Mechanistic Investigation of Drug Supersaturation in the Presence of Polysorbates as Solubilizing Additives by Solution Nuclear Magnetic Resonance Spectroscopy

The introduction of solubilizing additives has historically been an attractive approach to address the ever-growing proportion of poorly water-soluble drug (PWSD) compounds within the modern drug discovery pipeline. Lipid-formulations, and more specifically micelle formulations, have garnered particular interest because of their simplicity, size, scalability, and avoidance of solid-state limitations. Although micelle formulations have been widely utilized, the molecular mechanism of drug solubilization in surfactant micelles is still poorly understood. In this study, a series of modern nuclear magnetic resonance (NMR) methods are utilized to gain a molecular-level understanding of intermolecular interactions and kinetics in a model system. This approach enabled the understanding of how a PWSD, 17β-Estradiol (E2), solubilizes within a nonionic micelle system composed of polysorbate 80 (PS80). Based on one-dimensional (1D) ¹H chemical shift differences of E2 in PS80 solutions, as well as intermolecular correlations established from 1D selective nuclear Overhauser effect (NOE) and two-dimensional NOE spectroscopy experiments, E2 was found to accumulate within the palisade layer of PS80 micelles. A potential hydrogen-bonding interaction between a hydroxyl group of E2 and a carbonyl group of PS80 alkane chains may allow for stabilizing E2-PS80 mixed micelles. Diffusion and relaxation NMR analysis and particle size measurements using dynamic light scattering indicate a slight increase in the micellar size with increasing degrees of supersaturation, resulting in slower mobility of the drug molecule. Based on these structural findings, a theoretical orientation model of E2 molecules with PS80 molecules was developed and validated by computational docking simulations.

Facile fabrication of 17β-estradiol electrochemical sensor using polyaniline/carbon dot-coated glassy carbon electrode with synergistically enhanced electrochemical stability

Previous 17β-estradiol sensors required expensive reagents or complicated fabrication of sensing probes. In this work, a cheap, simple, and reusable electrochemical sensor based on commercially available polyaniline (PANI) and carbon dots (CDs) synthesized from iota-carrageenan was developed for the sensitive detection of 17β-estradiol. The sensor was simply prepared by drop-casting CDs/PANI composite on a glassy carbon electrode (GCE) using poly(vinylidene fluoride) as a binder. With synergistic contributions from both CDs and PANI, the CDs-PANI/GCE was much more electrochemically stable than the CDs/GCE or PANI/GCE. The CDs-PANI/GCE was sensitive to 17β-estradiol across a linear range from 0.001 to 100 μmol L^-1 with a detection limit of 43 nmol L^-1. The electrochemical measurement can be performed in 2 min and the probe can be reused for several hundred times. The CDs-PANI/GCE was selective towards 17β-estradiol against several interferences and gave excellent recovery between 94.4 and 103.7 % from real sample analysis. From intensive investigation on electron transfer process and energy levels, the oxidation reaction of 17β-estradiol occurred on the surface of CDs-PANI/GCE via favorable energy levels and dominantly surface adsorption process through π-π stacking and hydrogen bonding between 17β-estradiol and CDs/PANI. Such unique interfacial interactions also resulted in the synergistically enhanced electrochemical stability of the modified electrode.

Brain-derived estrogen and neural function

Although classically known as an endocrine signal produced by the ovary, 17β-estradiol (E₂) is also a neurosteroid produced in neurons and astrocytes in the brain of many different species. In this review, we provide a comprehensive overview of the localization, regulation, sex differences, and physiological/pathological roles of brain-derived E₂ (BDE₂). Much of what we know regarding the functional roles of BDE₂ has come from studies using specific inhibitors of the E₂ synthesis enzyme, aromatase, as well as the recent development of conditional forebrain neuron-specific and astrocyte-specific aromatase knockout mouse models. The evidence from these studies support a critical role for neuron-derived E₂ (NDE₂) in the regulation of synaptic plasticity, memory, socio-sexual behavior, sexual differentiation, reproduction, injury-induced reactive gliosis, and neuroprotection. Furthermore, we review evidence that astrocyte-derived E₂ (ADE₂) is induced following brain injury/ischemia, and plays a key role in reactive gliosis, neuroprotection, and cognitive preservation. Finally, we conclude by discussing the key controversies and challenges in this area, as well as potential future directions for the field.

Toxicity of disinfection byproducts formed during the chlorination of sulfamethoxazole, norfloxacin, and 17β-estradiol in the presence of bromide

Brominated disinfection byproducts (Br-DBPs) are formed during the disinfection process of water containing bromine ions, such as marine aquaculture water. Little attention has been paid to Br-DBPs with anthropogenic chemicals as precursors. This study summarized the sodium hypochlorite (NaClO) oxidation of three frequently used pharmaceuticals, including two antibiotics, norfloxacin (NOR) and sulfamethoxazole (SMX), and the growth hormone estrogen 17β-estradiol (E2). Transformations of the pharmaceuticals were found to be faster in marine aquaculture water than in distilled water. Several Br-DBPs and Cl-DBPs were identified for NOR, SMX, and E2. It was shown that the carboxyl group, piperazine ring, C3, and C8 atoms were the primary reaction sites on NOR. The aniline moiety and S-N bond were identified to be the reaction sites on SMX. The C2, C4, C9, and C16 atoms were the potential reaction centers on E2. Preliminary calculation by QSAR model indicated that the value of logKow significantly increased with an increase in the number of bromine atoms in the Br-DBPs. The results of the bioconcentration factors (BCF) analysis suggested that the bioaccumulation of Br-DBPs were greater than that chlorinated DBPs (Cl-DBPs) in distilled water.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Expression of miR-34a and miR-15b during the progression of cervical cancer in a murine model expressing the HPV16 E7 oncoprotein

The high-risk human papillomavirus (HR-HPV) E7 oncoprotein appears to be a major determinant for cell immortalization and transformation altering critical processes such as cell proliferation, apoptosis, and immune response. This oncoprotein plays an essential role in cervical carcinogenesis, but other cofactors such as long-term use of hormonal contraceptives are necessary to modulate the risk of cervical cancer (CC). The role of HR-HPVs in the alteration of microRNA (miRNA) levels in persistent viral infections currently remains unclear. The aim of this study was to evaluate the miR-34a and miR-15b expression levels in the murine HPV16K14E7 (K14E7) transgenic model after chronic estrogen (E₂) treatment and their involvement in CC. Interestingly, results showed that, although miR-34a expression is elevated by the HPVE7 oncogene, this expression was downregulated in the presence of both the E7 oncoprotein and chronic E₂ in cervical carcinoma. On the other hand, miR-15b expression was upregulated along cervical carcinogenesis mainly by the effect of E₂. These different changes in the expression levels of miR-34a and miR-15b along cervical carcinogenesis conduced to low apoptosis levels, high cell proliferation and finally, to cancerous cervical tissue development. In this work, we also determined the relative mRNA expression of Cyclin E2 (Ccne2), Cyclin A2 (Ccna2), and B cell lymphoma 2 (Bcl-2) (target genes of miR-34a and miR-15b); Sirtuin 1 (Sirt1), Cmyc, and Bax (miR-34a target genes); and p21/WAF1 (mir15b target gene) and the H-ras oncogene. Given the modifications in the expression levels of miR-34a and miR-15b during the development of cervical cancer, it will be useful to carry out further investigation to confirm them as molecular biomarkers of cancer.

Effect of oral administration of GnRHa+nanoparticles of chitosan in oogenesis acceleration of goldfish Carassius auratus

Several methods have been used to accelerate previtellogenesis and vitellogenesis stages in fish, including hormonal induction, sustained-release delivery systems, and oral delivery of gonadotropin-releasing hormone (GnRH). In this study, we proposed the oral administration of GnRH analog + nanoparticles of chitosan to accelerate oogenesis in goldfish as a model fish in reproductive biology and aquaculture. In this regard, adult female goldfish were fed with six experimental groups: chitosan, 50 μg GnRHa/kg b.w., 100 μg GnRHa/kg b.w., chitosan + 50 μg GnRHa/kg b.w., and chitosan + 100 μg GnRHa/kg b.w., and diet without any additive as the control for 40 days in triplicate. Every 10 days, ovarian samples were collected, and gonadosomatic index (GSI), oocyte diameter (OD), zona radiata thickness (Zr), and diameter of the follicular layer (Fl) were measured to assess ovarian developmental stage for each treatment. Additionally, blood sampling was done to measure serum 17β-estradiol concentration at the end of the experiment. All parameters remained unchanged during the experiment in the chitosan-fed group. In the group fed with 100 μg GnRH or chitosan nanoparticle + 100 μg GnRHa, these parameters in general were increased. However, the effects in 50 μg GnRHa or chitosan nanoparticle + 50 μg GnRHa treatments were uncertain; they affected serum E2 levels as a trend toward a significant increase was observed in goldfish treated with chitosan nanoparticle + 100 μg GnRHa. Finally, the results indicated the oral administration of chitosan + 100 μg GnRHa/kg b.w. significantly accelerated the oocyte development and growth of ovary.

Induced self-enhanced electrochemiluminescence aptamer sensor for 17β-estradiol detection based on nitrogen-doped carbon quantum dots as Ru(dcbpy)32+ coreactant: What role of intermolecular hydrogen bonds play in the system?

Herein, an induced self-enhanced electrochemiluminescence (ECL) sensor with superior ECL performances was simply fabricated by just dropping the ECL reagent (tris(4,4'-dicarboxylicacid-2,2'-bipyridyl) ruthenium (II) dichloride, Ru(dcbpy)₃Cl₂) and coreactant (nitrogen-doped carbon quantum dots, NCQDs) pair onto the surface of glassy carbon electrode. In this strategy, based on the carboxyl (-COOH) groups in Ru(dcbpy)₃²⁺ and oxygen, nitrogen-containing groups on NCQDs surface, an intermolecular hydrogen bonds-induced self-enhanced ECL composite was generated in the solid contact layer for the first time. Since Ru(dcbpy)₃²⁺ and NCQDs were co-existing in the same composite, the electron-transfer distance between them was shortened and the energy loss was decreased, thereby higher ECL efficiency was acquired. This working process greatly avoided the introduction of signal amplifier and simplified the experimental operation. On this basis, 17β-estradiol (E2) was selected as a target model to fabricate a self-enhanced ECL aptamer sensor for the investigation of its analytical performances. Resultantly, excellent detection properties of E2, including wider linear range of 1.0 × 10^-14 - 1.0 × 10^-6 mol L^-1 and lower detection limit of 1.0 × 10^-15 mol L^-1 with superior selectivity, were successfully achieved. Finally, E2 spiked into milk powder was quantified to assess the practicability of this sensor. Prospectively, this strategy could be extensively applied for other analytes determination by adjusting the corresponding target aptamers.

17β-Estradiol strongly inhibits azoxymethane/dextran sulfate sodium-induced colorectal cancer development in Nrf2 knockout male mice

Nuclear factor erythroid 2-related factor 2 (Nrf2) has dual effects on inflammation and cancer progression depending on the microenvironment. Estrogens have a protective effect on colorectal cancer (CRC) development. The aim of this study was to investigate CRC development in Nrf2 knockout (KO) mice. Azoxymethane (AOM) and dextran sulfate sodium (DSS)-treated wild-type (WT) and Nrf2 KO male mice were sacrificed at weeks 2 and 16 after AOM injection with/without 17β-estradiol (E2) treatment during week 1. Disease activity index and colon tissue damage at week 2 showed strong attenuation following E2 administration in WT mice but to a lesser extent in Nrf2 KO male mice. At week 16, E2 significantly diminished AOM/DSS-induced adenoma/cancer incidence at distal colon in the Nrf2 KO group, but not in the WT. Furthermore, mRNA or protein levels of NF-κB-related mediators (i.e., iNOS, TNF-α, and IL-1β) and Nrf2-related antioxidants (i.e., NQO1 and HO-1) were significantly lower in the Nrf2 KO group regardless of E2 treatment compared to the WT. The expression of estrogen receptor beta (ERβ) was higher in the Nrf2 KO group than in the WT. In conclusion, estrogen further inhibits CRC by upregulating ERβ-related alternate pathways in the absence of Nrf2.

Concise synthesis of 2-methoxyestradiol through C(sp2)-H methoxylation

An efficient and concise synthesis of 2-methoxyestradiol (4) from 17β-estradiol (1) has been achieved in three synthetic steps with a 63.3% overall yield. The key step was the palladium-catalyzed direct C(sp²)-H methoxylation of 2-aryloxypyridines. Using 2-pyridyloxyl as the directing group, Pd(OAc)₂ as the catalyst, PhI(OAc)₂ as the oxidant and methanol as both the methoxylation reagent and solvent, the methoxy group could be handily installed at the 2-position of 3-(2-pyridoxy) estradiol (2). Subsequently, the pyridyl group could be easily removed by nucleophilic substitution with a methoxy anion after being oxidized to a pyridyl N-oxide by m-chloroperoxybenzoic acid, delivering the target product 2-methoxyestradiol (4) in quantitative yield. In contrast, when the pyridyl directing group was removed by the TfOMe-NaOMe/MeOH system as reported in the literature, TfOMe inevitably methylated the 17-OH of 2-methoxy-3-(2-pyridoxy) estradiol (3). In effect, we have fortuitously found a new method to cleave the pyridyl directing group, which is highly suitable for substrates bearing hydroxy groups.

Identification, functional characterization, and estrogen regulation on gonadotropin-releasing hormone in the spotted scat, Scatophagus argus

Gonadotropin-releasing hormone (GnRH) is a key neuropeptide of the reproductive system. However, little is known about the role of GnRH in the spotted scat (Scatophagus argus). Here, three GnRH subtypes (cGnRH-II, sGnRH, and sbGnRH) were identified in the spotted scat. cGnRH-II and sGnRH were only expressed in the brains and gonads of both male and female fish, exhibiting a tissue-specific expression pattern, while sbGnRH was expressed at different transcription levels in all examined tissues. During ovarian maturation, hypothalamus-associated sbGnRH was upregulated, while the expression of sGnRH was variable and cGnRH-II first increased and then decreased. In vivo experiments showed that sbGnRH significantly promoted the expression of fsh and lh genes in a dose-dependent manner and exhibited a desensitization effect on lh expression at high concentrations. For sGnRH and cGnRH-II, only high concentrations could induce fsh and lh expression. Furthermore, treatment with highly concentrated sbGnRH peptide also induced fsh and lh expression, whereas the sGnRH and cGnRH-II peptides only induced fsh expression in vitro. 17β-Estradiol (E₂) significantly inhibited the expression of sbGnRH mRNA in a dose-dependent manner and did not impact sGnRH and cGnRH-II mRNA levels in vivo or in vitro. The inhibitory effect of E₂ on sbGnRH expression was attenuated by the estrogen receptor (ER) broad-spectrum antagonist (fulvestrant) and the ERα-specific antagonist (methyl-piperidinopyrazole), respectively, implying that the feedback regulation on sbGnRH is mediated via ERα. This study provides a theoretical basis for the reproductive endocrinology of the spotted scat by studying GnRH.

Risk-based decision making in rats: Modulation by sex and amphetamine

Decision-making is a complex process essential to daily adaptation in many species. Risk is an inherent aspect of decision-making and it is influenced by gonadal hormones. Testosterone and 17β-estradiol may modulate decision making and impact the mesocorticolimbic dopamine pathway. Here, we explored sex differences, the effect of gonadal hormones and the dopamine agonist amphetamine on risk-based decision making. Intact or gonadectomised (GDX) male and female rats underwent to a probabilistic discounting task. High and low doses of testosterone propionate (1.0 or 0.2 mg) and 17β-estradiol benzoate (0.3 μg) were administered to assess acute effects on risk-based decision making. After 3-days of washout period, intact and GDX rats received high or low (0.5 or 0.125 mg/kg) doses of amphetamine and re-tested in the probabilistic discounting task. Under baseline conditions, males made more risky choices during probability discounting compared to female rats, particularly in the lower probability blocks, but GDX did not influence risky choice. The high, but not the low dose, of testosterone modestly reduced risky decision making in GDX male rats. Conversely, 17β-estradiol had no significant effect on risky choice regardless of GDX status in either sex. Lastly, a higher dose of amphetamine increased risky decision making in both intact males and females, but had no effect in GDX rats. These findings demonstrated sex differences in risk-based decision making, with males showing a stronger bias toward larger, uncertain rewards. GDX status influenced the effects of amphetamine, suggesting different dopaminergic regulation in risk-based choices among males and females.

17β-Estradiol augments the neuroprotective effect of agomelatine in depressive- and anxiety-like behaviors in ovariectomized rats

RATIONALE AND OBJECTIVE

Estradiol decline has been associated with depression and anxiety in post-menopausal women. Agomelatine (Ago) is an agonist of the melatonergic MT1/MT2 receptors and an antagonist of the serotonergic 5-HT2c receptors. The present study aimed to evaluate the effects of combining Ago with 17β-estradiol (E2) on ovariectomy (OVX)-induced depressive- and anxiety-like behaviors in young adult female rats.

METHODS

OVX rats were treated with Ago (40 mg/kg/day, p.o.) for 10 days starting 1 week after surgery alone or combined with two doses of E2 (40 μg/kg/day, s.c.) given before behavioral testing.

RESULTS

Co-administration of E2 enhanced the anti-depressant and anxiolytics effects of Ago as evidenced by decreased immobility time in the forced swimming test, as well as increased time spent in the open arms and number of entries to open arms in the elevated plus-maze. In parallel, Ago increased hippocampal norepinephrine, dopamine, melatonin, and brain-derived neurotrophic factor (BDNF). Meanwhile, Ago-treated rats exhibited reduced hippocampal nuclear factor kappa beta (NF-kB) P65 expression and pro-inflammatory cytokine level. Ago upregulated estrogen receptor (ER α and β) mRNA expression in the hippocampus of OVX rats and elevated serum estradiol levels. Co-administration of E2 with Ago synergistically decreased NF-kB P65 expression and pro-inflammatory cytokines, and increased BDNF levels.

CONCLUSION

E2 augmented the neuroprotective effect of Ago in OVX rats via its anti-inflammatory and neurotrophic effects. The combined treatment of E2 and Ago should be further investigated as a treatment of choice for depression, anxiety, and sleep disturbances associated with menopause.

Extracellular Neuroglobin as a Stress-Induced Factor Activating Pre-Adaptation Mechanisms against Oxidative Stress and Chemotherapy-Induced Cell Death in Breast Cancer

Components of tumor microenvironment, including tumor and/or stromal cells-derived factors, exert a critical role in breast cancer (BC) progression. Here we evaluated the possible role of neuroglobin (NGB), a monomeric globin that acts as a compensatory protein against oxidative and apoptotic processes, as part of BC microenvironment. The extracellular NGB levels were evaluated by immunofluorescence of BC tissue sections and by Western blot of the culture media of BC cell lines. Moreover, reactive oxygen species (ROS) generation, cell apoptosis, and cell migration were evaluated in different BC cells and non-tumorigenic epithelial mammary cells treated with BC cells (i.e., Michigan Cancer Foundation-7, MCF-7) conditioned culture media and extracellular NGB. Results demonstrate that NGB is a component of BC microenvironment. NGB is released in tumor microenvironment by BC cells only under oxidative stress conditions where it can act as autocrine/paracrine factor able to communicate cell resilience against oxidative stress and chemotherapeutic treatment.

Neuroprotective effects of vitamin D and 17ß-estradiol against ovariectomy-induced neuroinflammation and depressive-like state: Role of the AMPK/NF-κB pathway

Estrogen replacement therapy (ERT) has been proven to relieve menopausal-related mental disorders including depression in postmenopausal women. However, the unsafety of ERT hinders its clinical use. In this study, we would evaluate whether vitamin D (VD), a hormone with optimal safety profile, could relieve the depressive-like symptom in ovariectomized (OVX) rats. Furthermore, we would determine whether vitamin D and 17β-estradiol (E2) exert neurological function through their immunomodulatory effect in OVX rats. Middle-aged female SD rats were randomly divided into four groups, namely, control (SHAM), OVX, OVX + VD, and OVX + E2. Vitamin D (calcitriol, 100 ng/kg) and 17β-estradiol (30 μg/kg) had been daily gavaged in the OVX + VD and OVX + E2 group, respectively. After 10-week administration, vitamin D and 17β-estradiol both showed anti-depressive-like activity in the OVX rats. Using the method of immunofluorescent staining and western blot, vitamin D and 17β-estradiol were demonstrated to upregulate each other's receptors, including VDR, ERα, and ERβ in the hippocampus of OVX rats. Additionally, the upregulation of VDR, calbindin-D28k, and calbindin-D9k suggested that the vitamin D signaling system was amplified by vitamin D and 17β-estradiol. Vitamin D and 17β-estradiol showed neuroprotective effects by decreasing OVX-induced apoptosis and neuronal damage, regulating the AMPK/NF-κB signaling pathway, and reducing the proinflammatory cytokines (IL-1β, IL-6, and TNFα), as well as iNOS and COX-2 in the hippocampus of OVX rats. Collectively, the present study demonstrated that vitamin D and 17β-estradiol could upregulate each other's receptors and regulate the AMPK/NF-κB pathway to relieve the OVX-induced depressive-like state. The results could stimulate translational research towards the vitamin D potential for prevention or treatment of menopause-related depression.

Involvement of glutamate receptors of the paragigantocellularis lateralis nucleus in the pain modulatory effect of 17β-estradiol in male rats

The pain modulatory role of the paragigantocellularis lateralis nucleus (LPGi) and the 17β-estradiol has thoroughly been probed. This study investigates the contribution of ionotropic glutamate receptors in pain modulatory effect of intra-LPGi injection of 17β-estradiol. For this purpose, the LPGi nucleus cannulation was performed and drugs were injected into this nucleus, 15 min prior to the formalin test. The duration of formalin-induced flexing and licking behaviors was recorded for 60 min immediately after formalin injection. The results showed that the flexing behavior is significantly decreased by intra-LPGi injection of 0.8 µmol 17β-estradiol duringboth phases of formalin test (P < 0.001). However, 17β-estradiol attenuated the licking duration only in the second phase (P < 0.001). Interestingly, NMDA and AMPA/kainate receptor antagonists (AP5 and CNQX, respectively) significantly counteracted the analgesic effect of intra-LPGi injection of 17β-estradiol in both phases of the formalin test (P < 0.001). Consequently, the revealing results showed that the analgesic effect of intra-LPGi injection of 17β-estradiol on acute inflammatory pain might be mediated via the activation of ionotropic glutamate receptors.

Spatio-temporal distribution and transformation of 17α- and 17β-estradiol in sterilized soil: A column experiment

The environmental behaviors of steroid estrogens (SEs) associated with land irrigation and application are of critical concern worldwide. Understanding the spatio-temporal distribution and transformation process of these estrogenic compounds in soil is greatly significant. In this study, laboratory soil column experiments were conducted to investigate and explore the migration and abiotic transformation of 17α-estradiol (17α-E2) and 17β-estradiol (17β-E2) over spatial and time scales. Results indicated that the migration tendency of 17α-E2 and 17β-E2 was similar. Discrepancies in transport for different SEs groups might be due to the competitive sorption and isomeric transformation in the binary-solute system. 17α-E2 and 17β-E2 can also undergo the abiotic transformation during soil column transport. The soil with naturally abundant mineral substances (e.g., iron and manganese oxides) indicated that E2 isomers tended to mineral-promoted racemization, oxidation, reduction, and radical coupling reactions. Some possible transformation products (e.g., SE₂₃₉, E2₃₇₈, and SE dimer₄₇₆) were identified and proposed in soil samples. Compared to the single compound tests, the estimated 17β-estradiol equivalency (EEQ) values of E2 mixture were higher during SEs migration process.

Isolation and characterization of a new highly effective 17β-estradiol-degrading Gordonia sp. strain R9

In this report, Gordonia sp. strain R9 isolated from an enrichment culture of chicken leachate was confirmed to degrade 17β-estradiol (E2), which can also use other estrogens (estrone, estriol, and 17α-ethynylestradiol) and testosterone as sole carbon and energy sources. Optimization of growth conditions showed that Gordonia sp. strain R9 can tolerate a very wide range of temperature (4-40 °C) and pH (1.0-11.0), and is sensitive to antibiotics including kanamycin, ampicillin, chloramphenicol, and carbenicillin. Optimal culture conditions for E2 degradation were 30 °C and pH 7.0 with almost 100% degradation of E2 concentrations ranging from 50 µg/L to 5 mg/L within 24 h. The E2 intermediates so generated included estrone (E1), estratriol (E3), (3Z)-3-(3-hydroxy-3a-methyl-7-oxododecahydro-6H-cyclopenta[a]naphthalen-6-ylidene) propanoic acid and 3-hydroxy-3a-methyl-7-oxododecahydro-1H-cyclopenta[a]naphthalene-6-carboxylic acid. These results indicate that the highly effective E2-degradative ability of Gordonia sp. strain R9 merits further investigation as a candidate for large-scale estrogen biodegradation.

Telmisartan/17β-estradiol mitigated cognitive deficit in an ovariectomized rat model of Alzheimer's disease: Modulation of ACE1/ACE2 and AT1/AT2 ratio

AIMS

The higher incidence rate of Alzheimer's disease (AD) among women has led to explorations on the association between estrogen deficiency and AD. Also, usage of antihypertensive drugs has been suggested to reduce the incidence of AD in elderly hypertensive patients. Thus, this study aimed to investigate the effects of telmisartan and/or 17β-estradiol on a cognitively impaired ovariectomized rat model of AD.

MAIN METHODS

75 female Wistar rats were randomly allocated into five groups. One group was sham operated and the other four groups were subjected to ovariectomy, received D-galactose and either untreated or treated with telmisartan and/or 17β-estradiol for 6 weeks.

KEY FINDINGS

Ovariectomized rats showed cognitive impairment in Morris water maze and novel object recognition tests, increasing inflammatory biomarkers (tumor necrosis factor-α, and interleukin-1β), increasing AD biomarkers (amyloid beta1-42, and acetylcholine esterase), and over activation of classical arm of renin angiotensin system (RAS) (ACE1/Ang2/AT1) in hippocampi. Also, hippocampi histopathological examination revealed amyloid beta deposition. Whereas, administration of telmisartan and/or 17β-estradiol improved animals' behavior, alleviated histopathological alterations and reduced the level of inflammatory and AD biomarkers, modulated RAS activity favoring the novel neuroprotective arm (ACE2/Ang(1-7)/MasR).

SIGNIFICANCE

Our findings suggest that combined administration of both drugs has synergetic neuroprotective effects; supporting their potential application in AD treatment.

Prevalence of Premature Thelarche at 18 Months of Age: A Population- and Hospital-Based Study of Prevalence and Incidence in Girls Born at Northern Älvsborg County Hospital in Sweden

OBJECTIVE

The aim of this work was to investigate the prevalence of premature thelarche (PT) in 18-month-old girls, and the incidence of clinically evaluated PT for girls aged 18-36 months.

METHODS

In the prevalence substudy, a prospective population-based cohort of 3,140 girls born at Northern Älvsborg county hospital (NÄL) in Trollhättan, Sweden, was followed for 2 years. Girls with breast development at the 18-month health check were referred to one pediatric center in NÄL for evaluation. All girls with PT were included and followed for clinical outcome and 17β-estradiol. The prospective incidence substudy covered 8 years in a 10-year period and included all girls aged 18-36 months born at NÄL who were clinically evaluated for PT.

RESULTS

The prevalence of PT at 18 months in our cohort was 1.6/1,000. The 5 girls with PT no longer showed symptoms at the follow-up 3-6 months later. The incidence was 1.1/1,000 for girls aged 18-36 months and 1.0/1,000 for girls aged 18-30 months who were clinically evaluated for their PT.

CONCLUSION

This is the first prospective population-based study of PT and it shows a prevalence of PT at age 18 months of 1.6/1,000. The incidence of clinically evaluated PT was 1.1/1,000. Our result is in line with other studies reporting the incidence of PT from medical records (0.4-40/1,000). The outcome of PT in our study, as in the other studies, is that the great majority of girls show only benign symptoms.

Rapid signalling responses via the G protein-coupled estrogen receptor, GPER, in a hippocampal cell line

The rapid non-genomic actions of 17β-estradiol in multiple tissues, including the nervous system, may involve the activation of the G-protein-coupled receptor, GPER. Different signalling pathways have been suggested to be activated by GPER in different cell lines and tissues. Controversially, GPER has also been suggested to be activated by the mineralocorticoid aldosterone, and by the non-steroidal diphenylacrylamide compound, STX, in some preparations. Evidence for the ability of the GPER agonist, G-1, and for aldosterone in the presence of the mineralocorticoid receptor antagonist, eplerenone, to potentiate forskolin-stimulated cyclic AMP levels in the hippocampal clonal cell line, mHippoE-18 is reviewed. The effects of both agents are blocked by the GPER antagonist G36, by PTX, (suggesting the involvement of Gi/o G proteins), by BAPTA-AM, (suggesting they are calcium sensitive), by wortmannin (suggesting an involvement of PI3Kinase) and by soluble amyloid-β peptides. STX also stimulates cyclic AMP levels in mHippoE-18 cells and these effects are blocked by G36 and PTX, as well as by amyloid-β peptides. This suggests that both aldosterone and STX may be capable of activating GPER in mHippoE-18 cells. Possible molecular mechanisms that may underlie these effects are discussed, together with possible forward directions for research on rapid non-genomic signalling by GPER, emphasising the importance of understanding the spatio-temporal aspects of its signalling in various tissues.

Spontaneous changes in dissolved organic matter affect the bio-removal of steroid estrogens

Microbial action is the main pathway removing steroid estrogens (SEs) from both aerobic and anaerobic natural waters. The rate is influenced by other active substances present, particularly dissolved organic matter (DOM). DOM in natural surface waters has unstable components which undergo spontaneous photochemical oxidation, biological oxidation, chemical oxidation changes. How these changes influence the biosorption and bio-removal of SEs was the subject of this research. Photo oxidation-induced DOM increased the proportion of the fluorescence in area V, but biological oxidation and chemical oxidation caused fluorescence area V to decrease. All three oxidation processes can reduce the proportions of molecular weight (MW) > 5 kg·mol^-1 and increase the proportions of MW < 5 kg·mol^-1. Both the electron transfer capacity decreased monotonically with photo oxidation and chemical oxidation ageing, but biological oxidation ageing increased them. 17β-estradiol (E2) was the SEs used in the experiments. In aerobic conditions, fresh river humic acids (RHA) and aged RHA had the stronger mediating effect on the rate of E2 bio-removal under aerobic conditions. Its greater effectiveness was probably related to its binding with E2. Binding, biosorption of E2 and bio-removal of E2 were strongly positively correlated with the elemental C (R > 0.8, p ≤ 0.01) and SUVA₂₅₄ (R > 0.8, p ≤ 0.01) by correlation matrix. Besides, fresh river fulvic acids (RFA) and aged RFA had the bigger mediating effect on E2 bio-removal under anaerobic conditions, and this imply that changes in aged DOM affected by other electron transfer groups in an anaerobic water environment. In anaerobic conditions, biosorption of E2 and binding action could cluster together with SUVA₂₅₄, p(v), and 1 kg·mol^-1 < MW < 5 kg·mol^-1 by redundancy analysis, and but bio-removal of E2 could be well polymerized with EAC, EDC, p(iv), and MW > 5 kg·mol^-1.

Aldosterone, STX and amyloid-β1-42 peptides modulate GPER (GPR30) signalling in an embryonic mouse hippocampal cell line (mHippoE-18)

The GPCR, GPER, mediates many of the rapid, non-genomic actions of 17β-estradiol in multiple tissues, including the nervous system. Controversially, it has also been suggested to be activated by aldosterone, and by the non-steroidal diphenylacrylamide compound, STX, in some preparations. Here, the ability of the GPER agonist, G-1, and aldosterone in the presence of the mineralocorticoid receptor antagonist, eplerenone, to potentiate forskolin-stimulated cyclic AMP levels in the hippocampal clonal cell line, mHippoE-18, are compared. Both stimulatory effects are blocked by the GPER antagonist G36, by PTX, (suggesting the involvement of Gi/o G proteins), by BAPTA-AM, (suggesting they are calcium sensitive), by wortmannin (suggesting an involvement of PI3Kinase) and by soluble amyloid-β peptides. STX also stimulates cyclic AMP levels in mHippoE-18 cells and these effects are blocked by G36 and PTX, as well as by amyloid-β peptides. This suggests that both aldosterone and STX may modulate GPER signalling in mHippoE-18 cells.

Development and validation of an analytical method for the determination of 17β-estradiol residues in muscle of tambaqui (Colossoma macropomum Cuvier, 1818) by LC-MS/MS and its application in samples from a fish sexual reversion study

Tambaqui (Colossoma macropomum Cuvier, 1818) is the main native fish species farmed in Brazil, and 17β-estradiol (E₂) is a natural steroid hormone commonly used for the production of female fish monosex population, which, in tambaqui, shows a higher growth rate than the male. Thus, to assess whether the fish meat of treated tambaqui contains hormonal residue levels, a high-performance liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS) method for the determination of E₂ residues in fish muscle was developed and validated. A QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) dispersive solid phase extraction method was used for the sample preparation. The chromatographic separation was performed in a Poroshel EC-18 reverse phase column. The mobile phase was a mixture of acetonitrile with 0.01% ammonium hydroxide (A) and water with 0.01% ammonium hydroxide (B). The ratio of A:B phases was 60:40 (v/v) used in an isocratic mode. The method validation was performed according to Commission Decision 2002/657/EC and Veterinary International Conference Harmonization (VICH GL49). Since matrix effects were observed, matrix-matched analytical curves are recommended for quantitation. The linearity, selectivity, intraday and interday precision, accuracy, decision limit, detection capability, and detection and quantitation limits of the method are reported. The limits of detection and quantitation were 0.3 ng/g and 1.0 ng/g, respectively. At these limits and slaughtering fish 7 months after the end of the treatment, the muscle of tambaqui did not show detectable hormone residue level. Thus, consumption of tambaqui edible tissue from fish treated with E₂ for the purpose of sexual reversion is unlikely to represent a risk associated with the exposure of human subjects as residue levels of this hormone are not detected in the fish muscle.

17β-Estradiol Modulates SIRT1 and Halts Oxidative Stress-Mediated Cognitive Impairment in a Male Aging Mouse Model

Oxidative stress has been considered the main mediator in neurodegenerative disease and in normal aging processes. Several studies have reported that the accumulation of reactive oxygen species (ROS), elevated oxidative stress, and neuroinflammation result in cellular malfunction. These conditions lead to neuronal cell death in aging-related neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease. Chronic administration of d-galactose (d-gal) for a period of 10 weeks causes ROS generation and neuroinflammation, ultimately leading to cognitive impairment. In this study, we evaluated the estrogen receptor α (ERα)/silent mating type information regulation 2 homolog 1 (SIRT1)-dependent antioxidant efficacy of 17β-estradiol against d-gal-induced oxidative damage-mediated cognitive dysfunction in a male mouse model. The results indicate that 17β-estradiol, by stimulating ERα/SIRT1, halts d-gal-induced oxidative stress–mediated JNK/NF-ҡB overexpression, neuroinflammation and neuronal apoptosis. Moreover, 17β-estradiol ameliorated d-gal-induced AD-like pathophysiology, synaptic dysfunction and memory impairment in adult mouse brains. Interestingly, inhibition of SIRT1 with Ex527 (a potent and selective SIRT1 inhibitor) further enhanced d-gal-induced toxicity and abolished the beneficial effect of 17β-estradiol. Most importantly, for the first time, our molecular docking study reveals that 17β-estradiol allosterically increases the expression of SIRT1 and abolishes the inhibitory potential of d-ga. In summary, we can conclude that 17β-estradiol, in an ERα/SIRT1-dependent manner, abrogates d-gal-induced oxidative stress–mediated memory impairment, neuroinflammation, and neurodegeneration in adult mice.