Advances in the design and discovery of drugs for the treatment of prostatic hyperplasia

Novel and Predictive QSAR Model for Steroidal and Nonsteroidal 5α- Reductase Type II Inhibitors

AIMS AND OBJECTIVE

In this study, a novel quantitative structure activity relationship (QSAR) model has been developed for inhibitors of human 5-alpha reductase type II, which are used to treat benign prostate hypertrophy (BPH).

METHODS

The dataset consisted of 113 compounds-mainly nonsteroidal-with known inhibitory concentration. Then 3D structures of compounds were optimized and molecular structure descriptors were calculated. The stepwise multiple linear regression was used to select descriptors encoding the inhibitory activity of the compounds. Multiple linear regression (MLR) was used to build up the linear QSAR model.

RESULTS

The results obtained revealed that the descriptors which best describe the activity were atom type electropological state, carbon type, radial distribution function (RDF), barysz matrix and molecular linear free energy relation. The suggested model could achieve satisfied square correlation coefficient of R² = 0.72, higher than of many previous studies, indicating its superiority. Rigid validation criteria were met using external data with Q² ˃ 0.5 and R² = 0.75, reflecting the predictive power of the model.

CONCLUSION

The QSAR model was applied for screening botanical components of herbal preparations used to treat BPH, and could predict the activity of some, among others, making reasonable attribution to the proposed effect of these preparations. Gamma tocopherol was found to be an active inhibitor, in consistence with many previous studies, anticipating the power of this model in the prediction of new candidate molecules and suggesting further investigations.

Heritability and genome-wide association study of benign prostatic hyperplasia (BPH) in the eMERGE network

Benign prostatic hyperplasia (BPH) results in a significant public health burden due to the morbidity caused by the disease and many of the available remedies. As much as 70% of men over 70 will develop BPH. Few studies have been conducted to discover the genetic determinants of BPH risk. Understanding the biological basis for this condition may provide necessary insight for development of novel pharmaceutical therapies or risk prediction. We have evaluated SNP-based heritability of BPH in two cohorts and conducted a genome-wide association study (GWAS) of BPH risk using 2,656 cases and 7,763 controls identified from the Electronic Medical Records and Genomics (eMERGE) network. SNP-based heritability estimates suggest that roughly 60% of the phenotypic variation in BPH is accounted for by genetic factors. We used logistic regression to model BPH risk as a function of principal components of ancestry, age, and imputed genotype data, with meta-analysis performed using METAL. The top result was on chromosome 22 in SYN3 at rs2710383 (p-value = 4.6 × 10-7; Odds Ratio = 0.69, 95% confidence interval = 0.55-0.83). Other suggestive signals were near genes GLGC, UNCA13, SORCS1 and between BTBD3 and SPTLC3. We also evaluated genetically-predicted gene expression in prostate tissue. The most significant result was with increasing predicted expression of ETV4 (chr17; p-value = 0.0015). Overexpression of this gene has been associated with poor prognosis in prostate cancer. In conclusion, although there were no genome-wide significant variants identified for BPH susceptibility, we present evidence supporting the heritability of this phenotype, have identified suggestive signals, and evaluated the association between BPH and genetically-predicted gene expression in prostate.

Hypothesis on Serenoa repens (Bartram) small extract inhibition of prostatic 5α-reductase through an in silico approach on 5β-reductase x-ray structure

Benign prostatic hyperplasia is a common disease in men aged over 50 years old, with an incidence increasing to more than 80% over the age of 70, that is increasingly going to attract pharmaceutical interest. Within conventional therapies, such as α-adrenoreceptor antagonists and 5α-reductase inhibitor, there is a large requirement for treatments with less adverse events on, e.g., blood pressure and sexual function: phytotherapy may be the right way to fill this need. Serenoa repens standardized extract has been widely studied and its ability to reduce lower urinary tract symptoms related to benign prostatic hyperplasia is comprehensively described in literature. An innovative investigation on the mechanism of inhibition of 5α-reductase by Serenoa repens extract active principles is proposed in this work through computational methods, performing molecular docking simulations on the crystal structure of human liver 5β-reductase. The results confirm that both sterols and fatty acids can play a role in the inhibition of the enzyme, thus, suggesting a competitive mechanism of inhibition. This work proposes a further confirmation for the rational use of herbal products in the management of benign prostatic hyperplasia, and suggests computational methods as an innovative, low cost, and non-invasive process for the study of phytocomplex activity toward proteic targets.

Synthesis and structure-activity relationships of novel arylpiperazines as potent antagonists of α1-adrenoceptor

Arylpiperazines 2-11 were synthesized, and their biological profiles at α1-adrenergic receptors (α1-ARs) assessed by binding assays in CHO cells expressing human cloned subtypes and by functional experiments in isolated rat vas deferens (α1A), spleen (α1B), and aorta (α1D). Modifications at the 1,3-benzodioxole and phenyl phamacophoric units resulted in the identification of a number of potent compounds (moderately selective with respect to the α1b-AR), in binding experiments. Notably, compound 7 (LDT451) showed a subnanomolar pKi of 9.41 towards α1a-AR. An encouragingly lower α1B-potency was a general trend for all the series of compounds, which showed α1A/D over α1B selectivity in functional assays. If adequately optimized, such peculiar selectivity could have relevance for a potential LUTS/BPH therapeutic application.

Transurethral plasmakinetic resection of the prostate is a reliable minimal invasive technique for benign prostate hyperplasia: a meta-analysis of randomized controlled trials

To evaluate the efficacy and safety of plasmakinetic resection of the prostate (PKRP) versus transurethral resection of the prostate (TURP) for the treatment of patients with benign prostate hyperplasia (BPH), a meta-analysis of randomized controlled trials was carried out. We searched PubMed, Embase, Web of Science and the Cochrane Library. The pooled estimates of maximum flow rate, International Prostate Symptom Score, operation time, catheterization time, irrigated volume, hospital stay, transurethral resection syndrome, transfusion, clot retention, urinary retention and urinary stricture were assessed. There was no notable difference in International Prostate Symptom Score between TURP and PKRP groups during the 1-month, 3 months, 6 months and 12 months follow-up period, while the pooled Q max at 1-month favored PKRP group. PKRP group was related to a lower risk rate of transurethral resection syndrome, transfusion and clot retention, and the catheterization time and operation time were also shorter than that of TURP. The irrigated volume, length of hospital stay, urinary retention and urinary stricture rate were similar between groups. In conclusion, our study suggests that the PKRP is a reliable minimal invasive technique and may anticipatorily prove to be an alternative electrosurgical procedure for the treatment of BPH.

Generation of comparative pharmacophoric model for steroidal 5α-reductase I and II inhibitors: A 3D-QSAR study on 6-azasteroids

Steroidal 5α-reductase, a key enzyme involved in the transformation of testosterone to dihydrotestosterone, is unstable during the purification leading to loss of the activity. Therefore, due to unstable nature, the crystal structure of the 5α-reductase is unknown. In the present study, we have generated a comparative pharmacophoric model for both isoforms of steroidal 5α-reductase using 6-azasteroids. The steric and electrostatic maps generated for both isoforms provides structure framework for designing of new inhibitors. Further, 3D-maps are also helpful in understanding variability in the activity of the compounds. Statistical measures generated for both enzymes showed good internal and external prediction. Overall, the analyses of models provides structural requirement of dual and selective steroidal 5α-reductase inhibitors in an interactive fashion.