but not always the anti-estrogenic activity. This can be explained by an incomplete removal of anti-estrogenic micropollutants or by formation of transformation products (TPs) which retain the activity. The present study investigates the degradation of the anti-estrogenic pharmaceutical tamoxifen in pure water, regarding TP formation and related anti-estrogenic effect using Arxula adeninivorans yeast estrogen screen (A-YES). In total, five transformation products were detected: three N-oxides and two further products (TP 270 and TP 388). For the transformation product TP 270 a correlation of the extent of formation with an increase of the anti-estrogenic activity was determined, demonstrating that transformation products from ozonation can be more active in a bioassay than the parent compounds. Our study shows also that the transformation of tamoxifen to N-oxides reduces the anti-estrogenic activity. The reactivity of amines towards ozone typically increases with pH, since only deprotonated amines react with ozone. Hence, removal of the endocrine activity by N-oxide formation may be disfavored at low pH.

DDT exposure of frogs: A case study from Limpopo Province, South Africa

Amphibians are globally under pressure with environmental contaminants contributing to this. Despite caution aired more than 80 years ago of threats posed to amphibians by DDT spraying for disease vector control, no data have been published on concentrations or effects of DDT contamination in frogs from areas where DDT is actively sprayed to control the insect vectors of malaria. In this study, we sampled fat bodies of Xenopus laevis and Xenopus muelleri naturally occurring in an area where indoor residual spraying of DDT is employed and from adjacent, non-sprayed, areas. ΣDDT concentrations ranged between <LOQ and 280 ng/g ww (wet weight) from the non-sprayed area, and 5.5-910 ng/g ww from the sprayed area, but statistical significance could not be shown. We observed significant asymmetric testicular morphology in frogs from the sprayed area, possibly due to endocrine disruption by compounds such as the DDTs. A previous study from the same area found very high concentrations of DDT in the eggs of the Grey Heron Ardea cinerea. This suggests that the DDT we found in frogs may have contributed to DDT loadings higher in the food web. These findings, combined with other studies from this area, support the need to reduce and eventually move away from DDT in malaria control safely and sustainably.