Early exposure to mercury and cardiovascular function of seven-year old children in Guadeloupe (French West Indies).

BACKGROUND: The cardiotoxicity of prenatal exposure to mercury has been suggested in populations having regular contaminated seafood intake, though replications in the literature are inconsistent. METHODS: The Timoun Mother-Child Cohort Study was set up in Guadeloupe, an island in the Caribbean Sea where seafood consumption is regular. At seven years of age, 592 children underwent a medical examination, including cardiac function assessment. Blood pressure (BP) was taken using an automated blood pressure monitor, heart rate variability (HRV, 9 parameters) and electrocardiogram (ECG) characteristics (QT, T-wave parameters) were measured using Holter cardiac monitoring during the examination. Total mercury concentrations were measured in cord blood at birth (median = 6.6 µg/L, N = 399) and in the children's blood at age 7 (median = 1.7 µg/L, N = 310). Adjusted linear and non-linear modelling was used to study the association of each cardiac parameter with prenatal and childhood exposures. Sensitivity analyses included co-exposures to lead and cadmium, adjustment for maternal seafood consumption, selenium and polyunsaturated fatty acids (n3-PUFAs), and for sporting activity. RESULTS: Higher prenatal mercury was associated with higher systolic BP at 7 years of age (ßlog2 = 1.02; 95% Confidence Interval (CI) = 0.10, 1.19). In boys, intermediate prenatal exposure was associated with reduced overall HRV and parasympathetic activity, and longer QT was observed with increasing prenatal mercury (ßlog2 = 4.02; CI = 0.48, 7.56). In girls, HRV tended to increase linearly with prenatal exposure, and no association was observed with QT-wave related parameters. Mercury exposure at 7 years was associated with decreased BP in girls (ßlog2 = -1.13; CI = -2.22, -0.004 for diastolic BP). In boys, the low/high-frequency (LF/HF) ratio increased for intermediate levels of exposure. CONCLUSION: Our study suggests sex-specific and non-monotonic modifications in some cardiac health parameters following prenatal exposure to mercury in pre-pubertal children from an insular fish-consuming population.

Characterization of organic contaminants in hair for biomonitoring purposes.

Biological monitoring is one way to assess human exposure to contaminants. Blood and urine are often used as biological matrices, but hair is an innovative and effective tool for quantifying more biomarkers over a wider exposure window. In order to improve the use of hair in exposure assessment, this article identifies relevant compounds in the literature to investigate hair contamination. Statistical analysis was performed to correlate the physical-chemical properties of the relevant compounds and their concentration levels in hair. Phthalates, pyrethroids and organophosphate flame retardants were chosen for further study of the interpretation of hair measurements for exposure assessment. No significant correlation was found between the average concentration levels in the literature and the physical-chemical properties of the selected compounds. This work also explores the properties of hair and the analytical process that may impact the quantification of organic contaminants in hair. The sample preparation method (sampling, storage, washing) were also studied and adaptations were suggested to improve the existing methods.

Natural glyceollin soybean extracts elicited with Aspergillus sojae reduce estrogen-dependent breast cancer growth in orally fed mice.

Previous studies have demonstrated antiestrogenic and antiproliferative effects of these molecules in breast cancer cells. Notably, we have reported that pure synthetic glyceollins I and II act through various pathways, including ERα, FOXM1, AhR, and HIF pathways to inhibit cell proliferation and migration. In this study, the potential antitumor activity of glyceollins enriched in crude soybean extracts, obtained by solid fermentation with Aspergillus sojae, was investigated in vivo on MCF-7 breast cancer cells implanted in the chorioallantoic membrane of the chick egg and on ovariectomized nude mice. The first trial showed a substantial reduction in the migration of MCF-7 cells treated with the natural extracts. However, the natural extracts significantly reduced the estrogen-dependent growth of transplanted tumors in orally fed nude mice. Our results showed that natural soybean extracts slightly but significantly reduced estrogen-dependent growth of the transplanted tumors in orally fed nude mice. These results were confirmed by immunohistochemistry of Ki-67 and histone H3S10 phosphorylation (H3S10P), revealing lower expression of these proliferation markers in the transplanted tumors from mice fed with the fermented extracts. Additionally, compared to the control animals, we observed a lower expression of angiogenesis markers such as CD31 and CD34. Surprisingly, transcriptomic analysis of RNA from transplanted MCF-7 cells revealed no differential gene expression. These results may suggest that orally consumed natural glyceollins exert biological effects throughout the body, acting indirectly to reduce tumor angiogenesis and consequently tumor volume. Overall, our results indicate that glyceollins, elicited components of the soy origin, hold potential therapeutic applications for the prevention and treatment of breast cancer.