Multi-Anticancer Activities of Phytoestrogens in Human Osteosarcoma.

Phytoestrogens are plant-derived bioactive compounds with estrogen-like properties. Their potential health benefits, especially in cancer prevention and treatment, have been a subject of considerable research in the past decade. Phytoestrogens exert their effects, at least in part, through interactions with estrogen receptors (ERs), mimicking or inhibiting the actions of natural estrogens. Recently, there has been growing interest in exploring the impact of phytoestrogens on osteosarcoma (OS), a type of bone malignancy that primarily affects children and young adults and is currently presenting limited treatment options. Considering the critical role of the estrogen/ERs axis in bone development and growth, the modulation of ERs has emerged as a highly promising approach in the treatment of OS. This review provides an extensive overview of current literature on the effects of phytoestrogens on human OS models. It delves into the multiple mechanisms through which these molecules regulate the cell cycle, apoptosis, and key pathways implicated in the growth and progression of OS, including ER signaling. Moreover, potential interactions between phytoestrogens and conventional chemotherapy agents commonly used in OS treatment will be examined. Understanding the impact of these compounds in OS holds great promise for developing novel therapeutic approaches that can augment current OS treatment modalities.

Icariin, a phytoestrogen, exerts rapid estrogenic actions through crosstalk of estrogen receptors in osteoblasts.

Icariin, a flavonoid glycoside derived from Epimedium brevicornum Maxim, exerts bone protective effects via estrogen receptors (ERs). This study aimed to investigate the role of ER-α66, ER-α36, and GPER in bone metabolism in osteoblasts following treatment with icariin. Human osteoblastic MG-63 cells and osteoblast-specific ER-α66 knockout mice were employed. The ERs crosstalk in the estrogenic action of icariin was evaluated in ER-α66-negative human embryonic kidney HEK293 cells. Icariin, like E2, regulated ER-α36 and GPER protein expression in osteoblasts by downregulating them and upregulating ER-α66. ER-α36 and GPER suppressed the actions of icariin and E2 in bone metabolism. However, the in vivo administration of E2 (2 mg/kg/day) or icariin (300 mg/kg/day) restored bone conditions in KO osteoblasts. ER-α36 and GPER expression increased significantly and rapidly activated and translocated in KO osteoblasts after treatment with E2 or icariin. ER-α36 overexpression in KO osteoblasts further promoted the OPG/RANKL ratio induced by E2 or icariin treatment. This study showed icariin and E2 elicit rapid estrogenic responses in bone through recruiting ER-α66, ER-α36, and GPER. Notably, in osteoblasts lacking ER-α66, ER-α36, and GPER mediate the estrogenic effects of icariin and E2, while in intact osteoblasts, ER-α36 and GPER act as negative regulators of ER-α66.

The Phytoestrogenic Effect of Hibiscus sabdariffa Involves Estrogen Receptor α in Ovariectomized Wistar Rats.

The calyxes of Hibiscus sabdariffa present multiple pharmacological effects primarily attributed to their high anthocyanin content; however, little is known about their phytoestrogenic effect. Ovarian hypofunction (OH) is a process characterized by the rapid detention of the production of ovarian hormones, which compromises reproductive and cognitive functions. Hormone replacement therapy (HRT) efficiently compensates for OH; nevertheless, questions have been raised on its secondary effects and safety. One of the alternatives to tackling OH involves using phytoestrogens such as anthocyanins for their structural similarity to natural estrogens. In a Wistar rat model of ovariectomy (OVX), we recently reported the beneficial properties of an anthocyanin-rich extract prepared from the calyces of H. sabdariffa (HSE) in hindering the adverse effects of OH on memory performance and highlighted a possible phytoestrogenic impact through the modulation of estrogen receptor (ER) expression. We now report that HSE and estradiol differentially affected the expression of ERα and ERß. ERα was more sensitive to HSE; meanwhile, estradiol preferentially modulated ERß. Thus, our study leads to further research on using H. sabdariffa as a nutrition-based alternative to HRT.

Fisetin attenuates doxorubicin-induced cardiotoxicity by inhibiting the insulin-like growth factor II receptor apoptotic pathway through estrogen receptor-α/-ß activation.

Doxorubicin (DOX), an effective chemotherapeutic drug, has been used to treat various cancers; however, its cardiotoxic side effects restrict its therapeutic efficacy. Fisetin, a flavonoid phytoestrogen derived from a range of fruits and vegetables, has been reported to exert cardioprotective effects against DOX-induced cardiotoxicity; however, the underlying mechanisms remain unclear. This study investigated fisetin's cardioprotective role and mechanism against DOX-induced cardiotoxicity in H9c2 cardiomyoblasts and ovariectomized (OVX) rat models. MTT assay revealed that fisetin treatment noticeably rescued DOX-induced cell death in a dose-dependent manner. Moreover, western blotting and TUNEL-DAPI staining showed that fisetin significantly attenuated DOX-induced cardiotoxicity in vitro and in vivo by inhibiting the insulin-like growth factor II receptor (IGF-IIR) apoptotic pathway through estrogen receptor (ER)-α/-ß activation. The echocardiography, biochemical assay, and H&E staining results demonstrated that fisetin reduced DOX-induced cardiotoxicity by alleviating cardiac dysfunction, myocardial injury, oxidative stress, and histopathological damage. These findings imply that fisetin has a significant therapeutic potential against DOX-induced cardiotoxicity.

Er-xian ameliorates myocardial ischemia-reperfusion injury in rats through RISK pathway involving estrogen receptors.

Curculigo orchioides (CUR) and Epimedium (EPI) are traditional Chinese medicines with estrogen-like biological activity, called Xianmao and Xianlingpi (Er-xian) in Chinese. However, whether Er-xian exerts protective effects on myocardial ischemia-reperfusion injury (MIRI) is unknown. This study aimed to investigate the cardioprotective effects of Er-xian preconditioning against MIRI and the underlying mechanisms. CUR or EPI was administered intragastrically to aged female rats as a monotherapy or combination therapy. 2 weeks later, a rat MIRI model was established. Myocardial infarction size, myocardial morphology, cTnT, cell apoptosis rate, intracellular calcium concentration, mitochondrial permeability transition pore (MPTP) opening and reperfusion injury salvage kinase (RISK) signaling pathway molecules were observed after the surgery. To evaluate the mechanisms of Er-xian, estrogen receptors antagonists ICI 182780 and G15 were used. In this study, Er-xian notably alleviated myocardial tissue damage, maintained mitochondrial morphology, reduced infarct size and cardiac markers, and increased sera levels of E2. Moreover, Er-xian inhibited calcium overload and mPTP opening, and decreased cardiomyocyte apoptosis. We found that the dual therapy of CUR and EPI elicited more noticeable results than CUR or EPI monotherapy. The significant protective effects of Er-xian on ischemia-reperfusion myocardium were attributed to the up-regulation of AKT, ERK1/2 and GSK-3ß phosphorylation levels. The cardioprotective effects of Er-xian were significantly reduced after estrogen receptor blockade, especially GPER30. These results indicate that Er-xian attenuates MIRI through RISK signaling pathway and estrogen receptors are the critical mediators.

Silibinin improves L-cell mass and function through an estrogen receptor-mediated antioxidative mechanism.

BACKGROUND: Silibinin, a major component of milk thistle extract silymarin, promotes hypoglycemia by activating estrogen receptor (ER) α and ß-mediated pathways in pancreatic ß-cells. Glucagon-like peptide-1 (GLP-1) is the enteroendocrine peptide produced in L-cells, and it controls glucose homeostasis through multiple pathways. The effect of silibinin on L-cell mass and function is still unknown. PURPOSE: The protective effect of silibinin on palmitate (PA)-treated intestinal L-cell line GLUTag cells and the SHRSP•Z-Leprfa/Izm-Dmcr (SP•ZF) diabetic rat model was investigated in current study. METHODS: After pre-incubation with 50 µM silibinin for 4 h, GLUTag cells were treated with 0.125 mM PA. MTT, Annexin V/PI apoptosis, Hoechst 33342 staining, western blot, DCFH-DA, GLP-1 ELISA, qRT-PCR and immunofluorescence analyses were undertaken to determine ER-dependent protection of silibinin against PA-induced cellular damage. The differential protein expression of GLUTag cells under different treatments was examined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). The SP•ZF diabetic rat model was chosen for in vivo study. After 4 weeks of gastric gavage with 100 or 300 mg kg-1 of silibinin, the physiological indexes of the rats were measured. Cells expressing GLP-1, 8­hydroxy-2'-deoxyguanosine (8-OHdG), ERα, and/or ERß in duodenum tissues were detected by immunofluorescence. RESULTS: The current study showed that the GLUTag cells preincubated with silibinin activated the transcription factor nuclear erythroid-2 like factor-2 (Nrf2)-antioxidant pathway, reduced reactive oxygen species (ROS) generation, and improved cell survival and GLP-1 content, while the antioxidative effect of silibinin was blocked by the selective ERα antagonist MPP or ERß antagonist PHTPP in GLUTag cells. Our proteomics data further revealed that ERα or ß inactivation reduced glutathione peroxide and proteins associated with endocytosis and reproduction, thus at least partially reversing the protective effect of silibinin. SP•ZF rats received silibinin treatment showed increased serum GLP-1 content and improved glucose homeostasis. Furthermore, silibinin upregulated ERα and ß levels and reduced the level of 8-OHdG in GLP-1-positive cells. CONCLUSIONS: Our study showed that silibinin improved L-cell mass and function through an ER-mediated antioxidant pathway, and the proteomics analysis revealed for the first time the differential regulation of proteins by PA and silibinin in GLUTag cells.

Water Extract of Rhizoma Drynaria Selectively Exerts Estrogenic Activities in Ovariectomized Rats and Estrogen Receptor-Positive Cells.

Our previous study demonstrated that the bone protective actions of herbal medicine Rhizoma Drynariae (Gusuibu, RD) were mainly mediated by flavonoid phytoestrogens via estrogen receptors, raising concerns about the safety of using RD as it may induce estrogen-like risk-benefit profile and interact with other ER ligands, such as selective estrogen receptor modulators (SERMs), when coadministered. The present study evaluated the estrogenic activities of RD and its potential interaction with tamoxifen, a SERM, in estrogen-sensitive tissues by using mature ovariectomized (OVX) rats and ER-positive cells. Similar to but weaker than tamoxifen, RD at its clinical dose dramatically ameliorated OVX-induced changes in bone and dopamine metabolism-related markers in OVX rats. However, tamoxifen, but not RD, induced uterotrophic effects. No significant alteration in mammary gland was observed in OVX rats treated with RD, which was different from the inhibitory actions of tamoxifen. The two-way ANOVA results indicated the interactions between RD and tamoxifen in the bone, brain, and uterus of OVX rats while RD did not alter their responses to tamoxifen. Our results demonstrate that RD selectively exerts estrogenic actions in a different manner from tamoxifen. Moreover, RD interacts with tamoxifen without altering its effects in OVX rats.

Beneficial effects of the fructus Sophorae extract on experimentally induced osteoporosis in New Zealand white rabbits.

Sophora japonica is a source of several flavonol, flavone and isoflavone glycosides that are reported to positively affect menopausal symptoms including osteoporotic complications. In the present study fructus Sophorae extract (FSE) was administered orally for three months at a dose of 200 mg kg-1 in ovariectomized (OVX) New Zealand rabbits. 3D computed tomography scans and histopathological images revealed microstructural disturbances in the bones of the castrated animals. FSE recovered most of the affected parameters in bones in a manner similar to zoledronic acid (ZA) used as a positive control. The aglycones of the main active compounds of FSE, daidzin, and genistin, were docked into the alpha and beta estrogen receptors and stable complexes were found. The findings of this study provide an insight into the effects of FSE on bone tissue loss and suggest that it could be further developed as a potential candidate for the prevention of postmenopausal osteoporotic complications.

Comparative study of estrogenic activities of phytoestrogens using OECD in vitro and in vivo testing methods.

With growing scientific interest in phytoestrogens, a number of studies have investigated the estrogenic potential of phytoestrogens in a wide variety of assay systems. However, evaluations of individual phytoestrogens with different assay systems make it difficult for predicting their relative estrogenic potency. The objective of this study was to compare estrogenic properties of fifteen known phytoestrogens using an estrogen receptor-α (ER-α) dimerization assay and Organization for Economic Cooperation and Development (OECD) standardized methods including in vitro estrogen receptor (ER) transactivation assay using VM7Luc4E2 cells and in vivo uterotrophic assay using an immature rat model. Human ER-α dimerization assay showed positive responses of eight test compounds and negative responses of seven compounds. These results were consistently found in luciferase reporter assay results for evaluating ER transactivation ability. Seven test compounds exhibiting relatively higher in vitro estrogenic activities were subjected to uterotrophic bioassays. Significant increases in uterine weights were only found after treatments with biochanin A, 8-prenylnaringenin, and coumestrol. Importantly, their uterotrophic effects were lost when animals were co-treated with antagonist of ER, indicating their ER-dependent effects in the uterus. In addition, analysis of estrogen responsive genes revealed that these phytoestrogens regulated uterine gene expressions differently compared to estrogens. Test methods used in this study provided a high consistency between in vitro and in vivo results. Thus, they could be used as effective screening tools for phytoestrogens, particularly focusing on their interactions with ER-α.

Evaluation of Estrogen Receptor Agonistic Activity of Medicinal Herbs Using Organization for Economic Cooperation and Development Transactivation Assay with Rat Liver S9 Fraction.

A number of studies employing different in vitro assays have demonstrated the estrogen-like activity of natural substances. All assays have their advantages and limitations as a screening tool. No single in vitro assay is considered ideal for predicting estrogenic action in a complex in vivo system. To assess agonistic activities of several medicinal herbs on the estrogen receptor (ER) and their metabolic alteration, the Organization for Economic Cooperation and Development (OECD) Performance-Based Test Guideline No. 455 in vitro assay was performed in this study using recombinant VM7Luc4E2 cells in combination with rat liver S9 fractions. Ethanol extracts of medicinal herbs showed binding affinities for ER-α and ER-ß at different levels. However, luciferase reporter assay using VM7Luc4E2 cells revealed that only two test extracts [Pueraria lobata root extract (PLE); Glycyrrhiza glabra root extract (GGE)] exhibited ER transcriptional activity when their activities were compared with the response by 17ß-estradiol. Importantly, incubation of PLE or GGE with rat liver S9 fractions increased their ER transcriptional activities, in particular when phase I metabolic enzymes were activated. Puerarin and glabridin were the most abundant isoflavones found in PLE and GGE, respectively. The present results demonstrate that PLE and GGE possess potential as ER agonists with their metabolic activation. This study also suggests that the application of OECD in vitro assay with rat liver S9 fraction is an efficient screening tool to evaluate estrogenic activities of natural substances.

Exploring the Biological Activity and Mechanism of Xenoestrogens and Phytoestrogens in Cancers: Emerging Methods and Concepts.

Xenoestrogens and phytoestrogens are referred to as "foreign estrogens" that are produced outside of the human body and have been shown to exert estrogen-like activity. Xenoestrogens are synthetic industrial chemicals, whereas phytoestrogens are chemicals present in the plant. Considering that these environmental estrogen mimics potentially promote hormone-related cancers, an understanding of how they interact with estrogenic pathways in human cells is crucial to resolve their possible impacts in cancer. Here, we conducted an extensive literature evaluation on the origins of these chemicals, emerging research techniques, updated molecular mechanisms, and ongoing clinical studies of estrogen mimics in human cancers. In this review, we describe new applications of patient-derived xenograft (PDX) models and single-cell RNA sequencing (scRNA-seq) techniques in shaping the current knowledge. At the molecular and cellular levels, we provide comprehensive and up-to-date insights into the mechanism of xenoestrogens and phytoestrogens in modulating the hallmarks of cancer. At the systemic level, we bring the emerging concept of window of susceptibility (WOS) into focus. WOS is the critical timing during the female lifespan that includes the prenatal, pubertal, pregnancy, and menopausal transition periods, during which the mammary glands are more sensitive to environmental exposures. Lastly, we reviewed 18 clinical trials on the application of phytoestrogens in the prevention or treatment of different cancers, conducted from 2002 to the present, and provide evidence-based perspectives on the clinical applications of phytoestrogens in cancers. Further research with carefully thought-through concepts and advanced methods on environmental estrogens will help to improve understanding for the identification of environmental influences, as well as provide novel mechanisms to guide the development of prevention and therapeutic approaches for human cancers.

Sexual differentiation of the human hypothalamus: Relationship to gender identity and sexual orientation.

Gender identity (an individual's perception of being male or female) and sexual orientation (heterosexuality, homosexuality, or bisexuality) are programmed into our brain during early development. During the intrauterine period in the second half of pregnancy, a testosterone surge masculinizes the fetal male brain. If such a testosterone surge does not occur, this will result in a feminine brain. As sexual differentiation of the brain takes place at a much later stage in development than sexual differentiation of the genitals, these two processes can be influenced independently of each other and can result in gender dysphoria. Nature produces a great variability for all aspects of sexual differentiation of the brain. Mechanisms involved in sexual differentiation of the brain include hormones, genetics, epigenetics, endocrine disruptors, immune response, and self-organization. Furthermore, structural and functional differences in the hypothalamus relating to gender dysphoria and sexual orientation are described in this review. All the genetic, postmortem, and in vivo scanning observations support the neurobiological theory about the origin of gender dysphoria, i.e., it is the sizes of brain structures, the neuron numbers, the molecular composition, functions, and connectivity of brain structures that determine our gender identity or sexual orientation. There is no evidence that one's postnatal social environment plays a crucial role in the development of gender identity or sexual orientation.

Erxian Decoction, a Famous Chinese Medicine Formula, Ameliorate Depression- Like Behavior in Perimenopausal Mice.

AIMS: The present study was performed in order to find out the anti-depression effect of Erxian Decoction in perimenopausal mice. BACKGROUND: Erxian Decoction (EXD) has been used in folk medicine for the treatment of perimenopausal syndrome, but it has not been researched on perimenopausal depression. OBJECTIVE: The present study aimed to evaluate the effect of extraction of Erxian Decoction on perimenopausal depressive mice. METHODS: In this study, female ICR mice were randomly divided into 6 groups: Low, medium and high dose of EXD groups (0.5, 1.5, and 4.5 g/kg), soy isoflavones group (250 mg/kg) and Sham group. The mice in the Sham group received sham surgery (within ovaries), and the others were excised with bilateral ovaries and exerted by 28-day chronic mild unpredictable stimulation for the establishment of a perimenopausal depression model. RESULTS: Behavioral tests showed that EXD could relieve depression symptoms and improve spatial memory in mice. Western blotting showed that EXD significantly up-regulated the expression of brain-derived neurotrophic factor (BDNF) and Bcl-2 in hippocampus and estrogen receptors (ERs) in the uterus and adrenals, protecting hippocampal tissue and antagonizing the symptoms of estrogen deficiency in mice, which was further proved within a uterine morphology test. In addition, EXD reduced the serum levels of follicle-stimulating hormone, luteinizing hormone, and interleukin- 6. CONCLUSION: These results indicated that EXD can regulate hormone secretion and recover hippocampal damage in perimenopausal depressed mice. Besides, it can antagonize the symptoms of ovarian hormone deficiency as well as relieve perimenopausal syndrome.

The controversy on the beneficial effect of phytoestrogens in diabetic treatment in postmenopausal women.

Phytoestrogens have been identified as a natural, plant-based alternative to synthetically derived estrogens, to supplement the absence of endogenous estrogens in post-menopausal women, and attenuate the progression of pathologies and side-effects associated with menopause. The increased availability of these plant's derived compounds as diet or nutritional supplements makes their ingestion and consumption easier and more accessible as compared to pharmacological alternatives. Further, phytoestrogen intake has shown beneficial effects as estrogens alternatives in attenuating severe complications in diseases such as type 2 diabetes, metabolic syndrome, NAFLD, and obesity. However, in many cases phytoestrogen effectiveness remains largely circumstantial or just anecdotal as significant uncertainties on the relative abundance of different phytoestrogens in a given diet, the need for conversion to an active principle through the gut microbiome, the possibility of an effect threshold, the synergistic effect of different phytoestrogens possible due to different modality of actions still persist. The present article aims at highlighting the main issues and concerns plaguing the field as well as some of the possible causes of inconsistencies observed in the various nutritional and clinical studies attempted so far.

Molting method alternative and detection of estrogen receptors by immunohistochemical methods on molted layers.

Three experiments were designed to evaluate the effects of different molting methods on the growth performance, detection of estrogen receptors (ERs), and immunohistochemical properties of some tissues in pre-, during, and post-molting of layers. In experiment 1, 302 Hy-line W-36 were reared from 75 to 76 weeks. In experiment 2, a total of 252 Hy-line W-36 were randomly allocated to 7 groups, with 6 replications and 6 birds in each. Hens fed in the E and D groups reached 30% of loss weight sooner (P < 0.05). Egg production was also sooner stopped in the FW group than in other ones (P < 0.05). In experiment 3, after inducing molting, each group in experiment 2 was divided into 2 groups with and without Humulus lupulus (Hop). The E group feed intake was increased, as compared to groups F and C (P < 0.05). A significant increase in egg weight was found by applying Hop and molting methods (P < 0.05). Days for return to the initial egg production and 10% egg laying were significantly decreased in the birds fed by Hop in the E and D groups (P < 0.05). The W-D, N-D, W-E, and N-E groups sooner returned to 50% egg laying, in comparison to other treatments (P < 0.05). Plasma estrogen and ERs were decreased by the molting programs, as compared with pre-molting; however, Hop increased their post-molting. After the molting period, egg production and ERs were increased significantly, as compared with the pre-molting period. To conclude, the white button mushroom residual, through decreasing ERs, could be used successfully for forced molting, and Hop could lead to a good performance by increasing ERs in the second laying cycle.

A standardized extract of Danggui Buxue Tang decoction selectively exerts estrogenic activities distinctly from tamoxifen.

More and more menopausal women use Danggui Buxue Tang (DBT) for relieving their symptoms. Concerns for its safety have been raised as it contains phytoestrogen and acts via estrogen receptors (ERs). Our study aimed to determine whether DBT could selectively exert estrogenic activities and interact with tamoxifen in bone, brain, uterus, and breast by using ovariectomized (OVX) rats and ER-positive cells. In OVX rats, DBT induced a 31.4% increase in bone mineral density and restored the mRNA expression of dopamine biomarker in striatum, 3.32-fold for tyrosine hydrolase (p < .001) and 0.21-fold for dopamine transporter (p < .001), which was similar to tamoxifen; tamoxifen, but not DBT, increased uterus weight and Complement component 3 expression by more than twofold (p < .001); unlike tamoxifen, DBT induced mild proliferation in mammary gland. Two-way ANOVA indicated the interactions between them in OVX rats (p < .05) but DBT did not alter the responses to tamoxifen. DBT stimulated proliferation or differentiation and estrogen response element in MCF-7, MG-63, Ishikawa, and SHSY5Y cells and altered the effects of tamoxifen. In summary, DBT exerted estrogenic effects in tissue-selective manner, which was different from tamoxifen. DBT interacted with tamoxifen but did not significantly alter its effects in OVX rats.

Long-term supplementation of dehydroepiandrosterone improved depressive-like behaviors by increasing BDNF expression in the hippocampus in ovariectomized rats.

OBJECTIVE: Dehydroepiandrosterone (DHEA), a precursor of estrogen, partially exhibits its biological effect after conversion to estrogen. Its biological significance in perimenopausal depressive disorder or postpartum depression remains unknown. Here, we observed the effects of long-term supplementation of DHEA on depression-like behaviors in ovariectomized rats. METHODS: We established the model as one of sex hormone deficiency in female rats by bilateral ovariectomy. We observed the effects of 13.3 mg/kg DHEA or 0.27 mg/kg estradiol were given daily by gavage for 12 weeks on lipid metabolism, glucose tolerance, and depression-like behaviors in ovariectomized rats. Furthermore, the expression of brain-derived neurotrophic factor (BDNF) and its signaling molecule in the hippocampus was analyzed. RESULTS: The 12-week supplementation of DHEA or estradiol significantly alleviated weight gain and improved the glucose tolerance in the ovariectomized rats. Moreover, Long-term supplement of DHEA or estradiol significantly increased sucrose preference and locomotion activities, and reduced immobility duration of the ovariectomized rats in the water. Both DHEA and estradiol treatments increased the expression of BDNF, phosphorylation of ERK and CREB, and ERß, but not that of ERα in the hippocampus of the ovariectomized rats. CONCLUSIONS: Overall, chronic treatment with DHEA improved depression-like behaviors in ovariectomized rats, suggesting that it may be useful for the treatment of sex hormone deficiency such as perimenopausal depressive disorder or postpartum depression.

BPA Differentially Regulates NPY Expression in Hypothalamic Neurons Through a Mechanism Involving Oxidative Stress.

Bisphenol A (BPA), a ubiquitous endocrine-disrupting chemical, interferes with reproduction and is also considered an obesogen. The neuropeptide Y (NPY) neurons of the hypothalamus control both food intake and reproduction and have emerged as potential targets of BPA. These functionally diverse subpopulations of NPY neurons are differentially regulated by peripheral signals, such as estrogen and leptin. Whether BPA also differentially alters Npy expression in subpopulations of NPY neurons, contributing to BPA-induced endocrine dysfunction is unclear. We investigated the response of 6 immortalized hypothalamic NPY-expressing cell lines to BPA treatment. BPA upregulated Npy mRNA expression in 4 cell lines (mHypoA-59, mHypoE-41, mHypoA-2/12, mHypoE-42), and downregulated Npy in 2 lines (mHypoE-46, mHypoE-44). This differential expression of Npy occurred concurrently with differential expression of estrogen receptor mRNA levels. Inhibition of G-protein coupled estrogen receptor GPR30 or estrogen receptor ß prevented the BPA-mediated decrease in Npy, whereas inhibition of energy sensor 5' adenosine monophosphate-activated protein kinase (AMPK) with compound C prevented BPA-induced increase in Npy. BPA also altered neuroinflammatory and oxidative stress markers in both mHypoA-59 and mHypoE-46 cell lines despite the differential regulation of Npy. Remarkably, treatment with BPA in an antioxidant-rich media, Neurobasal A (NBA), or with reactive oxygen species scavenger tauroursodeoxycholic acid mitigated the BPA-induced increase and decrease in Npy. Furthermore, 2 antioxidant species from NBA-N-acetylcysteine and vitamin B6-diminished the induction of Npy in the mHypoA-59 cells, demonstrating these supplements can counteract BPA-induced dysregulation in certain subpopulations. Overall, these results illustrate the differential regulation of Npy by BPA in neuronal subpopulations, and point to oxidative stress as a pathway that can be targeted to block BPA-induced Npy dysregulation in hypothalamic neurons.

A Single Molecule Drug Targeting Photosensitizer for Enhanced Breast Cancer Photothermal Therapy.

Targeting is one of the most important strategies for enhancing the efficacy of cancer photothermal therapy (PTT) and reducing damage to surrounding normal tissues. Compared with the traditional targeting approaches, the active targeting of breast cancer cells in PTT using chemotherapeutic drugs, such as tamoxifen (TAM), in combination with single-molecule photothermal photosensitizers has superior selectivity and therapeutic effects. However, single-molecule drug-targeting photosensitizers for improved PTT efficacy are not widely reported. Accordingly, herein, a near-infrared induced small-molecule photothermal photosensitizer (CyT) is developed that actively targets the estrogen receptors (ERs) of breast cancer cells as well as targets mitochondria by structure-inherent targeting. Cell uptake and cytotoxicity studies using different types of cells show that CyT enhances the efficiency of TAM-based PTT by targeting ER-overexpressing breast cancer cells and selectively killing them. In vivo experiments demonstrate that CyT can be used as a photothermal agent for fluorescence imaging-guided PTT. More importantly, the intravenous injection of CyT results in better targeting and efficiency of tumor inhibition compared with that achieved with the TAM-free control molecule Cy. Thus, the study presents an excellent small-molecule photothermal agent for breast cancer therapy with potential clinical application prospects.

Transgenerational Inheritance of Betaine-Induced Epigenetic Alterations in Estrogen-Responsive IGF-2/IGFBP2 Genes in Rat Hippocampus.

SCOPE: Betaine serves as a methyl donor for DNA methylation. Here, the effects of betaine on hippocampal expression of neurogenesis genes and their DNA methylation status across three generations are investigated. METHODS AND RESULTS: Pregnant rats (F0) are fed control and betaine-supplemented diets throughout gestation and lactation. Female F1 and F2 offspring at weaning, together with the F0 dams, are used in the study. Hippocampal expression of aromatase, estrogen receptor α, and estrogen-related receptor ß is downregulated in F1, together with the estrogen-responsive insulin-like growth factor 2/insulin-like growth factor binding protein 2 (IGF-2/IGFBP2) genes. However, all these genes are upregulated in F2, which follows the same pattern of F0. In agreement with changes in mRNA expression, the imprinting control region (ICR) of IGF-2 gene is hypomethylated in F1 but hypermethylated in F2 and F0. In contrast, the promoter DNA methylation status of all the affected genes is hypermethylated in F1 but hypomethylated in F2 and F0. Methyl transfer enzymes, such as betaine homocysteine methyltransferase and DNA methyltransferase 1, follow the same pattern of transgenerational inheritance. CONCLUSION: These results indicate that betaine exerts a transgenerational effect on hippocampal expression of estrogen-responsive genes in rat offspring, which is associated with corresponding alterations in DNA methylation on ICR of IGF-2 gene and the promoter of affected genes.