Human Estrogen Receptor Alpha Research Articles

The physiological and biochemical basis of potency thresholds modeled using human estrogen receptor alpha: implications for identifying endocrine disruptors

The endocrine system functions by interactions between ligands and receptors. Ligands exhibit potency for binding to and interacting with receptors. Potency is the product of affinity and efficacy. Potency and physiological concentration determine the ability of a ligand to produce physiological effects. The kinetic behavior of ligand-receptor interactions conforms to the laws of mass action. The laws of mass action define the relationship between the affinity of a ligand and the fraction of cognate receptors that it occupies at any physiological concentration. We previously identified the minimum ligand potency required to produce clinically observable estrogenic agonist effects via the human estrogen receptor-alpha (ERα). By examining data on botanical estrogens and dietary supplements, we demonstrated that ERα ligands with potency lower than one one-thousandth that of the primary endogenous hormone 17β-estradiol (E2) do not produce clinically observable estrogenic effects. This allowed us to propose a Human-Relevant Potency Threshold (HRPT) for ERα ligands of 1 × 10–4 relative to E2. Here, we test the hypothesis that the HRPT for ERα arises from the receptor occupancy by the normal metabolic milieu of endogenous ERα ligands. The metabolic milieu comprises precursors to hormones, metabolites of hormones, and other normal products of metabolism. We have calculated fractional receptor occupancies for ERα ligands with potencies below and above the previously established HRPT when normal circulating levels of some endogenous ERα ligands and E2 were also present. Fractional receptor occupancy calculations showed that individual ERα ligands with potencies more than tenfold higher than the HRPT can compete for occupancy at ERα against individual components of the endogenous metabolic milieu and against mixtures of those components at concentrations found naturally in human blood. Ligands with potencies less than tenfold higher than the HRPT were unable to compete successfully for ERα. These results show that the HRPT for ERα agonism (10–4 relative to E2) proposed previously is quite conservative and should be considered strong evidence against the potential for disruption of the estrogenic pathway. For chemicals with potency 10–3 of E2, the potential for estrogenic endocrine disruption must be considered equivocal and subject to the presence of corroborative evidence. Most importantly, this work demonstrates that the endogenous metabolic milieu is responsible for the observed ERα agonist HRPT, that this HRPT applies also to ERα antagonists, and it provides a compelling mechanistic explanation for the HRPT that is grounded in basic principles of molecular kinetics using well characterized properties and concentrations of endogenous components of normal metabolism.

Pinostrobin and its derivatives as novel anti-breast cancer agents against human oestrogen receptor alpha: In silico studies of ADMET, docking, and molecular dynamics

Background: Breast cancer is the main cause of cancer death among women. The issue is more complex due to the side effects and resistance of the currently used breast cancer drugs. Pinostrobin, a compound found in Boesenbergia pandurata, has anticancer activity. Modifying the structure of pinostrobin can improve drug bioavailability, reduce toxicity, and work more selectively. Objective: This study aimed to predict the potentials of pinostrobin and its derivatives as anti-breast cancer agents against human oestrogen receptors by an in silico approach. Methods: The pkCSM was utilised to predict the ADMET characteristics. The interaction of ligands with the binding site of the human oestrogen receptor alpha with PDB ID 3ERT was used for molecular docking using MOE, and AMBER was then used for molecular dynamic simulation. Results: Pinostrobin pentanoate had good pharmacokinetic properties and was neither mutagenic nor hepatotoxic. Based on molecular docking, it was more potent compared to pinostrobin, with binding free energy values of -7.849 kcal/mol. Furthermore, in the interaction stability evaluation using 100 ns molecular dynamic simulation by the MM-GBSA calculation method, pinostrobin pentanoate had a stable interaction with a total bond energy value of -9.943 kcal/mol. Conclusion: Pinostrobin pentanoate has the potential as an anti-breast cancer alternative through the human oestrogen receptor alpha.

Molecular Dynamic Simulation and 3d-pharmacophore Modeling of Alpha Mangostin and Its Derivatives against Estrogen Alpha Receptor

Background: Human estrogen receptor alpha (ERα), which is known to play a role in mediating cell proliferation, metastasis, and resistance to apoptosis, is one of the targets of breast cancer therapies. Alpha mangostin (AM) is an active xanthone compound from Garcinia mangostana L. which has activity as an ERα inhibitor. Objectives: This research aims to predict the pharmacokinetic and toxicity, and to study the molecular interactions of AM derivatives with the ERα using computer-aided simulation approaches through molecular docking, molecular dynamic, and pharmacophore screening to develop novel anti-breast cancer agents. Methods: Marvinsketch and Chimera programs were used to design and optimize the structure of AM and its derivatives. For screening the pharmacokinetic and toxicity profiles, the PreADMET web was used. The AutoDockTools 1.5.6 and LigandScout 4.4.3 Advanced software were used to conduct the molecular docking simulation and pharmacophore screening, respectively, while the molecular dynamic simulation was performed using AMBER 16. The results were visualized by Biovia Discovery Studio. Results: Molecular docking using Autodock showed that FAT10 derivate has lower binding free energy (ΔG) (-12.04 kcal/mol) than AM (-8.45 kcal/mol) when docking to ERα and both performed the same hydrogen bond with Thr347. These support the results of the MMPBSA calculation on dynamic simulation which shows FAT10 (-58.4767 kcal/mol) has lower ΔG than AM (-42.7041 kcal/mol) and 4-OHT (- 49.0821 kcal/mol). The pharmacophore screening results also showed that FAT10 fitted the pharmacophore with a fit score of 47.08. Conclusion: From the results, it can be suggested that FAT10 has promising activity as ERα antagonist. Further in vitro and in vivo experiments should be carried out to support these in silico studies.

Phytochemical Characterization and Anticancer Screening of Cladophora goensis and Cladophora glomerata Extracts

Background Cladophora goensis and Cladophora glomerata has been widely identified in the Indian Oceans. Marine algae have been identified as potential pharmacological agents useful in the treatment of diabetes, hypertension, infections, and cancers. Objectives The present study aimed to evaluate the phytochemicals in C. goensis and C. glomerata using gas chromatography-mass spectroscopy (GC-MS), and to study the molecular interactions with cancer-related proteins using molecular docking techniques. Materials and methods GC-MS analysis was done using electron impact ionization at 70eV and the data was evaluated using total ion count for compound identification and quantification. AutoDock 4.0 version was used for the molecular docking analysis. Results The methanolic extracts of algae when subjected to GC-MS analysis, 19 compounds from C. goensis and 11 phytocompounds from C. glomerata were identified. The significant molecular interactions of phytochemicals of C. goensis (6-nitro-3 H-quinazolin-4-one, Isoquinoline, 1,2,3,4-tetrahydro-7-methoxy-2-methyl-8-(phenyl methoxy) and 9-Decen-1-ol, pentafluropropionate) and C. glomerata (phytol, palmitic acid, and octadec-9-enoic acid) against human epidermal growth factor receptor (4WRG), poly (ADP-ribose) polymerase-1 (4UND), human estrogen receptor alpha ligand-binding domain (3ERT), human peroxisome proliferator-activated receptor alpha ligand-binding domain (3VI8), and human topoisomerase (1EJ9) have been demonstrated. Conclusion The phytochemicals of methanolic extracts of C. goensis and C. glomerata showed potential interactions with cancer-related proteins.

Synthesis, Structure, and In Vitro Pharmacological Evaluation of some New Pyrimidine-2-Sulfonamide Derivatives and Their Molecular Docking Studies on Human Estrogen Receptor Alpha and CDK2/Cyclin Proteins

Synthesis, Structure, and In Vitro Pharmacological Evaluation of some New Pyrimidine-2-Sulfonamide Derivatives and Their Molecular Docking Studies on Human Estrogen Receptor Alpha and CDK2/Cyclin Proteins

Molecular Docking Studies and In-silico ADMET Profile Analysis of Triphala Plant constituents Morin and 9, 10-anthraquinone as Potential Inhibitors of human Estrogen Receptor Alpha

The expanding global burden of cancer demands novel treatment options. Herbal medicine offers a viable alternative to conventional cancer treatment. Breast cancer is frequently diagnosed cancer among women all over the world. Normal breast cells and specific breast cancer cells containestrogen and progesterone receptors. Estrogen and progesterone bind to receptors and stimulate cancer cell proliferation and expansion with growth factors (e.g., oncogenes and mutated gene suppressors). Tamoxifen, raloxifene, andtoremifene are among the most frequently used drugs for breast cancer, whereas estrogen continues to be produced in breast cancer cells. These medications primarily function against theestrogen binding to theestrogenreceptors on these cells. Protein-ligand interaction plays a major role in structural drug design. In this study, the molecular interactions between theHuman estrogen receptor alpha (PDB ID: 2IOK), and the two ligands isolated from Triphala Ayurvedic formulation morin, and 9,10-anthraquinone, an endogenous estrogen receptor ligand, estradiol, and the three economically available breast cancer drug, tamoxifen, raloxifene, and toremifene using the AutodockVina software tool. The ADMET properties of these substances were determinedusing popular web-based software tools that include preADMET, admetSAR, Molinspiration, and SwissADME.The present available anti-cancer drugs have so many side effects. The present work is aimed at determining the efficacy ofestrogen receptor inhibitors and the safety profile of morin, anthraquinone molecules isolated from Triphalapolyherbal formulation by in-silico methods. The binding energies (Kcal/mol) of ligands with human estrogen receptor were calculated as follows: morin (-9.0), 9,10-anthraquinone (-8.7), estradiol (-10.1), tamoxifen (-9.6), raloxifene (-9.8) and toremifene (-8.9). The resultssupported the drug-like properties of the molecules tested and they are likely to have a therapeutic effect.Further,in vivo and pre-clinical trials of the most active compound are also worthwhile for producing effective inhibitors.

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.

Investigating Endocrine Disrupting Impacts of Nine Disinfection Byproducts on Human and Zebrafish Estrogen Receptor Alpha.

Disinfection byproducts (DBPs) cause endocrine disruption via estrogenic or anti-estrogenic effects on estrogen receptors. However, most studies have focused on human systems, with little experimental data being presented on aquatic biota. This study aimed to compare the effects of nine DBPs on zebrafish and human estrogen receptor alpha (zERα and hERα). In vitro enzyme response-based tests, including cytotoxicity and reporter gene assays, were performed. Additionally, statistical analysis and molecular docking studies were employed to compare ERα responses. Iodoacetic acid (IAA), chloroacetonitrile (CAN), and bromoacetonitrile (BAN) showed robust estrogenic activity on hERα(maximal induction ratios of 108.7%, 50.3%, and 54.7%, respectively), while IAA strongly inhibited the estrogenic activity induced by 17β-estradiol (E2) in zERα (59.8% induction at the maximum concentration). Chloroacetamide (CAM) and bromoacetamide (BAM) also showed robust anti-estrogen effects in zERα (48.1% and 50.8% induction at the maximum concentration, respectively). These dissimilar endocrine disruption patterns were thoroughly assessed using Pearson correlation and distance-based analyses. Clear differences between the estrogenic responses of the two ERαs were observed, whereas no pattern of anti-estrogenic activities could be established. Some DBPs strongly induced estrogenic endocrine disruption as agonists of hERα, while others inhibited estrogenic activity as antagonists of zERα. Principal coordinate analysis (PCoA) showed similar correlation coefficients for estrogenic and anti-estrogenic responses. Reproducible results were obtained from computational analysis and the reporter gene assay. Overall, the effects of DBPs on both human and zebrafish highlight the importance of controlling their differences in responsiveness for estrogenic activities including the water quality monitoring and endocrine disruption, as DBPs have species-specific ligand-receptor interactions.

Synthesis, Cytotoxicity, Molecular Docking and ADME Assay of Novel Morpholine appended 1,2,3‐Triazole Analogues

AbstractSynthesis of novel 4‐(1‐(2‐cyclopropylphenyl)‐2‐(4‐substituted‐1H‐1,2,3‐triazol‐1‐yl)ethyl)morpholine analogues were demonstrated by conventional synthetic procedures. The structure of all the newly synthesized compounds were determined by 1H‐NMR, 13C‐NMR, HRMS and CHN analysis. Cytotoxicity of all synthesized compounds were tested against MCF‐7 Cell lines in different concentrations. The IC50 value of compounds was calculated using graph Pad Prism Version5.1. 4‐chloro substituted analogue exhibited superior result than the standard reference Doxorubicin drug. Compounds which are containing 3‐methoxy, 2‐methoxy and 4‐methoxy substituents showed a moderate effect, and 2‐chloro, 3‐triflouromethyl and 2‐methyl substituted analogues showed lower results. Molecular docking studies performed on the crystal structure of human estrogen receptor alpha ligand‐binding domain with all molecules and are well in agreement with cell line studies. The predicted pharmacokinetics support that these compounds have more drug‐likeness properties.

Azole pesticide products and their hepatic metabolites cause endocrine disrupting potential by suppressing the homo-dimerization of human estrogen receptor alpha

We selected azole pesticides products that are managed by setting maximum residue limits (MRLs) in the Republic of Korea and describe the estrogen receptor (ER) α-related negative effect to endocrine system using in vitro Organization for Economic Cooperation and Development performance-based test guideline. No azoles were found to be an ERα agonist. Conversely, three azoles (bitertanol, cafenstrole, and tebufenpyrad) were determined to be ERα antagonists. In addition, the ERα antagonistic activities of bitertanol, cafenstrole, and tebufenpyrad were not significantly perturbed in the existence of phase I (hydroxylation, dealkylation, oxidation or reduction) and phase II (conjugation). Regarding the mechanism underlying their ERα-mediated endocrine disrupting potentials, ERα proteins cannot be translocated to the nucleus by suppressing the dimerization of ERα in the cytoplasm by bitertanol, cafenstrole, and tebufenpyrad.These data indicated that azole pesticide products show the capability to interfere the ERα-related human endocrine system. Furthermore, we identified the mechanism of ERα-mediated endocrine disrupting by azole insecticide products through this study.

Pharmacophore Modeling and Molecular Docking of Flavonoid Derivatives in Abelmoschus manihot Against Human Estrogen Receptor Alpha of Breast Cancer

Tamoxifen is the most commonly used anti-estrogen adjuvant therapy for estrogen receptor-positive breast cancer. However, it is associated with an increased risk of some serious side effects, such as uterine cancer, stroke, and pulmonary embolism. The flavonoid compounds in the leaves of A. manihot inhibited the growth of 4T1 breast cancer cells at a CTC50 concentration of 185.06 μg/ml. Therefore, this study aims to examine the molecular interactions and pharmacophore modeling based on the interaction of 4-OHT with human ER, followed by the molecular docking of the flavonoid derivatives with human ERα. The molecular docking simulations and 3D structure-based pharmacophore models were used to identify the molecular interactions of flavonoid derivatives in A. manihot on estrogen receptors (ERα) (PDB ID: 3ERT). The results showed that the binding energies of the flavonoid derivatives in isorhamnetin and isoquercitrin were -8.68 kcal/mol and -8.75 kcal/mol, respectively. This compound also interacted with Arg394 and Glu353 important amino acid residues in the ERα-binding pocket. Meanwhile, the pharmacophore fit scores of isorhamnetin and isoquercitrin were 82.36% and 84.91%, respectively. The flavonoid derivatives in A. manihot had pharmacophore fit resulting from the 4-OHT complex with ER, and therefore they had potential as ERα antagonists. Out of the 10 flavonoid derivatives, isorhamnetin and isoquercitrin showed the best docking scores and could be used as candidates for new anti-breast cancer drugs with antagonistic activity against ERα.

Generation and Characterization of Novel Diagnostic Mouse Monoclonal Antibodies Against Human Estrogen Receptor Alpha and Progesterone Receptor.

Estrogen and progesterone regulate the growth and development of several human cells and tissues. Their corresponding receptors (ER and PR) are important diagnostic and prognostic indicators for cancers of the breast and reproductive organs. Immunohistochemical analysis of ER and PR is the current standard method for evaluating the expression of these receptors in different cancers. Nonetheless, there is a significant lack of reproducibility of IHC results in laboratories worldwide, necessitating to develop more sensitive and specific antibodies for ER and PR IHC staining. ER and PR-specific monoclonal antibodies (MAbs) were generated by immunizing mice with synthetic peptides from ERα and PR. The isotypes and affinity constants of the selected MAbs were determined, and their specificities were assessed by peptide-specific ELISA, IHC, Western-blot analysis, and flow cytometry. In addition, the reactivity of generated MAbs was compared with that of the commercially-available anti-ER and anti-PR antibodies in IHC using normal and cancerous tissue sections. Moreover, 200 breast cancer tissue samples were stained using the newly generated MAbs along with commercial antibodies by IHC, and the sensitivity, specificity and accuracy of our MAbs were evaluated. Among different MAbs generated in this study, two anti-ER and one anti-PR MAbs specifically detected the target antigens in normal and cancerous tissues in IHC. Further analyses confirmed the specificity of the MAbs in Western blotting and flow cytometry using a panel of ER and PR positive cell lines. The sensitivity, specificity and accuracy calculated for clone 1B9 (anti-ER) were 92.3%, 94.8% and 93%, and for clone 3D6 (anti-PR) were 93.0%, 94.3% and 93.5%, respectively. Our novel anti-ER and PR MAbs could be considered as suitable tools for diagnostic and research purposes.

Design, synthesis, bioevaluation, DFT, docking, and molecular dynamic simulation for selected novel 1,3,4-Oxadiazole - indole derivatives hybrid against estrogen receptor alpha

Breast tumors overexpress ER alpha and it initiates, as well as the progression of breast cancer. Studies have proven that anti-estrogen therapy (tamoxifen) is used to treat breast cancer. For the first time, in vitro bioevaluation, molecular docking, and DFT simulations were used to investigate the essential interactions of the estrogen receptor (ER) alpha with selected novel 1,3,4-Oxadiazole - indole derivatives hybrid against Triple Negative Breast Cancer (TNBC) cell lines. The key step of this synthesis is the oxidative cyclization of N-acylhydrazones, 2(a-j), in 20 min using reagent BTI [bis(trilfuoroacetoxy)iodobenzene]. Synthesized compounds, 3(a-j), were screened against a series of cancer cell lines, and among these compounds, the compound, 3d ((5′-Bromo-1H-indol-1-yl) methyl)-5′’-(3-bromo-4-methylphenyl)-1,3,4-Oxadiazole), as a potent molecule which displayed IC50 values of 10.56 and 22.61 µM against MDA MB 468, and MDA MB 231 cell lines respectively. In vitro antibody specific for Human Estrogen Receptor alpha assay showed an IC50 value of 5.27 µM for compound 3d. The structures were optimized to their molecular geometry (3d) by the DFT method with B3LYP hybrid functional and 6–311++g(d,p) basis set. The electrostatic potential map was plotted to understand the energy distribution and chemical reactive regions of the molecule. The optimized structures were used to perform in silico studies. Molecular docking followed by molecular dynamics trajectories is essential to investigate the stable binding of 3d to estrogen receptor alpha. Overall, results show that 3d has the potential to be further explored for the treatment of metastatic breast cancer.

Experimental, DFT study, and in silico molecular docking investigations of dichlorodiphenyltrichloroethane against human estrogen receptor alpha

Advanced computational tools allowed to study a pure commercial sample of dichlorodiphenyltrichloroethane (DDT) prepared in liquid phase in KBr pellets and characterized using FT-IR and GC-MS followed by the application of DDT for molecular docking against human estrogen receptor alpha. The compound was modelled using GaussView software. Using Veda 04 program, the theoretical vibrational energy distributions and experimental vibrational frequencies were compared. Interestingly, C1 and C2�possess the highest atomic charge density distribution (ACDD)�of -0.284e and -0.283e while C21 and C11 have lowest ACDD of -0.064e and -0.063e in a relative manner, since the deactivating power of chlorine atoms decreases charge densities of the bonded carbon. The highest intramolecular interacting perturbation energy is 1121.92 kJ mol�1 occurs between ?*C19�C21 donor orbital and ?*C14�C16 acceptor orbital while the least intramolecular interaction occurs in the lone pair of LPC26 and the�sigma nonbonding (??C1�Cl24) NBO orbitals with E(2) of 32.21�kJ mol�1. Steric interaction was the only interaction found within the complex after the docking.

Experimental, DFT study, and in silico molecular docking investigations of dichlorodiphenyltrichloroethane against human estrogen receptor alpha

Advanced computational tools allowed to study a pure commercial sample of dichlorodiphenyltrichloroethane (DDT) prepared in liquid phase in KBr pellets and characterized using FT-IR and GC-MS followed by the application of DDT for molecular docking against human estrogen receptor alpha. The compound was modelled using GaussView software. Using Veda 04 program, the theoretical vibrational energy distributions and experimental vibrational frequencies were compared. Interestingly, C1 and C2�possess the highest atomic charge density distribution (ACDD)�of -0.284e and -0.283e while C21 and C11 have lowest ACDD of -0.064e and -0.063e in a relative manner, since the deactivating power of chlorine atoms decreases charge densities of the bonded carbon. The highest intramolecular interacting perturbation energy is 1121.92 kJ mol�1 occurs between ?*C19�C21 donor orbital and ?*C14�C16 acceptor orbital while the least intramolecular interaction occurs in the lone pair of LPC26 and the�sigma nonbonding (??C1�Cl24) NBO orbitals with E(2) of 32.21�kJ mol�1. Steric interaction was the only interaction found within the complex after the docking.

Human Estrogen Receptor Alpha Antagonists, Part 3: 3-D Pharmacophore and 3-D QSAR Guided Brefeldin A Hit-to-Lead Optimization toward New Breast Cancer Suppressants

The estrogen receptor α (ERα) is an important biological target mediating 17β-estradiol driven breast cancer (BC) development. Aiming to develop innovative drugs against BC, either wild-type or mutated ligand-ERα complexes were used as source data to build structure-based 3-D pharmacophore and 3-D QSAR models, afterward used as tools for the virtual screening of National Cancer Institute datasets and hit-to-lead optimization. The procedure identified Brefeldin A (BFA) as hit, then structurally optimized toward twelve new derivatives whose anticancer activity was confirmed both in vitro and in vivo. Compounds as SERMs showed picomolar to low nanomolar potencies against ERα and were then investigated as antiproliferative agents against BC cell lines, as stimulators of p53 expression, as well as BC cell cycle arrest agents. Most active leads were finally profiled upon administration to female Wistar rats with pre-induced BC, after which 3DPQ-12, 3DPQ-3, 3DPQ-9, 3DPQ-4, 3DPQ-2, and 3DPQ-1 represent potential candidates for BC therapy.

Discovery of Promising Inhibitors of Epidermal Growth Factor Receptor (EGFR), Human Epidermal Growth Factor Receptor 2 (HER2), Estrogen Receptor (ER), and Phosphatidylinositol-3-kinase a (PI3Ka) for Personalized Breast Cancer Treatment.

Despite the rapid developments and advancements to improve treatments, Breast cancer remains one of the deadliest health challenges and the most frequently diagnosed tumor. One of the major problems with treatment is the unique difference that each cancerous cell exhibits. As a result, treatment of breast cancer has now become more personalized based on the specific features of the tumor such as overexpression of growth factor receptors (Epidermal growth factor receptor (EGFR), Human Epidermal Growth Factor Receptor 2 (HER2)), hormone receptors (Human Estrogen receptor alpha (ER)) and kinases involved in pivotal signaling associated with growth (Phosphatidylinositol 3-kinase (PI3K)). Several chemotherapeutic agents have been developed to curb the menace, but the associated adverse drug effects cannot be overlooked. To this end, this study employed a molecular modeling approach to identify novel compounds of natural origin that can potentially antagonize the receptors (mentioned above) associated with the pathophysiology of breast cancer and at the same time pose very little or no side effects. The results of the molecular model of biological interactions between a library of 118 anthocyanins and the binding pockets of the protein targets identified 5 compounds (Pelargonin, Delphinidin 3-O-rutinoside, Malvin, Cyanidin-3-(6-acetylglucoside), and Peonidin 3-O-rutinoside) with good binding affinities to the protein targets. Further MM-GBSA calculations returned high binding energies. The specific molecular interactions between the compounds and the targets were analyzed and reported herein. Also, all the compounds exhibited good pharmacokinetic profiles and are therefore recommended for further analyses as they could be explored as new treatment options for a broad range and personalized breast cancer treatments.

An Efficient One Pot Multicomponent Synthesis of Dihydro Pyrazolyl Bisthiazole Derivatives as Potential Anticancer Agents and their Molecular Docking Studies

A novel series of dihydropyrazolyl bisthiazoles were synthesized through simple reaction conditions via one pot multicomponent reaction of 2-bromo-1-(4-methyl-2-phenyl thiazol-5-yl)ethan-1-one, thiosemicarbazide and chalcones in the presence of sodium hydroxide in ethanol under reflux condition. The reaction generates two potential five membered heterocylic pharmacophores i.e. Hantzsch thiazole and dihydropyrazole in one step through simple operation, in shorter reaction time with high yields. The newly synthesized compounds were well characterized by IR, 1H, 13C NMR and mass spectral data. All the newly synthesized compounds were evaluated for their anticancer activity against human cancer cell lines and calculated their binding energy values with respect to 3ert protein. Some of the compounds exhibited excellent activity against MCF-7 cancer cell line and studied molecular interaction of probable target protein, human estrogen receptor alpha protein (3ert.pdb) using docking simulation.

Biocompatible silver(I) complexes with heterocyclic thioamide ligands for selective killing of cancer cells and high antimicrobial activity – A combined in vitro and in silico study

A series of heteroleptic Ag(I) complexes bearing 4,6-dimethyl-2-pyrimidinethiol (dmp2SH), i.e., [AgCl(dmp2SH)(PPh3)2] (1), [Ag(dmp2SH)(PPh3)2]NO3 (2), [Ag(dmp2SΗ)(xantphos)]NO3 (3), [Ag(μ-dmp2S)(PPh3)]2 (4), [Ag(dmp2S)(xantphos)] (5), [Ag(μ-dmp2S)(DPEphos)]2 (6) (xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and DPEPhos = bis[(2-diphenylphosphino)phenyl]ether) were synthesized. The complexes display systematic variation of particular structural characteristics which were proved to have a significant impact on their in vitro cytotoxicity and antimicrobial properties. A moderate-to-high potential for bacteria growth inhibition was observed for all complexes, with 2, 3 and 5 being particularly effective against Gram-(+) bacteria (IC50 = 1.6–4.5 μM). The three complexes exhibit high in vitro cytotoxicity against HeLa and MCF-7 cancer cells (IC50 = 0.32–3.00 μΜ), suggesting the importance of coordination unsaturation and cationic charge for effective bioactivity. A very low cytotoxicity against HDFa normal cells was observed, revealing a high degree of selectivity (selectivity index ~10) and, hence, biocompatibility. Fluorescence microscopy using 2 showed effective targeting on the membrane of the HeLa cancer cells, subsequently inducing cell death. Binding of the complexes to serum albumin proteins is reasonably strong for potential uptake and subsequent release to target sites. A moderate in vitro antioxidant capacity for free radicals scavenging was observed and a low potential to destroy the double-strand structure of calf-thymus DNA by intercalation, suggesting likely implication of these properties in the bioactivity mechanisms of these complexes. Further insight into possible mechanisms of bioactivity was obtained by molecular modeling calculations, by exploring their ability to act as potential inhibitors of DNA-gyrase, human estrogen receptor alpha, human cyclin-dependent kinase 6, and human papillomavirus E6 oncoprotein.

Estetrol: A New Choice for Contraception.

Estetrol (E4) is a natural estrogenic steroid that is normally produced by human fetal liver. Recent research has demonstrated that it is a potent, orally bioavailable, natural selective estrogen receptor modulator; it has a moderate affinity for both human estrogen receptor alpha (ERα) and ERβ, with a preference for ERα. Clinical studies have demonstrated possible use as an estrogen in combined oral contraceptives (COC). COCs containing E4 and drospirenone (DRSP) showed a high acceptability, tolerability, and user satisfaction also when compared to COCs containing ethinylestradiol (EE). E4/DRSP effectively inhibits ovulation, with a similar effect on endometrium thickness than that of EE-containing COCs. Low doses (15 mg) of E4 with DRSP (3 mg) showed promising results in term of bleeding pattern and cycle control, also when compared to other COCs containing synthetic estrogens. Moreover, the association has limited effects on serum lipids, liver, SHBG levels, and carbohydrate metabolism. This combination also could drive a lower risk of venous thromboembolism than EE-containing COCs. In this review, we will summarize the actual knowledge about the new E4-containing contraceptive. Further large-scale studies in the full target population are needed to provide more insights into the cardiovascular safety profile and user satisfaction of E4/DRSP.