Potent aromatase inhibitors and molecular mechanism of inhibitory action

Exploring the effect and mechanism of Hippophae rhamnoides L. triterpenoid acids on improving NAFLD based on network pharmacology and experimental validation in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) is a traditional Chinese medicinal and possesses a rich medical history in terms of treating gastric disorders, sputum and cough and liver injuries in oriental medicinal system. By reason of the complicated chemical constituents, the material basis and potential pharmacological mechanism of sea buckthorn acting on Non-alcoholic fatty liver disease (NAFLD) has not been clearly elucidated.

AIM OF THE STUDY

To explore the pharmacological efficacy and underlying mechanism of sea buckthorn triterpenoid acid enrichment (STE) in the treatment of NAFLD.

MATERIALS AND METHODS

The approaches of Network pharmacology and experiment validation in vitro and in vivo were applied in this study. Firstly, targets of triterpenoid acid compounds and NAFLD were collected from databases. The crucial targets were screened by the construction of protein-protein interaction (PPI) network. Furthermore, the potential signaling pathways and targets affected by STE was predicted by GO together with KEGG enrichment analysis. Finally, the experiment validation was carried out through high-fat feeding NAFLD mice and lipid accumulation HepG2 cell model. Lipids and liver related biochemical indicators were determined, Oil Red O and H&E staining were employed to observe fat accumulation. In addition, the expression levels of proteins of key target and signal pathway anticipated in network pharmacology were detected to elaborated its action mechanism.

RESULTS

A total of 180 intersecting potential targets for enhancing NAFLD with STE were eventually identified. 6 key targets including AKT1, TNF, IL6, INS, JUN, STAT3 and TP53 were further identified and the AMPK-SREBP1 pathway was enriched. Animal experiment result showed that STE treatment could significantly reduce the levels of TG, TC, LDL-C, ALT and AST, increase the levels of HDL-C in serum, and improve lipid accumulation of epididymal fat and liver. The results of the lipid accumulation cell model indicated that STE and key compound oleanolic acid could diminish intracellular lipid levels of TG, TC, LDL-C and number of lipid droplets. Western blot results showed that the above beneficial effects could be achieved by regulating the expression of p-AMPK/AMPK, SREBP1, FAS, ACC, SCD protein.

CONCLUSION

This study confirmed the effect of STE on improving NAFLD and the potential action mechanism was involved in the regulation of the AMPK-SREBP1 pathway.

Aromatase Inhibitors as a Promising Direction for the Search for New Anticancer Drugs

Aromatase is an enzyme that plays a crucial role in the biosynthesis of estrogens, which are hormones that contribute to the growth of certain types of breast cancer. In particular, aromatase catalyzes the conversion of androgens (male hormones) into estrogens (female hormones) in various tissues, including the adrenal glands, ovaries, and adipose tissue. Given the role of estrogen in promoting the growth of hormone-receptor-positive breast cancers, aromatase has become an important molecular target for the development of anticancer agents. Aromatase inhibitors can be classified into two main groups based on their chemical structure: steroidal and non-steroidal inhibitors. This work presents a review of the literature from the last ten years regarding the search for new aromatase inhibitors. We present the directions of search, taking into account the impact of structure modifications on anticancer activity.

New 1,2,3-Triazole/1,2,4-triazole Hybrids as Aromatase Inhibitors: Design, Synthesis, and Apoptotic Antiproliferative Activity

A novel series of 1,2,3-triazole/1,2,4-triazole hybrids 5a, 5b, and 6a-i was designed and synthesized as antiproliferative agents targeting aromatase enzymes. The antiproliferative activity of the new hybrids against four cancer cells was studied using Erlotinib as a control. Compounds 6a and 6b demonstrated the highest antiproliferative activity among these hybrids, with GI50 values of 40 nM and 35 nM, respectively. Compound 6b was the most potent derivative, with a GI50 of 35 nM, comparable to Erlotinib's GI50 of 33 nM. Compound 6b inhibited all cancer cell lines with comparable efficacy to Erlotinib. Compounds 5a, 5b, and 6a-i were tested for inhibitory action against aromatase as a potential target for their antiproliferative activity. Results revealed that compounds 6a and 6b were the most potent aromatase inhibitors, with IC50 values of 0.12 ± 0.01 µM and 0.09 ± 0.01 µM, respectively, being more potent than the reference Ketoconazole (IC50 = 2.6 ± 0.20 µM) but less potent than Letrozole (IC50 = 0.002 ± 0.0002). These findings indicated that compounds 6a and 6b had significant aromatase inhibitory action and are potential antiproliferative candidates. The findings were further linked to molecular docking investigations, which gave models of strong interactions with the aromatase domain for inhibitors with high binding scores.

Vaginal Laser Treatment for the Genitourinary Syndrome of Menopause in Breast Cancer Survivors: A Narrative Review

Vulvovaginal atrophy (VVA) is a chronic condition resulting from reduced estrogen levels during menopause. The North American Menopause Society and the International Society for the Study of Women's Sexual Health suggested the term "genitourinary syndrome of menopause" (GSM) to indicate the broader aspects of VVA. Breast cancer treatments, such as chemotherapy and endocrine therapy, can induce early and abrupt menopausal symptoms, including GSM, which negatively affects sexual function and the quality of life of the survivors. Vaginal laser therapy has emerged as a safe and effective option for the management of GSM in breast cancer survivors (BCSs). Two main types of lasers, the non-ablative erbium:YAG laser and fractional microablative CO2 vaginal laser, have been evaluated for GSM treatment. While there are few randomized controlled trials (RCTs) on the subject of BCSs, a wealth of prospective and retrospective studies have highlighted the beneficial effects of vaginal laser therapy on the symptoms of VVA, vaginal health, sexual function, and overall quality of life. More comprehensive research is essential to confirm its enduring effectiveness and safety, with a focus on conducting standardized and meticulously controlled investigations. This study is a narrative review that summarizes clinical trials ranging from the earliest to the most recent ones on laser treatment for GSM in BCSs.

Ferrozoles: Ferrocenyl derivatives of letrozole with dual effects as potent aromatase inhibitors and cytostatic agents

In the treatment of hormone-dependent cancers, aromatase inhibitors (AI) are receiving increased attention due to some undesirable effects such as the risk of endometrial cancer and thromboembolism of SERMs (selective estrogen receptor modulators). Letrozole is the most active AI with 99% aromatase inhibition. Unfortunately, this compound also exhibits some adverse effects such as hot flashes and fibromyalgias. Therefore, there is an urgent need to explore new types of AIs that retain the same-or even increased-antitumor ability. Inspired by the letrozole structure, a set of new derivatives has been synthesized that include a ferrocenyl moiety and different heterocycles. The derivative that contains a benzimidazole ring, namely compound 6, exhibits a higher aromatase inhibitory activity than letrozole and it also shows potent cytostatic behavior when compared to other well-established aromatase inhibitors, as demonstrated by dose-response, cell cycle, apoptosis and time course experiments. Furthermore, 6 promotes the inhibition of cell growth in both an aromatase-dependent and -independent fashion, as indicated by the study of A549 and MCF7 cell lines. Molecular docking and molecular dynamics calculations on the interaction of 6 or letrozole with the aromatase binding site revealed that the ferrocene moiety increases the van der Waals and hydrophobic interactions, thus resulting in an increase in binding affinity. Furthermore, the iron atom of the ferrocene fragment can form a metal-acceptor interaction with a propionate fragment, and this results in a stronger coupling with the heme group-a possibility that is consistent with the strong aromatase inhibition of 6.

Nitroarenes and nitroalkenes as potential amino sources for the synthesis of N-heterocycles

Nitro-compounds are one of the cheapest and most readily available materials in the chemical industry and are commonly utilized as versatile building blocks. Previously, the synthesis of N-heterocycles was largely based on anilines. The utilization of nitroarenes and nitroalkenes for the synthesis of N-heterocyclic compounds can save at least one step, however, as compared to anilines. Thus, considerable attention has been paid to nitroarenes and nitroalkenes as new potential amino sources. Significant progress has been made in the reductive cyclization of nitroarenes or nitroalkenes to access various N-heterocycles in recent years. Herein, we comprehensively summarize the recent progress in the construction of N-heterocycles using nitroarenes and nitroalkenes as potential amino sources. The compatibility of the reaction substrate, its mechanism, applications, advantages, and limitations in this field are also discussed in detail.

Emerging Use of Vaginal Laser to Treat Genitourinary Syndrome of Menopause for Breast Cancer Survivors: A Review

Breast cancer treatment, such as chemotherapy and endocrine therapy, can cause earlier and more sudden menopausal symptoms. Genitourinary syndrome of menopause (GSM) is one of the most bothersome side effects of breast cancer treatment, resulting in sexual dysfunction and impaired quality of life. GSM includes genital, urinary, and sexual symptoms. However, alleviating symptoms of GSM for breast cancer survivors may be challenging due to ineffectiveness, contraindications, and low adherence to treatment. The most recent data show the feasibility and safety of vaginal laser to treat GSM for breast cancer survivors. This narrative review provides the aspects of GSM in breast cancer patients, putting the focus on the efficacy and safety of vaginal laser therapy.

Breast cancer heterogeneity and its implication in personalized precision therapy

Breast cancer heterogeneity determines cancer progression, treatment effects, and prognosis. However, the precise mechanism for this heterogeneity remains unknown owing to its complexity. Here, we summarize the origins of breast cancer heterogeneity and its influence on disease progression, recurrence, and therapeutic resistance. We review the possible mechanisms of heterogeneity and the research methods used to analyze it. We also highlight the importance of cell interactions for the origins of breast cancer heterogeneity, which can be further categorized into cooperative and competitive interactions. Finally, we provide new insights into precise individual treatments based on heterogeneity.

4th generation nonsteroidal aromatase inhibitors: An iterative SAR-guided design, synthesis, and biological evaluation towards picomolar dual binding inhibitors

One in every eight women will be diagnosed with breast cancer during their lifetime and approximately 70% of all patients are oestrogen receptor (ER) positive depending upon oestrogen for their growth accounting for third generation aromatase (CYP19A1) inhibitors being the mainstay in the treatment of ER-positive breast cancer. Despite the success of current aromatase inhibitors, acquired resistance occurs after prolonged therapy. Although the precise mechanisms of resistance are not known, lack of cross resistance among aromatase inhibitors drives the need for a newer generation of inhibitors to overcome this resistance alongside minimising toxicity and adverse effects. Novel triazole-based inhibitors were designed based on previously published parent compound 5a, making use of the now available crystal structure of CYP19A1 (PDB 3S79), to make modifications at specific sites to explore the potential of dual binding at both the active site and the access channel. Modifications included adding long chain substituents e.g. but-2-ynyloxy and pent-2-ynyloxy at different positions including the most active compound 13h with IC₅₀ value in the low picomolar range (0.09 nM). Aromatase inhibition results paired with molecular dynamics studies provided a clear structure activity relationship and favourable dual binding mode was verified. Toxicity assays and CYP selectivity profile studies for some example compounds were performed to assess the safety profile of the prepared inhibitors providing the basis for the 4th generation nonsteroidal aromatase inhibitors.

LINC00094/miR-19a-3p/CYP19A1 axis affects the sensitivity of ER positive breast cancer cells to Letrozole through EMT pathway

The endocrine therapy resistance of breast cancer is the difficulty and challenge to be urgently solved in the current treatment. In this study, we examined the effects of noncoding RNA LINC00094 and miR-19a-3p on breast cancer in vivo and in vitro by RT-QPCR, Western Blot, luciferase assay, immunofluorescence and drug sensitivity tests. The plasma level of CYP19A1 in patients with breast cancer resistance was lower than that in drug sensitive patients. Compared with normal subjects, miR-19a-3p was highly expressed in plasma of patients with breast cancer. miR-19a-3p is highly expressed in estrogen receptor positive breast cancer cells. The expression of miR-19a-3p promoted the migration and EMT of breast cancer cells and reduced the sensitivity of breast cancer to Letrozole. LINC00094 sponge adsorbed miR-19a-3p. LINC00094 promotes the expression of CYP19A1, the target gene of miR-19a-3p, and inhibits the EMT process of breast cancer, ultimately promoting the sensitivity of ER-positive breast cancer cells to Letrozole. This study found a new mechanism of Letrozole sensitivity in ER positive breast cancer.

Triazoles Synthesis & Applications as Nonsteroidal Aromatase Inhibitors for Hormone-Dependent Breast Cancer Treatment

In the last few years, nonsteroidal aromatase inhibitors (AIs) have been emerged as promising agents for treating hormone-dependent breast cancer in postmenopausal women because of their inhibitory effect on estrogen synthesis. Indeed, these compounds can block the activity of aromatase, the enzyme that intervenes in the last steps of estrogen production pathway. Triazoles are the core structures of nonsteroidal AIs. The nitrogen atom of the triazole moiety plays a fundamental role in the aromatase functionality by interacting with the iron ions of the heme group. In general, AIs possess numerous advantages as they quench the last step of estrogen synthesis without any inhibitory effects on the production of other steroids produced via the same pathway. Some AIs as anastrozole, letrozole, and vorozole have already been approved by the Food and Drug Administration in the treatment of breast cancer. The previously mentioned compounds present severe and adverse effects as polycystic ovary syndrome (PCOS), resistance onset on long-term treatments, and a higher risk of bone fractures. This review focuses intensively on the role of AIs in the treatment of hormone-sensitive types of cancers, especially the role of triazoles as nonsteroidal AIs. Also, the review provides an overview about the chemistry of triazoles along with the different methods by which the $v$ -triazoles and s-triazoles are synthesized.

Bone Health Considerations in Breast Cancer

OBJECTIVES

The treatment of breast cancer requires the use of multiple modalities to achieve local control of disease and to prevent distant recurrence. Among patients whose tumors are hormone-receptor positive, endocrine therapy for up to 10 years in the adjuvant setting can be an important component of such therapy, but it is not without adverse events. Ovarian suppression or estrogen restriction can have a rapid and clinically significant detrimental effect on bone mineral density, leading to potential osteoporotic fracture. This article reviews the major causes of breast cancer treatment-induced bone loss and pharmacologic and nonpharmacologic management strategies to maintain bone health in this population.

DATA SOURCES

PubMed and international clinical practice guidelines were used.

CONCLUSION

A holistic, long-term approach is needed to identify and offer early intervention to patients at high-risk of significant bone density loss. A combination of routine screening, use of oral or intravenous bone-modifying agents, oral supplementation of calcium and vitamin D, and physical activity, including weight-bearing exercise, are required to maintain adequate bone health during treatment for breast cancer.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses are well-situated in the primary and survivorship care teams for patients with breast cancer to provide proactive education on the need to assess and actively manage bone health. Nonpharmacologic interventions such as dietary supplementation and physical activity are essential to health promotion and are within the nursing scope of practice to emphasize with this patient population.

Exploration of structural requirements for azole chemicals towards human aromatase CYP19A1 activity: Classification modeling, structure-activity relationships and read-across study

Human aromatase, also called CYP19A1, plays a major role in the conversion of androgens into estrogens. Inhibition of aromatase is an important target for estrogen receptor (ER)-responsive breast cancer therapy. Use of azole compounds as aromatase inhibitors is widespread despite their low selectivity. A toxicological evaluation of commonly used azole-based drugs and agrochemicals with respect to CYP19A1is currently requested by the European Union- Registration, Evaluation, Authorization and Restriction of Chemicals (EU-REACH) regulations due to their potential as endocrine disruptors. In this connection, identification of structural alerts (SAs) is an effective strategy for the toxicological assessment and safe drug design. The present study describes the identification of SAs of azole-based chemicals as guiding experts to predict the aromatase activity. Total 21 SAs associated with aromatase activity were extracted from dataset of 326 azole-based drugs/chemicals obtained from Tox21 library. A cross-validated classification model having high accuracy (error rate 5%) was proposed which can precisely classify azole chemicals into active/inactive toward aromatase. In addition, mechanistic details and toxicological properties (agonism/antagonism) of azoles with respect to aromatase were explored by comparing active and inactive chemicals using structure-activity relationships (SAR). Lastly, few structural alerts were applied to form chemical categories for read-across applications.

Novel imidazole derivatives as potential aromatase and monoamine oxidase-B inhibitors against breast cancer

The activity of the synthesized compounds against breast cancer was investigated. Molecular docking studies were performed against aromatase, MAO-B, and Caspase-3 enzymes.

Deoxygenation reactions in organic synthesis catalyzed by dioxomolybdenum(VI) complexes

Dioxomolybdenum(VI) complexes have been applied as efficient, inexpensive and benign catalysts to deoxygenation reactions of a diverse number of compounds in the last two decades. Dioxomolybdenum complexes have demonstrated wide applicability to the deoxygenation of sulfoxides into sulfides and reduction of N-O bonds. Even the challenging nitro functional group was efficiently deoxygenated, affording amines or diverse heterocycles after reductive cyclization reactions. More recently, carbon-based substrates like epoxides, alcohols and ketones have been successfully deoxygenated. Also, dioxomolybdenum complexes accomplished deoxydehydration (DODH) reactions of biomass-derived vicinal 1,2-diols, affording valuable alkenes. The choice of the catalytic systems and reductant is decisive to achieve the desired transformation. Commonly found reducing agents involved phosphorous-based compounds, silanes, molecular hydrogen, or even glycols and other alcohols.

Design, Synthesis and Biological Evaluation of Aromatase Inhibitors Based on Sulfonates and Sulfonamides of Resveratrol

A library of sulfonate and sulfonamide derivatives of Resveratrol was synthesized and tested for its aromatase inhibitory potential. Interestingly, sulfonate derivatives were found to be more active than sulfonamide bioisosteres with IC₅₀ values in the low micromolar range. The sulfonate analogues 1b–c and 1j exhibited good in vitro antiproliferative activity on the MCF7 cell line, evidenced by MTT and LDH release assays. Structure–activity relationships suggested that electronic and lipophilic properties could have a different role in promoting the biological response for sulfonates and sulfonamides, respectively. Docking studies disclosed the main interactions at a molecular level of detail behind the observed inhibition of the more active compounds whose chemical stability has been evaluated with nano-liquid chromatography. Finally, 1b–c and 1j were highlighted as sulfonates to be further developed as novel and original aromatase inhibitors.

A review on diverse heterocyclic compounds as the privileged scaffolds in non-steroidal aromatase inhibitors

Breast cancer, emerging malignancy is common among women due to overexpression of estrogen. Estrogens are biosynthesized from androgens by aromatase, a cytochrome P450 enzyme complex, and play a pivotal role in stimulating cell proliferation. Therefore, deprivation of estrogen by blocking aromatase is considered as the effective way for the inhibition and treatment of breast cancer. In recent years, various non-steroidal heterocyclic functionalities have been extensively developed and studied for their aromatase inhibition activity. This review provides information about the structural-activity relationship of heterocycles (Type II) towards aromatase. This aids the medicinal chemist around the significance of different heterocyclic moieties and helps to design potent aromatase inhibitors.

Synthesis and anticancer activity evaluation of naphthalene-substituted triazole spirodienones

Building on our previous work that discovered 1,2,4-triazole-spirodienone as a promising pharmacophore for anticancer activity, we have further diversified 1,2,4-triazole- spirodienone derivatives and synthesized a series of novel naphthalene-substituted triazole spirodienones to explore their antineoplastic activity. Of these, compound 6a possesses remarkable in vitro cytotoxic activity by arresting cell cycle and inducing apoptosis in MDA-MB-231 cells. Subsequently, acute toxicity assay showed that 6a at 20 mg/kg has no apparent toxicity to the major organ in mice. In addition, compound 6ain vivo suppressed breast cancer 4T1 tumor growth. Taken together, these results indicate that compound 6a may be a potential anticancer agent for further development.

Application of Various Molecular Modelling Methods in the Study of Estrogens and Xenoestrogens

In this review, applications of various molecular modelling methods in the study of estrogens and xenoestrogens are summarized. Selected biomolecules that are the most commonly chosen as molecular modelling objects in this field are presented. In most of the reviewed works, ligand docking using solely force field methods was performed, employing various molecular targets involved in metabolism and action of estrogens. Other molecular modelling methods such as molecular dynamics and combined quantum mechanics with molecular mechanics have also been successfully used to predict the properties of estrogens and xenoestrogens. Among published works, a great number also focused on the application of different types of quantitative structure-activity relationship (QSAR) analyses to examine estrogen's structures and activities. Although the interactions between estrogens and xenoestrogens with various proteins are the most commonly studied, other aspects such as penetration of estrogens through lipid bilayers or their ability to adsorb on different materials are also explored using theoretical calculations. Apart from molecular mechanics and statistical methods, quantum mechanics calculations are also employed in the studies of estrogens and xenoestrogens. Their applications include computation of spectroscopic properties, both vibrational and Nuclear Magnetic Resonance (NMR), and also in quantum molecular dynamics simulations and crystal structure prediction. The main aim of this review is to present the great potential and versatility of various molecular modelling methods in the studies on estrogens and xenoestrogens.

The Influence of Physical Activity and Epigenomics On Cognitive Function and Brain Health in Breast Cancer

The risk of breast cancer increases with age, with the majority of women diagnosed with breast cancer being postmenopausal. It has been estimated that 25-75% of women with breast cancer experience changes in cognitive function (CF) related to disease and treatment, which compromises psychological well-being, decision making, ability to perform daily activities, and adherence to cancer therapy. Unfortunately, the mechanisms that underlie neurocognitive changes in women with breast cancer remain poorly understood, which in turn limits the development of effective treatments and prevention strategies. Exercise has great potential as a non-pharmaceutical intervention to mitigate the decline in CF in women with breast cancer. Evidence suggests that DNA methylation, an epigenetic mechanism for gene regulation, impacts CF and brain health (BH), that exercise influences DNA methylation, and that exercise impacts CF and BH. Although investigating DNA methylation has the potential to uncover the biologic foundations for understanding neurocognitive changes within the context of breast cancer and its treatment as well as the ability to understand how exercise mitigates these changes, there is a dearth of research on this topic. The purpose of this review article is to compile the research in these areas and to recommend potential areas of opportunity for investigation.

Recent Development in Indole Derivatives as Anticancer Agents for Breast Cancer

BACKGROUND

Breast Cancer (BC) is the second most common cause of cancer related deaths in women. Due to severe side effects and multidrug resistance, current therapies like hormonal therapy, surgery, radiotherapy and chemotherapy become ineffective. Also, the existing drugs for BC treatment are associated with several drawbacks such as poor oral bioavailability, non-selectivity and poor pharmacodynamics properties. Therefore, there is an urgent need for the development of more effective and safer anti BC agents.

OBJECTIVE

This article explored in detail the possibilities of indole-based heterocyclic compounds as anticancer agents with breast cancer as their major target.

METHODS

Recent literature related to indole derivatives endowed with encouraging anti BC potential is reviewed. With special focus on BC, this review offers a detailed account of multiple mechanisms of action of various indole derivatives: aromatase inhibitor, tubulin inhibitor, microtubule inhibitor, targeting estrogen receptor, DNA-binding mechanism, induction of apoptosis, inhibition of PI3K/AkT/NFkB/mTOR, and HDAC inhibitors, by which these derivatives have shown promising anticancer potential.

RESULTS

Exhaustive literature survey indicated that indole derivatives are associated with properties of inducing apoptosis and disturbing tubulin assembly. Indoles are also associated with the inhibition of NFkB/mTOR/PI3K/AkT and regulation of estrogen-mediated activity. Furthermore, indole derivatives have been found to modulate critical targets such as topoisomerase and HDAC. These derivatives have shown significant activity against breast cancer cells.

CONCLUSION

In BC, indole derivatives seem to be quite competent and act through various mechanisms that are well established in case of BC. This review has shown that indole derivatives can further be explored for the betterment of BC chemotherapy. A lot of potential is still hidden which demands to be discovered for upgrading BC chemotherapy.

Towards an Understanding of the Mode of Action of Human Aromatase Activity for Azoles through Quantum Chemical Descriptors-Based Regression and Structure Activity Relationship Modeling Analysis

Aromatase is an enzyme member of the cytochrome P450 superfamily coded by the CYP19A1 gene. Its main action is the conversion of androgens into estrogens, transforming androstenedione into estrone and testosterone into estradiol. This enzyme is present in several tissues and it has a key role in the maintenance of the balance of androgens and estrogens, and therefore in the regulation of the endocrine system. With regard to chemical safety and human health, azoles, which are used as agrochemicals and pharmaceuticals, are potential endocrine disruptors due to their agonist or antagonist interactions with the human aromatase enzyme. This theoretical study investigated the active agonist and antagonist properties of “chemical classes of azoles” to determine the relationships of azole interaction with CYP19A1, using stereochemical and electronic properties of the molecules through classification and multilinear regression (MLR) modeling. The antagonist activities for the same substituent on diazoles and triazoles vary with its chemical composition and its position and both heterocyclic systems require aromatic substituents. The triazoles require the spherical shape and diazoles have to be in proper proportion of the branching index and the number of ring systems for the inhibition. Considering the electronic aspects, triazole antagonist activity depends on the electrophilicity index that originates from interelectronic exchange interaction (ω_HF) and the LUMO energy (ELUMOPM7), and the diazole antagonist activity originates from the penultimate orbital (EHOMONLPM7) of diazoles. The regression models for agonist activity show that it is opposed by the static charges but favored by the delocalized charges on the diazoles and thiazoles. This study proposes that the electron penetration of azoles toward heme group decides the binding behavior and stereochemistry requirement for antagonist activity against CYP19A1 enzyme.

Anti-masculinization induced by aromatase inhibitors in adult female zebrafish

Background

Early sex differentiation genes of zebrafish remain an unsolved mystery due to the difficulty to distinguish the sex of juvenile zebrafish. However, aromatase inhibitors (AIs) could direct juvenile zebrafish sex differentiation to male and even induce ovary-to-testis reversal in adult zebrafish.

Results

In order to determine the transcriptomic changes of sex differentiation in juvenile zebrafish and early sex-reversal in adult zebrafish, we sequenced the transcriptomes of juvenile and adult zebrafish treated with AI exemestane (EM) for 32 days, when juvenile zebrafish sex differentiation finished. EM treatment in females up-regulated the expression of genes involved in estrogen metabolic process, female gamete generation and oogenesis, including gsdf, macf1a and paqr5a, while down-regulated the expression of vitellogenin (vtg) genes, including vtg6, vtg2, vtg4, and vtg7 due to the lower level of Estradiol (E2). Furthermore, EM-juveniles showed up-regulation in genes related to cell death and apoptosis, such as bcl2l16 and anax1c, while the control-juveniles exhibited up-regulation of genes involved in positive regulation of reproductive process and oocyte differentiation such as zar1 and zpcx. Moreover, EM-females showed higher enrichment than control females in genes involved in VEGF signaling pathway, glycosaminoglycan degradation, hedgehog signaling pathway, GnRH signaling pathway and steroid hormone biosynthesis.

Conclusions

Our study shows anti-masculinization in EM-treated adult females but not in EM-treated juveniles. This may be responsible for the lower sex plasticity in adults than juveniles.

Straight access to highly fluorescent angular indolocarbazoles via merging Au- and Mo-catalysis

A straightforward and efficient synthesis of the two less explored types of indolocarbazoles has been developed giving rise to highly fluorescent compounds with fluorescence quantum yields around 0.7.

Steroidal alkaloids efficient aromatase inhibitors with potential for the treatment of postmenopausal breast cancer

Plant-derived natural products are of great interest due to their diversity in modern drug discovery. Sarcococca saligna has been used for the treatment of different diseases. The present study was aimed at isolating phytochemical constituents including Alkaloid-C (a), Dictyophlebine (b), Sarcovagine-D (c) and Saracodine (d) Holaphylline (e) from Sarcococca saligna to investigate the anticancer effect of these compounds. These compounds were evaluated for inhibition of aromatase enzyme of breast cancer in assistance by molecular docking simulations to understand molecular interaction between the enzyme and ligands. The IC₅₀ values of compound 1 and 5 were found 138.27 ± 0.01 µl and 12.91 ± 0.01 µl, respectively, and both were found active due to their bulky structures in comparison to the active site of aromatase enzyme. The standard drug exemestane showed potent activity in comparison with the test compounds, having IC₅₀ values of 0.052 ± 0.01 µl. Both compounds showed favorable electrostatic interactions with the active site of aromatase enzyme but the shape and steric bulk of the compounds was the limiting factor in their inhibitory effects. New lead compounds could be generated after extensive modifications guided by computational and experimental tools as a possible anticancer agents by targeting aromatase enzyme.

Effect of Hyperin and Icariin on steroid hormone secretion in rat ovarian granulosa cells

AIM OF THE STUDY

This study was designed to investigate the effect of different concentrations of Hyperin and Icariin (ICA)on proliferation and the secretion of estrogen (E2), and progesterone (P) in granulosa cells, and to explore the effect of Hyperin and Icariin on the expression of CYP17 and CYP19.

MATERIALS AND METHODS

Rat ovary granulosa cells were cultured in vitro and treated with different concentrations of Hyperin and Icariin. The proliferation of ovarian granulosa cells was measured with the MTT assay. The concentration of estradiol was measured with a magnetic particle-based enzyme-linked immunosorbent assay (ELISA) kit. The CYP17 and CYP19 mRNA expression was detected by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). The CYP17 and CYP19 protein expression was determined with Western blotting.

RESULTS

Hyperin (50 μg/l) and Icariin (10 μg/l) significantly increased proliferation of ovarian granulosa cells and secretion of estrogen and progesterone. Hyperin and Icariin stimulated the mRNA and protein expression of CYP17 and CYP19.

CONCLUSIONS

These results showed that Hyperin and Icariin can promote the secretion of E2 and P through up-regulation of CYP17 and CYP19. Frequently used Chinese herbs like Cuscuta Chinensis Lam and Epimedium Brevicornu maxim, which contain Hyperin and Icariin, could improve the ovarian endocrine function through these effects.

Human cytochrome P450 enzymes 5-51 as targets of drugs and natural and environmental compounds: mechanisms, induction, and inhibition - toxic effects and benefits

Cytochrome P450 (P450, CYP) enzymes have long been of interest due to their roles in the metabolism of drugs, pesticides, pro-carcinogens, and other xenobiotic chemicals. They have also been of interest due to their very critical roles in the biosynthesis and metabolism of steroids, vitamins, and certain eicosanoids. This review covers the 22 (of the total of 57) human P450s in Families 5-51 and their substrate selectivity. Furthermore, included is information and references regarding inducibility, inhibition, and (in some cases) stimulation by chemicals. We update and discuss important aspects of each of these 22 P450s and questions that remain open.

Current research on anti-breast cancer synthetic compounds

Breast cancer (BC) is the most common cancer for females and its incidence tends to increase year by year.