5 research outputs found
Plasticizer endocrine disruption: Highlighting developmental and reproductive effects in mammals and non-mammalian aquatic species
AbstractDue to their versatility, robustness, and low production costs, plastics are used in a wide variety of applications. Plasticizers are mixed with polymers to increase flexibility of plastics. However, plasticizers are not covalently bound to plastics, and thus leach from products into the environment. Several studies have reported that two common plasticizers, bisphenol A (BPA) and phthalates, induce adverse health effects in vertebrates; however few studies have addressed their toxicity to non-mammalian species. The aim of this review is to compare the effects of plasticizers in animals, with a focus on aquatic species. In summary, we identified three main chains of events that occur in animals exposed to BPA and phthalates. Firstly, plasticizers affect development by altering both the thyroid hormone and growth hormone axes. Secondly, these chemicals interfere with reproduction by decreasing cholesterol transport through the mitochondrial membrane, leading to reduced steroidogenesis. Lastly, exposure to plasticizers leads to the activation of peroxisome proliferator-activated receptors, the increase of fatty acid oxidation, and the reduction in the ability to cope with the augmented oxidative stress leading to reproductive organ malformations, reproductive defects, and decreased fertility
Sediment Contaminated with the Azo Dye Disperse Yellow 7 Alters Cellular Stress- and Androgen-Related Transcription in <i>Silurana tropicalis</i> Larvae
Azo
dyes are the most commonly used type of dye, accounting for
60–70% of all organic dye production worldwide. They are used
as direct dyes in the textile, leather, printing ink, and cosmetic
industries. The aim of this study was to assess the lethal and sublethal
effects of the disazo dye Disperse Yellow 7 (DY7) in frogs to address
a knowledge gap regarding mechanisms of toxicity and the potential
for endocrine disrupting properties. Larvae of <i>Silurana tropicalis</i> (Western clawed frog) were exposed to DY7-contaminated water (0
to 22 μg/L) and sediment (0 to 209 μg/g) during early
larval development. The concentrations used included the range of
similar azo dyes found in surface waters in Canada. A significant
decrease in tadpole survivorship was observed at 209 μg/g while
there was a significant increase in malformations at the two highest
concentrations tested in sediment. In the 209 μg/g treatment,
DY7 significantly induced <i>hsp70</i> (2.5-fold) and <i>hsp90</i> (2.4-fold) mRNA levels, suggesting that cells required
oxidative protection. The same treatment also altered the expression
of two androgen-related genes: decreased <i>ar</i> (2-fold)
and increased <i>srd5a2</i> (2.6-fold). Furthermore, transcriptomics
generated new hypotheses regarding the mechanisms of toxic action
of DY7. Gene network analysis revealed that high concentrations of
DY7 in sediment induced cellular stress-related gene transcription
and affected genes associated with necrotic cell death, chromosome
condensation, and mRNA processing. This study is the first to report
on sublethal end points for azo dyes in amphibians, a growing environmental
pollutant of concern for aquatic species