New steroidal 17β-carboxy derivatives present anti-5α-reductase activity and anti-proliferative effects in a human androgen-responsive prostate cancer cell line

The Structural Diversity and Biological Activity of Steroid Oximes

Steroids and their derivatives have been the subject of extensive research among investigators due to their wide range of pharmacological properties, in which steroidal oximes are included. Oximes are a chemical group with the general formula R₁R₂C=N-OH and they exist as colorless crystals and are poorly soluble in water. Oximes can be easily obtained through the condensation of aldehydes or ketones with various amine derivatives, making them a very interesting chemical group in medicinal chemistry for the design of drugs as potential treatments for several diseases. In this review, we will focus on the different biological activities displayed by steroidal oximes such as anticancer, anti-inflammatory, antibacterial, antifungal and antiviral, among others, as well as their respective mechanisms of action. An overview of the chemistry of oximes will also be reported, and several steroidal oximes that are in clinical trials or already used as drugs are described. An extensive literature search was performed on three main databases-PubMed, Web of Science, and Google Scholar.

High altitude exposure affects male reproductive parameters: Could it also affect the prostate?†

Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic, or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia's direct action on the prostate could help understand this exposure's effect and prevent worse prostate illness impact in males at high altitudes.

The potential clinical benefit of targeting androgen receptor (AR) in estrogen-receptor positive breast cancer cells treated with Exemestane

The development of acquired resistance to the aromatase inhibitors (AIs) used in clinic is being considered the major concern in estrogen-receptor positive (ER⁺) breast cancer therapy. Recently, androgen receptor (AR) has gained attention in the clinical setting, since it has been implicated in AIs-resistance, although, different roles for AR in cell fate have been described. In this work, our group elucidates, for the first time, the oncogenic role of AR in sensitive and resistant ER⁺ breast cancer cells treated with the potent third-generation steroidal AI Exemestane (Exe). We demonstrate that Exe promotes an overexpression/activation of AR, which has an oncogenic and pro-survival role in Exe-sensitive and Exe-resistant cells. Moreover, we also disclose that targeting AR with bicalutamide (CDX) in Exe-treated cells, enhances the efficacy of this AI in sensitive cells and re-sensitizes resistant cells to Exe treatment. Furthermore, by targeting AR in Exe-resistant cells, it is also possible to block the activation of the ERK₁/₂ and PI3K cell survival pathways, hamper ERα activation and increase ERβ expression. Thus, this study, highlights a new mechanism involved in Exe-acquired resistance, implicating AR as a key molecule in this setting and suggesting that Exe-resistant cells may have an AR-dependent but ER-independent mechanism. Hence we propose AR antagonism as a potential and attractive therapeutic strategy to overcome Exe-acquired resistance or to enhance the growth inhibitory properties of Exe on ER⁺ breast cancer cells, improving breast cancer treatment.

Discovery of Natural Steroid 5 Alpha-Reductase Inhibitors

Human steroid 5 alpha-reductases (S5αRs) and NADPH irreversibly reduce testosterone to the more potent dihydrotestosterone (DHT). S5αR inhibitors are useful treatments for DHT-dependent diseases, including benign prostatic hyperplasia, androgenic alopecia and hair growth, and acne. There are three S5αR isozymes, and there is a need for safer and more isozyme selective inhibitors than finasteride and dutasteride currently licensed. In this study, we review the methods used to screen for S5αR inhibitory activity and describe studies that characterize the ability of herbal preparations and their constituents to inhibit S5αRs. We identified enormous variations between studies in IC₅₀s for finasteride and dutasteride used as standards. Accordingly, we make several recommendations: Stable isozyme specific transfection systems need creating a standardized enzyme/microsome preparation and all three isozymes, as well as androgen receptor binding, should be tested; agreed reaction conditions, especially the substrate concentrations, and separation/quantitation method optimized for high throughput screening; systematic screening of herbal compounds and most extensive use of leads to develop more potent and isozyme specific inhibitors.

Design, synthesis and biological evaluation of novel androst-3,5-diene-3-carboxylic acid derivatives as inhibitors of 5α-reductase type 1 and 2

5α-Reductase is a key enzyme responsible for dihydrotestosterone biosynthesis and has been recognized as an important target for discovering new drugs against benign prostatic hyperplasia (BPH). In this study, a series of novel steroidal androst-3,5-diene-3-carboxylic acids have been designed and synthesized. Biological evaluations were performed on their 5α-reductase inhibitory activities by both in vitro enzyme inhibition assay and in vivo by prostate weighing method. Results showed that most of them displayed excellent 5α-reductase inhibitory potency. Detailed evaluation indicated that most of the compounds displayed slightly higher inhibition potency towards type 2 isozyme. Among all the compounds, 16a was found to be the most potential inhibitor with the IC₅₀ of 0.25μM and 0.13μM against type 1 and 2 isozymes respectively. In vivo 5a-reductase inhibitory evaluation of 16a also showed a more significant reduction effect (p<0.001) in rat prostate weight than epristeride. Furthermore, the results of in silico ADME study indicated that compound 16a exhibited good pharmacokinetic properties. Thus, 16a could serve as promising lead candidates for further study.

Finasteride-loaded biodegradable nanoparticles: Near-infrared quantification of plasma and prostate levels

Finasteride is an orally active testosterone 5-alpha-reductase inhibitor that is used for the treatment of benign prostatic hyperplasia as a surgical alternative. The aim of this work was to improve finasteride levels in plasma and prostate through the formulation of biodegradable finasteride nanoparticles and to quantify finasteride levels using near-infrared application. Finasteride nanoparticles were prepared by emulsion solvent evaporation method utilizing the biodegradable polymers poly(lactic- co-glycolic acid) and poly-ϵ-caprolactone. The prepared nanoparticles were characterized by particle size, zeta potential, and encapsulation efficiency. The selected finasteride-biodegradable formula was examined in vivo, and both plasma and prostate levels of finasteride were quantified utilizing near-infrared technique. Results revealed that the prepared finasteride nanoparticles size range was from 231 ± 78 to 956 ± 224 nm with finasteride–poly-ϵ-caprolactone nanoparticles showing larger particle sizes compared with finasteride–poly(lactic- co-glycolic acid) nanoparticles. The encapsulation efficiency ranged from 68.89% ± 2.99% to 99.15% ± 4.32%. The selected formula of finasteride nanoparticles showed improved levels of finasteride in both plasma and prostate of the investigated rats. The realization of sustained release of biodegradable finasteride nanoparticles for possible oral or parenteral application could improve the activity of the drug for sustaining release time with lower dosing recurrence that improves patient compliance.

A synopsis of drugs currently in preclinical and early clinical development for the treatment of benign prostatic hyperplasia

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common disease among men and significantly impacts quality of life by causing lower urinary tract symptoms (LUTS). Current medical therapies are not always adequate in controlling LUTS or slowing disease progression, and there is unmet need for new effective therapeutic options.

AREAS COVERED

The authors review the standard current medical therapies for BPH which include the use of α-1 blockers, 5-α reductase inhibitors, combination therapy and PDE inhibitors. Following this, the authors then discuss new therapies that are currently undergoing preclinical and clinical investigation.

EXPERT OPINION

Existing preclinical and clinical trials have highlighted many promising therapies to treat BPH. Further investigation with larger clinical trials is needed to establish these drugs as standard therapies. As the number of drugs in the arsenal against BPH continues to grow, providers and patients will have to engage in a discussion that weighs the risks and benefits of each therapy.

Synthesis and biological evaluation of steroidal derivatives as selective inhibitors of AKR1B10

AKR1B10 is a member of human aldo-keto reductase superfamily, and a promising anti-cancer therapeutic target. In this paper, androst-5-ene-3β-ol, dehydroepiandrosterone, pregnenolone and cholesterol were used as reactants, sixteen products were obtained through Jones reaction and reduction reaction using NaBH4. Their inhibitory activities against AKR1B10 and AKR1B1 were measured. The most active compound (3a) has the IC50 of 0.50μM for AKR1B10, and the most AKR1B10 selective compound (2a) has the IC50 of 0.81μM with AKR1B1/AKR1B10 selectivity of 195. In addition, the binding modes of 2a and 3a in the active site of human AKR1B10 were identified by docking.