Endocrine Disruptors - HH-RA.org

Bibliography Tag: endocrine disruptors

Pham et al., 2019

Pham, T. H., Derian, L., Kervarrec, C., Kernanec, P. Y., Jegou, B., Smagulova, F., & Gely-Pernot, A.; “Perinatal Exposure to Glyphosate and a Glyphosate-Based Herbicide Affect Spermatogenesis in Mice;” Toxicological Science, 2019, 169(1), 260-271; DOI: 10.1093/toxsci/kfz039.

ABSTRACT:

Glyphosate is the most widely used herbicide in the world. Several studies have investigated the effects of glyphosate and glyphosate-based herbicides (GBHs) on male reproduction, but there is still little and conflicting evidence for its toxicity. In this study, we analyzed the effects of glyphosate, alone or in formula, on the male reproductive system. Pregnant mice were treated from E10.5 to 20 days postpartum by adding glyphosate or a GBH (Roundup 3 Plus) to their drinking water at 0.5 (the acceptable daily intake, ADI dose), 5 and 50 mg/kg/day. Male offspring derived from treated mice were sacrificed at 5, 20, and 35 days old (d.o.) and 8 months old (m.o.) for analysis. Our result showed that exposure to glyphosate, but not GBH, affects testis morphology in 20 d.o. and decrease serum testosterone concentrations in 35 d.o. males. We identified that the spermatozoa number decreased by 89% and 84% in 0.5 and 5 mg/kg/day of GBH and glyphosate groups, respectively. Moreover, the undifferentiated spermatogonia numbers were decreased by 60% in 5 mg/kg/day glyphosate group, which could be due to the alterations in the expression of genes involved in germ cell differentiation such as Sall4 and Nano3 and apoptosis as Bax and Bcl2. In 8 m.o. animals, a decreased testosterone level was observed in GBH groups. Our data demonstrate that glyphosate and GBHs could cause endocrine-disrupting effects on male reproduction at low doses. As glyphosate has effects at the ADI level, our data suggest that the current ADI for glyphosate could be overestimated.

Rattan and Flaws, 2019

Rattan, S., & Flaws, J. A.; “The epigenetic impacts of endocrine disruptors on female reproduction across generationsdagger;” Biology of Reproduction, 2019, 101(3), 635-644; DOI: 10.1093/biolre/ioz081.

ABSTRACT:

Humans and animals are repeatedly exposed to endocrine disruptors, many of which are ubiquitous in the environment. Endocrine disruptors interfere with hormone action; thus, causing non-monotonic dose responses that are atypical of standard toxicant exposures. The female reproductive system is particularly susceptible to the effects of endocrine disruptors. Likewise, exposures to endocrine disruptors during developmental periods are particularly concerning because programming during development can be adversely impacted by hormone level changes. Subsequently, developing reproductive tissues can be predisposed to diseases in adulthood and these diseases can be passed down to future generations. The mechanisms of action by which endocrine disruptors cause disease transmission to future generations are thought to include epigenetic modifications. This review highlights the effects of endocrine disruptors on the female reproductive system, with an emphasis on the multi- and transgenerational epigenetic effects of these exposures. FULL TEXT

Ingaramo et al., 2020

Ingaramo, P., Alarcon, R., Munoz-de-Toro, M., & Luque, E. H.; “Are glyphosate and glyphosate-based herbicides endocrine disruptors that alter female fertility?;” Molecular and Cellular Endocrinology, 2020, 110934; DOI: 10.1016/j.mce.2020.110934.

ABSTRACT:

Numerous evidences have alerted on the toxic effects of the exposure to glyphosate on living organisms. Glyphosate is the herbicide most used in crops such as maize and soybean worldwide, which implies that several non-target species are at a high risk of exposure. Although the Environmental Protection Agency (EPA-USA) has reaffirmed that glyphosate is safe for users, there are controversial studies that question this statement. Some of the reported effects are due to exposure to high doses; however, recent evidences have shown that exposure to low doses could also alter the development of the female reproductive tract, with consequences on fertility. Different animal models of exposure to glyphosate or glyphosate-based herbicides (GBHs) have shown that the effects on the female reproductive tract may be related to the potential and/or mechanisms of actions of an endocrine-disrupting compound. Studies have also demonstrated that the exposure to GBHs alters the development and differentiation of ovarian follicles and uterus, affecting fertility when animals are exposed before puberty. In addition, exposure to GBHs during gestation could alter the development of the offspring (F1 and F2). The main mechanism described associated with the endocrine-disrupting effect of GBHs is the modulation of estrogen receptors and molecules involved in the estrogenic pathways. This review summarizes the endocrine-disrupting effects of exposure to glyphosate and GBHs at low or “environmentally relevant” doses in the female reproductive tissues. Data suggesting that, at low doses, GBHs may have adverse effects on the female reproductive tract fertility are discussed. FULL TEXT

Christensen et al., 2016

Christensen, C. H., Barry, K. H., Andreotti, G., Alavanja, M. C., Cook, M. B., Kelly, S. P., Burdett, L. A., Yeager, M., Beane Freeman, L. E., Berndt, S. I., & Koutros, S.; “Sex Steroid Hormone Single-Nucleotide Polymorphisms, Pesticide Use, and the Risk of Prostate Cancer: A Nested Case-Control Study within the Agricultural Health Study;” Frontiers in Oncology, 2016, 6, 237; DOI: 10.3389/fonc.2016.00237.

ABSTRACT:

Experimental and epidemiologic investigations suggest that certain pesticides may alter sex steroid hormone synthesis, metabolism or regulation, and the risk of hormone-related cancers. Here, we evaluated whether single-nucleotide polymorphisms (SNPs) involved in hormone homeostasis alter the effect of pesticide exposure on prostate cancer risk. We evaluated pesticide-SNP interactions between 39 pesticides and SNPs with respect to prostate cancer among 776 cases and 1,444 controls nested in the Agricultural Health Study cohort. In these interactions, we included candidate SNPs involved in hormone synthesis, metabolism or regulation (N = 1,100), as well as SNPs associated with circulating sex steroid concentrations, as identified by genome-wide association studies (N = 17). Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Multiplicative SNP-pesticide interactions were calculated using a likelihood ratio test. We translated p-values for interaction into q-values, which reflected the false discovery rate, to account for multiple comparisons. We observed a significant interaction, which was robust to multiple comparison testing, between the herbicide dicamba and rs8192166 in the testosterone metabolizing gene SRD5A1 (p-interaction = 4.0 x 10(-5); q-value = 0.03), such that men with two copies of the wild-type genotype CC had a reduced risk of prostate cancer associated with low use of dicamba (OR = 0.62 95% CI: 0.41, 0.93) and high use of dicamba (OR = 0.44, 95% CI: 0.29, 0.68), compared to those who reported no use of dicamba; in contrast, there was no significant association between dicamba and prostate cancer among those carrying one or two copies of the variant T allele at rs8192166. In addition, interactions between two organophosphate insecticides and SNPs related to estradiol metabolism were observed to result in an increased risk of prostate cancer. While replication is needed, these data suggest both agonistic and antagonistic effects on circulating hormones, due to the combination of exposure to pesticides and genetic susceptibility, may impact prostate cancer risk. FULL TEXT

Hernandez et al, 2013

Hernandez, A. F., Parron, T., Tsatsakis, A. M., Requena, M., Alarcon, R., & Lopez-Guarnido, O.; “Toxic effects of pesticide mixtures at a molecular level: their relevance to human health;” Toxicology, 2013, 307, 136-145; DOI: 10.1016/j.tox.2012.06.009.

ABSTRACT:

Pesticides almost always occur in mixtures with other ones. The toxicological effects of low-dose pesticide mixtures on the human health are largely unknown, although there are growing concerns about their safety. The combined toxicological effects of two or more components of a pesticide mixture can take one of three forms: independent, dose addition or interaction. Not all mixtures of pesticides with similar chemical structures produce additive effects; thus, if they act on multiple sites their mixtures may produce different toxic effects. The additive approach also fails when evaluating mixtures that involve a secondary chemical that changes the toxicokinetics of the pesticide as a result of its increased activation or decreased detoxification, which is followed by an enhanced or reduced toxicity, respectively. This review addresses a number of toxicological interactions of pesticide mixtures at a molecular level. Examples of such interactions include the postulated mechanisms for the potentiation of pyrethroid, carbaryl and triazine herbicides toxicity by organophosphates; how the toxicity of some organophosphates can be potentiated by other organophosphates or by previous exposure to organochlorines; the synergism between pyrethroid and carbamate compounds and the antagonism between triazine herbicides and prochloraz. Particular interactions are also addressed, such as those of pesticides acting as endocrine disruptors, the cumulative toxicity of organophosphates and organochlorines resulting in estrogenic effects and the promotion of organophosphate-induced delayed polyneuropathy. FULL TEXT

Curl et al., 2020

Curl, C. L., Spivak, M., Phinney, R., & Montrose, L.; “Synthetic Pesticides and Health in Vulnerable Populations: Agricultural Workers;” Current Environmental Health Reports, 2020, 7(1), 13-29; DOI: 10.1007/s40572-020-00266-5.

ABSTRACT:

PURPOSE OF REVIEW: This review aims to summarize epidemiological literature published between May 15, 2018, and May 14, 2019, that examines the relationship between exposure to synthetic pesticides and health of agricultural workers.

RECENT FINDINGS: Current research suggests that exposure to synthetic pesticides may be associated with adverse health outcomes. Agricultural workers represent a potentially vulnerable population, due to a combination of unique social and cultural risk factors as well as exposure to hazards inherent in agricultural work. Pesticide exposure among agricultural workers has been linked to certain cancers, DNA damage, oxidative stress, neurological disorders, and respiratory, metabolic, and thyroid effects.

SUMMARY: This review describes literature suggesting that agricultural workers exposed to synthetic pesticides are at an increased risk of certain cancers and neurological disorders. Recent research on respiratory effects is sparse, and more research is warranted regarding DNA damage, oxidative stress, metabolic outcomes, and thyroid effects. FULL TEXT

Romano et al., 2010

Romano, R. M., Romano, M. A., Bernardi, M. M., Furtado, P. V., & Oliveira, C. A.; “Prepubertal exposure to commercial formulation of the herbicide glyphosate alters testosterone levels and testicular morphology;” Archives of Toxicology, 2010, 84(4), 309-317; DOI: 10.1007/s00204-009-0494-z.

ABSTRACT:

Glyphosate is a herbicide widely used to kill weeds both in agricultural and non-agricultural landscapes. Its reproductive toxicity is related to the inhibition of a StAR protein and an aromatase enzyme, which causes an in vitro reduction in testosterone and estradiol synthesis. Studies in vivo about this herbicide effects in prepubertal Wistar rats reproductive development were not performed at this moment. Evaluations included the progression of puberty, body development, the hormonal production of testosterone, estradiol and corticosterone, and the morphology of the testis. Results showed that the herbicide (1) significantly changed the progression of puberty in a dose-dependent manner; (2) reduced the testosterone production, in semineferous tubules’ morphology, decreased significantly the epithelium height (P < 0.001; control = 85.8 +/- 2.8 microm; 5 mg/kg = 71.9 +/- 5.3 microm; 50 mg/kg = 69.1 +/- 1.7 microm; 250 mg/kg = 65.2 +/- 1.3 microm) and increased the luminal diameter (P < 0.01; control = 94.0 +/- 5.7 microm; 5 mg/kg = 116.6 +/- 6.6 microm; 50 mg/kg = 114.3 +/- 3.1 microm; 250 mg/kg = 130.3 +/- 4.8 microm); (4) no difference in tubular diameter was observed; and (5) relative to the controls, no differences in serum corticosterone or estradiol levels were detected, but the concentrations of testosterone serum were lower in all treated groups (P < 0.001; control = 154.5 +/- 12.9 ng/dL; 5 mg/kg = 108.6 +/- 19.6 ng/dL; 50 mg/dL = 84.5 +/- 12.2 ng/dL; 250 mg/kg = 76.9 +/- 14.2 ng/dL). These results suggest that commercial formulation of glyphosate is a potent endocrine disruptor in vivo, causing disturbances in the reproductive development of rats when the exposure was performed during the puberty period. FULL TEXT

Pandey and Rudraiah, 2015

Pandey, Aparamita, & Rudraiah, Medhamurthy; “Analysis of endocrine disruption effect of Roundup ® in adrenal gland of male rats;” Toxicology Reports, 2015, 2, 1075-1085; DOI: 10.1016/j.toxrep.2015.07.021.

ABSTRACT:

The effect of Roundup((R)) on adrenal gland steroidogenesis and signaling pathway associated with steroid production was investigated. Doses of 10, 50, 100 and 250 mg/kg bw/d Roundup((R)) were administered for two weeks to adult male rats. The 10 mg/kg bw/d dose which reduced circulatory corticosterone levels, but did not change food consumption and body weight, was selected for further study. The expression of cholesterol receptor (low density lipoprotein receptor), de novo cholesterol synthesis enzyme (3-hydroxy-3-methylglutaryl-coenzyme A synthase), hormone-sensitive lipase, steroidogenic acute regulatory protein (StAR) mRNA and phosphorylated form was decreased. Adrenocorticotropic hormone receptor (ACTH), melanocortin-2 receptor, expression was not changed but circulatory ACTH levels and adrenal cortex protein kinase A (PKA) activity were reduced. Surprisingly, exogenous ACTH treatment rescued steroidogenesis in Roundup((R))-treated animals. Apoptosis was evident at 250 mg/kg bw/d, but not at 10 mg/kg bw/d dose. These results suggest that Roundup((R)) may be inhibitory to hypothalamic-pituitary axis leading to reduction in cyclic adenosine monophosphate (cAMP)/PKA pathway, StAR phosphorylation and corticosterone synthesis in the adrenal tissue. FULL TEXT

Zanardi et al., 2020

Zanardi, M. V., Schimpf, M. G., Gastiazoro, M. P., Milesi, M. M., Munoz-de-Toro, M., Varayoud, J., & Durando, M.; “Glyphosate-based herbicide induces hyperplastic ducts in the mammary gland of aging Wistar rats;” Molecular and Cellular Endocrinology, 2019, 501, 110658; DOI: 10.1016/j.mce.2019.110658.

ABSTRACT:

Glyphosate-based herbicide (GBH) exposure is known to have adverse effects on endocrine-related tissues. Here, we aimed to determine whether early postnatal exposure to a GBH induces long-term effects on the rat mammary gland. Thus, female Wistar pups were injected with saline solution (Control) or GBH (2 mg glyphosate/kg/day) on postnatal days (PND) 1, 3, 5 and 7. At 20 months of age, mammary gland samples were collected to determine histomorphological features, proliferation index and the expression of steroid hormone receptors expression, by immunohistochemistry, and serum samples were collected to assess 17beta-estradiol (E2) and progesterone (P4) levels. GBH exposure induced morphological changes evidenced by a higher percentage of hyperplastic ducts and a fibroblastic-like stroma in the mammary gland. GBH-treated rats also showed a high expression of steroid hormone receptors in hyperplastic ducts. The results indicate that early postnatal exposure to GBH induces long-term alterations in the mammary gland morphology of aging female rats. FULL TEXT

Lajmanovich et al., 2019

Lajmanovich, R. C., Peltzer, P. M., Attademo, A. M., Martinuzzi, C. S., Simoniello, M. F., Colussi, C. L., Cuzziol Boccioni, A. P., & Sigrist, M.; “First evaluation of novel potential synergistic effects of glyphosate and arsenic mixture on Rhinella arenarum (Anura: Bufonidae) tadpoles;” Heliyon, 2019, 5(10), e02601; DOI: 10.1016/j.heliyon.2019.e02601.

ABSTRACT:

The toxicity of glyphosate-based herbicide (GBH) and arsenite (As(III)) as individual toxicants and in mixture (50:50 v/v, GBH-As(III)) was determined in Rhinella arenarum tadpoles during acute (48 h) and chronic assays (22 days). In both types of assays, the levels of enzymatic activity [Acetylcholinesterase (AChE), Carboxylesterase (CbE), and Glutathione S-transferase (GST)] and the levels of thyroid hormones (triiodothyronine; T3 and thyroxine; T4) were examined. Additionally, the mitotic index (MI) of red blood cells (RBCs) and DNA damage index were calculated for the chronic assay. The results showed that the LC50 values at 48 h were 45.95 mg/L for GBH, 37.32 mg/L for As(III), and 30.31 mg/L for GBH-As(III) (with similar NOEC = 10 mg/L and LOEC = 20 mg/L between the three treatments). In the acute assay, Marking’s additive index (S = 2.72) indicated synergistic toxicity for GBH-As(III). In larvae treated with GBH and As(III) at the NOEC-48h (10 mg/L), AChE activity increased by 36.25% and 33.05% respectively, CbE activity increased by 22.25% and 39.05 % respectively, and GST activity increased by 46.75% with the individual treatment with GBH and by 131.65 % with the GBH-As(III) mixture. Larvae exposed to the GBH-As(III) mixture also showed increased levels of T4 (25.67 %). In the chronic assay at NOEC-48h/8 (1.25 mg/L), As(III) and GBH-As(III) inhibited AChE activity (by 39.46 % and 35.65%, respectively), but did not alter CbE activity. In addition, As(III) highly increased (93.7 %) GST activity. GBH-As(III) increased T3 (97.34%) and T4 (540.93%) levels. Finally, GBH-As(III) increased the MI of RBCs and DNA damage. This study demonstrated strong synergistic toxicity of the GBH-As(III) mixture, negatively altering antioxidant systems and thyroid hormone levels, with consequences on RBC proliferation and DNA damage in treated R. arenarum tadpoles. FULL TEXT

Bibliography Index