Unconventional Estrogen Signaling in Health and Disease

miR-10a/b-5p-NCOR2 Regulates Insulin-Resistant Diabetes in Female Mice

Gender and biological sex have distinct impacts on the pathogenesis of type 2 diabetes (T2D). Estrogen deficiency is known to predispose female mice to T2D. In our previous study, we found that a high-fat, high-sucrose diet (HFHSD) induces T2D in male mice through the miR-10b-5p/KLF11/KIT pathway, but not in females, highlighting hormonal disparities in T2D susceptibility. However, the underlying molecular mechanisms of this hormonal protection in females remain elusive. To address this knowledge gap, we utilized ovariectomized, estrogen-deficient female mice, fed them a HFHSD to induce T2D, and investigated the molecular mechanisms involved in estrogen-deficient diabetic female mice, relevant cell lines, and female T2D patients. Initially, female mice fed a HFHSD exhibited a delayed onset of T2D, but ovariectomy-induced estrogen deficiency promptly precipitated T2D without delay. Intriguingly, insulin (INS) was upregulated, while insulin receptor (INSR) and protein kinase B (AKT) were downregulated in these estrogen-deficient diabetic female mice, indicating insulin-resistant T2D. These dysregulations of INS, INSR, and AKT were mediated by a miR-10a/b-5p-NCOR2 axis. Treatment with miR-10a/b-5p effectively alleviated hyperglycemia in estrogen-deficient T2D female mice, while β-estradiol temporarily reduced hyperglycemia. Consistent with the murine findings, plasma samples from female T2D patients exhibited significant reductions in miR-10a/b-5p, estrogen, and INSR, but increased insulin levels. Our findings suggest that estrogen protects against insulin-resistant T2D in females through miR-10a/b-5p/NCOR2 pathway, indicating the potential therapeutic benefits of miR-10a/b-5p restoration in female T2D management.

Uterine Uptake of Estrogen and Progestogen-Based Radiotracers in Rhesus Macaques with Endometriosis

PURPOSE

Endometriosis is an estrogen-dependent disorder of menstruating primates where tissues similar to the inner lining of the uterus exist "ectopically" outside of the uterus. The ectopic endometrium, like the endometrium within the uterus, expresses estrogen receptors (ER) and progesterone receptors (PR) and undergoes hormone-dependent cell proliferation and bleeding each menstrual cycle. The goal of this study was to conduct abdominopelvic positron emission tomography (PET) scans with computed tomography (CT) imaging of rhesus macaques (Macaca mulatta) using radiotracers that target ER and PR [16α-[18F]fluoroestradiol (FES) and 12-[18F]fluoro-furanyl-nor-progesterone (FFNP)] in individuals with and without endometriosis. We also aimed to determine if menstrual cycle phase and/or the presence of endometriosis affected the uptake of these radiotracers.

PROCEDURES

Rhesus macaques with either clinically diagnosed endometriosis (n = 6) or no endometriosis (n = 4) underwent PET/CT scans with FES. A subset of the animals also underwent PET/CT scans with FFNP. Standard uptake values corrected for body weight (SUVs) were obtained for each radiotracer in target and background tissues (e.g., intestinal). We performed repeated measure analysis of variance tests to determine how uterine and background uptake differed with scan time, phase of the menstrual cycle, and disease state.

RESULTS

Abdominopelvic PET/CT could not resolve small, individual endometriotic lesions. However, macaques with endometriosis displayed higher uterine uptake compared to those without the disorder. Radiotracer uptake differed by menstrual cycle phase with increased uterine uptake of both radiotracers in the proliferative phase of the menstrual cycle. Background intestinal uptake of FFNP increased over time after infusion, but only during the proliferative phase.

CONCLUSIONS

PET/CT with FES and FFNP support the concept that ER and PR levels are altered in individuals with endometriosis. This highlights the impact of the disease on typical reproductive tract function and may provide a novel pathway for the identification of individuals with endometriosis.

Synergistic Anti-Cancer Effects of ERB-041 and Genistein through Estrogen Receptor Suppression-Mediated PI3K/AKT Pathway Downregulation in Canine Mammary Gland Tumor Cells

Canine-mammary-gland tumors (CMTs) are prevalent in female dogs, with approximately 50% of them being malignant and often presenting as inoperable owing to their size or metastasis. Owing to poor outcomes, effective alternatives to conventional chemotherapy for humans are necessary. Two estrogen receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which act in opposition to each other, are involved, and CMT growth involves ERα through the phosphoinositide 3-kinases (PI3K)/AKT pathway. In this study, we aimed to identify the synergistic anti-cancer effects of ERB-041, an ERβ agonist, and genistein, an isoflavonoid from soybeans known to have ERβ-specific pseudo-estrogenic actions, on CMT-U27 and CF41.Mg CMT cell lines. ERB-041 and genistein synergistically inhibited cell proliferation and increased the number of annexin V-positive cells in both cell lines. Furthermore, we observed a synergistic increase in the Bax/Bcl-2 ratio and cleaved caspase-3 expression. Additionally, cell-cycle arrest occurred through the synergistic regulation of cyclin D1 and cyclin-dependent kinase 4 (CDK4). We also found a synergistic decrease in the expression of ERα, and the expression of proteins involved in the PI3K/AKT pathway, including p-PI3K, phosphatase and tensin homolog (PTEN), AKT, and mechanistic target of rapamycin (mTOR). In conclusion, ERB-041 and genistein exhibited a synergistic anticancer effect on CMTs, suggesting that cotreatment with ERB-041 and genistein is a promising treatment for CMTs.

Computational Screening of Some Phytochemicals to Identify Best Modulators for Ligand Binding Domain of Estrogen Receptor Alpha

OBJECTIVE

The peculiar aim of this study is to discover and identify the most effective and potential inhibitors against the most influential target ERα receptor by in silico studies of 45 phytochemicals from six diverse ayurvedic medicinal plants.

METHODS

The molecular docking investigation was carried out by the genetic algorithm program of AutoDock Vina. The molecular dynamic (MD) simulation investigations were conducted using the Desmond tool of Schrödinger molecular modelling. This study identified the top ten highest binding energy phytochemicals that were taken for drug-likeness test and ADMET profile prediction with the help of the web-based server QikpropADME.

RESULTS

Molecular docking study revealed that ellagic acid (-9.3 kcal/mol), emodin (-9.1 kcal/mol), rhein (-9.1 kcal/mol), andquercetin (-9.0 kcal/mol) phytochemicals showed similar binding affinity as standard tamoxifen towards the target protein ERα. MD studies showed that all four compounds possess comparatively stable ligand-protein complexes with ERα target compared to the tamoxifen-ERα complex. Among the four compounds, phytochemical rhein formed a more stable complex than standard tamoxifen. ADMET studies for the top ten highest binding energy phytochemicals showed a better safety profile.

CONCLUSION

Additionally, these compounds are being reported for the first time in this study as possible inhibitors of ERα for treating breast cancer, according to the notion of drug repurposing. Hence, these phytochemicals can be further studied and used as a parent core molecule to develop innovative lead molecules for breast cancer therapy.

Regulation of mRNA translation by estrogen receptor in breast cancer

Breast cancer is one of the leading causes of cancer-related fatalities and the most often diagnosed malignancy in women globally. Dysregulation of sex hormone signaling pathways mediated by the estrogen receptor (ER) in breast cancer is well characterized. Although ER is known to promote cell growth and survival by altering gene transcription, recent research suggests that its effects in cancers are also mediated through dysregulation of protein synthesis. This implies that ER can coordinately affect gene expression through both translational and transcriptional pathways, leading to the development of malignancy. In this review, we will cover the current understanding of how the ER controls mRNA translation in breast cancer and discuss any potential clinical implications of this phenomenon.

Critical Roles of SRC-3 in the Development and Progression of Breast Cancer, Rendering It a Prospective Clinical Target

Breast cancer (BCa) is the most frequently diagnosed malignant tumor in women and is also one of the leading causes of cancer-related death. Most breast tumors are hormone-dependent and estrogen signaling plays a critical role in promoting the survival and malignant behaviors of these cells. Estrogen signaling involves ligand-activated cytoplasmic estrogen receptors that translocate to the nucleus with various co-regulators, such as steroid receptor co-activator (SRC) family members, and bind to the promoters of target genes and regulate their expression. SRC-3 is a member of this family that interacts with, and enhances, the transcriptional activity of the ligand activated estrogen receptor. Although SRC-3 has important roles in normal homeostasis and developmental processes, it has been shown to be amplified and overexpressed in breast cancer and to promote malignancy. The malignancy-promoting potential of SRC-3 is diverse and involves both promoting malignant behavior of tumor cells and creating a tumor microenvironment that has an immunosuppressive phenotype. SRC-3 also inhibits the recruitment of tumor-infiltrating lymphocytes with effector function and promotes stemness. Furthermore, SRC-3 is also involved in the development of resistance to hormone therapy and immunotherapy during breast cancer treatment. The versatility of SRC-3 in promoting breast cancer malignancy in this way makes it a good target, and methodical targeting of SRC-3 probably will be important for the success of breast cancer treatment.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Estrogen receptor alpha mediates 17β-estradiol, up-regulates autophagy and alleviates hydrogen peroxide-induced vascular senescence

Atherosclerosis threatens human health by developing cardiovascular diseases, the deadliest disease world widely. The major mechanism contributing to the formation of atherosclerosis is mainly due to vascular endothelial cell (VECs) senescence. We have shown that 17β-estradiol (17β-E2) may protect VECs from senescence by upregulating autophagy. However, little is known about how 17β-E2 activates the autophagy pathway to alleviate cellular senescence. Therefore, the aim of this study is to determine the role of estrogen receptor (ER) α and β in the effects of 17β-E2 on vascular autophagy and aging through in vitro and in vivo models. Hydrogen peroxide (H2O2) was used to establish Human Umbilical Vein Endothelial Cells (HUVECs) senescence. Autophagy activity was measured through immunofluorescence and immunohistochemistry staining of light chain 3 (LC3) expression. Inhibition of ER activity was established using shRNA gene silencing and ER antagonist. Compared with ER-β knockdown, we found that knockdown of ER-α resulted in a significant increase in the extent of HUVEC senescence and senescence-associated secretory phenotype (SASP) secretion. ER-α-specific shRNA was found to reduce 17β-E2-induced autophagy, promote HUVEC senescence, disrupt the morphology of HUVECs, and increase the expression of Rb dephosphorylation and SASP. These in vitro findings were found consistent with the in vivo results. In conclusion, our data suggest that 17β-E2 activates the activity of ER-α and then increases the formation of autophagosomes (LC3 high expression) and decreases the fusion of lysosomes with autophagic vesicles (P62 low expression), which in turn serves to decrease the secretion of SASP caused by H2O2 and consequently inhibit H2O2-induced senescence in HUVEC cells.

A Novel Rhipicephalus microplus Estrogen Related Receptor (RmERR), a Molecular and In Silico Characterization of a Potential Protein Binding Estrogen

The search for targets to control ticks and tick-borne diseases has been an ongoing problem, and so far, we still need efficient, non-chemical alternatives for this purpose. This search must consider new alternatives. For example genomics analysis is a widely applied tool in veterinary health studies to control pathogens. On the other hand, we propose that regulation of endocrine mechanisms represents a feasible alternative to biologically controlling tick infestations. Thus, we performed the molecular identification of an estrogen-related receptor gene of Rhipicephalus microplus called RmERR by RT-PCR in tick ovaries, embryonic cells, and hemolymph, which allowed us to analyze its expression and propose potential functions in endocrine mechanisms and developmental stages. In addition, we performed an in silico characterization to explore the molecular interactions of RmERR with different estrogens, estrogenic antagonists, and endocrine disruptor Bisphenol A (BPA), finding potential interactions predicted by docking analysis and supported by negative values of ΔG (which suggests the potential interaction of RmERR with the molecules evaluated). Additionally, phylogenetic reconstruction revealed that RmERR is grouped with other tick species but is phylogenetically distant from host vertebrates' ERRs. In summary, this study allowed for the identification of an ERR in cattle tick R. microplus for the first time and suggested its interaction with different estrogens, supporting the idea of a probable transregulation process in ticks. The elucidation of this interaction and its mechanisms unveiled its potential as a target to develop tick control strategies.

Novel hybrid motifs of 4-nitroimidazole-piperazinyl tagged 1,2,3-triazoles: Synthesis, crystal structure, anticancer evaluations, and molecular docking study

4-((4-(1-benzyl-2-methyl-4-nitro-1H-imidazole-5-yl)piperazine-1-yl)methyl)-1-substituted-1H-1,2,3-triazole motifs are designed and synthesized via click chemistry. The reaction of 1-(N1-benzyl- 2-methyl-4-nitro-1H-imidazole- 5-yl)-4-(prop-2-yn-1-yl) piperazine 5 as new scaffold with diverse primary azides to selectively produce 1,4-disubstituted-1,2,3-triazoles 9a-k, 10a-c and 11a-q. Physicochemical methods: when 1H NMR, 13C NMR, and HRMS are utilized to fully characterize all synthesized compounds. X-ray structural determination and analysis for compound 9a is also performed. The newly designed chromophores are assessed for their anti-proliferative potency against three selected human cancer cell lines (MCF-7, HepG2, and PC3), and one normal cell line (Dermal/Fibroblast). Compounds 9g and 9k have shown potent activities against the MCF-7 cell line with IC50 values of (2.00 ± 0.03 μM) and (5.00 ± 0.01 μM) respectively. ADMET studies and Molecular docking investigations are performed on the most active hybrid nitroimidazole derivatives 9g and 9k with 4-hydroxytamoxifen (4-OHT) at the human estrogen receptor alpha (hER) during binding active sites to study the ligand-protein interactions and free binding energies at atomic levels. The triazole ring in the 9g derivative forms a hydrogen bond with Asp58 with distance 3.2 Å. And it is found that polar contact with His231 amino acid residue. In silico assessment of the compounds showed very good pharmacokinetic properties based on their physicochemical values, also the ADMET criteria of the most active hybrid systems are within the acceptable range.

Divergent roles of estrogen receptor subtypes in regulating estrogen-modulated colonic ion transports and epithelial repair

Although it was described previously for estrogen (E2) regulation of intestinal epithelial Cl- and HCO3- secretion in sex difference, almost nothing is known about the roles of estrogen receptor (ER) subtypes in regulating E2-modulated epithelial ion transports and epithelial restitution. Here, we aimed to investigate ERα and ERβ subtypes in the regulation of E2-modulated colonic epithelial HCO3- and Cl- secretion and epithelial restitution. Through physiological and biochemical studies, in combination of genetic knockdown, we showed that ERα attenuated female colonic Cl- secretion but promoted Ca2+-dependent HCO3- secretion via store-operated calcium entry (SOCE) mechanism in mice. However, ERβ attenuated HCO3- secretion by inhibiting Ca2+via the SOCE and inhibiting cAMP via protein kinases. Moreover, ERα but not ERβ promoted epithelial cell restitution via SOCE/Ca2+ signaling. ERα also enhanced cyclin D1, proliferating cell nuclear antigen, and β-catenin expression in normal human colonic epithelial cells. All ERα-mediated biological effects could be attenuated by its selective antagonist and genetic knockdown. Finally, both ERα and ERβ were expressed in human colonic epithelial cells and mouse colonic tissues. We therefore conclude that E2 modulates complex colonic epithelial HCO3- and Cl- secretion via ER subtype-dependent mechanisms and that ERα is specifically responsible for colonic epithelial regeneration. This study provides novel insights into the molecular mechanisms of how ERα and ERβ subtypes orchestrate functional homeostasis of normal colonic epithelial cells.

Endocrine Disruptor-Induced Bone Damage Due to Hormone Dysregulation: A Review

Hormones are indispensable for bone development, growth, and maintenance. While many of the genes associated with osteogenesis are well established, it is the recent findings in endocrinology that are advancing the fields of bone biology and toxicology. Endocrine-disrupting chemicals (EDCs) are defined as chemicals that interfere with the function of the endocrine system. Here, we report recent discoveries describing key hormone pathways involved in osteogenesis and the EDCs that alter these pathways. EDCs can lead to bone morphological changes via altering hormone receptors, signaling pathways, and gene expression. The objective of this review is to highlight the recent discoveries of the harmful effects of environmental toxicants on bone formation and the pathways impacted. Understanding the mechanisms of how EDCs interfere with bone formation contributes to providing a comprehensive toxicological profile of a chemical.

Estetrol: From Preclinical to Clinical Pharmacology and Advances in the Understanding of the Molecular Mechanism of Action

Estetrol (E4) is the most recently described natural estrogen. It is produced by the human fetal liver during pregnancy and its physiological function remains unclear. E4 is the estrogenic component of a recently approved combined oral contraceptive. It is also in development for use as menopausal hormone therapy. In the context of these developments, the pharmacological activity of E4, alone or in combination with a progestin, has been extensively characterized in preclinical models as well as in clinical studies in women of reproductive age and postmenopausal women. Despite the clinical benefits, the use of oral estrogens for contraception or menopause is also associated with unwanted effects, such as an increased risk of breast cancer and thromboembolic events, due to their impact on non-target tissues. Preclinical and clinical data for E4 point to a tissue-specific activity and a more selective pharmacological profile compared with other estrogens, including a low impact on the liver and hemostasis balance. This review summarizes the characterization of the pharmacological properties of E4 as well as recent advances made in the understanding of the molecular mechanisms of action driving its activity. How the unique mode of action and the different metabolism of E4 might support its favorable benefit-risk ratio is also discussed.

17β-Estradiol Suppresses Gastric Inflammatory and Apoptotic Stress Responses and Restores nNOS-Mediated Gastric Emptying in Streptozotocin (STZ)-Induced Diabetic Female Mice

Gastroparesis (Gp) is a severe complication of diabetes mellitus (DM) observed predominantly in women. It is characterized by abnormal gastric emptying (GE) without mechanical obstruction in the stomach. Nitric oxide (NO) is an inhibitory neurotransmitter produced by neuronal nitric oxide synthase (nNOS). It plays a critical role in gastrointestinal (GI) motility and stomach emptying. Here, we wanted to demonstrate the protective effects of supplemental 17β-estradiol (E2) on NO-mediated gastric function. We showed E2 supplementation to alleviate oxidative and inflammatory stress in streptozotocin (STZ)-induced diabetic female mice. Our findings suggest that daily administration of E2 at therapeutic doses is beneficial for metabolic homeostasis. This restoration occurs via regulating and modulating the expression/function of glycogen synthase kinase-3β (GSK-3β), nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), Phase II enzymes, MAPK- and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB)-mediated inflammatory cytokines (IL-1β, IL-6, TNFα, IGF-1), and gastric apoptotic regulators. We also showed E2 supplementation to elevate GCH-1 protein levels in female diabetic mice. Since GCH-1 facilitates the production of tetrahydrobiopterin (BH4, cofactor for nNOS), an increase in GCH-1 protein levels in diabetic mice may improve their GE and nitrergic function. Our findings provide new insights into the impact of estrogen on gastric oxidative stress and intracellular inflammatory cascades in the context of Gp.

Intercommunication between Voltage-Gated Calcium Channels and Estrogen Receptor/Estrogen Signaling: Insights into Physiological and Pathological Conditions

Voltage-gated calcium channels (VGCCs) and estrogen receptors are important cellular proteins that have been shown to interact with each other across varied cells and tissues. Estrogen hormone, the ligand for estrogen receptors, can also exert its effects independent of estrogen receptors that collectively constitute non-genomic mechanisms. Here, we provide insights into the VGCC regulation by estrogen and the possible mechanisms involved therein across several cell types. Notably, most of the interaction is described in neuronal and cardiovascular tissues given the importance of VGCCs in these electrically excitable tissues. We describe the modulation of various VGCCs by estrogen known so far in physiological conditions and pathological conditions. We observed that in most in vitro studies higher concentrations of estrogen were used while a handful of in vivo studies used meager concentrations resulting in inhibition or upregulation of VGCCs, respectively. There is a need for more relevant physiological assays to study the regulation of VGCCs by estrogen. Additionally, other interacting receptors and partners need to be identified that may be involved in exerting estrogen receptor-independent effects of estrogen.

Modulatory Effects of Estradiol and Its Mixtures with Ligands of GPER and PPAR on MAPK and PI3K/Akt Signaling Pathways and Tumorigenic Factors in Mouse Testis Explants and Mouse Tumor Leydig Cells

The present study was designed to evaluate how estradiol alone or in combination with G protein-coupled estrogen receptor (GPER) agonists and GPER and peroxisome proliferator-activated receptor (PPAR) antagonists alter the expression of tumor growth factor β (TGF-β), cyclooxygenase-2 (COX-2), hypoxia inducible factor 1-alpha (HIF-1α), and vascular endothelial growth factor (VEGF) in mouse testis explants and MA-10 mouse tumor Leydig cells. In order to define the hormone-associated signaling pathway, the expression of MAPK and PI3K/Akt was also examined. Tissue explants and cells were treated with estradiol as well as GPER agonist (ICI 182,780), GPER antagonist (G-15), PPARα antagonist (GW6471), and PPARγ antagonist (T00709072) in various combinations. First, we showed that in testis explants GPER and PPARα expressions were activated by the GPER agonist and estradiol (either alone or in mixtures), whereas PPARγ expression was activated only by GPER agonist. Second, increased TGF-β expression and decreased COX-2 expression were found in all experimental groups of testicular explants and MA-10 cells, except for up-regulated COX-2 expression in estradiol-treated cells, compared to respective controls. Third, estradiol treatment led to elevated expression of HIF-1α and VEGF, while their lower levels versus control were noted in the remaining groups of explants. Finally, we demonstrated the up-regulation of MAPK and PI3Kp85/Akt expressions in estradiol-treated groups of both ex vivo and in vitro models, whereas estradiol in mixtures with compounds of agonistic or antagonistic properties either up-regulated or down-regulated signaling kinase expression levels. Our results suggest that a balanced estrogen level and its action together with proper GPER and PPAR signaling play a key role in the maintenance of testis homeostasis. Moreover, changes in TGF-β and COX-2 expressions (that disrupted estrogen pathway) as well as disturbed GPER-PPAR signaling observed after estradiol treatment may be involved in testicular tumorigenesis.

Role of estrogen receptors in health and disease

Estrogen receptors (ERs) regulate multiple complex physiological processes in humans. Abnormal ER signaling may result in various disorders, including reproductive system-related disorders (endometriosis, and breast, ovarian, and prostate cancer), bone-related abnormalities, lung cancer, cardiovascular disease, gastrointestinal disease, urogenital tract disease, neurodegenerative disorders, and cutaneous melanoma. ER alpha (ERα), ER beta (ERβ), and novel G-protein-coupled estrogen receptor 1 (GPER1) have been identified as the most prominent ERs. This review provides an overview of ERα, ERβ, and GPER1, as well as their functions in health and disease. Furthermore, the potential clinical applications and challenges are discussed.

Dietary essential amino acids restore liver metabolism in ovariectomized mice via hepatic estrogen receptor α

In female mammals, the cessation of ovarian functions is associated with significant metabolic alterations, weight gain, and increased susceptibility to a number of pathologies associated with ageing. The molecular mechanisms triggering these systemic events are unknown because most tissues are responsive to lowered circulating sex steroids. As it has been demonstrated that isoform alpha of the estrogen receptor (ERα) may be activated by both estrogens and amino acids, we test the metabolic effects of a diet enriched in specific amino acids in ovariectomized (OVX) mice. This diet is able to block the OVX-induced weight gain and fat deposition in the liver. The use of liver-specific ERα KO mice demonstrates that the hepatic ERα, through the control of liver lipid metabolism, has a key role in the systemic response to OVX. The study suggests that the liver ERα might be a valuable target for dietary treatments for the post-menopause.

LC-ESI-QTOF-MS/MS Analysis, Cytotoxic, Antiviral, Antioxidant, and Enzyme Inhibitory Properties of Four Extracts of Geranium pyrenaicum Burm. f.: A Good Gift from the Natural Treasure

This study focused on the biological evaluation and chemical characterization of Geranium pyrenaicum Burm. f. Different solvent extracts (hexane, ethyl acetate, methanol, and water extracts) were prepared. The phytochemical profile, antioxidant, and enzyme inhibitory activity were investigated. Cytotoxicity was assessed using VERO, FaDu, HeLa and RKO cells. The antiviral activity was carried out against HSV-1 (Herpes simplex virus 1) propagated in VERO cell line. The aqueous extract, possessing high phenolic content (170.50 mg gallic acid equivalent/g extract), showed the highest reducing capacity (613.27 and 364.10 mg Trolox equivalent/g extract, for cupric reducing antioxidant capacity and ferric reducing antioxidant power, respectively), radical scavenging potential (469.82 mg Trolox equivalent/g extract, against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), metal chelating ability (52.39 mg ethylenediaminetetraacetic acid equivalent/g extract) and total antioxidant capacity (3.15 mmol Trolox equivalent/g extract). Liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (LC-ESI-QTOF-MS/MS) alloved to tentatively identify a total of 56 compounds in the extracts, including ellagitannins, gallic acid and galloyl derivatives amongst others. The ethyl acetate extracts substantially depressed cholinesterase enzymes (4.49 and 12.26 mg galantamine equivalent/g extract against AChE and BChE, respectively) and α-amylase enzyme (1.04 mmol acarbose equivalent/g extract). On the other hand, the methanolic extract inhibited tyrosinase (121.42 mg kojic acid equivalent/g extract) and α-glucosidase (2.39 mmol acarbose equivalent/g extract) activities. The highest selectivity towards all cancer cell lines (SI 4.5-10.8) was observed with aqueous extract with the FaDu cells being the most sensitive (CC50 40.22 µg/mL). It can be concluded that the presence of certain bioactive antiviral molecules may be related to the high anti HSV-1 activity of the methanolic extract. This work has generated vital scientific data on this medicinal plant, which is a prospective candidate for the creation of innovative phyto-pharmaceuticals.

Protective Effects of Estrogen on Cardiovascular Disease Mediated by Oxidative Stress

Perimenopause is an important stage of female senescence. Epidemiological investigation has shown that the incidence of cardiovascular disease in premenopausal women is lower than that in men, and the incidence of cardiovascular disease in postmenopausal women is significantly higher than that in men. This phenomenon reveals that estrogen has a definite protective effect on the cardiovascular system. In the cardiovascular system, oxidative stress is considered important in the pathogenesis of atherosclerosis, myocardial dysfunction, cardiac hypertrophy, heart failure, and myocardial ischemia. From the perspective of oxidative stress, estrogen plays a regulatory role in the cardiovascular system through the estrogen receptor, providing strategies for the treatment of menopausal women with cardiovascular diseases.

Unraveling the multifaceted nature of the nuclear function of mTOR

Positioned at the axis between the cell and its environment, mTOR directs a wide range of cellular activity in response to nutrients, growth factors, and stress. Our understanding of the role of mTOR is evolving beyond the spatial confines of the cytosol, and its role in the nucleus becoming ever more apparent. In this review, we will address various studies that explore the role of nuclear mTOR (nmTOR) in specific cellular programs and how these pathways influence one another. To understand the emerging roles of nuclear mTOR, we discuss data and propose plausible mechanisms to offer novel ideas, hypotheses, and future research directions.