Endocrine and metabolic alterations in the mink (Mustela vison) due to chronic phytoestrogen exposure

Early Postnatal Genistein Administration Affects Mice Metabolism and Reproduction in a Sexually Dimorphic Way

The phytoestrogen genistein (GEN) may interfere with permanent morphological changes in the brain circuits sensitive to estrogen. Due to the frequent use of soy milk in the neonatal diet, we aimed to study the effects of early GEN exposure on some physiological and reproductive parameters. Mice of both sexes from PND1 to PND8 were treated with GEN (50 mg/kg body weight, comparable to the exposure level in babies fed with soy-based formulas). When adult, we observed, in GEN-treated females, an advanced pubertal onset and an altered estrous cycle, and, in males, a decrease of testicle weight and fecal testosterone concentration. Furthermore, we observed an increase in body weight and altered plasma concentrations of metabolic hormones (leptin, ghrelin, triiodothyronine) limited to adult females. Exposure to GEN significantly altered kisspeptin and POMC immunoreactivity only in females and orexin immunoreactivity in both sexes. In conclusion, early postnatal exposure of mice to GEN determines long-term sex-specific organizational effects. It impairs the reproductive system and has an obesogenic effect only in females, which is probably due to the alterations of neuroendocrine circuits controlling metabolism; thus GEN, should be classified as a metabolism disrupting chemical.

Anthropogenic pressure in a Portuguese river: Endocrine-disrupting compounds, trace elements and nutrients

Natural organic compounds such as phytoestrogens and phytosterols found in various plants, as well as mycotoxins produced by fungi, can be found in aquatic environments. The aim of this study was to investigate the occurrence of three different classes of natural estrogenic compounds, i.e., phytoestrogens, phytosterols and mycotoxins, in estuarine water samples from the Ave River estuary. For that, water samples were collected at five sampling points distributed along the estuary at low tide, during 1 year, processed by solid-phase extraction (SPE) and analyzed by gas chromatography coupled to mass spectrometry (GC-MS). To correlate the presence of phytoestrogens and phytosterols in the estuarine water, local flora was collected on riverside. Trace elements content and physicochemical parameters such as nutrients and dissolved oxygen were also determined seasonally at each sampling point, to give insights for the evaluation of water quality and anthropogenic pressure. Both phytoestrogens and phytosterols showed a seasonal variation, with the highest values observed in spring and summer and the lowest in winter. Daidzein (DAID) was found up to 404.0 ng L(-1) in spring and coumestrol (COUM) was found up to 165.0 ng L(-1) in summer. The mycotoxin deoxynivalenol (DON) was ubiquitously determined with values ranging from 59.5 to 642.4 ng L(-1). Nutrients and metals distribution and concentration varied among sampling stations and seasons. This study revealed for the first time the presence of mycotoxins, various classes of phytoestrogens and stigmasterol (STG) in estuarine water from the Ave River (Portugal), and the evaluation of the water quality confirmed that this estuary is still highly impacted by anthropogenic activities.

Occurrence of Natural Contaminants of Emerging Concern in the Douro River Estuary, Portugal

Many studies demonstrated the presence of diverse environmental contaminants in the Douro River estuary, such as natural and synthetic estrogens, pharmaceuticals, industrial compounds and pesticides. This estuary is located between two densely populated cities and is highly impacted due to anthropogenic activities, such as industry and agriculture. Although the presence of mycotoxins and phytoestrogens, such as lignans and coumestrans, in the aquatic environment is reported by some authors, their occurrence in Portuguese waters was not investigated yet. To evaluate the presence of phytoestrogens, phytosterols and mycotoxins in Douro River estuary, water samples were collected seasonally at nine sampling points, preconcentrated by solid phase extraction and analysed by gas chromatography mass spectrometry. Local flora was collected on the riverside, in the same sampling points, for identification and evaluation of the possible relation to the presence of phytoestrogens and/or phytosterols in the estuarine water. Results showed the ubiquitous presence of mycotoxins, namely deoxynivalenol up to 373.5 ng L(-1). Both phytoestrogens and phytosterols showed a possible seasonal fluctuation, which is in accordance to the life cycle of the local flora and agricultural practices. Physicochemical parameters were also determined for water quality evaluation. This study revealed for the first time the presence of mycotoxins and lignans in estuarine waters from Portugal, and highlights the need to consider natural contaminants in future monitoring programs.

Activated sludge versus aerated lagoon treatment of kraft mill effluents containing beta-sitosterol and stigmasterol

In the present study the performance of an activated sludge system (AS) and an aerated lagoon (AL) are compared for the treatment of kraft cellulose effluents. Both reactors were operated at organic loading rates (OLR) up to 9 g COD/L. d. The activated sludge system presented better performance at high OLR than the aerated lagoon with removal percentages of 57-67% and 95% of COD and BOD(5), respectively. The removal percentages of specific compounds were always slightly higher in the case of the AS than in the AL with exception of the total phenolic compounds which concentration increased in the former. Furthermore the analyzed fractions from the effluents indicated that in the AS the compounds were fully removed while in the case of the aerated lagoon were transformed into compound with low molecular weight P2 (5 kD < MW < 10 kD). In the case of the AS system the increase of the total phenolic compounds concentrations was corroborated with the increase of the fractions P2, P3 and P4. The studied phytosterol were removed from the effluent at concentrations up to 2 mg/L in percentages close to 100% mainly by adsorption in the case of the AL and by a combining adsorption and mainly degradation in the AS. The BOD(5) concentration in the effluent of both systems fulfilled the requirements of the Chilean regulations for effluent discharge indicating the feasibility of aerobic treatment of this kind of effluents.

Multi-functional sample preparation procedure for measuring phytoestrogens in milk, cereals, and baby-food by liquid-chromatography tandem mass spectrometry with subsequent determination of their estrogenic activity using transcriptomic assay

A method dedicated to the determination of a multiple range of phytoestrogens as endocrine disruptor compounds in infant food products was developed, with as double objective the specific measurement of 13 parameters and the evaluation of the estrogenic potency associated to this quantitative profile. A combined enzymatic and acidic chemical hydrolysis followed by a double purification on two successive C(18) and SiOH Solid Phase Extraction cartridges permitted to efficiently purify milk, cereals and baby-food samples while eliminating naturally occurring estrogen hormones. A specific liquid chromatography-tandem mass spectrometric measurement authorised unambiguous identification and quantification of the target compounds. The proposed methodology was fully validated and applied to a set of around 30 real samples, demonstrating the presence of phytoestrogens at levels globally ranging from several microgkg(-1) (ppb) to several tens mgkg(-1) (ppm). The prepared sample extracts were proven to be suitable and compatible with the evaluation of their induced biological transcriptional activity on MCF-7 cell lines. Because permitting to cope with difficult issues such as low-dose and mixture effects, this proposed methodology may appear of particular interest for further exposure assessment studies and hazard characterisation investigations related to this class of endocrine disruptor compounds.

Evaluation of reproductive safety of beta-sitosterol on the American mink (Neovison vison)

beta-Sitosterol is a weakly estrogenic phytosterol used extensively in functional foods to lower elevated serum cholesterol concentrations due to its inhibitory action on intestinal cholesterol absorption. It caused previously decreased sex steroid concentrations in fish and lowered sperm counts in rats. In the American mink (Neovison vison), litter size increased slightly due to dietary beta-sitosterol supplement. The aim of the present experiment was to conduct a dose-response study on the effects of beta-sitosterol on the reproduction of the American mink. Juvenile male and female mink (n=480) were exposed to 0, 5, 10 or 50 mg of peroral beta-sitosterol kg(-1)d(-1) for 10 months. After 3 months of exposure in November, 15 males per group were sacrificed and general biochemical variables reflecting overall health were determined. The beta-sitosterol-treated male mink had increased absolute and relative masses of intraabdominal fat and higher blood hemoglobin and serum high-density lipoprotein cholesterol concentrations. In spring, the top-rated male mink were mated with multiple females within each study group and reproductive success was assessed. No differences in the reproductive performance of the males (10-11 per group) or females (47-50 per group) could be detected in the exposed groups and the kits of all groups developed in a similar manner. The results suggest that dietary beta-sitosterol presents no significant risk to mammalian fertility.