Cost effectiveness comparison of dutasteride and finasteride in patients with benign prostatic hyperplasia--The Markov model based on data from Montenegro.

PubMed

Dabanović, Vera; Kostić, Marina; Janković, Slobodan

2016-01-01

Benign prostatic hyperplasia (BPH) is one of the most common disease among males aging 50 years and more. The rise of the prevalence of BPH is related to aging, and since duration of life time period has the tendency of rising the prevalence of BPH will rise as costs of BPH treatment will and its influence on health economic budget. Dutasteride is a new drug similar to finasteride, inhibits enzyme testosterone 5-alpha reductase, diminish symptoms of BPH, reduce risk of the complications and increases quality of life in patients with BPH. But, the use of dutasteride is limited by its high costs. The aim of this study was to compare cost effectiveness of dutasteride and finasteride from the perspective of a purchaser of health care service (Republic Institute for Health Insuranse, Montenegro). We constructed a Markov model to compare cost effectivenss of dutasteride and finasteride using data from the available pharmacoeconomic literature and data about socioeconomic sphere actual in Montenegro. A time horizon was estimated to be 20 years, with the duration of 1 year per one cycle. The discount rate was 3%. We performed Monte Carlo simulation for virtual cohort of 1,000 patients with BPH. The total costs for one year treatment of BPH with dutasteride were estimated to be 6,458.00 € which was higher comparing with finasteride which were 6,088.56 €. The gain in quality adjusted life years (QALY) were higher with dutasteride (11.97 QALY) than with finasteride (11.19 QALY). The results of our study indicate that treating BPH with dutasteride comparing to finasteride is a cost effective option since the value of incremental cost-effectiveness ratio (ICER) is 1,245.68 €/QALY which is below estimated threshold (1,350.00 € per one gained year of life). Dutasteride is a cost effective option for treating BPH comparing to finasteride. The results of this study provide new information for health care decision makers about treatment of BPH in socioeconomic environment which is actual both in Montenegro and other countries with a recent history of socioeconomic transition.

Effects of Steroidal Antiandrogen or 5-alpha-reductase Inhibitor on Prostate Tissue Hormone Content.

PubMed

Shibata, Yasuhiro; Arai, Seiji; Miyazawa, Yoshiyuki; Shuto, Takahiro; Nomura, Masashi; Sekine, Yoshitaka; Koike, Hidekazu; Matsui, Hiroshi; Ito, Kazuto; Suzuki, Kazuhiro

2017-05-01

The effects of a steroidal antiandrogen (AA) and 5-alpha-reductase inhibitor (5ARI) on prostate tissue hormone content and metabolism are not fully elucidated. The objective of this study is to investigate the hormone content and metabolism of the prostate tissues of patients treated with AA or 5ARI using the ultra-sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Thirty-nine patients with benign prostatic hyperplasia (BPH) undergoing transurethral surgery were included. Serum and prostate tissue hormone and prostate tissue hormone metabolism analyses were performed using LC-MS/MS after 1 month of treatment with chlormadinone acetate (CMA; steroidal AA, 50 mg/day) or dutasteride (DUTA; dual 5ARI, 0.5 mg/day). Serum testosterone (T), dihydrotestosterone (DHT), and adrenal androgen levels were lower in the CMA group than the control group. Prostate tissue T and DHT levels were also lower in the CMA group than the control group. In the DUTA group, only serum and prostate DHT concentrations were reduced compared to the control group; in contrast, those of other hormones, especially T and 4-androstene-3,17-dione in the prostate tissue, showed marked elevations up to 70.4- and 11.4-fold normal levels, respectively. Moreover, the hormone metabolism assay confirmed that the conversion of T to DHT was significantly suppressed while that of T to 4-androstene-3,17-dione was significantly accelerated in the prostate tissue of DUTA-treated patients. Although treatment with AA and 5ARI show similar clinical outcomes, their effect on tissue hormone content and metabolism varied greatly. Prostate 77: 672-680, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The anti-androgen drug dutasteride renders triple negative breast cancer cells more sensitive to chemotherapy via inhibition of HIF-1α-/VEGF-signaling.

PubMed

von Wahlde, Marie-Kristin; Hülsewig, Carolin; Ruckert, Christian; Götte, Martin; Kiesel, Ludwig; Bernemann, Christof

2015-02-01

Triple negative breast cancer (TNBC) is characterized by lack of expression of both estrogen and progesterone receptor as well as lack of amplification of HER2. Patients with TNBC carry an unfavorable prognosis compared to other breast cancer subtypes given that endocrine or HER2 targeted therapies are not effective, rendering chemotherapy the sole effective treatment option to date. Therefore, there is a high demand for additional novel treatment options. We previously published a list of genes showing both higher gene expression rates in TNBC and, in addition, are known to encode targets of non-oncologic drugs. SRD5A1, which encodes the type-1 isoform of the steroid-5alpha-reductase, which is involved in androgen metabolism, was found to be one of these genes. Dutasteride is a dual blocker of both the type-1 and type-2 isoform of SRD5A1 and is indicated in the treatment of benign prostate hyperplasia. Treatment of TNBC cell lines with dutasteride was associated with a dose-dependent decrease in cell viability, altered protein expression of VEGF and HIF-1α and increased chemosensitivity. Our results demonstrate that the SRD5A1-corresponding anti-androgenic drug dutasteride might act as a combinatorial therapeutic option besides standard chemotherapy in highly aggressive TNBC.

The Direct Inhibitory Effect of Dutasteride or Finasteride on Androgen Receptor Activity is Cell Line Specific

PubMed Central

Chhipa, Rishi Raj; Halim, Danny; Cheng, Jinrong; Zhang, Huan Yi; Mohler, James L.; Ip, Clement; Wu, Yue

2014-01-01

BACKGROUND Finasteride and dutasteride were developed originally as 5α-reductase inhibitors to block the conversion of testosterone to dihydrotestosterone (DHT). These drugs may possess off-target effects on the androgen receptor (AR) due to their structural similarity to DHT. METHODS A total of 4 human prostate cancer cell models were examined: LNCaP (T877A mutant AR), 22Rv1 (H874Y mutant AR), LAPC4 (wild type AR) and VCaP (wild type AR). Cells were cultured in 10% charcoal-stripped fetal bovine serum, either with or without DHT added to the medium. AR activity was evaluated using the ARE-luciferase assay or the expression of AR regulated genes. RESULTS Dutasteride was more potent than finasteride in interfering with DHT-stimulated AR signaling. Disruption of AR function was accompanied by decreased cell growth. Cells that rely on DHT for protection against death were particularly vulnerable to dutasteride. Different prostate cancer cell models exhibited different sensitivities to dutasteride and finasteride. LNCaP was most sensitive, LAPC4 and VCaP were intermediate, while 22Rv1 was least sensitive. Regardless of the AR genotype, if AR was transfected into drug-sensitive cells, AR was inhibited by drug treatment; and if AR was transfected into drug-resistant cells, AR was not inhibited. CONCLUSIONS The direct inhibitory effect of dutasteride or finasteride on AR signaling is cell line specific. Mutations in the ligand binding domain of AR do not appear to play a significant role in influencing the AR antagonistic effect of these drugs. Subcellular constituent is an important factor in determining the drug effect on AR function. PMID:23813737

[What is the value of low-energie lasers in the treatment of androgenetic alopecia ?

PubMed

Paquet, Ph; Orduz, M; Franchimont, C; Nikkels, A F

2017-12-01

Male and female androgenetic alopecia is a common, chronic, psychologically stressful disorder affecting more than 50 % of the individuals by 50 years of age. Despite the current topical (minoxidil) or oral (the inhibitors of 5-? reductase finasteride or dutasteride) treatments, there is a need for more effective management options. The current clinical evidence, the possible mechanisms of action and the rare adverse events of the low level laser therapy in the treatment of androgenetic alopecia are presented.

Steroidal 5α-reductase and 17α-hydroxylase/17,20-lyase (CYP17) inhibitors useful in the treatment of prostatic diseases.

PubMed

Salvador, Jorge A R; Pinto, Rui M A; Silvestre, Samuel M

2013-09-01

The role of steroidal inhibitors of androgen biosynthesis as potential weapons in the treatment of prostatic diseases, such as benign prostatic hyperplasia and prostatic cancer will be reviewed. Two enzymes have been targeted in the development of inhibitors that potentially could be useful in the management of such conditions. 5α-Reductase is primarily of interest in benign prostatic disease, though some role in the chemoprevention of prostatic carcinoma have been considered, whereas the 17α-hydroxylase/17,20-lyase (CYP17) enzyme is of interest in the treatment of malignant disease. An overview of the main achievements obtained during the past years will be presented, however special focus will be made on steroidal molecules that reached clinical trials or have been commercially launched. Relevant examples of such drugs are finasteride, dutasteride, abiraterone acetate and galeterone (TOK-001, formerly known as VN/124-1). This article is part of a Special Issue entitled "Synthesis and biological testing of steroid derivatives as inhibitors". Copyright © 2013 Elsevier Ltd. All rights reserved.

Dutasteride reduces prostate size and prostate specific antigen in older hypogonadal men with benign prostatic hyperplasia undergoing testosterone replacement therapy.

PubMed

Page, Stephanie T; Hirano, Lianne; Gilchriest, Janet; Dighe, Manjiri; Amory, John K; Marck, Brett T; Matsumoto, Alvin M

2011-07-01

Benign prostatic hyperplasia and hypogonadism are common disorders in aging men. There is concern that androgen replacement in older men may increase prostate size and symptoms of benign prostatic hyperplasia. We examined whether combining dutasteride, which inhibits testosterone to dihydrotestosterone conversion, with testosterone treatment in older hypogonadal men with benign prostatic hyperplasia reduces androgenic stimulation of the prostate compared to testosterone alone. We conducted a double-blind, placebo controlled trial of 53 men 51 to 82 years old with symptomatic benign prostatic hyperplasia, prostate volume 30 cc or greater and serum total testosterone less than 280 ng/dl (less than 9.7 nmol/l). Subjects were randomized to daily transdermal 1% T gel plus oral placebo or dutasteride for 6 months. Testosterone dosing was adjusted to a serum testosterone of 500 to 1,000 ng/dl. The primary outcomes were prostate volume measured by magnetic resonance imaging, serum prostate specific antigen and androgen levels. A total of 46 subjects completed all procedures. Serum testosterone increased similarly into the mid-normal range in both groups. Serum dihydrotestosterone increased in the testosterone only but decreased in the testosterone plus dutasteride group. In the testosterone plus dutasteride group prostate volume and prostate specific antigen (mean ± SEM) decreased 12% ± 2.5% and 35% ± 5%, respectively, compared to the testosterone only group in which prostate volume and prostate specific antigen increased 7.5% ± 3.3% and 19% ± 7% (p = 0.03 and p = 0.008), respectively, after 6 months of treatment. Prostate symptom scores improved in both groups. Combined treatment with testosterone plus dutasteride reduces prostate volume and prostate specific antigen compared to testosterone only. Coadministration of a 5α-reductase inhibitor with testosterone appears to spare the prostate from androgenic stimulation during testosterone replacement in older, hypogonadal men with symptomatic benign prostatic hyperplasia. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Rates of prostate surgery and acute urinary retention for benign prostatic hyperplasia in men treated with dutasteride or finasteride.

PubMed

Kuiper, Josephina G; Bezemer, Irene D; Driessen, Maurice T; Vasylyev, Averyan; Roehrborn, Claus G; Penning-van Beest, Fernie J A; Herings, Ron M C

2016-08-31

Previous studies have suggested a greater benefit for various outcomes in men diagnosed with benign prostatic hyperplasia (BPH) who are treated with dutasteride than for men treated with finasteride. This study investigates whether the rates of BPH-related prostate surgery and acute urinary retention (AUR) differ between dutasteride and finasteride users in the Netherlands. From the PHARMO Database Network, men aged ≥50 years with a dispensing of dutasteride or finasteride with or without concomitant alpha-blocker treatment between March 1, 2003 and December 31, 2011 were selected. The incidence of BPH-related prostate surgery and AUR was determined during dutasteride or finasteride treatment and stratified by type of initial BPH-treatment (5-ARI monotherapy or combination with alpha-blocker) and prescriber (general practitioner (GP) or urologist). Comparison of the incidence of BPH-related prostate surgery and AUR between the treatment groups was done by Cox proportional hazard regression. 11,822 dutasteride users and 5,781 finasteride users were identified. Most users started treatment in combination with an alpha-blocker. Overall, dutasteride users had a lower risk of BPH-related prostate surgery was lower among dutasteride users than finasteride users (HR: 0.75; 95 % CI: 0.56-0.99). This lower risk among dutasteride users was also seen when stratifying by monotherapy or combination therapy (HR: 0.73; 95 % CI: 0.54-0.98 for monotherapy and HR: 0.85; 95 % CI: 0.74-0.97 for combination therapy). However, the association was only present among men treated by urologists. For AUR the rates were low and no statistical significant difference was observed between dutasteride and finasteride users. The risk of undergoing BPH-related prostate surgery was lower among men using dutasteride compared to men using finasteride. The association was observed for monotherapy as well as combination therapy, however, only among men who received their prescription from a urologist.

Sexual dysfunction in subjects treated with inhibitors of 5α-reductase for benign prostatic hyperplasia: a comprehensive review and meta-analysis.

PubMed

Corona, G; Tirabassi, G; Santi, D; Maseroli, E; Gacci, M; Dicuio, M; Sforza, A; Mannucci, E; Maggi, M

2017-07-01

Despite their efficacy in the treatment of benign prostatic hyperplasia, the popularity of inhibitors of 5α-reductase (5ARIs) is limited by their association with adverse sexual side effects. The aim of this study was to review and meta-analyze currently available randomized clinical trials evaluating the rate of sexual side effects in men treated with 5ARIs. An extensive Medline Embase and Cochrane search was performed including the following words: 'finasteride', 'dutasteride', 'benign prostatic hyperplasia'. Only placebo-controlled randomized clinical trials evaluating the effect of 5ARI in subjects with benign prostatic hyperplasia were considered. Of 383 retrieved articles, 17 were included in this study. Randomized clinical trials enrolled 24,463 in the active and 22,270 patients in the placebo arms, respectively, with a mean follow-up of 99 weeks and mean age of 64.0 years. No difference was observed between trials using finasteride or dutasteride as the active arm considering age, trial duration, prostate volume or International Prostatic Symptoms Score at enrollment. Overall, 5ARIs determined an increased risk of hypoactive sexual desire [OR = 1.54 (1.29; 1.82); p < 0.0001] and erectile dysfunction [OR = 1.47 (1.29; 1.68); p < 0.0001]. No difference between finasteride and dutasteride regarding the risk of hypoactive sexual desire and erectile dysfunction was observed. Meta-regression analysis showed that the risk of hypoactive sexual desire and erectile dysfunction was higher in subjects with lower Q max at enrollment and decreased as a function of trial follow-up. Conversely, no effect of age, low urinary tract symptom or prostate volume at enrollment as well as Q max at end-point was observed. In conclusion, present data show that the use of 5ARI significantly increases the risk of erectile dysfunction and hypoactive sexual desire in subjects with benign prostatic hyperplasia. Patients should be adequately informed before 5ARIs are prescribed. © 2017 American Society of Andrology and European Academy of Andrology.

Risk of gynecomastia and breast cancer associated with the use of 5-alpha reductase inhibitors for benign prostatic hyperplasia

PubMed Central

Hagberg, Katrina Wilcox; Divan, Hozefa A; Fang, Shona C; Nickel, J Curtis; Jick, Susan S

2017-01-01

Background Clinical trial results suggest that 5-alpha reductase inhibitors (5ARIs) for the treatment of benign prostatic hyperplasia (BPH) may increase the risk of gynecomastia and male breast cancer, but epidemiological studies have been limited. Patients and methods We conducted a cohort study with nested case–control analyses using the UK Clinical Practice Research Datalink. We identified men diagnosed with BPH who were free from Klinefelter syndrome, prostate, genital or urinary cancer, prostatectomy or orchiectomy, or evidence of gynecomastia or breast cancer. Patients entered the cohort at age ≥40 years and at least 3 years after the start of their electronic medical record. We classified exposure as 5ARIs (alone or in combination with alpha blockers [ABs]), AB only, or unexposed to 5ARIs and ABs. Cases were men who had a first-time diagnosis of gynecomastia or breast cancer. Incidence rates and incidence rate ratios (IRRs) with 95% confidence intervals (CIs) in the gynecomastia analysis and crude and adjusted odds ratios (ORs) with 95% CIs in both analyses were calculated. Results Compared to no exposure, gynecomastia risk was elevated for users of 5ARIs (alone or in combination with ABs) in both the cohort (IRR=3.55, 95% CI 3.05–4.14) and case–control analyses (OR=3.31, 95% CI 2.66–4.10), whereas the risk was null for users of AB only. The increased risk of gynecomastia with the use of 5ARIs persisted regardless of the number of prescriptions, exposure timing, and presence or absence of concomitant prescriptions for drugs known to be associated with gynecomastia. The risk was higher for dutasteride than for finasteride. 5ARI users did not have an increased risk of breast cancer compared to unexposed men (OR=1.52, 95% CI 0.61–3.80). Conclusion In men with BPH, 5ARIs significantly increased the risk of gynecomastia, but not breast cancer, compared to AB use and no exposure. PMID:28228662

Potency of a novel saw palmetto ethanol extract, SPET-085, for inhibition of 5alpha-reductase II.

PubMed

Pais, Pilar

2010-08-01

The nicotinamide adenine dinucleotide phosphate (NADPH)-dependent membrane protein 5alpha-reductase irreversibly catalyses the conversion of testosterone to the most potent androgen, 5alpha-dihydrotestosterone (DHT). In humans, two 5alpha-reductase isoenyzmes are expressed: type I and type II. Type II is found primarily in prostate tissue. Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). The mechanisms of the pharmacological effects of SPE include the inhibition of 5alpha-reductase, among other actions. Clinical studies of SPE have been equivocal, with some showing significant results and others not. These inconsistent results may be due, in part, to varying bioactivities of the SPE used in the studies. The aim of the present study was to determine the in vitro potency of a novel saw palmetto ethanol extract (SPET-085), an inhibitor of the 5alpha-reductase isoenzyme type II, in a cell-free test system. On the basis of the enzymatic conversion of the substrate androstenedione to the 5alpha-reduced product 5alpha-androstanedione, the inhibitory potency was measured and compared to those of finasteride, an approved 5alpha-reductase inhibitor. SPET-085 concentration-dependently inhibited 5alpha-reductase type II in vitro (IC(50)=2.88+/-0.45 microg/mL). The approved 5alpha-reductase inhibitor, finasteride, tested as positive control, led to 61% inhibition of 5alpha-reductase type II. SPET-085 effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is very low compared to data reported for other extracts. It can be concluded from data in the literature that SPET-085 is as effective as a hexane extract of saw palmetto that exhibited the highest levels of bioactivity, and is more effective than other SPEs tested. This study confirmed that SPET-085 has prostate health-promoting bioactivity that also corresponds favorably to that reported for the established prescription drug standard of therapy, finasteride.

New Strategy for Prostate Cancer Prevention Based on Selenium Suppression of Androgen Receptor Signaling

DTIC Science & Technology

2006-10-01

dihydrotestosterone in the prostate by the enzyme 5α-reductase. The Prostate Cancer Prevention Trial (PCPT) demonstrated that treatment with finasteride , an...demand. Finasteride , despite being an older drug, has several advantages over dutasteride. First, its efficacy has been proven by a phase III trial... finasteride treatment. No such information is available with dutasteride. Third, finasteride is available commercially from Steraloids (Newport, RI

Targeted Androgen Pathway Suppression in Localized Prostate Cancer: A Pilot Study

PubMed Central

Mostaghel, Elahe A.; Nelson, Peter S.; Lange, Paul; Lin, Daniel W.; Taplin, Mary Ellen; Balk, Steven; Ellis, William; Kantoff, Philip; Marck, Brett; Tamae, Daniel; Matsumoto, Alvin M.; True, Lawrence D.; Vessella, Robert; Penning, Trevor; Hunter Merrill, Rachel; Gulati, Roman; Montgomery, Bruce

2014-01-01

Purpose Ligand-mediated activation of the androgen receptor (AR) is critical for prostate cancer (PCa) survival and proliferation. The failure to completely ablate tissue androgens may limit suppression of PCa growth. We evaluated combinations of CYP17A and 5-α-reductase inhibitors for reducing prostate androgen levels, AR signaling, and PCa volumes. Patients and Methods Thirty-five men with intermediate/high-risk clinically localized PCa were randomly assigned to goserelin combined with dutasteride (ZD), bicalutamide and dutasteride (ZBD), or bicalutamide, dutasteride, and ketoconazole (ZBDK) for 3 months before prostatectomy. Controls included patients receiving combined androgen blockade with luteinizing hormone-releasing hormone agonist and bicalutamide. The primary outcome measure was tissue dihydrotestosterone (DHT) concentration. Results Prostate DHT levels were substantially lower in all experimental arms (0.02 to 0.04 ng/g v 0.92 ng/g in controls; P < .001). The ZBDK group demonstrated the greatest percentage decline in serum testosterone, androsterone, and dehydroepiandrosterone sulfate (P < .05 for all). Staining for AR and the androgen-regulated genes prostate-specific antigen and TMPRSS2 was strongly suppressed in benign glands and moderately in malignant glands (P < .05 for all). Two patients had pathologic complete response, and nine had ≤ 0.2 cm3 of residual tumor (defined as a near-complete response), with the largest numbers of complete and near-complete responses in the ZBDK group. Conclusion Addition of androgen synthesis inhibitors lowers prostate androgens below that achieved with standard therapy, but significant AR signaling remains. Tissue-based analysis of steroids and AR signaling is critical to informing the search for optimal local and systemic control of high-risk prostate cancer. PMID:24323034

Phase II Study of Dutasteride for Recurrent Prostate Cancer During Androgen Deprivation Therapy

PubMed Central

Shah, Satyan K.; Trump, Donald L.; Sartor, Oliver; Tan, Wei; Wilding, Gregory E.; Mohler, James L.

2010-01-01

Purpose We determined the response rate to and safety of a dual 5α-reductase inhibitor, dutasteride, in men with castration recurrent prostate cancer. Materials and Methods A total of 28 men with asymptomatic castration recurrent prostate cancer were treated with 3.5 mg dutasteride daily (luteinizing hormone-releasing hormone treatment continued), and evaluated monthly for response and toxicity. Eligibility included appropriate duration antiandrogen withdrawal, baseline prostate specific antigen 2.0 ng/ml or greater and a new lesion on bone scan, increase in measurable disease using Response Evaluation Criteria in Solid Tumors criteria, or 2 or more consecutive prostate specific antigen measurements increased over baseline. Outcomes were progression, stable disease, partial response (prostate specific antigen less than 50% of enrollment for 4 or more weeks) or complete response. Results There were 25 evaluable men with a mean age of 70 years (range 57 to 88), a mean prostate specific antigen of 61.9 ng/ml (range 5.0 to 488.9) and mean Gleason score 8 (range 6 to 10), 15 of whom had bone metastases. Eight men had 10 grade 3 or higher adverse events using National Cancer Institute Common Terminology Criteria, all of which were judged to be unrelated to treatment. Of the 25 men 14 had disease progression by 2 months, 9 had stable (2.5, 3, 3, 4, 4, 5, 5, 8.5, 9 months) disease, 2 had a partial response and none had a complete response. Overall median time to progression was 1.87 months (range 1 to 10, 95% CI 1.15–3.91). Conclusions Dutasteride rarely produces biochemical responses in men with castration recurrent prostate cancer. However, further study is warranted given its favorable safety profile. PMID:19091347

Effect of a novel steroid (PM-9) on the inhibition of 5alpha-reductase present in Penicillium crustosum broths.

PubMed

Flores, Eugenio; Cabeza, Marisa; Quiroz, Alexandra; Bratoeff, Eugene; García, Genoveva; Ramírez, Elena

2003-03-01

The conversion of testosterone (T) to 5alpha-dihydrotestosterone (DHT) has been demonstrated in Penicillium crustosum broth obtained from fermented pistachios, lemons and corn tortillas. Furthermore, the presence of 5alpha-reductase enzyme, which is responsible for this conversion, has been established by electrophoretical techniques in these cultures.5alpha-Reductase enzyme is also present in animal and human androgen-dependent tissues as well as in prostate and seminal vesicles. The increase of the conversion of T to DHT in prostate gland, has been related to some illnesses such as benign prostate hyperplasia and prostate cancer. Furthermore, treatment with 5alpha-reductase inhibitors such as finasteride reduces the prostate growth. These data have stimulated research for the synthesis of new molecules with antiandrogenic activity, whose biological effect needs to be demonstrated. The purpose of this study is to determine the inhibition pattern of 5alpha-reductase in P. crustosum by finasteride and the new steroidal compound PM-9. K(m) and V(max) values for T, were determined in the broths by Lineweaver-Burk plots using different testosterone concentrations. The inhibition pattern of finasteride and PM-9 was also determined by Lineweaver-Burk using different concentrations of T and inhibitors. Results show that finasteride and PM-9 inhibit 5alpha-reductase present in the broth in a competitive manner.

Cyclohex-1-ene carboxylic acids: synthesis and biological evaluation of novel inhibitors of human 5 alpha reductase.

PubMed

Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

2003-03-01

In search of novel nonsteroidal mimics of steroidal inhibitors of 5 alpha reductase, 4-(2-phenylethyl)cyclohex-1-ene carboxylic acids 1-5 were synthesized with different substituents in para position of the phenyl ring (1: N, N-diisopropylcarbamoyl, 2: phenyl, 3: phenoxy, 4: benzoyl, and 5: benzyl). The principal synthetic approach for the desired compounds consisted of a Wittig olefination between 1, 4-dioxaspiro [4.5]-decane-8-carbaldehyde (4g and the appropriate phosphonium salts. The compounds were tested for inhibition of human 5 alpha reductase isozymes 1 and 2 using DU 145 cells and preparations from prostatic tissue, respectively. They turned out to be good inhibitors of the prostatic isozyme 2 with compound 1 being the most potent one (IC(50) = 760 nM). Isozyme 1 was only slightly inhibited. It is concluded that the novel structures are appropriate for being further optimized, aiming at the development of a novel drug for the treatment of benign prostatic hyperplasia.

Patient's behavior and attitudes toward the management of benign prostatic hyperplasia among patients with the risk of disease progression: prospective study by "Prostate and Expectations of Treatment Epidemiology Research (PETER) study group".

PubMed

Weibl, Peter; Klatte, Tobias; Laurinc, Peter; Tomaškin, Roman; Shariat, Shahrokh F; Helbich, Miroslav; Fackovcova, Danica; Bujdák, Peter

2015-05-01

The aim of the study was to evaluate patients attitudes with benign prostatic hyperplasia at the risk of progression during a 12-month period of observation. A total of 426 patients from 45 outpatients centers were included and prospectively followed. Inclusion criteria were: age > 50 years, International Prostate Symptom Score (IPSS) > 8, prostate volume > 30 cm(3) (transabdominal ultrasound) and PSA > 1.5 to < 10 ng/ml. In all, 28.6% patients were naive, 62.9% used monotherapy (alpha-blocker), and 8.5% combined treatment (alpha-blocker/5alpha-reductase inhibitor/dutasteride). The most bothersome symptoms were the weak urine stream (60.8%) and nocturia (59.2%). Patients expectations from the treatment were stabilization of the disease and reducing the risk of surgery rather than rapid resolution of symptoms. Despite the presence of symptoms, 2.3% patients claimed that benign prostatic hyperplasia/lower urinary tract symptoms had no impact on their quality of life (QoL), in 48.1 % only little impact on QoL, and 47.9% patients percepted their symptoms as severe. Out of 71.4% patients treated previously, 26.5% patients were indecisive about the satisfaction of present treatment. Visual analog score was percepted more optimistically rather than the IPSS. Pearson's correlation r = 0.68 at the beginning and r = 0.83 at the end of the study. Prostate and Expectations of Treatment Epidemiology Research study highlights and reflects on patients behavior and self-perception, patients self-perception of the disease and therapeutic priorities during the 1 year of observation.

Various treatment options for benign prostatic hyperplasia: A current update

PubMed Central

Shrivastava, Alankar; Gupta, Vipin B.

2012-01-01

In benign prostatic hyperplasia (BPH) there will be a sudden impact on overall quality of life of patient. This disease occurs normally at the age of 40 or above and also is associated with sexual dysfunction. Thus, there is a need of update on current medications of this disease. The presented review provides information on medications available for BPH. Phytotherapies with some improvements in BPH are also included. Relevant articles were identified through a search of the English-language literature indexed on MEDLINE, PUBMED, Sciencedirect and the proceedings of scientific meetings. The search terms were BPH, medications for BPH, drugs for BPH, combination therapies for BPH, Phytotherapies for BPH, Ayurveda and BPH, BPH treatments in Ayurveda. Medications including watchful waitings, Alpha one adrenoreceptor blockers, 5-alpha reductase inhibitors, combination therapies including tamsulosin-dutasteride, doxazosin-finasteride, terazosin-finasteride, tolterodine-tamsulosin and rofecoxib-finasteride were found. Herbal remedies such as Cernilton, Saxifraga stolonifera, Zi-Shen Pill (ZSP), Orbignya speciosa, Phellodendron amurense, Ganoderma lucidum, Serenoa Repens, pumpkin extract and Lepidium meyenii (Red Maca) have some improvements on BPH are included. Other than these discussions on Ayurvedic medications, TURP and minimally invasive therapies (MITs) are also included. Recent advancements in terms of newly synthesized molecules are also discussed. Specific alpha one adrenoreceptor blockers such as tamsulosin and alfuzosin will remain preferred choice of urologists for symptom relief. Medications with combination therapies are still needs more investigation to establish as preference in initial stage for fast symptom relief reduced prostate growth and obviously reduce need for BPH-related surgery. Due to lack of proper evidence Phytotherapies are not gaining much advantage. MITs and TURP are expensive and are rarely supported by healthcare systems. PMID:22923974

Exercise activates the PI3K-AKT signal pathway by decreasing the expression of 5α-reductase type 1 in PCOS rats.

PubMed

Wu, Chuyan; Jiang, Feng; Wei, Ke; Jiang, Zhongli

2018-05-22

Hyperandrogenism and hyperinsulinemia are main clinical endocrine features of PCOS. Exercise can adjust the androgen level, as well as increase the sensitivity of insulin by activating PI3K-Akt insulin signaling pathways. 5αR1 has certain effects on insulin resistance and can synthesize dihydrotestosterone by metabolizing testosterone. So 5αR1 may be the target of androgen and insulin for exercise-induced regulation. To investigate the role of 5αR1 in the PI3K-Akt signaling pathway in skeletal muscle of PCOS rats activated by exercise, fifty-four female rats were randomly divided into the PCOS group (n = 42) and the control group(n = 12). After injection of testosterone propionate for 28 days, the remaining 36 rats in the PCOS group were randomly assigned to six groups: the sedentary group (PS, n = 6), sedentary and 5αRI (5α-reductase inhibitor) group (PS + RI, n = 6), sedentary and 5αR2I (5α-reductase type 2 selective inhibitor) group (PS + R2I, n = 6), exercise group (PE, n = 6), exercise and 5αRI group (PE + RI, n = 6), and exercise and 5αR2I group (PE + R2I, n = 6). The rats undergoing exercise were trained to swim for 14 days. Finasteride (5α-reductase type 2 selective inhibitor) and dutasteride (5α-reductase inhibitor) were administered once daily and were dosed based on weight. At the end, the expression of 5αR1 proteins, the phosphorylation level of PI3K and AKT, were determined by Western blot. The PCOS non-exercise group and the PE + RI group displayed significantly lower phosphorylation of Akt, PI3K p85 and GLUT4 expression, while in the PE + R2I group, the level of Akt phosphorylation and PI3K p85 expression was significantly higher than that of the PCOS non-exercise group and the PE + RI group. In summary, our study demonstrated that exercise can activate the PI3K/AKT signal pathway of PCOS rats by decreasing the expression of 5αR1.

Quantitative evaluation of glandular and stromal compartments in hyperplastic dog prostates: effect of 5-alpha reductase inhibitors.

PubMed

Laroque, P A; Prahalada, S; Molon-Noblot, S; Cohen, S M; Soper, K; Duprat, P; Peter, C P; van Zwieten, M J

1995-09-01

The objective of this study was to determine the effects of 2 different 5-alpha reductase inhibitors (finasteride and MK-0434) on the glandular and stromal compartments of hyperplastic canine prostates. In this study, dogs received 1 of the 2 compounds orally, at a dose of 1 mg/kg/day for 16 weeks; control dogs received a placebo. The morphological changes in the glandular and stromal compartments in the prostate were quantitated by a point-counting method on Masson's trichrome-stained sections. Treatment with 5-alpha reductase inhibitors resulted in significant (P < or = 0.05) decreases in mean prostatic volumes, microscopic evidence of prostatic atrophy, and significant (P < or = 0.05) decreases in the absolute volumes of the prostatic glandular and stromal compartments compared to controls. In finasteride-treated dogs, the mean percent change from baseline was: epithelium, -52; lumens, -58; fibrovascular stroma, -41; and smooth muscle, -29. In MK-0434-treated dogs, the mean percent change from baseline was: epithelium, -77; lumens, -58; fibrovascular stroma, -38; and smooth muscle, -42. The effect on the glandular compartment in dogs treated with MK-0434 was slightly greater than in dogs treated with finasteride; however, the effect on the stroma was similar. These results clearly demonstrate that inhibition of 5-alpha reductase enzyme activity affects growth and maintenance of both glandular and stromal compartments of dog hyperplastic prostates. It is likely that the decrease in size of the prostate in finasteride-treated (Proscar) men is due to shrinkage of both glandular and stromal compartments.

Sex hormone influence on hepatitis in young male A/JCr mice infected with Helicobacter hepaticus.

PubMed

Theve, Elizabeth J; Feng, Yan; Taghizadeh, Koli; Cormier, Kathleen S; Bell, David R; Fox, James G; Rogers, Arlin B

2008-09-01

Hepatitis B virus (HBV), the leading cause of human hepatocellular carcinoma, is especially virulent in males infected at an early age. Likewise, the murine liver carcinogen Helicobacter hepaticus is most pathogenic in male mice infected before puberty. We used this model to investigate the influence of male sex hormone signaling on infectious hepatitis. Male A/JCr mice were infected with H. hepaticus or vehicle at 4 weeks and randomized into surgical and pharmacologic treatment groups. Interruption of androgen pathways was confirmed by hormone measurements, histopathology, and liver gene and Cyp4a protein expression. Castrated males and those receiving the competitive androgen receptor antagonist flutamide had significantly less severe hepatitis as determined by histologic activity index than intact controls at 4 months. Importantly, the powerful androgen receptor agonist dihydrotestosterone did not promote hepatitis. No effect on hepatitis was evident in males treated with the 5alpha-reductase inhibitor dutasteride, the peroxisome proliferator-activated receptor-alpha agonist bezafibrate, or the nonsteroidal anti-inflammatory drug flufenamic acid. Consistent with previous observations of hepatitis-associated liver-gender disruption, transcriptional alterations involved both feminine (cytochrome P450 4a14) and masculine (cytochrome P450 4a12 and trefoil factor 3) genes, as well gender-neutral (H19 fetal liver mRNA, lipocalin 2, and ubiquitin D) genes. Hepatitis was associated with increased unsaturated C(18) long-chain fatty acids (oleic acid and linoleic acid) relative to saturated stearic acid. Our results indicate that certain forms of androgen interruption can inhibit H. hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV.

Persistent erectile dysfunction in men exposed to the 5α-reductase inhibitors, finasteride, or dutasteride

PubMed Central

Yarnold, Paul R.; Cashy, John; Brannigan, Robert E.; Nardone, Beatrice; Micali, Giuseppe; West, Dennis Paul

2017-01-01

Importance Case reports describe persistent erectile dysfunction (PED) associated with exposure to 5α-reductase inhibitors (5α-RIs). Clinical trial reports and the manufacturers’ full prescribing information (FPI) for finasteride and dutasteride state that risk of sexual adverse effects is not increased by longer duration of 5α-RI exposure and that sexual adverse effects of 5α-RIs resolve in men who discontinue exposure. Objective Our chief objective was to assess whether longer duration of 5α-RI exposure increases risk of PED, independent of age and other known risk factors. Men with shorter 5α-RI exposure served as a comparison control group for those with longer exposure. Design We used a single-group study design and classification tree analysis (CTA) to model PED (lasting ≥90 days after stopping 5α-RI). Covariates included subject attributes, diseases, and drug exposures associated with sexual dysfunction. Setting Our data source was the electronic medical record data repository for Northwestern Medicine. Subjects The analysis cohorts comprised all men exposed to finasteride or dutasteride or combination products containing one of these drugs, and the subgroup of men 16–42 years old and exposed to finasteride ≤1.25 mg/day. Main outcome and measures Our main outcome measure was diagnosis of PED beginning after first 5α-RI exposure, continuing for at least 90 days after stopping 5α-RI, and with contemporaneous treatment with a phosphodiesterase-5 inhibitor (PDE5I). Other outcome measures were erectile dysfunction (ED) and low libido. PED was determined by manual review of medical narratives for all subjects with ED. Risk of an adverse effect was expressed as number needed to harm (NNH). Results Among men with 5α-RI exposure, 167 of 11,909 (1.4%) developed PED (persistence median 1,348 days after stopping 5α-RI, interquartile range (IQR) 631.5–2320.5 days); the multivariable model predicting PED had four variables: prostate disease, duration of 5α-RI exposure, age, and nonsteroidal anti-inflammatory drug (NSAID) use. Of 530 men with new ED, 167 (31.5%) had new PED. Men without prostate disease who combined NSAID use with >208.5 days of 5α-RI exposure had 4.8-fold higher risk of PED than men with shorter exposure (NNH 59.8, all p < 0.002). Among men 16–42 years old and exposed to finasteride ≤1.25 mg/day, 34 of 4,284 (0.8%) developed PED (persistence median 1,534 days, IQR 651–2,351 days); the multivariable model predicting PED had one variable: duration of 5α-RI exposure. Of 103 young men with new ED, 34 (33%) had new PED. Young men with >205 days of finasteride exposure had 4.9-fold higher risk of PED (NNH 108.2, p < 0.004) than men with shorter exposure. Conclusion and relevance Risk of PED was higher in men with longer exposure to 5α-RIs. Among young men, longer exposure to finasteride posed a greater risk of PED than all other assessed risk factors. PMID:28289563

5α-Reductase inhibitor is less effective in men with small prostate volume and low serum prostatic specific antigen level.

PubMed

Lin, Victor C; Liao, Chun-Hou; Wang, Chung-Cheng; Kuo, Hann-Chorng

2015-09-01

Large total prostate volumes (TPVs) or high serum prostate-specific antigen (PSA) levels indicate high-risk clinical progression of benign prostatic hyperplasia. This prospective study investigated the treatment outcome of combined 5α-reductase inhibitor and α-blocker in patients with and without large TPVs or high PSA levels. Men aged ≥ 45 years with International Prostate Symptom scores (IPSS) ≥ 8, TPV ≥ 20 mL, and maximum flow rate ≤ 15 mL/s received a combination therapy (dutasteride plus doxaben) for 2 years. Patients with baseline PSA ≥ 4 ng/mL underwent prostatic biopsy for excluding malignancy. The changes in the parameters from baseline to 24 months after combination therapy were compared in those with and without TPV ≥ 40 mL or PSA levels ≥ 1.5 ng/mL. A total of 285 patients (mean age 72 ± 9 years) completed the study. Combination therapy resulted in significant continuous improvement in IPSS, quality of life index, maximum flow rate, and postvoid residual (all p < 0.0001) regardless of baseline TPV or PSA levels. However, only patients with baseline TPV ≥ 40 mL had significant improvements in IPSS-storage subscore, voided volume, reduction in TPV, transitional zone index, and PSA levels. In addition, patients with baseline TPV < 40 mL and PSA < 1.5 ng/mL had neither a reduction in TPV nor a decrease in serum PSA level. A high TPV indicates more outlet resistance, whereas elevated serum PSA level reflects glandular proliferation. Thus, patients with TPV<40 mL and low PSA levels has less benefit from 5α-reductase inhibitor therapy. The therapeutic effect of combined treatment may arise mainly from the α-blocker in these patients. Copyright © 2013. Published by Elsevier B.V.

Next-generation steroidogenesis inhibitors, dutasteride and abiraterone, attenuate but still do not eliminate androgen biosynthesis in 22RV1 cells in vitro.

PubMed

Pham, Steven; Deb, Subrata; Ming, Dong Sheng; Adomat, Hans; Hosseini-Beheshti, Elham; Zoubeidi, Amina; Gleave, Martin; Guns, Emma S Tomlinson

2014-10-01

Castration resistant prostate cancer (CRPC) is often lethal and inevitably develops after androgen ablation therapy. However, in the majority of cases it remains androgen dependent. CRPC tumors have the ability to synthesize their own androgens from cholesterol by engaging in de novo steroidogenesis. We investigated the potential of 22RV1 prostate cancer cells to convert the supplemented steroid precursors within this pathway under the effects of current clinical steroidogenesis inhibitors such as abiraterone and dutasteride, either alone or in combination. Under steroid starved conditions, enzymes responsible for de novo steroidogenesis were upregulated. Testosterone and dihydrotestosterone (DHT) were formed by using both dehydroepiandrosterone (DHEA) and progesterone as substrates. Formation of testosterone and DHT was higher following incubation with DHEA compared to progesterone. Progesterone decreased the mRNA expression of enzymes responsible for steroidogenesis. Abiraterone treatment decreased testosterone production but increased several precursor steroids in both classical and backdoor pathways in the presence of progesterone. In contrast, the DHT levels were elevated following treatment with abiraterone when progesterone was absent. Dutasteride decreased the formation of testosterone, DHT and precursor steroids in the backdoor pathway but increased steroid precursors in the classical steroidogenesis pathway. The combination of abiraterone and dutasteride decreased testosterone and DHT in the presence of progesterone but increased DHT in the absence of progesterone. Abiraterone inhibited androgen receptor (AR) activation but not to the same extent as MDV3100. However, abiraterone and dutasteride treatment, either alone or in combination, were more effective in decreasing prostate specific antigen secretion into the media than MDV3100. Thus, while interventions with these drugs alone or in combination fail to completely inhibit steroidogenesis in the 22RV1 cells, the combined inhibition of androgen production and blockade of AR can exceed the effect of MDV3100. Further characterization of bypass mechanisms that may develop as a response to these inhibitors is necessary to achieve optimal suppression of testosterone and DHT synthesis as a part of therapeutic regimens for the treatment of CRPC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Potential prostate cancer drug target: bioactivation of androstanediol by conversion to dihydrotestosterone.

PubMed

Mohler, James L; Titus, Mark A; Wilson, Elizabeth M

2011-09-15

High-affinity binding of dihydrotestosterone (DHT) to the androgen receptor (AR) initiates androgen-dependent gene activation, required for normal male sex development in utero, and contributes to prostate cancer development and progression in men. Under normal physiologic conditions, DHT is synthesized predominantly by 5α-reduction of testosterone, the major circulating androgen produced by the testis. During androgen deprivation therapy, intratumoral androgen production is sufficient for AR activation and prostate cancer growth, even though circulating testicular androgen levels are low. Recent studies indicate that the metabolism of 5α-androstane-3α, 17β-diol by 17β-hydroxysteroid dehydrogenase 6 in benign prostate and prostate cancer cells is a major biosynthetic pathway for intratumoral synthesis of DHT, which binds AR and initiates transactivation to promote prostate cancer growth during androgen deprivation therapy. Drugs that target the so-called backdoor pathway of DHT synthesis provide an opportunity to enhance clinical response to luteinizing-hormone-releasing hormone (LHRH) agonists or antagonists, AR antagonists, and inhibitors of 5α-reductase enzymes (finasteride or dutasteride), and other steroid metabolism enzyme inhibitors (ketoconazole or the recently available abiraterone acetate). ©2011 AACR.

Evolving Novel Chemical Entities for Management of Benign Prostatic Hyperplasia.

PubMed

Gupta, Sonal; Gupta, Gopal; Sharma, V L

2017-01-01

Proliferation of the smooth muscle and epithelial cells within the prostatic transition zone in older men leads to benign prostatic hyperplasia (BPH), which is hallmarked by the troublesome lower urinary tract symptoms. The affair responsible for the initiation and promotion of disease is still unresolved, though alpha-blockers and 5α-reductase inhibitors are used as management options for relief from the dynamic and static components respectively. Combination therapy including both the alpha blocker and 5α-reductase inhibitor is emerging as inclusive parcel for treatment. However, selective androgen receptor modulators (SARM) and selective estrogen receptor modulators (SERM) are the other management resources, which are in the limelight. This review gives a glimpse of BPH and the various chemical entities which have been reported in literature till date for the condition since 2005. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Aldose reductase inhibitors from the leaves of Myrciaria dubia (H. B. & K.) McVaugh.

PubMed

Ueda, H; Kuroiwa, E; Tachibana, Y; Kawanishi, K; Ayala, F; Moriyasu, M

2004-11-01

Ellagic acid (1) and its two derivatives, 4-O-methylellagic acid (2) and 4-(alpha-rhamnopyranosyl)ellagic acid (3) were isolated as inhibitors of aldose reductase (AR) from Myrciaria dubia (H. B. & K.) McVaugh. Compound 2 was the first isolated from the nature. Compound 3 showed the strongest inhibition against human recombinant AR (HRAR) and rat lens AR (RLAR). Inhibitory activity of compound 3 against HRAR (IC50 value = 4.1 x 10(-8) M) was 60 times more than that of quercetin (2.5 x 10(-6) M). The type of inhibition against HRAR was uncompetitive.

Different patterns of 5{alpha}-reductase expression, cellular distribution, and testosterone metabolism in human follicular dermal papilla cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shicheng; Yamauchi, Hitoshi

Androgens regulate hair growth, and 5{alpha}-reductase (5{alpha}R) plays a pivotal role in the action of androgens on target organs. To clarify the molecular mechanisms responsible for controlling hair growth, the present study presents evidence that the human follicular dermal papilla cells (DPCs) from either beard (bDPCs) or scalp hair (sDPCs) possess endogenous 5{alpha}R activity. Real-time RT-PCR revealed that the highest level of 5{alpha}R1 mRNA was found in bDPCs, followed by sDPCs, and a low but detectable level of 5{alpha}R1 mRNA was observed in fibroblasts. Minimally detectable levels of 5{alpha}R2 mRNA were found in all three cell types. A weak bandmore » at 26 kDa corresponding to the human 5{alpha}R1 protein was detected by Western blot in both DPCs, but not in fibroblasts. Immuonofluorescence analysis confirmed that 5{alpha}R1 was localized to the cytoplasm rather than in the nuclei in both DPCs Furthermore, a 5{alpha}R assay using [{sup 14}C]testosterone labeling in intact cells revealed that testosterone was transformed primarily into androstenedione, and in small amounts, into DHT. Our results demonstrate that the 5{alpha}R activities of either bDPCs or sDPCs are stronger than that of dermal fibroblasts, despite the fact that the major steroidogenic activity is attributed to 17{beta}-HSD rather than 5{alpha}R among the three cell types. The 5{alpha}R1 inhibitor MK386 exhibited a more potent inhibitory effect on 5{alpha}R activity than finasteride (5{alpha}R2 inhibitor) in bDPCs.« less

Abiraterone treatment in castration-resistant prostate cancer selects for progesterone responsive mutant androgen receptors.

PubMed

Chen, Eddy J; Sowalsky, Adam G; Gao, Shuai; Cai, Changmeng; Voznesensky, Olga; Schaefer, Rachel; Loda, Massimo; True, Lawrence D; Ye, Huihui; Troncoso, Patricia; Lis, Rosina L; Kantoff, Philip W; Montgomery, Robert B; Nelson, Peter S; Bubley, Glenn J; Balk, Steven P; Taplin, Mary-Ellen

2015-03-15

The CYP17A1 inhibitor abiraterone markedly reduces androgen precursors and is thereby effective in castration-resistant prostate cancer (CRPC). However, abiraterone increases progesterone, which can activate certain mutant androgen receptors (AR) identified previously in flutamide-resistant tumors. Therefore, we sought to determine if CYP17A1 inhibitor treatment selects for progesterone-activated mutant ARs. AR was examined by targeted sequencing in metastatic tumor biopsies from 18 patients with CRPC who were progressing on a CYP17A1 inhibitor (17 on abiraterone, 1 on ketoconazole), alone or in combination with dutasteride, and by whole-exome sequencing in residual tumor in one patient treated with neoadjuvant leuprolide plus abiraterone. The progesterone-activated T878A-mutant AR was present at high allele frequency in 3 of the 18 CRPC cases. It was also present in one focus of resistant tumor in the neoadjuvant-treated patient, but not in a second clonally related resistant focus that instead had lost one copy of PTEN and both copies of CHD1. The T878A mutation appeared to be less common in the subset of patients with CRPC treated with abiraterone plus dutasteride, and transfection studies showed that dutasteride was a more potent direct antagonist of the T878A versus the wild-type AR. These findings indicate that selection for tumor cells expressing progesterone-activated mutant ARs is a mechanism of resistance to CYP17A1 inhibition. ©2014 American Association for Cancer Research.

[Drug therapy of benign prostatic hyperplasia].

PubMed

Vahlensieck, W; Fabricius, P G; Hell, U

1996-11-10

BPH patients with Vahlensieck stage II or III disease are suitable for drug treatment. The points of attack are reduction of testosterone, conversion of testosterone to dihydrotestosterone, conversion of testosterone to estrogen using GnRH analogues, antiandrogens and alpha reductase inhibitors or aromatose inhibitors. Furthermore a reduction in obstruction is achieved through the use of phytopharmaceuticals containing 5-lipoxygenase and cyclooxygenase inhibitors. At present, Curcurbitae pepo seeds, Urtica dioica root, Pollinis siccae extract and Sabal serrulata seed extract are approved for the treatment of prostatic diseases in Germany. The use of alpha-1-sympathicolytic treatment may reduce muscular tone in the prostate. Combination of the various modes of action may also offer an effective form of treatment.

Biocatalytic synthesis of 4-pregnen-20,21-diol-3-one, a selective inhibitor of human 5alpha-reductase type II.

PubMed

Hannemann, Frank; Bernhardt, Rita; Jose, Joachim

2007-10-01

Biocatalysis, the conversion of substrates into valuable products by the use of enzymes, has some striking advantages in comparison to standard organic chemistry for drug synthesis. By biocatalysis, substrates that contain several identical reactive groups at different positions can be converted with high regio-selectivity and enantio-selectivity. In this study, an E. coli isolate (E132) was identified which was able to convert the steroid desoxycorticosterone into the product 4-pregnen-20,21-diol-3-one in real terms. The product was purified from the cell culture supernatant by HPLC and its structure was demonstrated by mass spectrometry and NMR spectroscopy. It was tested on inhibition of human 5alpha-reductases type I and type II. At a concentration of 10 microM, inhibition was 49.0% for type I and 81.8% for type II, whereas there was no inhibition of human aromatase (CYP19) at 20 microM and human 17alpha-hydroxylase-C17,20-lyase (CYP17) at 2.5 microM detectable. The IC50 value of 4-pregnen-20,21-diol-3-one for human 5alpha-reductase type II was determined to be 1.56 microM.

Pharmacologic Therapy in Men's Health: Hypogonadism, Erectile Dysfunction, and Benign Prostatic Hyperplasia.

PubMed

Berkseth, Kathryn E; Thirumalai, Arthi; Amory, John K

2016-07-01

This article reviews current pharmacologic treatment options for 3 common men's health concerns: hypogonadism, erectile dysfunction (ED), and benign prostatic hyperplasia (BPH). Specific topics addressed include: management of male hypogonadism using testosterone replacement therapy, use of oral phosphodiesterase inhibitors as first-line therapy for men with ED and the utility of intraurethral and intrapenile alprostadil injections for patients who do not respond to oral medications, and the role of alpha1-adrenergic antagonists, 5-alpha-reductase inhibitors, anticholinergic agents, and herbal therapies in the management of BPH. Copyright © 2016 Elsevier Inc. All rights reserved.

A Multiscale, Mechanism-Driven, Dynamic Model for the Effects of 5α-Reductase Inhibition on Prostate Maintenance

PubMed Central

Zager, Michael G.; Barton, Hugh A.

2012-01-01

A systems-level mathematical model is presented that describes the effects of inhibiting the enzyme 5α-reductase (5aR) on the ventral prostate of the adult male rat under chronic administration of the 5aR inhibitor, finasteride. 5aR is essential for androgen regulation in males, both in normal conditions and disease states. The hormone kinetics and downstream effects on reproductive organs associated with perturbing androgen regulation are complex and not necessarily intuitive. Inhibition of 5aR decreases the metabolism of testosterone (T) to the potent androgen 5α-dihydrotestosterone (DHT). This results in decreased cell proliferation, fluid production and 5aR expression as well as increased apoptosis in the ventral prostate. These regulatory changes collectively result in decreased prostate size and function, which can be beneficial to men suffering from benign prostatic hyperplasia (BPH) and could play a role in prostate cancer. There are two distinct isoforms of 5aR in male humans and rats, and thus developing a 5aR inhibitor is a challenging pursuit. Several inhibitors are on the market for treatment of BPH, including finasteride and dutasteride. In this effort, comparisons of simulated vs. experimental T and DHT levels and prostate size are depicted, demonstrating the model accurately described an approximate 77% decrease in prostate size and nearly complete depletion of prostatic DHT following 21 days of daily finasteride dosing in rats. This implies T alone is not capable of maintaining a normal prostate size. Further model analysis suggests the possibility of alternative dosing strategies resulting in similar or greater effects on prostate size, due to complex kinetics between T, DHT and gene occupancy. With appropriate scaling and parameterization for humans, this model provides a multiscale modeling platform for drug discovery teams to test and generate hypotheses about drugging strategies for indications like BPH and prostate cancer, such as compound binding properties, dosing regimens, and target validation. PMID:22970204

Effects of flutamide and finasteride on rat testicular descent.

PubMed

Spencer, J R; Torrado, T; Sanchez, R S; Vaughan, E D; Imperato-McGinley, J

1991-08-01

The endocrine control of descent of the testis in mammalian species is poorly understood. The androgen dependency of testicular descent was studied in the rat using an antiandrogen (flutamide) and an inhibitor of the enzyme 5 alpha-reductase (finasteride). Androgen receptor blockade inhibited testicular descent more effectively than inhibition of 5 alpha-reductase activity. Moreover, its inhibitory effect was limited to the outgrowth phase of the gubernaculum testis, particularly the earliest stages of outgrowth. Gubernacular size was also significantly reduced in fetuses exposed to flutamide during the outgrowth period. In contrast, androgen receptor blockade or 5 alpha-reductase inhibition applied after the initiation of gubernacular outgrowth or during the regression phase did not affect testicular descent. Successful inhibition of the development of epididymis and vas by prenatal flutamide did not correlate with ipsilateral testicular maldescent, suggesting that an intact epididymis is not required for descent of the testis. Plasma androgen assays confirmed significant inhibition of dihydrotestosterone formation in finasteride-treated rats. These data suggest that androgens, primarily testosterone, are required during the early phases of gubernacular outgrowth for subsequent successful completion of testicular descent.

A bibliometric study of scientific literature in Scopus on botanicals for treatment of androgenetic alopecia.

PubMed

Rondanelli, Mariangela; Perna, Simone; Peroni, Gabriella; Guido, Davide

2016-06-01

In androgenetic alopecia, a number of botanicals are available that can effectively slow or reduce hair loss and inflammation or stimulate partial hair regrowth. The aim of this study was to provide a descriptive overview of the impact and production of literature on botanicals used for androgenetic alopecia and to perform a citation analysis of the related research articles. We searched for "alopecia" OR "androgenetic alopecia" OR "hair loss" AND "Camelia sinensis" OR (and other 15 botanicals) in ARTICLE (Title/Abstract/Keyword) in Scopus database. A total of 29 references, that is, research articles, were retrieved by SCOPUS search, and 93.1% had been published since 2000. The majority (48.3%) describe applications of hair grow stimulants, followed by inhibitors of 5-alpha-reductase applications (27.6%), and studies concerning inhibitors of inflammation (24.1%). The citation analysis revealed a growing interest for this topic and the papers on hair grow stimulants are most cited. Citation trend of inhibition of 5-alpha-reductase articles is growing in the last years. This study has highlighted three important aspects: (1) growing interest for this topic; (2) evidences mainly in hair grow stimulants and recently in the inhibition of 5-alpha-reductase, as demonstrated by article and citation counts across years; (3) in addition, all major studies have been focused on green tea epigallocatechin-3-gallate, Serenoa repens, Citrullus colocynthis and Cuscuta reflexa. © 2015 Wiley Periodicals, Inc.

Evidence that steroid 5alpha-reductase isozyme genes are differentially methylated in human lymphocytes.

PubMed

Rodríguez-Dorantes, M; Lizano-Soberón, M; Camacho-Arroyo, I; Calzada-León, R; Morimoto, S; Téllez-Ascencio, N; Cerbón, M A

2002-03-01

The synthesis of dihydrotestosterone (DHT) is catalyzed by steroid 5alpha-reductase isozymes 1 and 2, and this function determines the development of the male phenotype during embriogenesis and the growth of androgen sensitive tissues during puberty. The aim of this study was to determine the cytosine methylation status of 5alpha-reductase isozymes types 1 and 2 genes in normal and in 5alpha-reductase deficient men. Genomic DNA was obtained from lymphocytes of both normal subjects and patients with primary 5alpha-reductase deficiency due to point mutations in 5alpha-reductase 2 gene. Southern blot analysis of 5alpha-reductase types 1 and 2 genes from DNA samples digested with HpaII presented a different cytosine methylation pattern compared to that observed with its isoschizomer MspI, indicating that both genes are methylated in CCGG sequences. The analysis of 5alpha-reductase 1 gene from DNA samples digested with Sau3AI and its isoschizomer MboI which recognize methylation in GATC sequences showed an identical methylation pattern. In contrast, 5alpha-reductase 2 gene digested with Sau3AI presented a different methylation pattern to that of the samples digested with MboI, indicating that steroid 5alpha-reductase 2 gene possess methylated cytosines in GATC sequences. Analysis of exon 4 of 5alpha-reductase 2 gene after metabisulfite PCR showed that normal and deficient subjects present a different methylation pattern, being more methylated in patients with 5alpha-reductase 2 mutated gene. The overall results suggest that 5alpha-reductase genes 1 and 2 are differentially methylated in lymphocytes from normal and 5alpha-reductase deficient patients. Moreover, the extensive cytosine methylation pattern observed in exon 4 of 5alpha-reductase 2 gene in deficient patients, points out to an increased rate of mutations in this gene.

Negative Impact of Testosterone Deficiency and 5α-Reductase Inhibitors Therapy on Metabolic and Sexual Function in Men.

PubMed

Traish, Abdulmaged M

2017-01-01

Androgens are steroid hormones with pleotropic and diverse biochemical and physiological functions, and androgen deficiency exerts a negative impact on human health. Testosterone (T) either directly or via its transformation into the more potent metabolite 5α-dihydrotestosterone (5α-DHT) or via aromatization into estradiol (E 2 ) modulates important biochemical signaling pathways of human physiology and plays a critical role in the growth and/or maintenance of functions in a host of tissues and organs. T and 5α-DHT play an important role in regulating physiology of the muscle, adipose tissue, liver, bone, and central nervous system, as well as reproductive and sexual functions. Thus, androgen deficiency (also referred to as hypogonadism) is a well-recognized medical condition and if remained untreated will have a negative impact on human health and quality of life.In this chapter, we have summarized the negative impact of T deficiency (TD) on a host of physiological functions including reduced lean body mass (LBM), increased fat mass (FM), increased insulin resistance (IR), metabolic syndrome (MetS) and adiposity, reduced bone mineral density (BMD), anemia, sexual dysfunction, and reduced quality of life and increased mortality. In addition, we discuss another critical aspect of unrecognized form of androgen deficiency resulting from inhibition of 5α-reductases with drugs, such as finasteride and dutasteride, to block transformation of T into 5α-DHT in the course of treatment of benign prostatic hyperplasia (BPH) and male pattern hair loss, also known as androgenetic alopecia (AGA). The negative impact of drugs that inhibit transformation of T to 5α-DHT by 5α-reductases on metabolic function is manifested in fat accumulation in the liver, which may predispose to nonalcoholic fatty liver disease (NAFLD). Also, inhibition of 5α-DHT formation increases glucose synthesis and reduces glucose disposal potentially contributing to hyperglycemia, IR, and elevated activities of liver function enzymes concomitant with reduction in circulating T levels, worsening erectile dysfunction (ED), and reduced quality of life.Although we have attempted to summarize the current literature pertaining to this critical topic "androgen deficiency" and its impact on men's health and quality of life, there remain many gaps in the knowledge regarding the biochemical pathways that are involved in the pathophysiology of androgen deficiency. We wish to clearly state that there are areas of controversies, including whether age-related androgen deficiency (functional hypogonadism) merits treatment and whether T therapy provided real proven benefits. Finally, considerable debate exists with respect to the potential and purported cardiovascular (CV) risks of treating TD with exogenous T. For brevity sake, we will not discuss in detail the benefits of T therapy in men with TD since this topic is comprehensively covered by Dr. F. Saad's chapter in this book, entitled "Testosterone Therapy and Glucose Homeostasis in Men with Testosterone Deficiency (Hypogonadism)."We have made a concerted effort to address the controversy of T therapy in men with TD in the discussion. However, we wish to acknowledge that these issues will remain a matter of debate for some time to come. Only with advances in fundamental basic science and clinical research, some of these controversial issues may be laid to rest. Nevertheless, we believe that there is considerable body of credible evidence to suggest that T therapy of men with TD is safe and effective and provides a host of health benefits and therefore merits considerations in men with TD, irrespective of the underlying cause or etiology. An additional aspect of androgen deficiency is the drug-induced reduction in 5α-DHT levels by the use of 5α-reductase inhibitors. We also believe that physicians prescribing 5α-reductase inhibitors (i.e., finasteride or dutasteride) for relief of BPH symptoms or treatment of hair loss should engage their patients in a productive discussion regarding the potential adverse side effects of these medications on their overall health and quality of life.

In vivo hair growth promotion effects of ultra-high molecular weight poly-γ-glutamic acid from Bacillus subtilis (Chungkookjang).

PubMed

Choi, Jae-Chul; Uyama, Hiroshi; Lee, Chul-Hoon; Sung, Moon-Hee

2015-03-01

We investigated the effect of ultra-high molecular weight poly-γ-glutamic acid (UHMW γ-PGA) on hair loss in vitro and in vivo. 5-Alpha reductase is an enzyme that metabolizes the male hormone testosterone into dihydrotestosterone. By performing an in vitro experiment to analyze the inhibitory effects of UHMW γ-PGA on 5-alpha reductase activity, we determined that UHMW γ-PGA did in fact inhibit 5-alpha reductase activity, indicating the use of UHMW γ-PGA as a potential 5-alpha reductase inhibitor in the treatment of men with androgenetic alopecia. To evaluate the promotion of hair growth in vivo, we topically applied UHMW γ-PGA and minoxidil on the shaved dorsal skin of telogenic C57BL/6 mice for 4 weeks. At 4 weeks, the groups treated with UHMW γ-PGA showed hair growth on more than 50% of the shaved skin, whereas the control group showed less hair growth. To investigate the progression of hair follicles in the hair cycle, hematoxylin and eosin staining was performed. Histological observations revealed that the appearance of hair follicles was earlier in the UHMW γ-PGA-treated group than in the control group. The number of hair follicles on the relative area of shaved skin in the UHMW γ-PGA-treated group was higher than that observed on the shaved skin in the control group. These results indicate that UHMW γ-PGA can promote hair growth by effectively inducing the anagen phase in telogenic C57BL/6 mice.

Progesterone's 5 alpha-reduced metabolite, 3 alpha,5 alpha-THP, mediates lateral displacement of hamsters.

PubMed

Frye, Cheryl A; Rhodes, Madeline E

2005-03-15

5 alpha-Pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP), progesterone (P4)'s 5 alpha-reduced, 3 alpha-hydroxysteroid oxidoreduced product, facilitates lordosis of rodents in part via agonist-like actions at GABA(A)/benzodiazepine receptor complexes in the ventral tegmental area (VTA). Whether 3 alpha,5 alpha-THP influences another reproductively-relevant behavior, lateral displacement, of hamsters was investigated. Lateral displacement is the movement that female hamsters make with their perineum towards male-like tactile stimulation. This behavior facilitates, and is essential for, successful mating. Hamsters in behavioral estrus had greater lateral displacement responses when endogenous progestin levels were elevated compared to when progestin levels were lower. Administration of P4, a prohormone for 3 alpha,5 alpha-THP, dose-dependently (500 > 200 > 100, 50, or 0 microg) enhanced lateral displacement of ovariectomized hamsters that had been primed with SC estradiol benzoate (5 or 10 microg). Inhibiting P4's metabolism to 3 alpha,5 alpha-THP by co-administering finasteride, a 5 alpha-reductase inhibitor, or indomethacin, a 3 alpha-hydroxysteroid oxidoreductase inhibitor, either systemically or to the VTA, significantly decreased lateral displacement and midbrain progestin levels of naturally receptive or hormone-primed hamsters compared to controls. These data suggest that lateral displacement is progestin-sensitive and requires the formation of 3 alpha,5 alpha-THP in the midbrain VTA.

Partial purification and some properties of a latent CO2 reductase from green potato tuber chloroplasts.

PubMed

Arora, S; Ramaswamy, N K; Nair, P M

1985-12-16

We have partially purified the CO2 reductase, present in green potato tuber chloroplasts, as a latent form. Illumination of the chloroplasts in the absence of substrate, bicarbonate, activated the enzyme, which could then be obtained in soluble forms. Purification of the enzyme was achieved by (NH4)2SO4 fractionation (0-30%) and adsorption and elution from a DEAE-Sephadex A-50 column. The final preparation showed 15-fold purification and 50% recovery of the activity. The pH optimum for CO2 reductase was 8.0. Hepes and Tricine buffers showed maximum activity whereas Tris/phosphate or borate failed to show any activity. The enzyme reaction was sensitive to the presence of metal ions like Fe3+, Hg2+, Cu2+, Mo6+ and Zn2+, however, a threefold activation was observed with Fe2+. The metal requirement for CO2 reductase was evident from the observed inhibition by metal chelators like o-phenanthroline, alpha, alpha'-dipyridyl, bathocuproine, 8-hydroxyquinoline etc. Out of these o-phenanthroline was the strongest inhibitor and its concentration for 50% inhibition was 40 microM. The presence of Fe2+ ions in the reaction mixture protected the enzyme from heat denaturation upto 50 degrees C. Maximum enzyme activity was observed at 15 degrees C. The enzyme activity showed a 30-s lag period and the maximum was reached in 90 s. Supplementation of sodium dithionite in the reaction activated enzyme activity threefold, suggesting involvement of dithiol groups in the catalytic activity. There was strong inhibition by -SH inhibitors like 5,5'-dithiobis(2-nitrobenzoic acid) and N-ethylmaleimide and -SH reagents like dithiothreitol, 2-mercaptoethanol and cysteine. Various nucleotide coenzyme tried inhibited the enzyme strongly.

Diabetic Neuropathy and Oxidative Stress: Therapeutic Perspectives

PubMed Central

Hosseini, Asieh; Abdollahi, Mohammad

2013-01-01

Diabetic neuropathy (DN) is a widespread disabling disorder comprising peripheral nerves' damage. DN develops on a background of hyperglycemia and an entangled metabolic imbalance, mainly oxidative stress. The majority of related pathways like polyol, advanced glycation end products, poly-ADP-ribose polymerase, hexosamine, and protein kinase c all originated from initial oxidative stress. To date, no absolute cure for DN has been defined; although some drugs are conventionally used, much more can be found if all pathophysiological links with oxidative stress would be taken into account. In this paper, although current therapies for DN have been reviewed, we have mainly focused on the links between DN and oxidative stress and therapies on the horizon, such as inhibitors of protein kinase C, aldose reductase, and advanced glycation. With reference to oxidative stress and the related pathways, the following new drugs are under study such as taurine, acetyl-L-carnitine, alpha lipoic acid, protein kinase C inhibitor (ruboxistaurin), aldose reductase inhibitors (fidarestat, epalrestat, ranirestat), advanced glycation end product inhibitors (benfotiamine, aspirin, aminoguanidine), the hexosamine pathway inhibitor (benfotiamine), inhibitor of poly ADP-ribose polymerase (nicotinamide), and angiotensin-converting enzyme inhibitor (trandolapril). The development of modern drugs to treat DN is a real challenge and needs intensive long-term comparative trials. PMID:23738033

New Approaches for Prostate Cancer Combination Therapy

DTIC Science & Technology

2007-04-01

in DU145 cells. Strong inducers of apoptosis included Sulindac sulfide, Finasteride , Diclofenac, Flufenamic acid, Flurbiprofen, Sulindac sulfone and... Finasteride , a selective 5-alpha-reductase inhibitor, is not known to inhibit COX-2, strongly induces MDA-7/IL-24 expression and apoptosis, whereas the...ibuprofen, aspirin, acet- aminophen, and naproxen were obtained from Sigma-Aldrich (St. Louis, MO). Meloxicam, celecoxib, diclofenac, finasteride , and

Inhibitors of sterol synthesis. Chemical syntheses and spectral properties of 26-oxygenated derivatives of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells.

PubMed

Siddiqui, A U; Wilson, W K; Ruecker, K E; Pinkerton, F D; Schroepfer, G J

1992-11-01

26-Oxygenated derivatives of delta 8(14)-15-ketosterols have been synthesized from (25R)-3 beta,26-diacetoxy-5 alpha-cholest-8(14)-en-15-one (IX) as part of a program to prepare potential metabolites and analogs of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (I), a potent regulator of cholesterol metabolism. Partial hydrolysis of IX gave a mixture, from which the 3 beta,26-diol II and the 26-acetate (XI) and 3 beta-acetate (X) monoesters were isolated. Mitsunobu reaction of XI followed by hydrolysis gave (25R)-3 alpha,26-dihydroxy-5 alpha-cholest-8(14)-en-15-one (VI). Oxidation of XI with pyridinium chlorochromate followed by hydrolysis of the acetate gave (25R)-26-hydroxy-5 alpha-cholest-8(14)-ene-3,15-dione (VII). Oxidation of X with Jones reagent followed by hydrolysis of the acetate gave (25R)-3 beta-hydroxy-15-keto-5 alpha-cholest-8(14)-en-26-oic acid (IVa). Jones oxidation of II gave (25R)-3,15-diketo-5 alpha-cholest-8(14)-en-26-oic acid (VII). 1H and 13C nuclear magnetic resonance assignments and analyses of mass spectral fragmentation data are presented for each of the new compounds and their derivatives. The 3,15-diketone VII was found to be highly active in lowering the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells, with a potency comparable to that of I. In contrast, 3 alpha,26-diol VI was less potent than I or VII. The two carboxylic acid analogs IVa and VIII were considerably less potent than VI in lowering the levels of HMG-CoA reductase activity.

Finasteride Inhibits Human Prostate Cancer Cell Invasion through MMP2 and MMP9 Downregulation

PubMed Central

Moroz, Andrei; Delella, Flávia K.; Almeida, Rodrigo; Lacorte, Lívia Maria; Fávaro, Wágner José; Deffune, Elenice; Felisbino, Sérgio L.

2013-01-01

Introduction The use of the 5-alpha reductase inhibitors (5-ARIs) finasteride and dutasteride for prostate cancer prevention is still under debate. The FDA recently concluded that the increased prevalence of high-grade tumors among 5-ARI-treated patients must not be neglected, and they decided to disallow the use of 5-ARIs for prostate cancer prevention. This study was conducted to verify the effects of finasteride on prostate cell migration and invasion and the related enzymes/proteins in normal human and tumoral prostatic cell lines. Materials and Methods RWPE-1, LNCaP, PC3 and DU145 cells were cultivated to 60% confluence and exposed for different periods to either 10 µM or 50 µM finasteride that was diluted in culture medium. The conditioned media were collected and concentrated, and MMP2 and MMP9 activities and TIMP-1 and TIMP-2 protein expression were determined. Cell viability, migration and invasion were analyzed, and the remaining cell extracts were submitted to androgen receptor (AR) detection by western blotting techniques. Experiments were carried out in triplicate. Results Cell viability was not significantly affected by finasteride exposure. Finasteride significantly downregulated MMP2 and MMP9 activities in RWPE-1 and PC3 cells and MMP2 in DU145 cells. TIMP-2 expression in RWPE-1 cells was upregulated after exposure. The cell invasion of all four tested cell lines was inhibited by exposure to 50 µM of finasteride, and migration inhibition only occurred for RWPE-1 and LNCaP cells. AR was expressed by LNCaP, RWPE-1 and PC3 cells. Conclusions Although the debate on the higher incidence of high-grade prostate cancer among 5-ARI-treated patients remains, our findings indicate that finasteride may attenuate tumor aggressiveness and invasion, which could vary depending on the androgen responsiveness of a patient’s prostate cells. PMID:24386413

Structure of the G225P/G226P mutant of mouse 3(17)alpha-hydroxysteroid dehydrogenase (AKR1C21) ternary complex: implications for the binding of inhibitor and substrate.

PubMed

Dhagat, Urmi; Endo, Satoshi; Mamiya, Hiroaki; Hara, Akira; El-Kabbani, Ossama

2009-03-01

3(17)alpha-Hydroxysteroid dehydrogenase (AKR1C21) is a unique member of the aldo-keto reductase (AKR) superfamily owing to its ability to reduce 17-ketosteroids to 17alpha-hydroxysteroids, as opposed to other members of the AKR family, which can only produce 17beta-hydroxysteroids. In this paper, the crystal structure of a double mutant (G225P/G226P) of AKR1C21 in complex with the coenzyme NADP(+) and the inhibitor hexoestrol refined at 2.1 A resolution is presented. Kinetic analysis and molecular-modelling studies of 17alpha- and 17beta-hydroxysteroid substrates in the active site of AKR1C21 suggested that Gly225 and Gly226 play an important role in determining the substrate stereospecificity of the enzyme. Additionally, the G225P/G226P mutation of the enzyme reduced the affinity (K(m)) for both 3alpha- and 17alpha-hydroxysteroid substrates by up to 160-fold, indicating that these residues are critical for the binding of substrates.

Histologic evaluation of human benign prostatic hyperplasia treated by dutasteride: a study by xenograft model with improved severe combined immunodeficient mice.

PubMed

Tsujimura, Akira; Fukuhara, Shinichiro; Soda, Tetsuji; Takezawa, Kentaro; Kiuchi, Hiroshi; Takao, Tetsuya; Miyagawa, Yasushi; Nonomura, Norio; Adachi, Shigeki; Tokita, Yoriko; Nomura, Taisei

2015-01-01

To evaluate histologic change in human prostate samples treated with dutasteride and to elucidate direct effects of dutasteride on human prostate tissue, the present study was conducted by using a xenograft model with improved severe combined immunodeficient (super-SCID) mice, although it is well known that dutasteride reduces prostate volume. After establishment of a xenograft model of human benign prostatic hyperplasia in morphology and function, samples implanted into super-SCID mice with and without dutasteride were evaluated pathohistologically at 2 and 6 months after initiation of dutasteride administration. The proliferative index evaluated by Ki-67 staining was significantly lower in the dutasteride group than the control at 2 and 6 months after administration. Apoptotic index evaluated by the terminal transferase TdT-mediated dUTP-biotin nick end labeling staining was higher in the dutasteride group than the control at 2 and 6 months after administration. Quick scores in the dutasteride group for staining of both cyclooxygenase-2 (Cox-2) and Ras homolog gene family, member A (RhoA) were significantly lower than those in the control group at 2 and 6 months after administration. Dutasteride inhibits cell proliferation and induces apoptosis of prostatic cells, causing a reduced prostate volume. Furthermore, decreased expression of Cox-2 and RhoA within benign prostatic hyperplasia tissue by dutasteride may induce an early effect on improvement of lower urinary tract symptoms, probably by attenuating inflammation reaction of the prostate and decreasing intraurethral pressure, other than the mechanism of reduced prostate volume. Copyright © 2015 Elsevier Inc. All rights reserved.

Alpha-1 adrenergic antagonists, 5-alpha reductase inhibitors, phosphodiesterase type 5 inhibitors, and phytotherapic compounds in men with lower urinary tract symptoms suggestive of benign prostatic obstruction: A systematic review and meta-analysis of urodynamic studies.

PubMed

Fusco, Ferdinando; Creta, Massimiliano; De Nunzio, Cosimo; Gacci, Mauro; Li Marzi, Vincenzo; Finazzi Agrò, Enrico

2018-03-31

To perform a systematic review and meta-analysis of studies evaluating the urodynamic outcomes of alpha-1 adrenergic antagonists (ABs), 5-alpha reductase inhibitors (5-ARIs), phosphodiesterase type 5 inhibitors (PDE5is), and phytotherapic compounds in patients with lower urinary tract symptoms related to benign prostatic obstruction (LUTS/BPO). A systematic review of PubMed/Medline, ISI Web of Knowledge, and Scopus databases was performed in June 2017. We included full papers that met the following criteria: original research; English language; human studies; enrolling LUTS/BPO patients; reporting maximum urinary flow (Qmax), and detrusor pressure at maximum urinary flow (PdetQmax). The primary endpoint was variation in bladder outlet obstruction index (BOOI). Secondary endpoints were variations in Qmax and PdetQmax. Twenty-three studies involving 1044 patients were included in the final analysis. Eighteen, three, two, and one study evaluated the urodynamic outcomes of ABs, 5-ARIs, PDE5is, and phytotherapic compounds, respectively. BOOI, PdetQmax, and Qmax improved in a statistically significant manner in patients receiving ABs and in those receiving 5-ARIs. The overall pooled data showed a mean BOOI change of -15.40 (P < 0.00001) and of -10.55 (P = 0,004) for ABs and 5-ARIs, respectively. Mean PdetQmax and Qmax changes were:12.30 cm H 2 O (P < 0.00001) and +2.27 ml/s (P < 0.00001) for ABs and -9.63 cm H 2 O (P = 0.05), and +1.18 mL/s (P = 0.04) for 5-ARIs. PDE5is and phytotherapic compounds had no significant effects on urodynamic parameters. ABs and 5-ARIs efficiently improve BOOI in men with LUTS/BPO. Both treatments are associated with a clinically significant decrease in PdetQmax but only marginal improvements in Qmax. © 2018 Wiley Periodicals, Inc.

Characterization and localization of progesterone 5 alpha-reductase from cell cultures of foxglove (Digitalis lanata EHRH).

PubMed Central

Wendroth, S; Seitz, H U

1990-01-01

Progesterone 5 alpha-reductase, which catalyses the reduction of progesterone to 5 alpha-pregnane-3,20-dione, was isolated and characterized from cell cultures of Digitalis lanata (foxglove). Optimum enzyme activity was observed at pH 7.0, and the enzyme had an apparent Km value of 30 microM for its substrate progesterone. The enzyme needs NADPH as reductant, which could not be replaced by NADH. For NADPH, the apparent Km value is 130 microM. The optimum temperature was 40 degrees C; at temperatures below 45 degrees C, the product 5 alpha-pregnane-3,20-dione was reduced by a second reaction to 5 alpha-pregnan-3 beta-ol-20-one. Progesterone 5 alpha-reductase activity was not dependent on bivalent cations. In the presence of EDTA, 0.1 mM-Mn2+ had no influence on enzyme activity, whereas 0.1 mM-Ca2+, -Co2+ and -Zn2+ decreased progesterone 5 alpha-reductase activity. Only 0.1 mM-Mg2+ was slightly stimulatory. EDTA and thiol reagents such as dithiothreitol stimulate progesterone 5 alpha-reductase activity. By means of linear sucrose gradient fractionation of the cellular membranes, progesterone 5 alpha-reductase was found to be located in the endoplasmic reticulum. PMID:2106876

Enhanced oral bioavailability and controlled release of dutasteride by a novel dry elixir.

PubMed

Jang, Dong-Jin; Kim, Sung Tae; Oh, Euichaul; Ban, Eunmi

2014-01-01

To develop a solid dosage form of dutasteride for improving its oral bioavailability, a novel dry elixir (DE) system was fabricated. DEs incorporating dextrin and/or xanthan gum were prepared using spray-drying and evaluated by morphology, ethanol content, crystallinity, dissolution and oral bioavailability. DEs were spherical with a smooth surface and had an average particle size of 20-25 μm. The ethanol content could be easily varied by controlling the spray-drying temperature. The dissolution profiles of dutasteride from each DE proved to be much faster than that of dutasteride powder due to the amorphous state and a high amount of incorporated ethanol. In particular, the pharmacokinetic profiles of dutasteride were significantly altered depending on the proportions of dextrin and xanthan gum. Blood concentrations of dutasteride from DE formulations were similar to those of market products and much greater than those of native dutasteride. Interestingly, the dissolution and pharmacokinetic profiles were easily controlled by changing the ratio of dextrin to xanthan gum. The data suggests that a DE using dextrin and/or xanthan gum could provide an applicable solid dosage form to improve the dissolution and bio-availability of dutasteride as well as to modulate its pharmacokinetics.

A preliminary investigation of the enzymatic inhibition of 5alpha-reduction and growth of prostatic carcinoma cell line LNCap-FGC by natural astaxanthin and Saw Palmetto lipid extract in vitro.

PubMed

Anderson, Mark L

2005-01-01

Inhibition of 5alpha-reductase has been reported to decrease the symptoms of benign prostate hyperplasia (BPH) and possibly inhibit or help treat prostate cancer. Saw Palmetto berry lipid extract (SPLE) is reported to inhibit 5alpha-reductase and decrease the clinical symptoms of BPH. Epidemiologic studies report that carotenoids such as lycopene may inhibit prostate cancer. In this investigation the effect of the carotenoid astaxanthin, and SPLE were examined for their effect on 5alpha-reductase inhibition as well as the growth of prostatic carcinoma cells in vitro. These studies support patent #6,277,417 B1. The results show astaxanthin demonstrated 98% inhibition of 5alpha-reductase at 300 microg/mL in vitro. Alphastat, the combination of astaxanthin and SPLE, showed a 20% greater inhibition of 5alpha-reductase than SPLE alone n vitro. A nine day treatment of prostatic carcinoma cells with astaxanthin in vitro produced a 24% decrease in growth at 0.1 mcg/mL and a 38% decrease at 0.01 mcg/mL. SPLE showed a 34% decrease at 0.1 mcg/mL. Low levels of carotenoid astaxanthin inhibit 5alpha-reductase and decrease the growth of human prostatic cancer cells in vitro. Astaxanthin added to SPLE shows greater inhibition of 5alpha-reductase than SPLE alone in vitro.

Long-Term Effect of Loxoprofen Sodium on Nocturia in Patients with Benign Prostatic Hyperplasia

PubMed Central

Shin, Hong Il; Kim, Byung Hoon; Chang, Hyuk Soo; Park, Choal Hee

2011-01-01

Purpose We evaluated the long-term effects of loxoprofen on nocturia in patients with benign prostatic hyperplasia (BPH). Materials and Methods Between January 2006 and December 2008, 40 BPH patients with 2 or more episodes of nocturia received an alpha-blocker, 5-alpha reductase inhibitor, and a single dose of 60 mg of loxoprofen at night before sleep for 12 months (Group I). During the same period, 38 BPH patients selected as the control group received an alpha-blocker and 5-alpha reductase inhibitor (Group II). Patients were reevaluated after 3, 6, and 12 months of treatment by the number of nocturia episodes and side effects. Results After 3 months of treatment, the number of nocturia episodes decreased significantly compared with baseline in both group I and group II (1.9±0.7, 2.1±0.7, respectively, p<0.05). The degree of decrease in nocturia was significantly different between the groups (-1.5±0.9, -1.1±0.9, respectively, p=0.034). After 6 and 12 months, the number of nocturia episodes decreased significantly compared with baseline in both group I and group II (p<0.05), but the degree of decrease was not significantly different between the groups (p>0.05). After 6 and 12 months of treatment in group I, treatment-emergent adverse events, including 5 cases of gastric discomfort (12.5%), 3 cases of leg edema (7.5%), and 1 case of decreased urine volume (2.5%), occurred in 9 of the 40 (22.5%) patients. Conclusions Loxoprofen can be an effective treatment for patients with nocturia secondary to BPH in the short term. Long-term use of loxoprofen is not recommended because of the side effects. PMID:21556213

Long-term effect of loxoprofen sodium on nocturia in patients with benign prostatic hyperplasia.

PubMed

Shin, Hong Il; Kim, Byung Hoon; Chang, Hyuk Soo; Park, Choal Hee; Kim, Chun Il

2011-04-01

We evaluated the long-term effects of loxoprofen on nocturia in patients with benign prostatic hyperplasia (BPH). Between January 2006 and December 2008, 40 BPH patients with 2 or more episodes of nocturia received an alpha-blocker, 5-alpha reductase inhibitor, and a single dose of 60 mg of loxoprofen at night before sleep for 12 months (Group I). During the same period, 38 BPH patients selected as the control group received an alpha-blocker and 5-alpha reductase inhibitor (Group II). Patients were reevaluated after 3, 6, and 12 months of treatment by the number of nocturia episodes and side effects. After 3 months of treatment, the number of nocturia episodes decreased significantly compared with baseline in both group I and group II (1.9±0.7, 2.1±0.7, respectively, p<0.05). The degree of decrease in nocturia was significantly different between the groups (-1.5±0.9, -1.1±0.9, respectively, p=0.034). After 6 and 12 months, the number of nocturia episodes decreased significantly compared with baseline in both group I and group II (p<0.05), but the degree of decrease was not significantly different between the groups (p>0.05). After 6 and 12 months of treatment in group I, treatment-emergent adverse events, including 5 cases of gastric discomfort (12.5%), 3 cases of leg edema (7.5%), and 1 case of decreased urine volume (2.5%), occurred in 9 of the 40 (22.5%) patients. Loxoprofen can be an effective treatment for patients with nocturia secondary to BPH in the short term. Long-term use of loxoprofen is not recommended because of the side effects.

Skin cancer associated with commonly prescribed drugs: tumor necrosis factor alpha inhibitors (TNF-αIs), angiotensin-receptor blockers (ARBs), phosphodiesterase type 5 inhibitors (PDE5Is) and statins -weighing the evidence.

PubMed

Nardone, Beatrice; Orrell, Kelsey A; Vakharia, Paras P; West, Dennis P

2018-02-01

Skin cancers, including both malignant melanoma (MM) and nonmelanoma skin cancer (NMSC), are the most commonly diagnosed cancers in the US. The incidence of both MM and NMSC continues to rise. Areas covered: Current evidence for an association between four of the most commonly prescribed classes of drugs in the U.S. and risk for MM and NMSC is reported. Medline was searched (January 2000 to May 2017) for each drug in the classes and for 'basal cell carcinoma', 'squamous cell carcinoma', 'non-melanoma skin cancer', 'skin cancer' and 'melanoma'. Skin cancer risk information was reported for: tumor necrosis factor alpha inhibitors (TNF-αIs), angiotensin-receptor blockers (ARBs), phosphodiesterase type 5 inhibitors (PDE5Is) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)-reductase inhibitors (statins). Expert opinion: Since skin cancer risk is associated with all four classes of these commonly prescribed drugs that represent nearly 20% of the Top 100 drugs in the U.S., these important findings warrant enhanced education, especially for prescribers and those patients at high risk for skin cancer.

BPH progression: concept and key learning from MTOPS, ALTESS, COMBAT, and ALF-ONE.

PubMed

Roehrborn, Claus G

2008-03-01

Benign prostatic hyperplasia (BPH) represents a significant burden in ageing men due to frequently associated lower urinary tract symptoms (LUTS), which may impair quality of life. BPH is also a progressive disease, mainly characterized by a deterioration of LUTS over time, and in some patients by the occurrence of serious outcomes such as acute urinary retention (AUR) and need for BPH-related surgery. The goals of therapy for BPH are not only to improve bothersome LUTS but also to identify those patients at risk of unfavourable outcomes, to optimize their management. In selected patients, combination of an alpha(1)-blocker and a 5alpha-reductase inhibitor is the most effective form of BPH medical therapy to reduce the risk of clinical progression and relieve LUTS. Monotherapy also significantly reduces the risk of BPH clinical progression, mainly through a reduction of LUTS deterioration for alpha(1)-blockers while 5alpha-reductase inhibitors also reduce the risk of AUR and need for BPH-related surgery. Enlarged prostate and high serum prostate-specific antigen levels have been consistently found to be good clinical predictors of AUR and BPH-related surgery in longitudinal population-based studies and placebo arms of controlled studies. High post-void residual urine (PVR) is also associated with an increased risk of LUTS deterioration and should thus be reconsidered in practice as a predictor of BPH progression. Conversely, baseline LUTS severity and low peak flow rate, initially identified as predictors of unfavourable outcomes in community setting, behave paradoxically in controlled trials, probably as a consequence of strict inclusion criteria and subsequent regression to the mean and glass ceiling effects. Lastly, there is increasing evidence that dynamic variables, such as LUTS and PVR worsening, and lack of symptomatic improvement with alpha(1)-blockers are important predictors of future LUTS/BPH-related events, allowing better identification and management of patients at risk of BPH progression.

[Referral criteria for benign prostatic hyperplasia in primary care.Sociedad Española de Médicos de Atención Primaria, Sociedad Española de Medicina General, Sociedad Española de Medicina de Familia y Comunitaria, Asociación Española de Urología].

PubMed

Castiñeiras Fernández, J; Cozar Olmo, J M; Fernández-Pro, A; Martín, J A; Brenes Bermúdez, F J; Naval Pulido, E; Molero, J M; Pérez Morales, D

2010-01-01

Benign prostatic hyperplasia (BPH) is a high prevalence condition in men over 50 years that requires continued assistance between primary care and urology. Therefore, consensus around common referral criteria was needed to guide and support both levels. Medical history, symptom assessment with International Prostate Symptom Score (IPSS) questionnaire, digital rectal examination and prostate-specific antigen (PSA) measurement are diagnostic tests available for general practitioners that allow setting a correct BPH diagnose. Patients with an IPSS<8 should be monitored by evaluating them annually. Treatment with alpha-blockers and an evaluation at the first and third month is recommended in patients with an IPSS 8-20 and if the prostate is small, if the prostate size is large treatment with alpha-blockers or 5alpha-reductase inhibitors and evaluation at the third and six month is recommended, and in patients with a large prostate and a PSA >1.5 ng/ ml combined treatment and evaluation at the first and sixth month is recommended. Some clear criteria for referral to urology are established in this document, which help in the management of these patients. Those patients with BPH who do not show any improvement at the third month of treatment with alpha-blockers, or the sixth month with 5alpha-reductase inhibitors, will be referred to urology. Patients will also be referred to urology if they have lower urinary tract symptoms, a pathological finding during rectal examination, IPSS>20, PSA>10 ng/ml or PSA>4 ng/ml and free PSA<20% or if they are <50 years with suspected BHP, or if they have any urological complication.

The Association between Phosphodiesterase Type 5 Inhibitors and Prostate Cancer: Results from the REDUCE Study.

PubMed

Jamnagerwalla, Juzar; Howard, Lauren E; Vidal, Adriana C; Moreira, Daniel M; Castro-Santamaria, Ramiro; Andriole, Gerald L; Freedland, Stephen J

2016-09-01

Despite routine use of phosphodiesterase type 5 inhibitor to treat erectile dysfunction the role in prostate cancer chemoprevention remains unclear. Only a few studies have explored the link between phosphodiesterase type 5 inhibitor use and prostate cancer. We tested the association between phosphodiesterase type 5 inhibitor and prostate cancer risk in the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) trial. REDUCE was a 4-year multicenter study testing the effect of daily dutasteride on prostate cancer risk in men with prostate specific antigen 2.5 to 10.0 ng/ml and negative biopsy who underwent study mandated biopsies at 2 and 4 years. The association of phosphodiesterase type 5 inhibitor with overall prostate cancer risk and disease grade (Gleason 2-6 and 7-10) was examined using adjusted logistic and multinomial regression analysis. Secondary analysis was performed to explore the association between phosphodiesterase type 5 inhibitor and prostate cancer risk in North American men, given the significantly higher use of phosphodiesterase type 5 inhibitor in these subjects. Phosphodiesterase type 5 inhibitor was not associated with prostate cancer diagnosis (OR 0.90, 95% CI 0.68-1.20, p = 0.476), low grade disease (OR 0.93, 95% CI 0.67-1.27, p = 0.632) or high grade disease (OR 0.85, 95% CI 0.51-1.39, p = 0.508). An inverse trend was seen between phosphodiesterase type 5 inhibitor and prostate cancer diagnosis in North American men but this was not statistically significant (OR 0.67, 95% CI 0.42-1.07, p = 0.091). Phosphodiesterase type 5 inhibitor use was not associated with decreased prostate cancer diagnoses on post-hoc analysis of REDUCE. In North American men, who had much higher baseline use of phosphodiesterase type 5 inhibitor, this treatment was associated with an inverse trend of prostate cancer diagnosis that approached but did not reach statistical significance. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Regulation of 5alpha-reductase isoforms by oxytocin in the rat ventral prostate.

PubMed

Assinder, S J; Johnson, C; King, K; Nicholson, H D

2004-12-01

Oxytocin (OT) is present in the male reproductive tract, where it is known to modulate contractility, cell growth, and steroidogenesis. Little is known about how OT regulates these processes. This study describes the localization of OT receptor in the rat ventral prostate and investigates if OT regulates gene expression and/or activity of 5alpha-reductase isoforms I and II. The ventral prostates of adult male Wistar rats were collected following daily sc administration of saline (control), OT, a specific OT antagonist or both OT plus antagonist for 3 d. Expression of the OT receptor was identified in the ventral prostate by RT-PCR and Western blot, and confirmed to be a single active binding site by radioreceptor assay. Immunohistochemistry localized the receptor to the epithelium of prostatic acini and to the stromal tissue. Real-time RT-PCR determined that OT treatment significantly reduced expression of 5alpha-reductase I but significantly increased 5alpha-reductase II expression in the ventral prostate. Activity of both isoforms of 5alpha-reductase was significantly increased by OT, resulting in increased concentration of prostatic dihydrotestosterone. In conclusion, OT is involved in regulating conversion of testosterone to the biologically active dihydrotestosterone in the rat ventral prostate. It does so by differential regulation of 5alpha-reductase isoforms I and II.

Effect of dutasteride on the risk of prostate cancer.

PubMed

Andriole, Gerald L; Bostwick, David G; Brawley, Otis W; Gomella, Leonard G; Marberger, Michael; Montorsi, Francesco; Pettaway, Curtis A; Tammela, Teuvo L; Teloken, Claudio; Tindall, Donald J; Somerville, Matthew C; Wilson, Timothy H; Fowler, Ivy L; Rittmaster, Roger S

2010-04-01

We conducted a study to determine whether dutasteride reduces the risk of incident prostate cancer, as detected on biopsy, among men who are at increased risk for the disease. In this 4-year, multicenter, randomized, double-blind, placebo-controlled, parallel-group study, we compared dutasteride, at a dose of 0.5 mg daily, with placebo. Men were eligible for inclusion in the study if they were 50 to 75 years of age, had a prostate-specific antigen (PSA) level of 2.5 to 10.0 ng per milliliter, and had had one negative prostate biopsy (6 to 12 cores) within 6 months before enrollment. Subjects underwent a 10-core transrectal ultrasound-guided biopsy at 2 and 4 years. Among 6729 men who underwent a biopsy or prostate surgery, cancer was detected in 659 of the 3305 men in the dutasteride group, as compared with 858 of the 3424 men in the placebo group, representing a relative risk reduction with dutasteride of 22.8% (95% confidence interval, 15.2 to 29.8) over the 4-year study period (P<0.001). Overall, in years 1 through 4, among the 6706 men who underwent a needle biopsy, there were 220 tumors with a Gleason score of 7 to 10 among 3299 men in the dutasteride group and 233 among 3407 men in the placebo group (P=0.81). During years 3 and 4, there were 12 tumors with a Gleason score of 8 to 10 in the dutasteride group, as compared with only 1 in the placebo group (P=0.003). Dutasteride therapy, as compared with placebo, resulted in a reduction in the rate of acute urinary retention (1.6% vs. 6.7%, a 77.3% relative reduction). The incidence of adverse events was similar to that in studies of dutasteride therapy for benign prostatic hyperplasia, except that in our study, as compared with previous studies, the relative incidence of the composite category of cardiac failure was higher in the dutasteride group than in the placebo group (0.7% [30 men] vs. 0.4% [16 men], P=0.03). Over the course of the 4-year study period, dutasteride reduced the risk of incident prostate cancer detected on biopsy and improved the outcomes related to benign prostatic hyperplasia. (ClinicalTrials.gov number, NCT00056407.) 2010 Massachusetts Medical Society

Hippocampal 3alpha,5alpha-THP may alter depressive behavior of pregnant and lactating rats.

PubMed

Frye, Cheryl A; Walf, Alicia A

2004-07-01

The 5alpha-reduced metabolite of progesterone (P), 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), may mediate progestins' effects to reduce depressive behavior of female rats in part through actions in the hippocampus. To investigate, forced swim test behavior and plasma and hippocampal progestin levels were assessed in groups of rats expected to differ in their 3alpha,5alpha-THP levels due to endogenous differences (pregnant and postpartum), administration of a 5alpha-reductase inhibitor (finasteride; 50 mg/kg sc), and/or gestational stress [prenatal stress (PNS)], an animal model of depression. Pregnant rats had higher plasma and hippocampal 3alpha,5alpha-THP levels and less depressive behavior (decreased immobility, increased struggling and swimming) in the forced swim test than did postpartum rats. Finasteride, compared to vehicle-administration, reduced plasma and hippocampal 3alpha,5alpha-THP levels and increased depressive behavior (increased immobility, decreased struggling and swimming). PNS was associated with lower hippocampal, but not plasma, 3alpha,5alpha-THP levels and increased swimming compared to that observed in control rats. Together, these data suggest that 3alpha,5alpha-THP in the hippocampus may mediate antidepressive behavior of female rats.

Direct imaging of the disruption of hepatitis C virus replication complexes by inhibitors of lipid metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyn, Rodney K.; Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, K1N 6N5; Kennedy, David C.

2009-11-10

Here we have simultaneously characterized the influence of inhibitors of peroxisome proliferator-activated receptor alpha (PPARalpha) and the mevalonate pathway on hepatocyte lipid metabolism and the subcellular localization of hepatitis C virus (HCV) RNA using two-photon fluorescence (TPF) and coherent anti-Stokes Raman scattering (CARS) microscopy. Using this approach, we demonstrate that modulators of PPARalpha signaling rapidly cause the dispersion of HCV RNA from replication sites and simultaneously induce lipid storage and increases in lipid droplet size. We demonstrate that reductions in the levels of cholesterol resulting from inhibition of the mevalonate pathway upregulates triglyceride levels. We also show that the ratemore » of dispersion of HCV RNA is very rapid when using a PPARalpha antagonist. This occurs with a faster rate to that of direct inhibition of 3-hydroxy-3-methyglutaryl CoA reductase (HMG-CoA reductase) using lovastatin in living cells, demonstrating the potential therapeutic value of modulating host cell pathways as part of a strategy to eliminate chronic HCV infection.« less

Inhibitors of sterol synthesis. Synthesis and spectral properties of 3 beta-hydroxy-5 alpha-cholestan-15-one and its 17 beta-epimer and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity.

PubMed

Siddiqui, A U; Wilson, W K; Parish, E J; Gerst, N; Pinkerton, F D; Schroepfer, G J

1994-10-20

3 beta-Hydroxy-5 alpha-cholestan-15-one (2a) and its 14 beta-epimer 2b were prepared from 3 beta-acetoxy-5 alpha-cholest-8(14)-ene (3). Hydroboration of 3 at 45-50 degrees C gave a mixture of 5 alpha,14 alpha-cholestane-3 beta,15 alpha-diol and 5 alpha,14 beta-cholestane-3 beta,15 beta-diol, which were separated on silica gel as their 3 beta-tert-butyldimethylsilyl ethers 5a and 5b. Oxidation of 5a with pyridinium chlorochromate, followed by desilylation with tetrabutylammonium fluoride gave 2a. Analogous transformations of 5b gave 2b contaminated with 2a. Desilylation of 5b followed by oxidation with pyridinium chlorochromate resulted in a mixture composed mainly of 5 alpha,14 beta-cholestane-3,15-dione and 2b. Successive chromatographic separations on silica gel and reversed phase media gave 2b of high purity. Compound 2a was also prepared by lithium-ammonia reduction of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (96% yield) and by selective reduction of 5 alpha-cholestane-3,15-dione with lithium tri-tert-butoxyaluminum hydride (90% yield). Isomers 2a and 2b were readily epimerized under acidic or basic conditions or under conditions used for gas chromatographic analysis. The purities of 2a and 2b were measured from nuclear magnetic resonance (NMR) spectra; chromatographic methods gave less reliable estimates of purity. NMR data also showed that ring C of the 14 beta sterols is predominantly in a chair conformation. The effects of 2a and 2b on the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase have been studied in Chinese hamster ovary cells.

The 5 Alpha-Reductase Isozyme Family: A Review of Basic Biology and Their Role in Human Diseases

PubMed Central

Azzouni, Faris; Godoy, Alejandro; Li, Yun; Mohler, James

2012-01-01

Despite the discovery of 5 alpha-reduction as an enzymatic step in steroid metabolism in 1951, and the discovery that dihydrotestosterone is more potent than testosterone in 1968, the significance of 5 alpha-reduced steroids in human diseases was not appreciated until the discovery of 5 alpha-reductase type 2 deficiency in 1974. Affected males are born with ambiguous external genitalia, despite normal internal genitalia. The prostate is hypoplastic, nonpalpable on rectal examination and approximately 1/10th the size of age-matched normal glands. Benign prostate hyperplasia or prostate cancer does not develop in these patients. At puberty, the external genitalia virilize partially, however, secondary sexual hair remains sparse and male pattern baldness and acne develop rarely. Several compounds have been developed to inhibit the 5 alpha-reductase isozymes and they play an important role in the prevention and treatment of many common diseases. This review describes the basic biochemical properties, functions, tissue distribution, chromosomal location, and clinical significance of the 5 alpha-reductase isozyme family. PMID:22235201

[Combination drug therapy in patients with BPH].

PubMed

Kuzmenko, A V; Kuzmenko, V V; Gyaurgiev, T A

2018-03-01

Introuction. One of the risk factors for LUTS is an infravesical obstruction, which is most often caused by benign prostatic hyperplasia (BPH). BPH symptoms are formed due to three components: static (mechanical), dynamic, and impaired functional capacity of the bladder. Medical treatment with 1-blockers decreases the outflow obstruction. 5-alpha reductase inhibitors are used to inhibit the static component of BPH. To investigate the effectiveness of various modifications of medical therapy of BPH using -blockers and 5-reductase inhibitors and combinations thereof. The study comprised 90 BPH patients who were divided into three groups, with each group containing 30 people. Patients of group I, II and III received monotherapy with -blockers, a combination of 5-reductase and -blockers, and fixed-dose combination drug Duodart, respectively. Evaluation of the treatment effectiveness included filling out voiding diaries, completing the I-PSS and QL questionnaires, uroflowmetry, transrectal ultrasonography of the prostate and estimation of the incidence of adverse effects. Also, compliance with the treatment was evaluated, and the number of patients who had episodes of acute urinary retention and required surgical treatment during the 12 month treatment course was registered. Compared to monotherapy, combination therapy with -blockers and 5-reductase inhibitors more effectively reduces the LUTS, increases Qmax and prevents the disease progression, which manifests in a lower incidence of AUR and fewer surgical interventions in groups II and III. However, the combination therapy can be associated with some side effects. Patients who received fixed-dose combination drug Duodart had a greater compliance rate than patients on the combination of drugs, which, in our opinion, is associated with fewer cases of AUR and surgical interventions. The use of Duodart in patients with BPH effectively alleviates LUTS and reduces the risk of the disease progression, which manifests itself in a reduced number of complications and thereby contributes to improving the quality of life of patients.

Influence of rete testis fluid deprivation on the kinetic parameters of goat epididymal 5 alpha-reductase.

PubMed

Kelce, W R; Lubis, A M; Braun, W F; Youngquist, R S; Ganjam, V K

1990-01-01

A surgical technique to cannulate the rete testis of the goat was utilized to examine the effects of rete testis fluid (RTF) deprivation on the enzymatic activity of epididymal 5 alpha-reductase. Kinetic techniques were used to determine whether the regional enzymatic effect of RTF deprivation is to decrease the apparent number of 5 alpha-reductase active sites or the catalytic activity of each active site within the epididymal epithelium. Paired comparisons of (Vmax)app and (Km)app values between control and RTF-deprived epididymides indicated that RTF deprivation affected the value of (Vmax)app with no apparent change in the values of (Km)app in caput, corpus, and cauda epididymal regions. We conclude that RTF deprivation in the goat epididymis for 7 days results in a decreased number of apparent 5 alpha-reductase active sites within the epididymal epithelium.

Likely gains in life expectancy of patients with coronary artery disease treated with HMG-CoA reductase inhibitors, as predicted by a decision analysis model.

PubMed

Kellett, J

1997-07-01

To estimate the likely gains in life expectancy of patients with coronary artery disease treated with HMG-CoA reductase inhibitors based on published reports and the results of the 4S and the West of Scotland Study. Decision analysis. Four likely scenarios of the effect of treatment with HMG-CoA reductase inhibitors on the life expectancy of medically and surgically managed coronary artery disease were modelled. Regardless of the scenario, treatment with HMG-CoA reductase inhibitors was estimated to provide a gain in life expectancy for medically managed patients of all ages with coronary artery disease, ranging from 4.6 to 10.1 quality adjusted life years (QALYs) for a 40 year old with three vessel disease (depending on the scenario assumed), to 0.2 QALYs for a 80 year old with two vessel disease. These gains were always greater than those predicted after bypass alone. If the use of HMG-CoA reductase inhibitors produces the same reduction in cardiac mortality after bypass as it does in medically managed patients it will increase the benefits of operation except for patients with two vessel disease over 70 years of age. Conversely, if HMG-CoA reductase inhibitors do not influence the course of coronary artery disease after bypass, the benefits of operation over medical treatment with HMG-CoA reductase inhibitors are either reduced or lost completely, ranging from a loss of -5.6 QALYs for a 40 year old with two vessel disease to a gain of 1.5 QALYs for 55 to 60 year old patients with left main stem disease. Although their effect on the progression of coronary artery disease after bypass must be defined, it is probable that HMG-CoA reductase inhibitors will produce considerable gains in life expectancy for patients with coronary artery disease.

Prostate-specific antigen increase during dutasteride to indicate the need for prostate biopsy: influence of prostatic inflammation.

PubMed

Sciarra, Alessandro; Maggi, Martina; Fasulo, Andrea; Salciccia, Stefano; Gentile, Vincenzo; Cattarino, Susanna; Gentilucci, Alessandro

2017-08-01

The aim of this study was to analyze the significance of an increase in total prostate-specific antigen (PSA) serum levels despite dutasteride treatment as a predictor of prostate cancer (PC) at biopsy. We focused our attention on the rate of the first PSA increase and on the influence of prostatic inflammation. From 2011 to 2016, 365 men with a previous negative prostate biopsy and persistent elevated PSA levels received dutasteride treatment. The population was followed for a range of 12-48 months. One hundred twelve cases with a confirmed PSA increase >0.5 ng/ml over the nadir value during the follow-up were included in Group A and underwent a new prostate biopsy. In Group A, the PSA increase was associated with PC at the re-biopsy in 66% of cases. The percentage of PSA reduction after 6 months of treatment was not a significant indicator of the risk for PC. The distribution of inflammatory infiltrates significantly (p<00.01) varied from positive to negative prostate biopsies. The relative risk for PC at biopsy significantly increased according to PSA level during dutasteride. Treatment with dutasteride can help to analyze PSA kinetic. A persistent prostatic inflammation is a factor able to reduce the performance of PSA kinetic during dutasteride treatment.

Sleep Problems are Associated with Development and Progression of Lower Urinary Tract Symptoms: Results from REDUCE.

PubMed

Branche, Brandee L; Howard, Lauren E; Moreira, Daniel M; Roehrborn, Claus; Castro-Santamaria, Ramiro; Andriole, Gerald L; Hopp, Martin L; Freedland, Stephen J

2018-02-01

Although lower urinary tract symptoms and sleep problems often develop together, to our knowledge it is unknown whether sleep disturbances are linked to lower urinary tract symptoms development and progression. As measured by the 6-item MOS-Sleep (Medical Outcomes Study Sleep Scale) survey we examined the relationship between sleep problems, and the development and progression of lower urinary tract symptoms in the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) study. REDUCE was a randomized trial testing prostate cancer chemoprevention with dutasteride in men with prostate specific antigen 2.5 to 10 ng/ml and a negative biopsy. At baseline men completed MOS-Sleep and a scaled average was used to calculate the sleep score. Men were followed for 4 years and I-PSS (International Prostate Symptom Score) was completed at baseline and every 6 months. Asymptomatic men had I-PSS less than 8 while symptomatic men had I-PSS 8 or greater. In the placebo arm of 2,588 men not receiving α-blockers or 5α-reductase inhibitors at baseline we tested the association between sleep problems and lower urinary tract symptom development and progression using Cox models. During followup lower urinary tract symptoms developed in 209 of 1,452 asymptomatic men (14%) and 580 of 1,136 (51%) with lower urinary tract symptoms demonstrated progression. On multivariable analysis higher sleep scores were suggestively associated with increased lower urinary tract symptoms in asymptomatic men (quartile 4 vs 1 HR 1.41, 95% CI 0.92-2.17, p = 0.12) and with lower urinary tract symptom progression in symptomatic men (per 10 points of sleep score HR 1.06, 95% CI 1.01-1.12, p = 0.029). Among men with lower urinary tract symptoms worse sleep scores were associated with the progression of lower urinary tract symptoms and among asymptomatic men worse sleep scores were suggestively associated with the development of lower urinary tract symptoms. If confirmed, these data suggest that sleep problems may precede such symptoms. Whether treating sleep problems would improve lower urinary tract symptoms requires further testing. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The effects of dutasteride and finasteride on BPH-related hospitalization, surgery and prostate cancer diagnosis: a record-linkage analysis.

PubMed

Cindolo, Luca; Fanizza, Caterina; Romero, Marilena; Pirozzi, Luisella; Autorino, Riccardo; Berardinelli, Francesco; Schips, Luigi

2013-06-01

To investigate differences in the risk of benign prostatic hyperplasia (BPH)-related hospitalization, for surgical and non-surgical reasons, and of new prostate cancer (PCa) diagnosis between patients using finasteride or dutasteride. A retrospective cohort study was conducted using data from record linkage of administrative databases (pharmaceutical prescription data, hospital discharge records, Italian population registry). Men aged ≥ 40 years old who had received a prescription for at least 10 packs/year between January 1, 2004 and December 31, 2004 were included and followed for 5 years. The association of the outcomes was assessed using a multiple Cox proportional hazard model. Propensity score-matched analysis and a 5-1, greedy 1:1 matching algorithm were performed. 8,132 patients were identified. Overall incidence rates of BPH hospitalization and BPH-related surgery were 21.05 (95 % CI 19.52-22.71) and 20.97 (95 % CI 19.45-22.61) per 1,000 person-years, respectively. In the dutasteride group compared with finasteride group, the incidence rate of both events was statistically significant lower: 16.07 versus 21.76 for BPH hospitalization and 15.91 versus 21.69 for BPH-related surgery. The incidence rate of new PCa was also lower for the dutasteride group [8.34 (95 % CI 5.96-11.68) vs. 10.25 (95 % CI 9.15-11.49)]. Dutasteride was associated with a reduction in BPH-related hospitalizations (HR 0.75, 95 % CI 0.58-0.98 and 0.58-0.98 for surgical and non-surgical reasons). The matched analysis confirmed the risk reduction with dutasteride for BPH-related surgery. These findings suggest that the clinical effects of dutasteride and finasteride might be different. Patients treated with dutasteride seem to be less likely to experience BPH-related hospitalization. Comparative studies are needed to confirm these results.

Cortisol metabolic predictors of response to psychotherapy for symptoms of PTSD in survivors of the World Trade Center attacks on September 11, 2001.

PubMed

Yehuda, Rachel; Bierer, Linda M; Sarapas, Casey; Makotkine, Iouri; Andrew, Ruth; Seckl, Jonathan R

2009-10-01

A proportion of subjects with symptoms of posttraumatic stress disorder (PTSD) are unresponsive to specialized psychotherapy, but a biological basis for this has not been described. To observe whether differences in cortisol or its metabolites predict or correlate with response to therapy for PTSD symptoms, cortisol and its metabolites were measured from urine samples at pre-treatment, at the conclusion of psychotherapy, and at 3-month follow-up. 28 survivors of the World Trade Center attacks on September 11, 2001 seeking psychological treatment for PTSD symptoms received four sessions of either exposure therapy or supportive counseling, followed by up to 10 sessions of prolonged exposure in a specialized PTSD treatment program at a private hospital serving the New York City metropolitan area. 24-h mean integrated cortisol excretion was assessed by radioimmunoassay (RIA); urinary free cortisol and metabolites cortisone, 5alpha-tetrahydrocortisol (5alpha-THF), 5beta-tetrahydrocortisol, and tetrahydrocortisone were assessed by gas chromatography-mass spectrometry (GC-MS); and indices of enzyme activity for 5alpha- and 5beta-reductase and for the 11beta-hydroxysteroid dehydrogenases were derived from the metabolite and glucocorticoid measures. 5alpha-Reductase activity was significantly lower at pre-treatment among non-responders, whereas there were no significant pre-treatment differences between responders and non-responders in any other hormone or metabolite level. In repeated measures analyses across the three time points, 5alpha-reductase activity, as well as 5alpha-THF and total glucocorticoids, significantly differed between responders and non-responders. For urinary cortisol measured by RIA, there was a significant groupxtime interaction indicating that, although not different at pre-treatment, urinary cortisol levels declined over time in the non-responder group, such that by follow-up, lowered cortisol significantly distinguished non-responders from responders. Indices of 5alpha-reductase activity, including 5alpha-THF and total glucocorticoids, were significantly negatively correlated with avoidance symptom severity at pre-treatment. At follow-up, indices of 5alpha-reductase activity were significantly negatively correlated with severity of all three PTSD symptom clusters and with total PTSD severity scores. Lower 5alpha-reductase activity is associated with avoidance severity and predicts non-responsiveness to psychological treatment for PTSD symptomatology. Relatively diminished 5alpha-reductase activity may mark a state of primary vulnerability, perhaps via attenuated peripheral catabolism of cortisol resulting in the suppression of hypothalamic-pituitary-adrenal axis responsiveness. Lower cortisol levels appear later in the progression to chronic, treatment-resistant PTSD.

Women with steroid 5 alpha-reductase 2 deficiency have normal concentrations of plasma 5 alpha-dihydroprogesterone during the luteal phase.

PubMed

Milewich, L; Mendonca, B B; Arnhold, I; Wallace, A M; Donaldson, M D; Wilson, J D; Russell, D W

1995-11-01

Steroid 5 alpha-reductase 2 deficiency has been identified in two adult women from unrelated families, one a homozygote and the other a compound heterozygote. The homozygote carries the G183S mutation and is the sister of an affected male; the compound heterozygote (R246W/splice junction abnormality) is married to a heterozygote (splice junction abnormality) and is the mother of two compound heterozygotes and two homozygotes. The fact that these two women are the mothers of seven children and appear to be endocrinologically normal confirms the previous deduction that this disorder is not manifest in women. Concentrations of plasma 5 alpha-dihydroprogesterone were normal in these two women during the luteal phase; this finding implies that circulating 5 alpha-dihydroprogesterone in women is derived principally from the steroid 5 alpha-reductase 1 isoenzyme and leaves unresolved the question of whether 5 alpha-dihydroprogesterone plays a physiological role in women.

The corpus cavernosum after treatment with dutasteride or finasteride: A histomorphometric study in a benign prostatic hyperplasia rodent model.

PubMed

Da Silva, Marcello H A; Costa, Waldemar S; B Sampaio, Francisco J; De Souza, Diogo B

2018-06-08

Erectile dysfunction is a common side effect of finasteride and dutasteride treatments. The objective of this study was to investigate the structural changes in the penis using a benign prostatic hyperplasia (BPH) rodent model treated with dutasteride or finasteride. Sixty male rats were divided into the following groups: C, untreated control rats; C + D, control rats receiving dutasteride; C + F, control rats receiving finasteride; H, untreated spontaneously hypertensive rats (SHRs); H + D, SHRs treated with dutasteride; and H + F, SHRs treated with finasteride. Treatments were performed for 40 days, and penises were collected immediately thereafter. The organs were analyzed using histomorphometric methods to determine the cross-sectional penile area, as well as the surface density (Sv) of smooth muscle fibers, connective tissue, elastic system fibers, and sinusoidal spaces of the corpus cavernosum. The results were compared using a one-way ANOVA with Bonferroni's posttest. Groups C + D and C + F had a significantly smaller penile cross-sectional area, but more elastic system fiber Sv compared to Group C. Group C + D showed less smooth muscle Sv, and Group H showed more connective tissue but a smaller sinusoidal space Sv in the corpus cavernosum compared to Group C. Groups H + D and H + F had less smooth muscle Sv than Group H. Group H + D also had more connective tissue and elastic system fiber Sv than Group H. Both dutasteride and finasteride promoted penile modifications in the control rat penis, although this affect was greater in Group H animals. In this rodent model, dutasteride was the drug that most affected the corpus cavernosum.

Unexpected ethical dilemmas in sex assignment in 46,XY DSD due to 5-alpha reductase type 2 deficiency.

PubMed

Byers, Heather M; Mohnach, Lauren H; Fechner, Patricia Y; Chen, Ming; Thomas, Inas H; Ramsdell, Linda A; Shnorhavorian, Margarett; McCauley, Elizabeth A; Amies Oelschlager, Anne-Marie E; Park, John M; Sandberg, David E; Adam, Margaret P; Keegan, Catherine E

2017-06-01

Sex assignment at birth remains one of the most clinically challenging and controversial topics in 46,XY disorders of sexual development (DSD). This is particularly challenging in deficiency of 5-alpha reductase type 2 given that external genitalia are typically undervirilized at birth but typically virilize at puberty to a variable degree. Historically, most individuals with 5-alpha reductase deficiency were raised females. However, reports that over half of patients who underwent a virilizing puberty adopted an adult male gender identity have challenged this practice. Consensus guidelines on assignment of sex of rearing at birth are equivocal or favor male assignment in the most virilized cases. While a male sex of rearing assignment may avoid lifelong hormonal therapy and/or allow the potential for fertility, female sex assignment may be more consistent with external anatomy in the most severely undervirilized cases. Herein, we describe five patients with 46,XY DSD due 5-alpha-reductase type 2 deficiency, all with a severe phenotype. An inter-disciplinary DSD medical team at one of two academic centers evaluated each patient. This case series illustrates the complicated decision-making process of assignment of sex of rearing at birth in 5-alpha reductase type 2 deficiency and the challenges that arise when the interests of the child, parental wishes, recommendations of the medical team, and state law collide. © 2017 Wiley Periodicals, Inc.

Frontal fibrosing alopecia treatment options.

PubMed

Fertig, Raymond; Tosti, Antonella

2016-11-01

Frontal fibrosing alopecia (FFA) is a rare dermatologic disease that causes scarring and hair loss and is increasing in prevalence worldwide. FFA patients typically present with hair loss in the frontal scalp region and eyebrows which may be associated with sensations of itching or burning. FFA is a clinically distinct variant of lichen planopilaris (LPP) that affects predominantly postmenopausal women, although men and premenopausal women may also be affected. Early diagnosis and prompt treatment are necessary to prevent definitive scarring and permanent hair loss. Data from retrospective studies indicate that 5-alpha-reductase inhibitors (5aRIs) are effective in stabilizing the disease. In our clinical experience, we have seen optimal results treating FFA patients with oral finasteride in conjunction with hydroxychloroquine, topical calcineurin inhibitors (tacrolimus) and excimer laser in patients with signs of active inflammation.

Pharmacological Characterization of a Novel Bifunctional Aldo-Keto Reductase 1C3 Inhibitor and Androgen Receptor Antagonist

DTIC Science & Technology

2013-10-01

Novel Bifunctional Aldo -Keto Reductase 1C3 Inhibitor and Androgen Receptor Antagonist” PRINCIPAL INVESTIGATOR: ADEGOKE ADENIJI, Ph.D...therapeutic benefit relative to targeting either mechanism alone. Aldo -keto reductase 1C3 (AKR1C3) is highly upregulated in APC and is localized within...therapy of Abi with MDV3100 has been proposed as a way to reduce resistance. 14, 15 Aldo -keto reductase IC3 (AKR1C3, type 5 17β hydroxysteroid

1,8-Dihydroxynaphthalene (DHN)-Melanin Biosynthesis Inhibitors Increase Erythritol Production in Torula corallina, and DHN-Melanin Inhibits Erythrose Reductase

PubMed Central

Lee, Jung-Kul; Jung, Hyung-Moo; Kim, Sang-Yong

2003-01-01

The yeast Torula corallina is a strong erythritol producer that is used in the industrial production of erythritol. However, melanin accumulation during culture represents a serious problem for the purification of erythritol from the fermentation broth. Melanin biosynthesis inhibitors such as 3,4-dihydroxyphenylalanine and 1,8-dihydroxynaphthalene (DHN)-melanin inhibitors were added to the T. corallina cultures. Only the DHN-melanin inhibitors showed an effect on melanin production, which suggests that the melanin formed during the culturing of T. corallina is derived from DHN. This finding was confirmed by the detection of a shunt product of the pentaketide pathway, flaviolin, and elemental analysis. Among the DHN-melanin inhibitors, tricyclazole was the most effective. Supplementation with tricyclazole enhanced the production of erythritol while significantly inhibiting the production of DHN-melanin and DHN-melanin biosynthetic enzymes, such as trihydroxynaphthalene reductase. The erythrose reductase from T. corallina was purified to homogeneity by ion-exchange and affinity chromatography. Purified erythrose reductase was significantly inhibited in vitro in a noncompetitive manner by elevated levels of DHN-melanin. In contrast, the level of erythrose reductase activity was unaffected by increasing concentrations of tricyclazole. These results suggest that supplemental tricyclazole reduces the production of DHN-melanin, which may lead to a reduction in the inhibition of erythrose reductase and a higher yield of erythritol. This is the first report to demonstrate that melanin biosynthesis inhibitors increase the production of a sugar alcohol in T. corallina. PMID:12788746

Current medical treatment of lower urinary tract symptoms/BPH: do we have a standard?

PubMed

Silva, João; Silva, Carlos Martins; Cruz, Francisco

2014-01-01

The pharmacological treatment of lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia (BPH) is based on alpha-blockers and 5α-reductase inhibitors isolated or in combination. Silodosin, an alpha-1A specific alpha-blocker is the only innovation in these groups of agents. This classical paradigm is being challenged by antimuscarinics, 5-phosphodiesterase inhibitors (PDE5i) and β3-adrenoreceptor agonists. Silodosin is effective in reducing BPH/LUTS, including nocturia and shows little cardiovascular adverse events. Antimuscarinic drugs isolated or in combination with alpha-blockers improve storage symptoms without any harmful effect to the voiding function. PDE5i alone improve BPH/LUTS. Combination of PDE5i with alpha-blockers provides better symptomatic control than alpha-blockers alone. A recent head-to-head comparison of tadalafil 5 mg/day with tamsulosin 0.4 mg/day showed that these agents provided the same improvement in BPH/LUTS and, surprisingly, the same improvement in the urinary flow. In fact, previous studies with tadalafil had not shown any effect of tadalafil on flow. In addition, tadalafil but not tamsulosin improved sexual function. Mirabegron, the first β3-adrenoreceptor agonist, while improving BPH/LUTS in men with bladder outlet obstruction, do not decrease urinary flow or detrusor pressure. The standard medical treatment for BPH/LUTS is still based on alpha-blockers, 5ARIs or its combination. In the future, it is expected that BPH/LUTS treatment will become individualized, according to the type of symptoms, presence of sexual dysfunction and risk of BPH progression. This will challenge our concept of standard treatment for BPH/LUTS.

ESR studies on reactivity of protein-derived tyrosyl radicals formed by prostaglandin H synthase and ribonucleotide reductase.

PubMed

Lassmann, G; Curtis, J; Liermann, B; Mason, R P; Eling, T E

1993-01-01

Using ESR spectroscopy, the ability of enzyme inhibitors to quench protein-derived tyrosyl radicals was studied in two different enzymes, prostaglandin H synthase and ribonucleotide reductase. The prostaglandin H synthase inhibitors indomethacin, eugenol, and MK-410 effectively prevent the formation of tyrosyl radicals during the oxidation of arachidonic acid by prostaglandin H synthase from ram seminal vesicles. A direct reaction with preformed tyrosyl radicals was observed only with eugenol. The other prostaglandin H synthase inhibitors were ineffective. The ribonucleotide reductase inhibitors hydroxyurea and 4-hydroxyanisole, which effectively inactivate the tyrosyl radical in the active site of ribonucleotide reductase present in tumor cells, exhibit a different reactivity with tyrosyl radicals formed by prostaglandin H synthase. Hydroxyurea quenches preformed tyrosyl radicals in prostaglandin H synthase weakly, whereas 4-hydroxyanisole does not quench tyrosyl radicals in prostaglandin H synthase at all. Eugenol, which quenches preformed prostaglandin H synthase-derived tyrosyl radicals, also quenches the tyrosyl radical in ribonucleotide reductase. The results suggest that the reactivity of protein-linked tyrosyl radicals in ribonucleotide reductase and those formed during prostaglandin H synthase catalysis are very different and have unrelated roles in enzyme catalysis.

Androgenic correlates of genetic variation in the gene encoding 5alpha-reductase type 1.

PubMed

Ellis, Justine A; Panagiotopoulos, Sianna; Akdeniz, Aysel; Jerums, George; Harrap, Stephen B

2005-01-01

Androgens determine male secondary sexual characteristics and influence a variety of metabolic pathways. Circulating levels of androgens are highly heritable; however, the genes involved are largely unknown. The 5alpha-reductase enzymes types 1 and 2 responsible for converting testosterone to the more potent androgen dihydrotestosterone are encoded by the SRD5A1 and SRD5A2 genes, respectively. We performed indirect genetic association studies of SRD5A1 and SRD5A2 and the dihydrotestosterone/testosterone ratio that reflects the activity of 5alpha-reductase in 57 males with type 2 diabetes. We found evidence of significant association between a single nucleotide polymorphism in SRD5A1 and the dihydrotestosterone/testosterone ratio (median 0.10, interquartile range 0.08 vs. median 0.06, interquartile range 0.04, P = 0.009). The polymorphism was not associated with any diabetic phenotypes. These results suggest that functional genetic variants might exist in or around SRD5A1 that affect the activity of the 5alpha-reductase enzyme type 1 and influence androgen levels.

Evidence for a Ustilago maydis steroid 5alpha-reductase by functional expression in Arabidopsis det2-1 mutants.

PubMed

Basse, Christoph W; Kerschbamer, Christine; Brustmann, Markus; Altmann, Thomas; Kahmann, Regine

2002-06-01

We have identified a gene (udh1) in the basidiomycete Ustilago maydis that is induced during the parasitic interaction with its host plant maize (Zea mays). udh1 encodes a protein with high similarity to mammalian and plant 5alpha-steroid reductases. Udh1 differs from those of known 5alpha-steroid reductases by six additional domains, partially predicted to be membrane-spanning. A fusion protein of Udh1 and the green fluorescent protein provided evidence for endoplasmic reticulum localization in U. maydis. The function of the Udh1 protein was demonstrated by complementing Arabidopsis det2-1 mutants, which display a dwarf phenotype due to a mutation in the 5alpha-steroid reductase encoding DET2 gene. det2-1 mutant plants expressing either the udh1 or the DET2 gene controlled by the cauliflower mosaic virus 35S promoter differed from wild-type Columbia plants by accelerated stem growth, flower and seed development and a reduction in size and number of rosette leaves. The accelerated growth phenotype of udh1 transgenic plants was stably inherited and was favored under reduced light conditions. Truncation of the N-terminal 70 amino acids of the Udh1 protein abolished the ability to restore growth in det2-1 plants. Our results demonstrate the existence of a 5alpha-steroid reductase encoding gene in fungi and suggest a common ancestor between fungal, plant, and mammalian proteins.

Preparation and in Vivo Evaluation of a Dutasteride-Loaded Solid-Supersaturatable Self-Microemulsifying Drug Delivery System

PubMed Central

Kim, Min-Soo; Ha, Eun-Sol; Choo, Gwang-Ho; Baek, In-Hwan

2015-01-01

The purpose of this study was to prepare a dutasteride-loaded solid-supersaturatable self-microemulsifying drug delivery system (SMEDDS) using hydrophilic additives with high oral bioavailability, and to determine if there was a correlation between the in vitro dissolution data and the in vivo pharmacokinetic parameters of this delivery system in rats. A dutasteride-loaded solid-supersaturatable SMEDDS was generated by adsorption of liquid SMEDDS onto Aerosil 200 colloidal silica using a spray drying process. The dissolution and oral absorption of dutasteride from solid SMEDDS significantly increased after the addition of hydroxypropylmethyl cellulose (HPMC) or Soluplus. Solid SMEDDS/Aerosil 200/Soluplus microparticles had higher oral bioavailability with 6.8- and 5.0-fold higher peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) values, respectively, than that of the equivalent physical mixture. A linear correlation between in vitro dissolution efficiency and in vivo pharmacokinetic parameters was demonstrated for both AUC and Cmax values. Therefore, the preparation of a solid-supersaturatable SMEDDS with HPMC or Soluplus could be a promising formulation strategy to develop novel solid dosage forms of dutasteride. PMID:25984604

6-Substituted 3,4-dihydro-naphthalene-2-carboxylic acids: synthesis and structure-activity studies in a novel class of human 5alpha reductase inhibitors.

PubMed

Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

2002-10-01

Novel 3,4-dihydro-naphthalene-2-carboxylic acids were synthesized and evaluated for 5alpha reductase inhibitory activity. This enzyme exists in two isoforms and is a pharmacological target for the treatment of benign prostatic hyperplasia, male pattern baldness and acne. In the present study non-steroidal compounds capable of mimicking the transition state of the steroidal substrates were prepared. The synthetic strategy for the preparation of compounds 1-6 consisted of triflation followed by subsequent Heck-type carboxylation or methoxy carbonylation for 6-phenyl-3,4-dihydronaphthalen-2(1H)-one 1c. A Negishi-type coupling reaction between 6-(trifluoro-methanesulfonyloxy)-3,4-dihydro-naphthalene-2-carboxylic acid methyl ester 7b and various aryl bromides led, after further transformations, to 6-substituted 3,4-dihydro-naphthalene-2-carboxylic acids 7-15. In a similar way the corresponding naphthalene-2-carboxylic acids 16 and 17 were obtained. The DU 145 cell line and prostate homogenates served as enzyme sources for the human type 1 and type 2 isozymes, whereas ventral prostate was employed to evaluate rat isozyme inhibitory potency. The most active inhibitors identified in this study were 6-[4-(N,N-dicyclohexylaminocarbonyl)phenyl]-3,4-dihydro-naphthalene-2-carboxylic acid (3) (IC50 = 0.09 microM, rat type 1), 6-[3-(N,N-dicyclohexylaminocarbonyl)phenyl]-3,4-dihydro-naphthalene-2-carboxylic acid (13) (IC50 = 0.75 microM, human type 2; IC50 = 0.81 microM, human type 1) and 6-[4-(N,N-diisopropylamino-carbonyl)phenyl]naphthalene-2-carboxylic acid (16) (IC50 = 0.2 microM, human type 2). The latter compound was shown to deactivate the enzyme in an uncompetitive manner (Ki = 90 nM; Km, Testosterone = 0.8-1.0 microM) similar to the steroidal inhibitor Epristeride. Select inhibitors (13 and 16) were tested in vivo using testosterone propionate-treated, juvenile, orchiectomized SD-rats. None of the compounds was active at a dose of 25 mg/kg. This result might in part be ascribed to the relatively poor in vitro rat isozyme inhibitory potency.

Membrane remodeling, an early event in benzo[alpha]pyrene-induced apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tekpli, Xavier; Rissel, Mary; Huc, Laurence

2010-02-15

Benzo[alpha]pyrene (B[alpha]P) often serves as a model for mutagenic and carcinogenic polycyclic aromatic hydrocarbons (PAHs). Our previous work suggested a role of membrane fluidity in B[alpha]P-induced apoptotic process. In this study, we report that B[alpha]P modifies the composition of cholesterol-rich microdomains (lipid rafts) in rat liver F258 epithelial cells. The cellular distribution of the ganglioside-GM1 was markedly changed following B[alpha]P exposure. B[alpha]P also modified fatty acid composition and decreased the cholesterol content of cholesterol-rich microdomains. B[alpha]P-induced depletion of cholesterol in lipid rafts was linked to a reduced expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase). Aryl hydrocarbon receptor (AhR) and B[alpha]P-related H{submore » 2}O{sub 2} formation were involved in the reduced expression of HMG-CoA reductase and in the remodeling of membrane microdomains. The B[alpha]P-induced membrane remodeling resulted in an intracellular alkalinization observed during the early phase of apoptosis. In conclusion, B[alpha]P altered the composition of plasma membrane microstructures through AhR and H{sub 2}O{sub 2} dependent-regulation of lipid biosynthesis. In F258 cells, the B[alpha]P-induced membrane remodeling was identified as an early apoptotic event leading to an intracellular alkalinization.« less

Isoprostane 8-epi-PGF2alpha is frequently increased in patients with muscle pain and/or CK-elevation after HMG-Co-enzyme-A-reductase inhibitor therapy.

PubMed

Sinzinger, H; Lupattelli, G; Chehne, F; Oguogho, A; Furberg, C D

2001-08-01

Muscle pains with or without CK-elevation are among the most frequently observed side-effects in patients with hyperlipoproteinemia on various statins. The pathophysiological background, however, remains obscure. We examined isoprostane 8-epi-PGF2alpha, a marker of in-vivo oxidation injury, in plasma, serum and urine in these patients at baseline, when muscle problems manifested and different time intervals after withdrawing the respective statin. A healthy control group and a group of untreated patients with hyperlipoproteinemia were run as controls. The majority of patients with muscular side-effects show elevated 8-epi-PGF2alpha in plasma and urine, whereas serum values were elevated only to a lesser extent. Stopping statin therapy or successfully changing to another member of this family of compounds resulted in a normalization of the values in all patients. These findings indicate a significant involvement of oxidative injury in the muscular side-effects of statins in patients suffering from hyperlipoproteinemia.

Identification of an anti-MRSA dihydrofolate reductase inhibitor from a diversity-oriented synthesis.

PubMed

Wyatt, Emma E; Galloway, Warren R J D; Thomas, Gemma L; Welch, Martin; Loiseleur, Olivier; Plowright, Alleyn T; Spring, David R

2008-10-28

The screening of a diversity-oriented synthesis library followed by structure-activity relationship investigations have led to the discovery of an anti-MRSA agent which operates as an inhibitor of Staphylococcus aureus dihydrofolate reductase.

Expression and kinetic properties of a recombinant 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase isoenzyme of human liver.

PubMed

Deyashiki, Y; Tamada, Y; Miyabe, Y; Nakanishi, M; Matsuura, K; Hara, A

1995-08-01

Human liver cytosol contains multiple forms of 3 alpha-hydroxysteroid dehydrogenase and dihydrodiol dehydrogenase with hydroxysteroid dehydrogenase activity, and multiple cDNAs for the enzymes have been cloned from human liver cDNA libraries. To understand the relationship of the multiple enzyme froms to the genes, a cDNA, which has been reported to code for an isoenzyme of human liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase, was expressed in Escherichia coli. The recombinant enzyme showed structural and functional properties almost identical to those of the isoenzyme purified from human liver. In addition, the recombinant isoenzyme efficiently reduced 5 alpha-dihydrotestosterone and 5 beta-dihydrocortisone, the known substrates of human liver 3 alpha-hydroxysteroid dehydrogenase and chlordecone reductase previously purified, which suggests that these human liver enzymes are identical. Furthermore, the steady-state kinetic data for NADP(+)-linked (S)-1-indanol oxidation by the recombinant isoenzyme were consistent with a sequential ordered mechanism in which NADP+ binds first. Phenolphthalein inhibited this isoenzyme much more potently than it did the other human liver dihydrodiol dehydrogenases, and was a competitive inhibitor (Ki = 20 nM) that bound to the enzyme-NADP+ complex.

Pharmacologically relevant receptor binding characteristics and 5alpha-reductase inhibitory activity of free Fatty acids contained in saw palmetto extract.

PubMed

Abe, Masayuki; Ito, Yoshihiko; Oyunzul, Luvsandorj; Oki-Fujino, Tomomi; Yamada, Shizuo

2009-04-01

Saw palmetto extract (SPE), used widely for the treatment of benign prostatic hyperplasia (BPH) has been shown to bind alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine (1,4-DHP) calcium channel antagonist receptors. Major constituents of SPE are lauric acid, oleic acid, myristic acid, palmitic acid and linoleic acid. The aim of this study was to investigate binding affinities of these fatty acids for pharmacologically relevant (alpha(1)-adrenergic, muscarinic and 1,4-DHP) receptors. The fatty acids inhibited specific [(3)H]prazosin binding in rat brain in a concentration-dependent manner with IC(50) values of 23.8 to 136 microg/ml, and specific (+)-[(3)H]PN 200-110 binding with IC(50) values of 24.5 to 79.5 microg/ml. Also, lauric acid, oleic acid, myristic acid and linoleic acid inhibited specific [(3)H]N-methylscopolamine ([(3)H]NMS) binding in rat brain with IC(50) values of 56.4 to 169 microg/ml. Palmitic acid had no effect on specific [(3)H]NMS binding. The affinity of oleic acid, myristic acid and linoleic acid for each receptor was greater than the affinity of SPE. Scatchard analysis revealed that oleic acid and lauric acid caused a significant decrease in the maximal number of binding sites (B(max)) for [(3)H]prazosin, [(3)H]NMS and (+)-[(3)H]PN 200-110. The results suggest that lauric acid and oleic acid bind noncompetitively to alpha(1)-adrenergic, muscarinic and 1,4-DHP calcium channel antagonist receptors. We developed a novel and convenient method of determining 5alpha-reductase activity using LC/MS. With this method, SPE was shown to inhibit 5alpha-reductase activity in rat liver with an IC(50) of 101 microg/ml. Similarly, all the fatty acids except palmitic acid inhibited 5alpha-reductase activity, with IC(50) values of 42.1 to 67.6 microg/ml. In conclusion, lauric acid, oleic acid, myristic acid, and linoleic acid, major constituents of SPE, exerted binding activities of alpha(1)-adrenergic, muscarinic and 1,4-DHP receptors and inhibited 5alpha-reductase activity.

Testing of Experimental Compounds for Efficacy Against Leishmania.

DTIC Science & Technology

1990-10-31

quinolines, pyridines, heavey metal complexes, berberine derivatives, and pyrazine or quinazoline inhibitors of dihydrofolate reductase. were among those...Quinolines, pyridines, and heavy metal complexes (for example sulfonamides) were active while pyrazine or quinazoline inhibitors of dihydrofolate...braziliensis panamensis 8-aminoquinolines pyridines dihydrofolate reductase inhibitors rAce For]"..toa T ] NTAISOeaO.&. 0Stkia:.oouned Id SJut If leaat i

Effect of pregnant mare's serum gonadotrophin on the activities of delta 4-5 alpha-reductase, aromatase, and other enzymes in the ovaries of immature rats.

PubMed

Suzuki, K; Kawakura, K; Tamaoki, B I

1978-05-01

After incubation of progesterone, 17 alpha-hydroxyprogesterone, androstenedione, and testostrone with an ovarian preparation (supernatant fluid at 10,000 x g) of immature rats (21-23 days of age) in the presence of NADPH, 3 alpha- and 3 beta-hydroxy-5 alpha-reduced steroids were obtained as the major metabolites. Among the enzyme activities relevant to the metabolism, delta 4-5 alpha-reductase and 3 beta-hydroxysteroid dehydrogenase were intracellularly localized to the microsomal fraction (10,000--105,000 x g), and 3 alpha-hydroxysteroid dehydrogenase was detected exclusively in the cytosol fraction (supernatant fluid at 105,000 x g). Within 2 days after a single injection of pregnant mare's serum gonadotrophin (10 IU/rat) to 21-day-old female rats, the following occurred: 1) an enhancement of 17 alpha-hydroxylase and C-17-C-20 lyase activities; 2) a suppression of delta 4-5 alpha-reductase activity; and 3) an increase in aromatizing activity. From the above-mentioned results, it was concluded that the increased secretion of estrogen from ovaries of immature rats stimulated by pregnant mare's serum gonadotrophin administration was caused by a modification of the ovarian enzyme activities relevant to estrogen production.

Effects of dutasteride on lower urinary tract symptoms and general health in men with benign prostatic hypertroplasia and hypogonadism: a prospective study.

PubMed

Shigehara, Kazuyoshi; Koh, Eitetsu; Sakamoto, Jiro; Yaegashi, Hiroshi; Izumi, Koji; Ueno, Satoru; Kitagawa, Yasuhide; Maeda, Yuji; Kadono, Yoshifumi; Konaka, Hiroyuki; Mizokami, Atsushi; Nakashima, Takao; Namiki, Mikio

2014-03-01

We investigated the effects of the relative increase in testosterone by dutasteride administration in patients with benign prostatic hyperplasia and hypogonadism on urinary symptoms or androgen-responsive general health. Seventy-six patients were enrolled, and were taking 0.5 mg dutasteride daily for 52 weeks. Before and after treatment, all participants underwent blood test, and body mass index, prostate volume (PV), bone mineral density (BMD), post-voiding residual (PVR) volume, and muscle volume were measured. All patients responded to the questionnaires: International prostatic symptom score (IPSS), Overactive Bladder Symptom score (OABSS). Patients were divided into two groups according to the increase rate of total testosterone (TT): group A, ≥20% increase in TT level; group B, <20% increase or decrease. Baseline TT and free testosterone (FT) levels were significantly lower in group A than group B. Both groups showed marked improvement in PV and PVR. Group A showed significant improvement in IPSS and OABSS with a significant increase of FT level, whereas group B showed no significant change. Dutasteride treatment contributed to a significant increase in BMD in group A. Dutasteride treatment significantly improved urinary symptoms and BMD in patients with low baseline serum TT and FT levels.

Preparation and characterization of dutasteride-loaded nanostructured lipid carriers coated with stearic acid-chitosan oligomer for topical delivery.

PubMed

Noor, Norhayati Mohamed; Sheikh, Khalid; Somavarapu, Satyanarayana; Taylor, Kevin M G

2017-08-01

Dutasteride, used for treating benign prostate hyperplasia (BPH), promotes hair growth. To enhance delivery to the hair follicles and reduce systemic effects, in this study dutasteride has been formulated for topical application, in a nanostructured lipid carrier (NLC) coated with chitosan oligomer-stearic acid (CSO-SA). CSO-SA has been successfully synthesized, as confirmed using 1 H NMR and FTIR. Formulation of dutasteride-loaded nanostructured lipid carriers (DST-NLCs) was optimized using a 2 3 full factorial design. This formulation was coated with different concentrations of stearic acid-chitosan solution. Coating DST-NLCs with 5% SA-CSO increased mean size from 187.6±7.0nm to 220.1±11.9nm, and modified surface charge, with zeta potentials being -18.3±0.9mV and +25.8±1.1mV for uncoated and coated DST-NLCs respectively. Transmission electron microscopy showed all formulations comprised approximately spherical particles. DST-NLCs, coated and uncoated with CSO-SA, exhibited particle size stability over 60days, when stored at 4-8°C. However, NLCs coated with CSO (without conjugation) showed aggregation when stored at 4-8°C after 30days. The measured particle size for all formulations stored at 25°C suggested aggregation, which was greatest for DST-NLCs coated with 10% CSO-SA and 5% CSO. All nanoparticle formulations exhibited rapid release in an in vitro release study, with uncoated NLCs exhibiting the fastest release rate. Using a Franz diffusion cell, no dutasteride permeated through pig ear skin after 48h, such that it was not detected in the receptor chamber for all samples. The amount of dutasteride in the skin was significantly different (p<0.05) for DST-NLCs (6.09±1.09μg/cm 2 ) without coating and those coated with 5% CSO-SA (2.82±0.40μg/cm 2 ), 10% CSO-SA (2.70±0.35μg/cm 2 ) and CSO (2.11±0.64μg/cm 2) . There was a significant difference (p<0.05) in the cytotoxicity (IC 50 ) between dutasteride alone and in the nanoparticles. DST-NLCs coated and uncoated with CSO-SA increased the maximum non-toxic concentration by 20-fold compared to dutasteride alone. These studies indicate that a stearic acid-chitosan conjugate was successfully prepared, and modified the surface charge of DST-NLCs from negative to positive. These stable, less cytotoxic, positively-charged dutasteride-loaded nanostructured lipid carriers, with stearic acid-chitosan oligomer conjugate, are appropriate for topical delivery and have potential for promotion of hair growth. Copyright © 2017. Published by Elsevier B.V.

Characterization of 5α-reductase activity and isoenzymes in human abdominal adipose tissues.

PubMed

Fouad Mansour, Mohamed; Pelletier, Mélissa; Tchernof, André

2016-07-01

The substrate for the generation of 5α-dihydrotestosterone (DHT) is either androstenedione (4-dione) which is first converted to androstanedione and then to DHT through 17-oxoreductase activity, or testosterone, which is directly converted to DHT. Three 5α-reductase isoenzymes have been characterized and designated as types 1, 2 and 3 (SRD5A1, 2 and 3). To define the predominant source of local DHT production in human adipose tissues, identify 5α-reductase isoenzymes and test their impact on preadipocyte differentiation. Cultures of omental (OM) and subcutaneous (SC) preadipocytes were treated for 0, 6 or 24h with 30nM (14)C-4-dione or (14)C-testosterone, with and without 500nM 5α-reductase inhibitors 17-N,N-diethylcarbamoyl-4-methyl-4-aza-5-androstan-3-one (4-MA) or finasteride. Protein level and mRNA abundance of 5α-reductase isoenzymes/transcripts were examined in whole SC and OM adipose tissue. HEK-293 cells stably transfected with 5α-reductase type 1, 2 or 3 were used to test 5α-reductase inhibitors. We also assessed the impact of 5α-reductase inhibitors on preadipocyte differentiation. Over 24h, DHT formation from 4-dione increased gradually (p<0.05) and was significantly higher compared to that generated from testosterone (p<0.001). DHT formation from both 4-dione and testosterone was blocked by both 5α-reductase inhibitors. In whole adipose tissue from both fat compartments, SRD5A3 was the most highly expressed isoenzyme followed by SRD5A1 (p<0.001). SRD5A2 was not expressed. In HEK-293 cells, 4-MA and finasteride inhibited activity of 5α-reductases types 2 and 3 but not type 1. In preadipocyte cultures where differentiation was inhibited by 4-dione (p<0.05, n=7) or testosterone (p<0.05, n=5), the inhibitors 4-MA and finasteride abolished these effects. Although 4-dione is the main source of DHT in human preadipocytes, production of this steroid by 5α-reductase isoenzymes mediates the inhibitory effect of both 4-dione and testosterone on preadipocyte differentiation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Singapore Urological Association Clinical Guidelines for Male Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia

PubMed Central

2017-01-01

The first clinical guidelines for male lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) were published in 2005. An update is urgently needed in view of BPH being recognised as one of ten chronic illnesses by the Ministry of Health, Singapore. This review summarises the definition of BPH and the epidemiology of male LUTS/BPH in Singapore. BPH can be phenotyped with noninvasive transabdominal ultrasonography, according to intravesical prostatic protrusion and prostate volume, and classified according to severity (staging) for individualised treatment. At the initial evaluation, the majority of patients (59%) can be managed with fluid adjustment, exercise and diet; 32% with medications, using alpha blockers and/or 5-alpha reductase inhibitors for prostates weighing more than 30 g; and 9% with surgical intervention for more advanced disease. The 2015 guidelines comprise updated evidence that will help family medicine practitioners and specialists manage this common ailment more cost-effectively. PMID:28848988

High dose androgen therapy in male pseudohermaphroditism due to 5 alpha-reductase deficiency and disorders of the androgen receptor.

PubMed

Price, P; Wass, J A; Griffin, J E; Leshin, M; Savage, M O; Large, D M; Bu'Lock, D E; Anderson, D C; Wilson, J D; Besser, G M

1984-10-01

We describe the clinical and biochemical features of six men with male pseudohermaphroditism due to androgen resistance. Each of the subjects had male-gender behavior but incomplete virilization. The underlying defects in androgen metabolism were defined by studies of the 5 alpha-reductase enzyme and the androgen receptor in fibroblasts cultured from biopsies of genital skin. Four of the six have 5 alpha-reductase deficiency, and two have defects of the androgen receptor (the Reifenstein syndrome). The responses of these men to androgen treatment were assessed by monitoring nitrogen balance, plasma luteinizing hormone (LH) values, and clinical parameters of virilization including penile growth, potency and ejaculatory volume, muscle bulk, and growth of body and facial hair. In all of the subjects with 5 alpha-reductase deficiency and one man with the Reifenstein syndrome significant response occurred, as evidence by nitrogen retention, lowered plasma LH levels, and improved virilization, with doses of parenteral testosterone esters that raised plasma testosterone levels above the normal male range and brought plasma dihydrotestosterone levels into the normal male range. The subject who did not respond with clinical virilization nevertheless showed nitrogen retention in response to acute testosterone administration. This patient had a profound deficiency of the androgen receptor, whereas the man with a receptor defect who did respond clinically to therapy had normal amounts of a qualitatively abnormal receptor. We conclude that high dose androgen therapy may be of benefit in improving virilization, self-image, and sexual performance in subjects with 5 alpha-reductase deficiency who have male-gender behavior and in some subjects with defects of the androgen receptor.

Structure-based design of pteridine reductase inhibitors targeting African sleeping sickness and the leishmaniases.

PubMed

Tulloch, Lindsay B; Martini, Viviane P; Iulek, Jorge; Huggan, Judith K; Lee, Jeong Hwan; Gibson, Colin L; Smith, Terry K; Suckling, Colin J; Hunter, William N

2010-01-14

Pteridine reductase (PTR1) is a target for drug development against Trypanosoma and Leishmania species, parasites that cause serious tropical diseases and for which therapies are inadequate. We adopted a structure-based approach to the design of novel PTR1 inhibitors based on three molecular scaffolds. A series of compounds, most newly synthesized, were identified as inhibitors with PTR1-species specific properties explained by structural differences between the T. brucei and L. major enzymes. The most potent inhibitors target T. brucei PTR1, and two compounds displayed antiparasite activity against the bloodstream form of the parasite. PTR1 contributes to antifolate drug resistance by providing a molecular bypass of dihydrofolate reductase (DHFR) inhibition. Therefore, combining PTR1 and DHFR inhibitors might improve therapeutic efficacy. We tested two new compounds with known DHFR inhibitors. A synergistic effect was observed for one particular combination highlighting the potential of such an approach for treatment of African sleeping sickness.

Atpenins, potent and specific inhibitors of mitochondrial complex II (succinate-ubiquinone oxidoreductase)

PubMed Central

Miyadera, Hiroko; Shiomi, Kazuro; Ui, Hideaki; Yamaguchi, Yuichi; Masuma, Rokuro; Tomoda, Hiroshi; Miyoshi, Hideto; Osanai, Arihiro; Kita, Kiyoshi; Ōmura, Satoshi

2003-01-01

Enzymes in the mitochondrial respiratory chain are involved in various physiological events in addition to their essential role in the production of ATP by oxidative phosphorylation. The use of specific and potent inhibitors of complex I (NADH-ubiquinone reductase) and complex III (ubiquinol-cytochrome c reductase), such as rotenone and antimycin, respectively, has allowed determination of the role of these enzymes in physiological processes. However, unlike complexes I, III, and IV (cytochrome c oxidase), there are few potent and specific inhibitors of complex II (succinate-ubiquinone reductase) that have been described. In this article, we report that atpenins potently and specifically inhibit the succinate-ubiquinone reductase activity of mitochondrial complex II. Therefore, atpenins may be useful tools for clarifying the biochemical and structural properties of complex II, as well as for determining its physiological roles in mammalian tissues. PMID:12515859

Lifestyle determinants of 5alpha-reductase metabolites in older African-American, white, and Asian-American men.

PubMed

Wu, A H; Whittemore, A S; Kolonel, L N; Stanczyk, F Z; John, E M; Gallagher, R P; West, D W

2001-05-01

Men with higher endogenous 5alpha-reductase activity may have higher prostate cancer risk. This hypothesis raises two questions: (a) Could racial differences in 5alpha-reductase activity explain the observed racial differences in prostate cancer risk? and (b) Could a man reduce his activity level by modifying his lifestyle? To address these questions, we measured two hormonal indices of 5alpha-reductase activity [serum levels of androstane-3alpha-17beta-diol glucuronide (3alpha-diol G) and androsterone glucuronide (AG)] in healthy, older African-American, white, and Asian-American men, who are at high, intermediate, and low prostate cancer risk, respectively. We also examined associations between these metabolite levels and such lifestyle characteristics as body size and physical activity as well as select aspects of medical history and family history of prostate cancer. Men included in this cross-sectional analysis (n = 1054) had served as control subjects in a population-based case-control study of prostate cancer we conducted in California, Hawaii, and Vancouver, Canada and provided information on certain personal attributes and donated blood between March 1990 and March 1992. In this study, concentrations of 3alpha-diol G declined significantly with age and increased significantly with body mass index. Mean levels of 3alpha-diol G, adjusted for age and body mass index, were 6.1 ng/ml in African-Americans, 6.9 ng/ml in whites and 4.8 ng/ml in Asian-Americans. These differences were statistically significant (African-Americans versus whites: P < 0.01; whites versus Asian-Americans: P < 0.001). Concentrations of AG decreased significantly with age, but only in whites, and were unrelated to any of the reported personal attributes. Mean levels of AG, adjusted for age, were 44.1 ng/ml in African-Americans, 44.9 ng/ml in whites, and 37.5 ng/ml in Asian-Americans (Asian-Americans versus whites, P < 0.001). In conclusion, older African-American and white men have similar levels of these two indices of 5alpha-reductase activity, and these levels are higher than those of older Asian-American men. This difference may be related to the lower prostate cancer risk in Asian-Americans.

Inhibition of aldose reductase activity by Cannabis sativa chemotypes extracts with high content of cannabidiol or cannabigerol.

PubMed

Smeriglio, Antonella; Giofrè, Salvatore V; Galati, Enza M; Monforte, Maria T; Cicero, Nicola; D'Angelo, Valeria; Grassi, Gianpaolo; Circosta, Clara

2018-02-07

Aldose reductase (ALR2) is a key enzyme involved in diabetic complications and the search for new aldose reductase inhibitors (ARIs) is currently very important. The synthetic ARIs are often associated with deleterious side effects and medicinal and edible plants, containing compounds with aldose reductase inhibitory activity, could be useful for prevention and therapy of diabetic complications. Non-psychotropic phytocannabinoids exert multiple pharmacological effects with therapeutic potential in many diseases such as inflammation, cancer, diabetes. Here, we have investigated the inhibitory effects of extracts and their fractions from two Cannabis sativa L. chemotypes with high content of cannabidiol (CBD)/cannabidiolic acid (CBDA) and cannabigerol (CBG)/cannabigerolic acid (CBGA), respectively, on human recombinant and pig kidney aldose reductase activity in vitro. A molecular docking study was performed to evaluate the interaction of these cannabinoids with the active site of ALR2 compared to known ARIs. The extracts showed significant dose-dependent aldose reductase inhibitory activity (>70%) and higher than fractions. The inhibitory activity of the fractions was greater for acidic cannabinoid-rich fractions. Comparative molecular docking results have shown a higher stability of the ALR2-cannabinoid acids complex than the other inhibitors. The extracts of Cannabis with high content of non-psychotropic cannabinoids CBD/CBDA or CBG/CBGA significantly inhibit aldose reductase activity. These results may have some relevance for the possible use of C. sativa chemotypes based preparations as aldose reductase inhibitors. Copyright © 2018 Elsevier B.V. All rights reserved.

NADPH-dependent coenzyme Q reductase is the main enzyme responsible for the reduction of non-mitochondrial CoQ in cells.

PubMed

Takahashi, Takayuki; Okuno, Masaaki; Okamoto, Tadashi; Kishi, Takeo

2008-01-01

We purified an NADPH-dependent coenzyme Q reductase (NADPH-CoQ reductase) in rat liver cytosol and compared its enzymatic properties with those of the other CoQ10 reductases such as NADPH: quinone acceptor oxidoreductase 1 (NQO1), lipoamide dehydrogenase, thioredoxine reductase and glutathione reductase. NADPH-CoQ reductase was the only enzyme that preferred NADPH to NADH as an electron donor and was also different from the other CoQ10 reductases in the sensitivities to its inhibitors and stimulators. Especially, Zn2+ was the most powerful inhibitor for NADPH-CoQ reductase, but CoQ10 reduction by the other CoQ10 reductases could not be inhibited by Zn2+. Furthermore, the reduction of the CoQ9 incorporated into HeLa cells was also inhibited by Zn2+ in the presence of pyrithione, a zinc ionophore. Moreover, NQO1 gene silencing in HeLa cells by transfection of a small interfering RNA resulted in lowering of both the NQO1 protein level and the NQO1 activity by about 75%. However, this transfection did not affect the NADPH-CoQ reductase activity and the reduction of CoQ9 incorporated into the cells. These results suggest that the NADPH-CoQ reductase located in cytosol may be the main enzyme responsible for the reduction of non-mitochondrial CoQ in cells.

Effect of oral contraceptive use on the erythrocytic glutathione reductase and aspartate aminotransferase activities in women with or without clinical signs of vitamin deficiency.

PubMed

Tovar, A; Bourges, H; Canto, T; Torres, N; Lopez-castro, B R

1985-07-01

The effect of the chronic use of combined oral contraceptives (OCs) on the "activity coefficients" (alpha = coenzyme-stimulated activity/basal activity) of erythrocytic glutathione reductase and aspartate aminotransferase was studied in 2 groups of 90 female volunteers each; 1 of the groups, from the state of Yucatan in southeast Mexico, presented clinical lesions of vitamin deficiency, while the other group, from Mexico City, did not have any clinical evidence of vitamin deficiency. One half of the women (45) in each group were chronic OC users and the other half were not. The results were analyzed comparing OC users with non-users in each location. For both glutathione reductase and aspartate aminotransferase, the Mexico City OC users had significantly higher (p 0.001) alpha values than nonusers, while in the Yucatan women, the alpha values were similarly high independent of OC use.

Evaluation of GABAergic neuroactive steroid 3alpha-hydroxy-5alpha-pregnane-20-one as a neurobiological substrate for the anti-anxiety effect of ethanol in rats.

PubMed

Hirani, Khemraj; Sharma, Ajay N; Jain, Nishant S; Ugale, Rajesh R; Chopde, Chandrabhan T

2005-07-01

Acute systemic ethanol administration is known to elevate plasma and cerebral levels of neuroactive steroid 3alpha-hydroxy-5alpha-pregnane-20-one (3alpha, 5alpha-THP; allopregnanolone) to a concentration sufficient to potentiate GABA(A) receptors. We have earlier demonstrated that 3alpha, 5alpha-THP mediates the antidepressant-like effect of ethanol in Porsolt forced swim test. The aim of the present study is to explain the relationship between endogenous GABAergic neurosteroids and anxiolytic effect of ethanol in Sprague-Dawley rats. The mediation of 3alpha, 5alpha-THP in the anti-anxiety effect of ethanol was assessed by pharmacological interactions of ethanol with various endogenous neurosteroidal modulators and using simulated physiological conditions of altered neurosteroid content in elevated plus maze (EPM) test. Pretreatment of 3alpha, 5alpha-THP (0.5-2.5 mug/rat, i.c.v.) or neurosteroidogenic agents such as 3alpha, 5alpha-THP precursor progesterone (5 or 10 mg/kg, i.p.), 11-beta hydroxylase inhibitor metyrapone (50 or 100 mg/kg, i.p.) or the GABA(A) receptor agonist muscimol (25 ng/rat, i.c.v.) significantly potentiated the anti-anxiety effect of ethanol (1 g/kg, i.p.). On the other hand, the GABAergic antagonistic neurosteroid dehydroepiandrosterone sulphate (DHEAS) (1 mg/kg, i.p.), the GABA(A) receptor blocker bicuculline (1 mg/kg, i.p.), the 5alpha-reductase inhibitor finasteride (50 x 2 mg/kg, s.c.) or the mitochondrial diazepam binding inhibitory receptor antagonist PK11195 (1 mg/kg, i.p.) reduced ethanol-induced preference of time spent and number of entries into open arms. Anti-anxiety effect of ethanol was abolished in adrenalectomized (ADX) rats as compared to sham-operated control. This ADX-induced blockade was restored by prior systemic injection of progesterone, signifying the contribution of peripheral steroidogenesis in ethanol anxiolysis. Socially isolated animals known to exhibit decreased brain 3alpha, 5alpha-THP and GABA(A) receptor functions displayed reduced sensitivity to the effects of ethanol and 3alpha, 5alpha-THP in EPM test. Our results demonstrated the contributory role of neuroactive steroid 3alpha, 5alpha-THP in the anti-anxiety effect of ethanol. It is speculated that ethanol-induced modulation of endogenous GABAergic neurosteroids, especially 3alpha, 5alpha-THP, might be crucial pertinent to the etiology of 'trait' anxiety (tension reduction) and ethanol abuse.

Reliable and sensitive determination of dutasteride in human plasma by liquid chromatography-tandem mass spectrometry.

PubMed

Contractor, Pritesh; Kurani, Hemal; Guttikar, Swati; Shrivastav, Pranav S

2013-09-01

An accurate and precise method was developed and validated using LC-MS/MS to quantify dutasteride in human plasma. The analyte and dutasteride-13C6 as internal standard (IS) were extracted from 300 μL plasma volume using methyl tert-butyl ether-n-hexane (80:20, v/v). Chromatographic analysis was performed on a Gemini C18 (150 × 4.6 mm, 5 µm) column using acetonitrile-5 mm ammonium formate, pH adjusted to 4.0 with formic acid (85:15, v/v) as the mobile phase. Tandem mass spectrometry in positive ionization mode was used to quantify dutasteride by multiple reaction monitoring. The entire data processing was done using Watson LIMS(TM) software, which provided excellent data integrity and high throughput with improved operational efficiency. The calibration curve was linear in the range of 0.1-25 ng/mL, with intra-and inter-batch values for accuracy and precision (coefficient of variation) ranging from 95.8 to 104.0 and from 0.7 to 5.3%, respectively. The mean overall recovery across quality controls was ≥95% for the analyte and IS, while the interference of matrix expressed as IS-normalized matrix factors ranged from 1.01 to 1.02. The method was successfully applied to support a bioequivalence study of 0.5 mg dutasteride capsules in 24 healthy subjects. Assay reproducibility was demonstrated by reanalysis of 103 incurred samples. Copyright © 2013 John Wiley & Sons, Ltd.

Pharmacokinetic Interactions between Nelfinavir and 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors Atorvastatin and Simvastatin

PubMed Central

Hsyu, Poe-Hirr; Schultz-Smith, Melissa D.; Lillibridge, James H.; Lewis, Ronald H.; Kerr, Bradley M.

2001-01-01

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are effective agents in lowering cholesterol and triglycerides and are being used by human immunodeficiency virus-positive patients to treat the lipid elevation that may be associated with antiretroviral therapy. Many HMG-CoA reductase inhibitors and protease inhibitors are metabolized by the same cytochrome P450 enzyme 3A4 (CYP3A4). In addition, many protease inhibitors are potent inhibitors of CYP3A4. Therefore, coadministration of these two classes of drugs may cause significant drug interactions. This open-label, multiple-dose study was performed to determine the interactions between nelfinavir, a protease inhibitor, and two HMG-CoA reductase inhibitors, atorvastatin and simvastatin, in healthy volunteers. Thirty-two healthy subjects received either atorvastatin calcium (10 mg once a day) or simvastatin (20 mg once a day) for the first 14 days of the study. Nelfinavir (1,250 mg twice a day) was added on days 15 to 28. Pharmacokinetic assessment was performed on days 14 and 28. The study drugs were well tolerated. Nelfinavir increased the steady-state area under the plasma concentration-time curve during one dosing period (AUCτ) of atorvastatin 74% and the maximum concentration (Cmax) of atorvastatin 122% and increased the AUCτ of simvastatin 505% and the Cmax of simvastatin 517%. Neither atorvastatin nor simvastatin appeared to alter the pharmacokinetics of nelfinavir. It is recommended that coadministration of simvastatin with nelfinavir should be avoided, whereas atorvastatin should be used with nelfinavir with caution. PMID:11709322

Ebselen: A thioredoxin reductase-dependent catalyst for {alpha}-tocopherol quinone reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang Jianguo; Zhong Liangwei; Zhao Rong

2005-09-01

The thioredoxin system, composed of thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH, is a powerful protein disulfide reductase system with a broad substrate specificity. Recently the selenazol drug ebselen was shown to be a substrate for both mammalian TrxR and Trx. We examined if {alpha}-tocopherol quinone (TQ), a product of {alpha}-tocopherol oxidation, is reduced by ebselen in the presence of TrxR, since TQ was not a substrate for the enzyme itself. Ebselen reduction of TQ in the presence of TrxR was caused by ebselen selenol, generated from fast reduction of ebselen by the enzyme. TQ has no intrinsic antioxidant activity,more » while the product of reduction of TQ, {alpha}-tocopherolhydroquinone (TQH{sub 2}), is a potent antioxidant. The thioredoxin system dependence of ebselen to catalyze reduction of other oxidized species, such as hydrogen peroxide, dehydroascorbate, and peroxynitrite, is discussed. The ability of ebselen to reduce TQ via the thioredoxin system is a novel mechanism to explain the effects of the drug as an antioxidant in vivo.« less

Dysregulation of glucocorticoid metabolism in murine obesity: comparable effects of leptin resistance and deficiency.

PubMed

Livingstone, Dawn E W; Grassick, Sarah L; Currie, Gillian L; Walker, Brian R; Andrew, Ruth

2009-05-01

In obese humans, metabolism of glucocorticoids by 11 beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) and A-ring reduction (by 5 alpha- and 5 beta-reductases) is dysregulated in a tissue specific manner. These changes have been recapitulated in leptin resistant obese Zucker rats but were not observed in high-fat fed Wistar rats. Recent data from mouse models suggest that such discrepancies may reflect differences in leptin signalling. We therefore compared glucocorticoid metabolism in murine models of leptin deficiency and resistance. Male ob/ob and db/db mice and their respective littermate controls (n=10-12/group) were studied at the age of 12 weeks. Enzyme activities and mRNA expression were quantified in snap-frozen tissues. The patterns of altered pathways of steroid metabolism in obesity were similar in ob/ob and db/db mice. In liver, 5 beta-reductase activity and mRNA were increased and 11 beta-HSD1 decreased in obese mice, whereas 5 alpha-reductase 1 (5 alpha R1) mRNA was not altered. In visceral adipose depots, 5 beta-reductase was not expressed, 11 beta-HSD1 activity was increased and 5 alpha R1 mRNA was not altered in obesity. By contrast, in subcutaneous adipose tissue 11 beta-HSD1 and 5 alpha R1 mRNA were decreased. Systematic differences were not found between ob/ob and db/db murine models of obesity, suggesting that variations in leptin signalling through the short splice variant of the Ob receptor do not contribute to dysregulation of glucocorticoid metabolism.

Nafuredin, a novel inhibitor of NADH-fumarate reductase, produced by Aspergillus niger FT-0554.

PubMed

Ui, H; Shiomi, K; Yamaguchi, Y; Masuma, R; Nagamitsu, T; Takano, D; Sunazuka, T; Namikoshi, M; Omura, S

2001-03-01

A novel compound, nafuredin, was isolated as an inhibitor of anaerobic electron transport (NADH-fumarate reductase). It was obtained from culture broth of Aspergillus niger FT-0554 isolated from a marine sponge. The structure was elucidated as an epoxy-delta-lactone with an attached methylated olefinic side chain on the basis of spectral analysis.

Mechanism of Action of Bolandiol (19-Nortestosterone-3β,17β-Diol), a Unique Anabolic Steroid with Androgenic, Estrogenic, and Progestational Activities*

PubMed Central

Attardi, Barbara J.; Page, Stephanie T.; Hild, Sheri A.; Coss, Christopher C.; Matsumoto, Alvin M.

2009-01-01

Bolandiol is a synthetic anabolic steroid that increases lean body mass and bone mineral density without significant stimulation of sex accessory glands in castrate adult male rats. Since bolandiol suppresses gonadotropins and endogenous testosterone (T) production, we investigated its mechanism of action. We compared the potency of bolandiol in vitro and in vivo with T, 5α-dihydrotestosterone (DHT), 19-nortestosterone (19-NT) and estradiol (E2). Bolandiol bound with lower affinity to the recombinant rat androgen receptor (AR) than the other androgens and had low, but measurable, affinity for recombinant human progestin receptors (PR-A, PR-B), and estrogen receptors (ERα and β-1). Functional agonist activity was assessed in transcription assays mediated by AR, PR, or ER. Bolandiol was stimulatory in all these assays, but only 4–9% as potent as T, DHT, and 19-NT via AR, 1% as potent as progesterone via PR, and 3% and 1% as potent as E2 acting through ERα or ERβ, respectively. In immature castrate rats, bolandiol was equipotent to T in stimulating growth of the levator ani muscle but less potent than T in stimulating growth of the sex accessory glands. Bolandiol also stimulated uterine weight increases in immature female rats, which were partly blocked by ICI 182,780, but it was not aromatized in vitro by recombinant human aromatase. In contrast to T, stimulation of sex accessory gland weights by bolandiol was not inhibited by concomitant treatment with the dual 5α-reductase inhibitor dutasteride. As bolandiol exhibits tissue selectivity in vivo, it may act via AR, PR, and/or ER, utilize alternative signaling pathway(s) or transcriptional coregulators, and/or be metabolized to a more potent selective steroid. PMID:19941958

Sex Hormone Influence on Hepatitis in Young Male A/JCr Mice Infected with Helicobacter hepaticus▿ †

PubMed Central

Theve, Elizabeth J.; Feng, Yan; Taghizadeh, Koli; Cormier, Kathleen S.; Bell, David R.; Fox, James G.; Rogers, Arlin B.

2008-01-01

Hepatitis B virus (HBV), the leading cause of human hepatocellular carcinoma, is especially virulent in males infected at an early age. Likewise, the murine liver carcinogen Helicobacter hepaticus is most pathogenic in male mice infected before puberty. We used this model to investigate the influence of male sex hormone signaling on infectious hepatitis. Male A/JCr mice were infected with H. hepaticus or vehicle at 4 weeks and randomized into surgical and pharmacologic treatment groups. Interruption of androgen pathways was confirmed by hormone measurements, histopathology, and liver gene and Cyp4a protein expression. Castrated males and those receiving the competitive androgen receptor antagonist flutamide had significantly less severe hepatitis as determined by histologic activity index than intact controls at 4 months. Importantly, the powerful androgen receptor agonist dihydrotestosterone did not promote hepatitis. No effect on hepatitis was evident in males treated with the 5α-reductase inhibitor dutasteride, the peroxisome proliferator-activated receptor-α agonist bezafibrate, or the nonsteroidal anti-inflammatory drug flufenamic acid. Consistent with previous observations of hepatitis-associated liver-gender disruption, transcriptional alterations involved both feminine (cytochrome P450 4a14) and masculine (cytochrome P450 4a12 and trefoil factor 3) genes, as well gender-neutral (H19 fetal liver mRNA, lipocalin 2, and ubiquitin D) genes. Hepatitis was associated with increased unsaturated C18 long-chain fatty acids (oleic acid and linoleic acid) relative to saturated stearic acid. Our results indicate that certain forms of androgen interruption can inhibit H. hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV. PMID:18559427

The stats are in: an update on statin use in COPD.

PubMed

Carlson, Alexa A; Smith, Ethan A; Reid, Debra J

2015-01-01

COPD is a chronic inflammatory disease of the lungs associated with an abnormal inflammatory response to noxious particles, the most prevalent of which is cigarette smoke. Studies have demonstrated that cigarette smoking is associated with activation of the bone marrow, and chronic smoking can lead to the inflammatory changes seen in COPD. Due to the inflammatory nature of the disease, medications affecting the inflammatory pathway may have clinical benefit and are being evaluated. One such class of medications, HMG-CoA reductase inhibitors, have been evaluated in the COPD population. Early studies have suggested that HMG-CoA reductase inhibitors have a variety of benefits in COPD including improvements in inflammatory markers, exacerbation rates, and mortality rates. However, the majority of this data comes from retrospective cohort studies, suggesting the need for randomized controlled trials. Recently, two randomized controlled trials, STATCOPE and RODEO, evaluated the benefit of HMG-CoA reductase inhibitors in the COPD population and found no benefit in exacerbation rates and vascular or pulmonary function, respectively. These results are reflected in practice guidelines, which do not support the use of HMG-CoA reductase inhibitors for the purpose of reducing COPD exacerbations.

Clinical, biochemical and morphologic diagnostic markers in an infant male pseudohermaphrodite patient with compound heterozygous mutations (G115D/R246W) in SRD5A2 gene.

PubMed

Fernández-Cancio, Mónica; Rodó, Joan; Andaluz, Pilar; Martínez de Osaba, María Jesús; Rodríguez-Hierro, Francisco; Esteban, Cristina; Carrascosa, Antonio; Audí, Laura

2004-01-01

A patient with male pseudohermaphroditism and clinical diagnosis of partial androgen insensitivity in the neonatal period was studied at pubertal age for a molecular diagnosis. Hormone studies were conducted at baseline and under hCG stimulation for testosterone and dihydrotestosterone determinations at 2 months of age. Gonadectomy was performed at 4 months. At the age of 13 years genital skin fibroblasts were studied for androgen binding and 5alpha-reductase activity and peripheral blood DNA was available for androgen receptor (AR) and 5alpha-reductase (SRD5A2) gene analysis. Exons 1-8 of AR gene and exons 1-5 of SRD5A2 gene were sequenced. AR gene coding sequences were normal. SRD5A2 gene analysis revealed two heterozygote mutations (G115D and R246W), with the mother carrying the G115D and the father the R246W mutations. The compound heterozygote mutations in SRD5A2 gene explained an extremely low 5alpha-reductase enzyme activity in genital skin fibroblasts. Revision of hormonal data from the neonatal period revealed an increased testosterone-to-dihydrotestosterone ratio at the end of an hCG stimulation test, which concurred with the molecular diagnosis. Testis morphology at 4 months of age was normal. Clinical and biochemical differential diagnosis between partial androgen insensitivity syndrome and 5alpha-reductase enzyme deficiency is difficult in the neonatal period and before puberty. Our results show that in our patient the testosterone-to-dihydrotestosterone ratio would have adequately orientated the diagnosis. The two mutations in SRD5A2 gene have been described in patients of different lineages, though not in combination to date. Testis morphology showed that, during early infancy, the 5alpha-reductase deficiency may not have affected interstitial or tubular development. Copyright (c) 2004 S. Karger AG, Basel.

Cloning and differential expression of steroid 5 alpha-reductase type 1 (Srd5a1) and type 2 (Srd5a2) from the Harderian glands of hamsters.

PubMed

Ramos, Luis; Chávez, Bertha; Vilchis, Felipe

2010-04-01

In hamsters, the Harderian glands (HGs) exhibit a marked sexual dimorphism which is thought to depend on dihydrotestosterone (DHT); however, it is unclear whether hamster HGs contain one or more 5 alpha-reductases and whether these enzymes are differentially expressed in males and females. In this study, we isolated specific cDNAs for 5 alpha-reductase 1 (Srd5a1) and 5 alpha-reductase 2 (Srd5a2), determined their sequences and investigated their expression in the HG of both sexes. Isozyme 1, cloned from liver mRNA, encodes a protein of 255 amino acids (aa); isozyme 2 cDNA, isolated from the epididymis encodes a 254-aa protein. When assayed in transfected HEK-293 cells, the type 1 isozyme displayed activity over a broad pH range (6.5-8), while isozyme 2 had a pH optimum of 5.5. Both isoenzymes efficiently catalyzed the in vitro transformation of T into DHT, with apparent K(m) values of 7.1 and 1.9 micromol/L for Srd5a1 and Srd5a2, respectively. Real-time PCR analysis revealed higher mRNA levels for Srd5a1 than for Srd5a2. Expression of both isoenzymes increased slightly in HGs of castrated males and showed variations during the estrous cycle in females. Hormonal replacement with 17beta-estradiol administered to spayed females induced the up-regulation of Srd5a2 mRNA levels. Altogether, our results demonstrated that both Srd5a1 and Srd5a2 are expressed in HGs without clear differences between males and females. The biochemical characteristics and relative expression of these 5 alpha-reductases support the view that both isozymes may play a relevant role in modulating androgen signaling in HG. (c) 2009 Elsevier Inc. All rights reserved.

Modeled structure of trypanothione reductase of Leishmania infantum.

PubMed

Singh, Bishal K; Sarkar, Nandini; Jagannadham, M V; Dubey, Vikash K

2008-06-30

Trypanothione reductase is an important target enzyme for structure-based drug design against Leishmania. We used homology modeling to construct a three-dimensional structure of the trypanothione reductase (TR) of Leishmania infantum. The structure shows acceptable Ramachandran statistics and a remarkably different active site from glutathione reductase(GR). Thus, a specific inhibitor against TR can be designed without interfering with host (human) GR activity.

Heme inhibition of ferrisiderophore reductase in Bacillus subtilis.

PubMed

Lodge, J S; Gaines, C G; Arceneaux, J E; Byers, B R

1982-11-01

Heme was a noncompetitive inhibitor (apparent K(i) and K'(i) = 0.043 mM) of a ferrisiderophore reductase purified from Bacillus subtilis; protoporphyrin IX had no effect. The cellular level of heme may partly regulate the function of this reductase to yield a controlled flow of iron into metabolism.

5Alpha-Reduced Steroids Are Major Metabolites in the Early Equine Embryo Proper and Its Membranes.

PubMed

Raeside, James I; Christie, Heather L; Betteridge, Keith J

2015-09-01

Steroid production and metabolism by early conceptuses are very important for the establishment and maintenance of pregnancy in horses. Our earlier work suggested the possible formation of 5alpha-reduced steroids in equine conceptuses. We have now demonstrated the formation of 5alpha-reduced metabolites of androstenedione, testosterone, and progesterone by the embryo and its membranes. A total of 44 conceptuses were collected from 26 mares between 20 and 31 days of pregnancy. Tissues from the embryo proper and from the separated components of the conceptus (bilaminar and trilaminar trophoblast, allantois) were incubated with tritium-labeled substrates. 5Alpha-reduced metabolites (5alpha-dihydro- and 3beta,5alpha-tetrahydro- steroids) as radiolabeled products were identified from a series of chromatographic steps using four solvent systems for high-performance liquid chromatography. Use of a 5alpha-reductase inhibitor confirmed the metabolites were indeed 5alpha-reduced steroids. For the embryo, the only products from androstenedione were 5alpha-dihydroandrostenedione and 3beta,5alpha-tetrahydroandrostenedione, with no evidence of more polar metabolites; there was some 3beta,5alpha-tetrahydrotestosterone but no 5alpha-dihydrotestosterone from testosterone, and formation of androstenedione was followed by the production of 5alpha-dihydroandrostenedione and 3beta,5alpha-tetrahydroandrostenedione. The major 5alpha-reduced product from progesterone was 3beta,5alpha-tetrahydroprogesterone, with lesser amounts of 5alpha-dihydroprogesterone. For the membranes, reductions to tetrahydro, 5alpha-reduced steroids were prominent in most instances, but also present were considerable amounts of products more polar than the substrates. The well-recognized activity of some 5alpha-reduced steroids--for example, 5alpha-dihydrotestosterone in male sexual differentiation--provokes interest in their even earlier appearance, as seen in this study, and suggests a possible role for them in early embryonic development in horses and, more generally, in other species. © 2015 by the Society for the Study of Reproduction, Inc.

Singapore Urological Association Clinical Guidelines for Male Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia.

PubMed

2017-08-01

The first clinical guidelines for male lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) were published in 2005. An update is urgently needed in view of BPH being recognised as one of ten chronic illnesses by the Ministry of Health, Singapore. This review summarises the definition of BPH and the epidemiology of male LUTS/BPH in Singapore. BPH can be phenotyped with noninvasive transabdominal ultrasonography, according to intravesical prostatic protrusion and prostate volume, and classified according to severity (staging) for individualised treatment. At the initial evaluation, the majority of patients (59%) can be managed with fluid adjustment, exercise and diet; 32% with medications, using alpha blockers and/or 5-alpha reductase inhibitors for prostates weighing more than 30 g; and 9% with surgical intervention for more advanced disease. The 2015 guidelines comprise updated evidence that will help family medicine practitioners and specialists manage this common ailment more cost-effectively. Copyright: © Singapore Medical Association.

Clinical outcomes after combined therapy with dutasteride plus tamsulosin or either monotherapy in men with benign prostatic hyperplasia (BPH) by baseline characteristics: 4-year results from the randomized, double-blind Combination of Avodart and Tamsulosin (CombAT) trial.

PubMed

Roehrborn, Claus G; Barkin, Jack; Siami, Paul; Tubaro, Andrea; Wilson, Timothy H; Morrill, Betsy B; Gagnier, R Paul

2011-03-01

• To investigate the influence of baseline variables on the 4-year incidence of acute urinary retention (AUR), benign prostatic hyperplasia (BPH)-related surgery and overall clinical progression in men treated with tamsulosin, dutasteride, or a combination of both. • The 4-year Combination of Avodart® and Tamsulosin (CombAT) study was a multicenter, randomized, double-blind, parallel-group study of clinical outcomes in men aged ≥ 50 years with symptomatic (International Prostate Symptom Score [IPSS]≥ 12) BPH, with prostate-specific antigen (PSA) levels of ≥ 1.5 ng/mL and ≤ 10 ng/mL, and a prostate volume (PV) of ≥ 30 mL. • Eligible patients received tamsulosin 0.4 mg, dutasteride 0.5 mg, or a combination of both. • The primary endpoint was time to first AUR or BPH-related surgery. Secondary endpoints included clinical progression of BPH and symptoms. Posthoc analyses of the influence of baseline variables (including age, IPSS health-related quality of life [HRQL], PV, PSA, IPSS, peak urinary flow rate [Q(max) ] and body-mass index [BMI]) on the incidence of AUR or BPH-related surgery, clinical progression of BPH, and symptoms were performed. • There were 4844 men in the intent-to-treat population. Overall baseline characteristics were similar across all patient groups. • Regardless of baseline subgroup, the incidence of AUR or BPH-related surgery was higher in men treated with tamsulosin than in those treated with dutasteride or combined therapy. • Combined therapy was statistically better than tamsulosin in reducing the risk of AUR or BPH-related surgery in subgroups of baseline PV > 42.0 mL, in all subgroups of baseline PSA level, and all other baseline subgroups (P ≤ 0.001). • Across treatment groups, the incidence of clinical progression was highest in men with a baseline IPSS of < 20 or IPSS HRQL score of < 4. The incidence of clinical progression was also higher in men receiving tamsulosin than dutasteride or combined therapy in all baseline subgroups, except for men with a baseline PV of < 40 mL. Combined therapy reduced the relative risk (RR) of clinical progression compared with tamsulosin across all baseline subgroups and compared with dutasteride across most baseline subgroups. • Symptom deterioration was the most common progression event in each treatment group regardless of baseline subgroup, except in those men with an IPSS of ≥ 20 at baseline. Combined therapy reduced the RR of symptom deterioration compared with tamsulosin across all but one baseline subgroup (the reduction was not significant for men with a baseline PV of < 40 mL) and compared with dutasteride in most subgroups. • Men with a baseline PV of ≥ 40 mL and any baseline PSA level of ≥1.5 ng/mL had greater reductions in the RR of AUR or BPH-related surgery and greater reductions in the RR of clinical progression and symptom deterioration on combined therapy or dutasteride monotherapy than on tamsulosin monotherapy. • These analyses support the long-term use of combined therapy with dutasteride plus tamsulosin in men with moderate-to-severe BPH symptoms and a slightly enlarged prostate. © 2011 THE AUTHORS; BJU INTERNATIONAL © 2011 BJU INTERNATIONAL.

The effect of competing direct-to-consumer advertising campaigns on the use of drugs for benign prostatic hyperplasia: time series analysis.

PubMed

Skeldon, Sean C; Kozhimannil, Katy B; Majumdar, Sumit R; Law, Michael R

2015-04-01

Direct-to-consumer advertising (DTCA) remains a controversial issue, with concerns that it leads to unnecessary and inappropriate prescribing. Whether DTCA shifts prescribing from first-line (guideline-recommended) therapy to second-line drugs has not been studied. The purpose of this study was to determine the impact of sequential DTCA campaigns for two drugs used to treat benign prostatic hyperplasia (BPH): one newer agent, dutasteride (Avodart(®)), and one older first-line agent, tamsulosin (Flomax(®)). Interrupted time series analysis was used to assess the impact of each DTCA campaign using data on consumer "response" from Google Trends and dispensed prescriptions from IMS Health. We analyzed data for the United States from January 2003 to December 2007. DTCA for dutasteride and tamsulosin commenced on July, 2005 and April, 2006, respectively. Monthly Internet search volume (scaled from 0 to 100) for the advertised trade name of each drug and monthly U.S. prescription rates per 1,000 population were analyzed. The dutasteride campaign was associated with an increase in Internet searches for both "Avodart" (level change +31.3 %, 95 % CI: 27.2-35.4) and "Flomax" (level change +8.3 %, 95 % CI: 0.9-15.7), whereas the tamsulosin campaign was associated with increased "Flomax" searches (level change +25.3 %, 95 % CI: 18.7-31.8). The dutasteride campaign was associated with an increase in the prescription of dutasteride (trend = 0.45/month, 95 % CI: 0.33-0.56), but a larger impact was observed with tamsulosin prescriptions (trend = 0.76/month, 95 % CI: 0.02-1.50). Similarly, the tamsulosin campaign was associated with an immediate fourfold increase in the prescribing of tamsulosin (level change +5.76 units, 95 % CI: 1.79-9.72) compared to dutasteride (level change +1.47 units, 95 % CI: 0.79-2.14). DTCA was associated with the utilization of drugs to treat symptomatic BPH. However, both campaigns were associated with greater increases in the use of the guideline-recommended first-line agent. DTCA campaigns may increase the overall levels of guideline-recommended treatments to a greater extent than the specific advertised agents.

Novel aldose reductase inhibitors: a patent survey (2006--present).

PubMed

Chatzopoulou, Maria; Alexiou, Polyxeni; Kotsampasakou, Eleni; Demopoulos, Vassilis J

2012-11-01

Initially studied for its central role in the pathogenesis of chronic diabetic complications, aldose reductase (ALR2) gains more attention over the years as its implication in inflammatory diseases is being established, along with the therapeutic potential of its inhibitors. Reviewing the patents that were published since 2006, it is getting clear that the search for new chemical entities has subsided, giving rise to natural products and plant extracts with ALR2 inhibitory activity. Other aspects that were prominent were the search for proper forms of known inhibitors, in a way to improve their impaired physicochemical profile, as well as potential combination therapies with other compounds of pharmaceutical interest. On the spotlight were patents enhancing the therapeutic usage of aldose reductase inhibitors (ARIs) to various pathological conditions including cancer and inflammation-mediated diseases such as sepsis, asthma, and cancer. Although new chemical entities are scarcely registered and patented after many years of inconclusive clinical trials, the involvement of ALR2 to inflammatory pathologies might renew the interest in the field of ARIs.

[Quality of care indicators for benign prostatic hyperplasia. A qualitative study].

PubMed

Navarro-Pérez, Jorge; Peiró, Salvador; Brotons-Muntó, Francisco; López-Alcina, Emilio; Real-Romaguera, Arcadio

2014-05-01

To assess quality of care indicators for benign prostatic hyperplasia (BPH), and to evaluate their strengths and weaknesses for incorporation into health information systems. Structured expert meeting, using procedures adapted from the nominal group techniques and the Rand consensus method. Valencian School of Health Studies. Forty panellists (74% doctors, 70% from primary care settings) with experience in the management of BPH from 15 departments of the Valencia Health Agency. Three workshops were held simultaneously (examination and diagnosis, drug therapy, and appropriateness and results), and the 15 quality indicators selected by the coordination group were assessed. Eleven of the 15 indicators scored in the range of high relevance. The 5 best rated were: the use of alpha-blockers + 5-alpha reductase inhibitor from certain severity level, digital rectal examination in the initial assessment, follow-up with the International Prostate Symptoms Score (IPSS), the rate of urgent catheterization in Hospital Accident & Emergency Units, initial assessment with the IPSS and the use of alpha-blockers prior to catheter removal for acute retention of urine. Some of the assessed indicators can be useful for incorporation into health information systems. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Biochemical characterization of the alpha-amylase inhibitor in mungbeans and its application in inhibiting the growth of Callosobruchus maculatus.

PubMed

Wisessing, Anussorn; Engkagul, Arunee; Wongpiyasatid, Arunee; Choowongkomon, Kiattawee

2010-02-24

The insect Callosobruchus maculatus causes considerable damage to harvested mungbean seeds every year, which leads to commercial losses. However, recent studies have revealed that mungbean seeds contain alpha-amylase inhibitors that can inhibit the protein C. maculatus, preventing growth and development of the insect larvae in the seed, thus preventing further damage. For this reason, the use of alpha-amylase inhibitors to interfere with the pest's digestion process has become an interesting alternative biocontrolling agent. In this study, we have isolated and purified the alpha-amylase inhibitor from mungbean seeds (KPS1) using ammonium sulfate precipitation, gel filtration chromatography and reversed phase HPLC. We found that the alpha-amylase inhibitor, isolated as a monomer, had a molecular weight of 27 kDa. The alpha-amylase inhibitor was purified 750-fold with a final yield of 0.4 mg of protein per 30 g of mungbean seeds. Its specific activity was determined at 14.5 U (mg of protein)(-1). Interestingly, we found that the isolated alpha-amylase inhibitor inhibits C. maculatus alpha-amylase but not human salivary alpha-amylase. After preincubation of the enzyme with the inhibitor, the mungbean alpha-amylase inhibitor inhibited C. maculatus alpha-amylase activity by decreasing V(max) while increasing the K(m) constant, indicating that the mungbean alpha-amylase is a mix noncompetitive inhibitor. The in vivo effect of alpha-amylase inhibitor on the mortality of C. maculatus shows that the alpha-amylase inhibitor acts on C. maculatus during the development stage, by reducing carbohydrate digestion necessary for growth and development, rather than during the end laying/hatching stage. Our results suggest that mungbean alpha-amylase inhibitor could be a useful future biocontrolling agent.

The in vitro inhibitory effects of crude extracts of traditional Chinese herbs on 3-hydroxy-3-methylglutaryl-coenzyme A reductase on Vero cells.

PubMed

Liu, Ju-Chi; Chan, Paul; Hsu, Feng-Lin; Chen, Yi-Jen; Hsieh, Ming-Hsiung; Lo, Ming-Yu; Lin, Jung-Yaw

2002-01-01

Cardiovascular disease is still the leading cause of death in Western countries. Epidemiological studies have shown that hypercholesterolemia is a major risk factor for coronary artery disease. Clinical trials of lipid lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A (HMG Co-A) reductase inhibitor have been shown to decrease coronary events and mortality. Flavonoids are polyphenolic natural antioxidants occurring in natural products such as traditional Chinese herbs, fruits and beverages such as tea and wine. The aim of this study was to evaluate the effects of crude extracts from traditional Chinese herbs on HMG Co-A reductase. The methods for analysis of specific inhibitors of mevalonate biosynthesis have been well-established by using Vero cells, a cell line obtained from kidneys of African green monkeys. Crude extracts from different traditional Chinese herbs were dissolved in 1% Dulbecco's modified Eagle's medium and incubated with Vero cells with or without the addition of 1 mM mevalonate or 5 mM sodium acetate for 24 hours in order to observe cell growth. Pravastatin, a specific HMG Co-A reductase inhibitor, was used as a positive control which inhibits Vero cells growth effectively and cell growth inhibition was reversible after 1 mM mevalonate. Among 100 traditional Chinese herbs used for the study, only two herbs: Curcuma zedoaria Roscoe and Poncirus trifoliata Raf. showed significant growth inhibition of Vero cells. This study shows that some crude extracts isolated from traditional medicinal herbs were effective HMG Co-A reductase inhibitors which might be developed into new hypocholesterolemic agents.

Inhibition of human anthracycline reductases by emodin — A possible remedy for anthracycline resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hintzpeter, Jan, E-mail: hintzpeter@toxi.uni-kiel.de; Seliger, Jan Moritz; Hofman, Jakub

2016-02-15

The clinical application of anthracyclines, like daunorubicin and doxorubicin, is limited by two factors: dose-related cardiotoxicity and drug resistance. Both have been linked to reductive metabolism of the parent drug to their metabolites daunorubicinol and doxorubicinol, respectively. These metabolites show significantly less anti-neoplastic properties as their parent drugs and accumulate in cardiac tissue leading to chronic cardiotoxicity. Therefore, we aimed to identify novel and potent natural inhibitors for anthracycline reductases, which enhance the anticancer effect of anthracyclines by preventing the development of anthracycline resistance. Human enzymes responsible for the reductive metabolism of daunorubicin were tested for their sensitivity towards anthrachinones,more » in particular emodin and anthraflavic acid. Intense inhibition kinetic data for the most effective daunorubicin reductases, including IC{sub 50}- and K{sub i}-values, the mode of inhibition, as well as molecular docking, were compiled. Subsequently, a cytotoxicity profile and the ability of emodin to reverse daunorubicin resistance were determined using multiresistant A549 lung cancer and HepG2 liver cancer cells. Emodin potently inhibited the four main human daunorubicin reductases in vitro. Further, we could demonstrate that emodin is able to synergistically sensitize human cancer cells towards daunorubicin at clinically relevant concentrations. Therefore, emodin may yield the potential to enhance the therapeutic effectiveness of anthracyclines by preventing anthracycline resistance via inhibition of the anthracycline reductases. In symphony with its known pharmacological properties, emodin might be a compound of particular interest in the management of anthracycline chemotherapy efficacy and their adverse effects. - Highlights: • Natural and synthetic compounds were identified as inhibitors for human daunorubicin reductases. • Emodin is a potent inhibitor for human daunorubicin reductases. • Emodin synergistically sensitizes multiresistant human cancer cells towards daunorubicin.« less

Dietary sources of aldose reductase inhibitors: prospects for alleviating diabetic complications.

PubMed

Saraswat, Megha; Muthenna, P; Suryanarayana, P; Petrash, J Mark; Reddy, G Bhanuprakash

2008-01-01

Activation of polyol pathway due to increased aldose reductase activity is one of the several mechanisms that have been implicated in the development of various secondary complications of diabetes. Though numerous synthetic aldose reductase inhibitors have been tested, these have not been very successful clinically. Therefore, a number of common plant/ natural products used in Indian culinary have been evaluated for their aldose reductase inhibitory potential in the present study. The aqueous extracts of 22 plant-derived materials were prepared and evaluated for the inhibitory property against rat lens and human recombinant aldose reductase. Specificity of these extracts towards aldose reductase was established by testing their ability to inhibit a closely related enzyme viz, aldehyde reductase. The ex vivo incubation of erythrocytes in high glucose containing medium was used to underscore the significance in terms of prevention of intracellular sorbitol accumulation. Among the 22 dietary sources tested, 10 showed considerable inhibitory potential against both rat lens and human recombinant aldose reductase. Prominent inhibitory property was found in spinach, cumin, fennel, lemon, basil and black pepper with an approximate IC50 of 0.2 mg/mL with an excellent selectivity towards aldose reductase. As against this, 10 to 20 times higher concentrations were required for 50% inhibition of aldehyde reductase. Reduction in the accumulation of intracellular sorbitol by the dietary extracts further substantiated their in vivo efficacy. The findings reported here indicate the scope of adapting life-style modifications in the form of inclusion of certain common sources in the diet for the management of diabetic complications.

Lack of effect of ketoconazole on the pharmacokinetics of rosuvastatin in healthy subjects

PubMed Central

Cooper, Kelvin J; Martin, Paul D; Dane, Aaron L; Warwick, Mike J; Raza, Ali; Schneck, Dennis W

2003-01-01

Aims To examine in vivo the effect of ketoconazole on the pharmacokinetics of rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Methods This was a randomized, double-blind, two-way crossover, placebo-controlled trial. Healthy male volunteers (n = 14) received ketoconazole 200 mg or placebo twice daily for 7 days, and rosuvastatin 80 mg was coadministered on day 4 of dosing. Plasma concentrations of rosuvastatin, and active and total HMG-CoA reductase inhibitors were measured up to 96 h postdose. Results Following coadministration with ketoconazole, rosuvastatin geometric least square mean AUC(0,t) and Cmax were unchanged compared with placebo (treatment ratios (90% confidence intervals): 1.016 (0.839, 1.230), 0.954 (0.722, 1.260), respectively). Rosuvastatin accounted for essentially all of the circulating active HMG-CoA reductase inhibitors and most (> 85%) of the total inhibitors. Ketoconazole did not affect the proportion of circulating active or total inhibitors accounted for by circulating rosuvastatin. Conclusions Ketoconazole did not produce any change in rosuvastatin pharmacokinetics in healthy subjects. The data suggest that neither cytochrome P450 3A4 nor P-gp-mediated transport contributes to the elimination of rosuvastatin. PMID:12534645

Effect of Cuscuta reflexa Roxb on androgen-induced alopecia.

PubMed

Pandit, Shweta; Chauhan, Nagendra Singh; Dixit, V K

2008-09-01

Alopecia is a psychologically distressing condition. Androgenetic alopecia, which affects millions of men and women, is an androgen-driven disorder. Here, Cuscuta reflexa Roxb is evaluated for hair growth activity in androgen-induced alopecia. Petroleum ether extract of C. reflexa was studied for its hair growth-promoting activity. Alopecia was induced in albino mice by testosterone administration for 20 days. Its inhibition by simultaneous administration of extract was evaluated using follicular density, anagen/telogen ratio, and microscopic observation of skin sections. To investigate the mechanism of observed activity, in vitro experiments were performed to study the effect of extract and its major component on activity of 5alpha-reductase enzyme. Petroleum ether extract of C. reflexa exhibited promising hair growth-promoting activity as reflected from follicular density, anagen/telogen ratio, and skin sections. Inhibition of 5alpha-reductase activity by extract and isolate suggest that the extract reversed androgen-induced alopecia by inhibiting conversion of testosterone to dihydrotestosterone. The petroleum ether extract of C. reflexa and its isolate is useful in treatment of androgen-induced alopecia by inhibiting the enzyme 5alpha-reductase.

Synthetic and Crystallographic Studies of a New Inhibitor Series Targeting Bacillus anthracis Dihydrofolate Reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beierlein, J.; Frey, K; Bolstad, D

2008-01-01

Bacillus anthracis, the causative agent of anthrax, poses a significant biodefense danger. Serious limitations in approved therapeutics and the generation of resistance have produced a compelling need for new therapeutic agents against this organism. Bacillus anthracis is known to be insensitive to the clinically used antifolate, trimethoprim, because of a lack of potency against the dihydrofolate reductase enzyme. Herein, we describe a novel lead series of B. anthracis dihydrofolate reductase inhibitors characterized by an extended trimethoprim-like scaffold. The best lead compound adds only 22 Da to the molecular weight and is 82-fold more potent than trimethoprim. An X-ray crystal structuremore » of this lead compound bound to B. anthracis dihydrofolate reductase in the presence of NADPH was determined to 2.25 A resolution. The structure reveals several features that can be exploited for further development of this lead series.« less

A role for 5alpha-reductase activity in the development of male homosexuality?

PubMed

Alias, A G

2004-12-01

Higher body hair with lower mesmorphism ratings were observed in Caucasian homosexual men compared with the general male population, reflecting elevated 5alpha-reductase (5alphaR) activity, and higher dihydrotestosterone-to-testosterone (DHT-to-T) ratio, in sharp contrast to 46,XY 5alphaR 2 deficiency subjects, who are often born with ambiguous, or female genitalia, but tend to grow up to be muscular, heterosexual men with very little body hair, or beard. One study also showed them scoring around dull normal IQs. A greater prevalence of liberal body hair growth in men with higher IQs and/or educational levels was also observed in several samples. The exceptions to this statistical trend are too unsettling, however. Nevertheless, the results of a number of published studies, including one showing higher DHT-to-T ratio in homosexual men, done with different objectives over a span of 80 years, together strongly support these findings. Furthermore, in an animal model, "cognitive-enhancing effects" of "5alpha-reduced androgen [metabolites]" were recently demonstrated.

Exploiting the 2-Amino-1,3,4-thiadiazole Scaffold To Inhibit Trypanosoma brucei Pteridine Reductase in Support of Early-Stage Drug Discovery

PubMed Central

2017-01-01

Pteridine reductase-1 (PTR1) is a promising drug target for the treatment of trypanosomiasis. We investigated the potential of a previously identified class of thiadiazole inhibitors of Leishmania major PTR1 for activity against Trypanosoma brucei (Tb). We solved crystal structures of several TbPTR1-inhibitor complexes to guide the structure-based design of new thiadiazole derivatives. Subsequent synthesis and enzyme- and cell-based assays confirm new, mid-micromolar inhibitors of TbPTR1 with low toxicity. In particular, compound 4m, a biphenyl-thiadiazole-2,5-diamine with IC50 = 16 μM, was able to potentiate the antitrypanosomal activity of the dihydrofolate reductase inhibitor methotrexate (MTX) with a 4.1-fold decrease of the EC50 value. In addition, the antiparasitic activity of the combination of 4m and MTX was reversed by addition of folic acid. By adopting an efficient hit discovery platform, we demonstrate, using the 2-amino-1,3,4-thiadiazole scaffold, how a promising tool for the development of anti-T. brucei agents can be obtained. PMID:28983525

Exploiting the 2-Amino-1,3,4-thiadiazole Scaffold To Inhibit Trypanosoma brucei Pteridine Reductase in Support of Early-Stage Drug Discovery.

PubMed

Linciano, Pasquale; Dawson, Alice; Pöhner, Ina; Costa, David M; Sá, Monica S; Cordeiro-da-Silva, Anabela; Luciani, Rosaria; Gul, Sheraz; Witt, Gesa; Ellinger, Bernhard; Kuzikov, Maria; Gribbon, Philip; Reinshagen, Jeanette; Wolf, Markus; Behrens, Birte; Hannaert, Véronique; Michels, Paul A M; Nerini, Erika; Pozzi, Cecilia; di Pisa, Flavio; Landi, Giacomo; Santarem, Nuno; Ferrari, Stefania; Saxena, Puneet; Lazzari, Sandra; Cannazza, Giuseppe; Freitas-Junior, Lucio H; Moraes, Carolina B; Pascoalino, Bruno S; Alcântara, Laura M; Bertolacini, Claudia P; Fontana, Vanessa; Wittig, Ulrike; Müller, Wolfgang; Wade, Rebecca C; Hunter, William N; Mangani, Stefano; Costantino, Luca; Costi, Maria P

2017-09-30

Pteridine reductase-1 (PTR1) is a promising drug target for the treatment of trypanosomiasis. We investigated the potential of a previously identified class of thiadiazole inhibitors of Leishmania major PTR1 for activity against Trypanosoma brucei ( Tb ). We solved crystal structures of several Tb PTR1-inhibitor complexes to guide the structure-based design of new thiadiazole derivatives. Subsequent synthesis and enzyme- and cell-based assays confirm new, mid-micromolar inhibitors of Tb PTR1 with low toxicity. In particular, compound 4m , a biphenyl-thiadiazole-2,5-diamine with IC 50 = 16 μM, was able to potentiate the antitrypanosomal activity of the dihydrofolate reductase inhibitor methotrexate (MTX) with a 4.1-fold decrease of the EC 50 value. In addition, the antiparasitic activity of the combination of 4m and MTX was reversed by addition of folic acid. By adopting an efficient hit discovery platform, we demonstrate, using the 2-amino-1,3,4-thiadiazole scaffold, how a promising tool for the development of anti- T. brucei agents can be obtained.

The use of dimethylsulfoxide as a solvent in enzyme inhibition studies: the case of aldose reductase.

PubMed

Misuri, Livia; Cappiello, Mario; Balestri, Francesco; Moschini, Roberta; Barracco, Vito; Mura, Umberto; Del-Corso, Antonella

2017-12-01

Aldose reductase (AR) is an enzyme devoted to cell detoxification and at the same time is strongly involved in the aetiology of secondary diabetic complications and the amplification of inflammatory phenomena. AR is subjected to intense inhibition studies and dimethyl sulfoxide (DMSO) is often present in the assay mixture to keep the inhibitors in solution. DMSO was revealed to act as a weak but well detectable AR differential inhibitor, acting as a competitive inhibitor of the L-idose reduction, as a mixed type of non-competitive inhibitor of HNE reduction and being inactive towards 3-glutathionyl-4-hydroxynonanal transformation. A kinetic model of DMSO action with respect to differently acting inhibitors was analysed. Three AR inhibitors, namely the flavonoids neohesperidin dihydrochalcone, rutin and phloretin, were used to evaluate the effects of DMSO on the inhibition studies on the reduction of L-idose and HNE.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinnecker, G.H.G; Hiort, O.; Kruse, K.

Conversion of testosterone (T) to dihydrotestosterone (DHT) in genital tissue is catalysed by the enzyme 5{alpha}-reductase 2, which is encoded by the SRD5A2 gene. The potent androgen DHT is required for full masculinization of the external genitalia. Mutations of the SRD5A2 gene inhibit enzyme activity, diminish DHT formation, and hence cause masculinization defects of varying degree. The classical syndrome, formerly described as pseudovaginal perineoscrotal hypospadias, is characterized by a predominantly female phenotype at birth and significant virilization without gynecomastia at puberty. We investigated nine patients with steroid 5{alpha}-reductase 2 deficiency (SRD). T/DHT-ratios were highly increased in the classical syndrome, butmore » variable in the less severe affected patients. Mutations in the SRD5A2 gene had been characterized using PCR-SSCP analysis and direct DNA sequencing. A small deletion was encountered in two patients, while all other patients had single base mutations which result in amino acid substitutions. We conclude that phenotypes may vary widely in patients with SRD5A2 gene mutations spanning the whole range from completely female to normal male without distinctive clinical signs of the disease. Hence, steroid 5{alpha}-reductase deficiency should be considered not only in sex reversed patients with female or ambiguous phenotypes, but also in those with mild symptoms of undermasculinization as encountered in patients with hypospadias and/or micropenis. A classification based on the severity of the masculinization defect may be used for correlation of phenotypes with enzyme activities and genotypes, and for comparisons of phenotypes between different patients as the basis for clinical decisions to be made in patients with pseudohermaphroditism due to steroid 5{alpha}-reductase 2 deficiency. 22 refs., 2 figs., 2 tabs.« less

Enhancement of DMNQ-induced hepatocyte toxicity by cytochrome P450 inhibition.

PubMed

Ishihara, Yasuhiro; Shiba, Dai; Shimamoto, Norio

2006-07-15

Two mechanisms have been proposed to explain quinone cytotoxicity: oxidative stress via the redox cycle and the arylation of intracellular nucleophiles. As the redox cycle is catalyzed by NADPH cytochrome P450 reductase, cytochrome P450 systems are expected to be related to the cytotoxicity induced by redox-cycling quinones. Thus, we investigated the relationship between cytochrome P450 systems and quinone toxicity for rat primary hepatocytes using an arylator, 1,4-benzoquinone (BQ), and a redox cycler, 2,3-dimethoxy-1,4-naphthoquinone (DMNQ). The hepatocyte toxicity of both BQ and DMNQ increased in a time- and dose-dependent manner. Pretreatment with cytochrome P450 inhibitors, such as SKF-525A (SKF), ketoconazole and 2-methy-1,2-di-3-pyridyl-1-propanone, enhanced the hepatocyte toxicity induced by DMNQ but did not affect BQ-induced hepatocyte toxicity. The production of superoxide anion and the levels of glutathione disulfide and thiobarbituric-acid-reactive substances were increased by treatment with DMNQ, and SKF pretreatment further enhanced their increases. In addition, NADPH oxidation in microsomes was increased by treatment with DMNQ and further augmented by pretreatment with SKF, and a NADPH cytochrome P450 reductase inhibitor, diphenyleneiodonium chloride completely suppressed NADPH oxidations increased by treatment with either DMNQ- or DMNQ + SKF. Pretreatment with antioxidants, such as alpha-tocopherol, reduced glutathione, N-acetyl cysteine or an iron ion chelator deferoxamine, totally suppressed DMNQ- and DMNQ + SKF-induced hepatocyte toxicity. These results indicate that the hepatocyte toxicity of redox-cycling quinones is enhanced under cytochrome P450 inhibition, and that this enhancement is caused by the potentiation of oxidative stress.

Regulation of neurosteroid allopregnanolone biosynthesis in the rat spinal cord by glycine and the alkaloidal analogs strychnine and gelsemine.

PubMed

Venard, C; Boujedaini, N; Belon, P; Mensah-Nyagan, A G; Patte-Mensah, C

2008-04-22

The neurosteroid allopregnanolone (3alpha,5alpha-THP) is well characterized as a potentially therapeutic molecule which exerts important neurobiological actions including neuroprotective, antidepressant, anxiolytic, anesthetic and analgesic effects. We have recently observed that neurons and glial cells of the rat spinal cord (SC) contain various key steroidogenic enzymes such as 5alpha-reductase and 3alpha-hydroxysteroid oxido-reductase which are crucial for 3alpha,5alpha-THP biosynthesis. Furthermore, we demonstrated that the rat SC actively produces 3alpha,5alpha-THP. As the key factors regulating neurosteroid production by nerve cells are unknown and because glycine is one of the pivotal inhibitory neurotransmitters in the SC, we investigated glycine effects on 3alpha,5alpha-THP biosynthesis in the rat SC. Glycine markedly stimulated [(3)H]-progesterone conversion into [(3)H]3alpha,5alpha-THP by SC slices. The alkaloid strychnine, well-known as a glycine receptor (Gly-R) antagonist, blocked glycine stimulatory effect on 3alpha,5alpha-THP formation. Gelsemine, another alkaloid containing the same functional groups as strychnine, increased 3alpha,5alpha-THP synthesis. The stimulatory effects of glycine and gelsemine on 3alpha,5alpha-THP production were additive when the two drugs were combined. These results demonstrate that glycine and gelsemine, acting via Gly-R, upregulate 3alpha,5alpha-THP biosynthesis in the SC. The data also revealed a structure-activity relationship of the analogs strychnine and gelsemine on neurosteroidogenesis. Possibilities are opened for glycinergic agents and gelsemine utilization to stimulate selectively 3alpha,5alpha-THP biosynthetic pathways in diseases evoked by a decreased neurosteroidogenic activity of nerve cells.

Identification of new potent inhibitor of aldose reductase from Ocimum basilicum.

PubMed

Bhatti, Huma Aslam; Tehseen, Yildiz; Maryam, Kiran; Uroos, Maliha; Siddiqui, Bina S; Hameed, Abdul; Iqbal, Jamshed

2017-12-01

Recent efforts to develop cure for chronic diabetic complications have led to the discovery of potent inhibitors against aldose reductase (AKR1B1, EC 1.1.1.21) whose role in diabetes is well-evident. In the present work, two new natural products were isolated from the ariel part of Ocimum basilicum; 7-(3-hydroxypropyl)-3-methyl-8-β-O-d-glucoside-2H-chromen-2-one (1) and E-4-(6'-hydroxyhex-3'-en-1-yl)phenyl propionate (2) and confirmed their structures with different spectroscopic techniques including NMR spectroscopy etc. The isolated compounds (1, 2) were evaluated for in vitro inhibitory activity against aldose reductase (AKR1B1) and aldehyde reductase (AKR1A1). The natural product (1) showed better inhibitory activity for AKR1B1 with IC 50 value of 2.095±0.77µM compare to standard sorbinil (IC 50 =3.14±0.02µM). Moreover, the compound (1) also showed multifolds higher activity (IC 50 =0.783±0.07µM) against AKR1A1 as compared to standard valproic acid (IC 50 =57.4±0.89µM). However, the natural product (2) showed slightly lower activity for AKR1B1 (IC 50 =4.324±1.25µM). Moreover, the molecular docking studies of the potent inhibitors were also performed to identify the putative binding modes within the active site of aldose/aldehyde reductases. Copyright © 2017 Elsevier Inc. All rights reserved.

Steroid 5 alpha-reductase deficiency in a 65-year-old male pseudohermaphrodite: the natural history, ultrastructure of the testes, and evidence for inherited enzyme heterogeneity.

PubMed

Imperato-McGinley, J; Peterson, R E; Leshin, M; Griffin, J E; Cooper, G; Draghi, S; Berenyi, M; Wilson, J D

1980-01-01

We report a 65-yr-old male pseudohermaphrodite with steroid 5 alpha-reductase deficiency in whom there was no medical intervention before, during, or after puberty, enabling us to observe the natural history of this condition. The affected subject has an android build, with more facial and body hair than in previously described affected adults. Although the subject was raised as a girl, a male gender identity evolved with the events of puberty, but social factors have delayed the complete expression of a male gender role. Plasma levels of dihydrotestosterone and the in vivo conversion of radiolabeled testosterone to dihydrotestosterone were decreased. There was an elevated urinary etiocholanolone to androsterone ratio, typical of the syndrome. Characterization of 5 alpha-reductase enzyme activity in cultured genital skin fibroblasts demonstrated a pattern of enzyme activity distinctly different from three previously described families with this condition. There was decreased enzyme affinity for testosterone and NADPH. Also, the stability of the enzyme to elevated temperature was not protected by NADPH, resulting in rapid disappearance of enzyme activity after inhibition of protein synthesis with cycloheximide. Electron microscopic evaluation of the testes was carried out.

Footprinting of Inhibitor Interactions of In Silico Identified Inhibitors of Trypanothione Reductase of Leishmania Parasite

PubMed Central

Venkatesan, Santhosh K.; Dubey, Vikash Kumar

2012-01-01

Structure-based virtual screening of NCI Diversity set II compounds was performed to indentify novel inhibitor scaffolds of trypanothione reductase (TR) from Leishmania infantum. The top 50 ranked hits were clustered using the AuPoSOM tool. Majority of the top-ranked compounds were Tricyclic. Clustering of hits yielded four major clusters each comprising varying number of subclusters differing in their mode of binding and orientation in the active site. Moreover, for the first time, we report selected alkaloids and dibenzothiazepines as inhibitors of Leishmania infantum TR. The mode of binding observed among the clusters also potentiates the probable in vitro inhibition kinetics and aids in defining key interaction which might contribute to the inhibition of enzymatic reduction of T[S] 2. The method provides scope for automation and integration into the virtual screening process employing docking softwares, for clustering the small molecule inhibitors based upon protein-ligand interactions. PMID:22550471

Structure-Guided Development of Efficacious Antifungal Agents Targeting Candida Glabrata Dihydrofolate Reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J.; Bolstad, D; Smith, A

2008-01-01

Candida glabrata is a lethal fungal pathogen resistant to many antifungal agents and has emerged as a critical target for drug discovery. Over the past several years, we have been developing a class of propargyl-linked antifolates as antimicrobials and hypothesized that these compounds could be effective inhibitors of dihydrofolate reductase (DHFR) from C. glabrata. We initially screened a small collection of these inhibitors and found modest levels of potency. Subsequently, we determined the crystal structure of C. glabrata DHFR bound to a representative inhibitor with data to 1.6 A resolution. Using this structure, we designed and synthesized second-generation inhibitors. Thesemore » inhibitors bind the C. glabrata DHFR enzyme with subnanomolar potency, display greater than 2000-fold levels of selectivity over the human enzyme, and inhibit the growth of C. glabrata at levels observed with clinically employed therapeutics.« less

Reverse electron transport effects on NADH formation and metmyoglobin reduction.

PubMed

Belskie, K M; Van Buiten, C B; Ramanathan, R; Mancini, R A

2015-07-01

The objective was to determine if NADH generated via reverse electron flow in beef mitochondria can be used for electron transport-mediated reduction and metmyoglobin reductase pathways. Beef mitochondria were isolated from bovine hearts (n=5) and reacted with combinations of succinate, NAD, and mitochondrial inhibitors to measure oxygen consumption and NADH formation. Mitochondria and metmyoglobin were reacted with succinate, NAD, and mitochondrial inhibitors to measure electron transport-mediated metmyoglobin reduction and metmyoglobin reductase activity. Addition of succinate and NAD increased oxygen consumption, NADH formation, electron transport-mediated metmyoglobin reduction, and reductase activity (p<0.05). Addition of antimycin A prevented electron flow beyond complex III, therefore, decreasing oxygen consumption and electron transport-mediated metmyoglobin reduction. Addition of rotenone prevented reverse electron flow, increased oxygen consumption, increased electron transport-mediated metmyoglobin reduction, and decreased NADH formation. Succinate and NAD can generate NADH in bovine tissue postmortem via reverse electron flow and this NADH can be used by both electron transport-mediated and metmyoglobin reductase pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beliav, Alex; Qiu, Dongru; Fredrickson, James K.

Shewanella putrefaciens W3-18-1 harbours two periplasmic nitrate reductase (Nap) gene clusters, NapC-associated nap-alpha (napEDABC) and CymA-dependent nap-beta (napDAGHB), for dissimilatory nitrate respiration. CymA is a member of the NapC/NirT quinol dehydrogenase family and acts as a hub to support different respiratory pathways, including those on iron [Fe(III)] and manganese [Mn(III, IV)] (hydr)oxide, nitrate, nitrite, fumarate and arsenate in Shewanella strains. However, in our analysis it was shown that another NapC/NirT family protein, NapC, was only involved in nitrate reduction, although both CymA and NapC can transfer quinol-derived electrons to a periplasmic terminal reductase or an electron acceptor. Furthermore, our resultsmore » showed that NapC could only interact specifically with the Nap-alpha nitrate reductase while CymA could interact promiscuously with Nap-alpha, Nap-beta and the NrfA nitrite reductase for nitrate and nitrite reduction. To further explore the difference in specificity, site-directed mutagenesis on both CymA and NapC was conducted and the phenotypic changes in nitrate and nitrite reduction were tested. Our analyses demonstrated that the Lys-91 residue played a key role in nitrate reduction for quinol oxidation and the Asp-166 residue might influence the maturation of CymA. The Asp-97 residue might be one of the key factors that influence the interaction of CymA with the cytochromes NapB and NrfA.« less

Probing the Active Site of Candida Glabrata Dihydrofolate Reductase with High Resolution Crystal Structures and the Synthesis of New Inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J.; Bolstad, D; Smith, A

2009-01-01

Candida glabrata, a fungal strain resistant to many commonly administered antifungal agents, has become an emerging threat to human health. In previous work, we validated that the essential enzyme, dihydrofolate reductase, is a drug target in C. glabrata. Using a crystal structure of dihydrofolate reductase from C. glabrata bound to an initial lead compound, we designed a class of biphenyl antifolates that potently and selectively inhibit both the enzyme and the growth of the fungal culture. In this work, we explore the structure-activity relationships of this class of antifolates with four new high resolution crystal structures of enzyme:inhibitor complexes andmore » the synthesis of four new inhibitors. The designed inhibitors are intended to probe key hydrophobic pockets visible in the crystal structure. The crystal structures and an evaluation of the new compounds reveal that methyl groups at the meta and para positions of the distal phenyl ring achieve the greatest number of interactions with the pathogenic enzyme and the greatest degree of selectivity over the human enzyme. Additionally, antifungal activity can be tuned with substitution patterns at the propargyl and para-phenyl positions.« less

Inhibition of 5-alpha-reductase activity induces stromal remodeling and smooth muscle de-differentiation in adult gerbil ventral prostate.

PubMed

Corradi, Lara S; Góes, Rejane M; Carvalho, Hernandes F; Taboga, Sebastião R

2004-06-01

Prostatic differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Dihydrotestosterone, which is synthesized from testosterone by 5 alpha-reductase (5 alpha-r), is the active molecule triggering androgen action within the prostate. In the present work, we examined the effects of 5 alpha-reductase inhibition by finasteride in the ventral prostate (VP) of the adult gerbil, employing histochemical and electron microscopy techniques to demonstrate the morphological and organizational changes of the organ. After 10 days of finasteride treatment at a dose of 100 mg/kg/day, the prostatic complex (VP and dorsolateral prostate) absolute weight was reduced to about 18%. The epithelial cells became short and cuboidal, with less secretory blebs and reduced acid phosphatase activity. The luminal sectional area diminished, suggestive of decreased secretory activity. The stromal/epithelial ratio increased, the stroma becoming thicker but less cellular. There was a striking accumulation of collagen fibrils, which was accompanied by an increase in deposits of amorphous granular material adjacent to the basal lamina and in the clefts between smooth muscle cells (SMC). Additionally, the periacinar smooth muscle became loosely packed. Some SMC were atrophic and showed a denser array of the cytoskeleton, whereas other SMC had a highly irregular outline with numerous spine-like projections. The present data indicate that 5 alpha-r inhibition causes epithelial and stromal changes by affecting intra-prostatic hormone levels. These alterations are probably the result of an imbalance of the homeostatic interaction between the epithelium and the underlying stroma.

Fragment Discovery for the Design of Nitrogen Heterocycles as Mycobacterium tuberculosis Dihydrofolate Reductase Inhibitors.

PubMed

Shelke, Rupesh U; Degani, Mariam S; Raju, Archana; Ray, Mukti Kanta; Rajan, Mysore G R

2016-08-01

Fragment-based drug design was used to identify Mycobacterium tuberculosis (Mtb) dihydrofolate reductase (DHFR) inhibitors. Screening of ligands against the Mtb DHFR enzyme resulted in the identification of multiple fragment hits with IC50 values in the range of 38-90 μM versus Mtb DHFR and minimum inhibitory concentration (MIC) values in the range of 31.5-125 μg/mL. These fragment scaffolds would be useful for anti-tubercular drug design. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiolabelling and positron emission tomography of PT70, a time-dependent inhibitor of InhA, the Mycobacterium tuberculosis enoyl-ACP reductase

DOE PAGES

Wang, Hui; Liu, Li; Lu, Yang; ...

2015-07-14

PT70 is a diaryl ether inhibitor of InhA, the enoyl-ACP reductase in the Mycobacterium tuberculosis fatty acid biosynthesis pathway. It has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. Due to the interest in studying target tissue pharmacokinetics of PT70, we developed a method to radiolabel PT70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography.

Radiolabelling and positron emission tomography of PT70, a time-dependent inhibitor of InhA, the Mycobacterium tuberculosis enoyl-ACP reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hui; Liu, Li; Lu, Yang

PT70 is a diaryl ether inhibitor of InhA, the enoyl-ACP reductase in the Mycobacterium tuberculosis fatty acid biosynthesis pathway. It has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. Due to the interest in studying target tissue pharmacokinetics of PT70, we developed a method to radiolabel PT70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography.

Biological evaluation of some uracil derivatives as potent glutathione reductase inhibitors

NASA Astrophysics Data System (ADS)

Güney, Murat; Ekinci, Deniz; Ćavdar, Huseyin; Şentürk, Murat; Zilbeyaz, Kani

2016-04-01

Discovery of glutathione reductase (GR) inhibitors has become very popular recently due to antimalarial and anticancer activities. In this study, GR inhibitory capacities of some uracil derivatives (UDCs) (1-4) were reported. Some commercially available molecules (5-6) were also tested for comparison reasons. The novel UDCs were obtained in high yields using simple chemical procedures and exhibited much potent inhibitory activities against GR at low nanomolar concentrations with IC50 values ranging from 2.68 to 166.6 nM as compared with well-known agents.

Time-specific androgen blockade with flutamide inhibits testicular descent in the rat.

PubMed

Husmann, D A; McPhaul, M J

1991-09-01

Inhibition of androgen action by flutamide, a nonsteroidal antiandrogen, blocked testicular descent in 40% of the testes exposed to this agent continuously from gestational day 13 through postpartal day 28. By contrast, only 11% of the testes failed to descend when blocked by 5 alpha-reductase inhibitors during the same period. Flutamide administration over narrower time intervals (gestational day 13-15, 16-17, or 18-19) revealed maximal interference with testicular descent after androgen inhibition during gestational days 16-17. No significant differences in testicular or epididymal weights were evident between descended and undescended testes; furthermore, no correlation was detected between the presence of epididymal abnormalities and testicular descent. These findings indicate that androgen inhibition during a brief period of embryonic development can block testicular descent. The mechanism through which this inhibition occurs remains to be elucidated.

Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system.

PubMed

Pais, Pilar; Villar, Agustí; Rull, Santiago

2016-01-01

The nicotinamide adenine dinucleotide phosphate-dependent membrane protein 5α-reductase catalyses the conversion of testosterone to the most potent androgen - 5α-dihydrotestosterone. Two 5α-reductase isoenzymes are expressed in humans: type I and type II. The latter is found primarily in prostate tissue. Saw palmetto extract (SPE) has been used extensively in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). The pharmacological effects of SPE include the inhibition of 5α-reductase, as well as anti-inflammatory and antiproliferative effects. Clinical studies of SPE have been inconclusive - some have shown significant results, and others have not - possibly the result of varying bioactivities of the SPEs used in the studies. To determine the in vitro potency in a cell-free test system of a novel SP supercritical CO2 extract (SPSE), an inhibitor of the 5α-reductase isoenzyme type II. The inhibitory potency of SPSE was compared to that of finasteride, an approved 5α-reductase inhibitor, on the basis of the enzymatic conversion of the substrate androstenedione to the 5α-reduced product 5α-androstanedione. By concentration-dependent inhibition of 5α-reductase type II in vitro (half-maximal inhibitory concentration 3.58±0.05 μg/mL), SPSE demonstrated competitive binding toward the active site of the enzyme. Finasteride, the approved 5α-reductase inhibitor tested as positive control, led to 63%-75% inhibition of 5α-reductase type II. SPSE effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is comparatively low. It can be confirmed from the results of this study that SPSE has bioactivity that promotes prostate health at a level that is superior to that of many other phytotherapeutic extracts. The bioactivity of SPSE corresponds favorably to that reported for the hexane extract used in a large number of positive BPH clinical trials, as well as to finasteride, the established standard of therapy among prescription drugs. Future in vitro and clinical trials involving SPEs would be useful for elucidating their comparative differences, as well as appropriate patient selection for their use.

Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system

PubMed Central

Pais, Pilar; Villar, Agustí; Rull, Santiago

2016-01-01

Background The nicotinamide adenine dinucleotide phosphate-dependent membrane protein 5α-reductase catalyses the conversion of testosterone to the most potent androgen – 5α-dihydrotestosterone. Two 5α-reductase isoenzymes are expressed in humans: type I and type II. The latter is found primarily in prostate tissue. Saw palmetto extract (SPE) has been used extensively in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). The pharmacological effects of SPE include the inhibition of 5α-reductase, as well as anti-inflammatory and antiproliferative effects. Clinical studies of SPE have been inconclusive – some have shown significant results, and others have not – possibly the result of varying bioactivities of the SPEs used in the studies. Purpose To determine the in vitro potency in a cell-free test system of a novel SP supercritical CO2 extract (SPSE), an inhibitor of the 5α-reductase isoenzyme type II. Materials and methods The inhibitory potency of SPSE was compared to that of finasteride, an approved 5α-reductase inhibitor, on the basis of the enzymatic conversion of the substrate androstenedione to the 5α-reduced product 5α-androstanedione. Results By concentration-dependent inhibition of 5α-reductase type II in vitro (half-maximal inhibitory concentration 3.58±0.05 μg/mL), SPSE demonstrated competitive binding toward the active site of the enzyme. Finasteride, the approved 5α-reductase inhibitor tested as positive control, led to 63%–75% inhibition of 5α-reductase type II. Conclusion SPSE effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is comparatively low. It can be confirmed from the results of this study that SPSE has bioactivity that promotes prostate health at a level that is superior to that of many other phytotherapeutic extracts. The bioactivity of SPSE corresponds favorably to that reported for the hexane extract used in a large number of positive BPH clinical trials, as well as to finasteride, the established standard of therapy among prescription drugs. Future in vitro and clinical trials involving SPEs would be useful for elucidating their comparative differences, as well as appropriate patient selection for their use. PMID:27186566

DISRUPTION OF THE SACCHAROMYCES CEREVISIAE GENE FOR NADPH-CYTOCHROME P450-REDUCTASE CAUSES INCREASED SENSITIVITY TO KETOCONAZOLE

EPA Science Inventory

Strains of Saccharomyces cerevisiae deleted in the NADPH-cytochrome P450 reductase gene by transplacement are 200-fold more sensitive to ketoconazole, an inhibitor of the cytochrome P450 lanosterol 14-demethylase. Resistance is restored through complementation by the plasmid-born...

Anti-HMG-CoA Reductase, Antioxidant, and Anti-Inflammatory Activities of Amaranthus viridis Leaf Extract as a Potential Treatment for Hypercholesterolemia

PubMed Central

Salvamani, Shamala; Gunasekaran, Baskaran; Shukor, Mohd Yunus; Shaharuddin, Noor Azmi; Sabullah, Mohd Khalizan

2016-01-01

Inflammation and oxidative stress are believed to contribute to the pathology of several chronic diseases including hypercholesterolemia (elevated levels of cholesterol in blood) and atherosclerosis. HMG-CoA reductase inhibitors of plant origin are needed as synthetic drugs, such as statins, which are known to cause adverse effects on the liver and muscles. Amaranthus viridis (A. viridis) has been used from ancient times for its supposedly medically beneficial properties. In the current study, different parts of A. viridis (leaf, stem, and seed) were evaluated for potential anti-HMG-CoA reductase, antioxidant, and anti-inflammatory activities. The putative HMG-CoA reductase inhibitory activity of A. viridis extracts at different concentrations was determined spectrophotometrically by NADPH oxidation, using HMG-CoA as substrate. A. viridis leaf extract revealed the highest HMG-CoA reductase inhibitory effect at about 71%, with noncompetitive inhibition in Lineweaver-Burk plot analysis. The leaf extract showed good inhibition of hydroperoxides, 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and ferric ion radicals in various concentrations. A. viridis leaf extract was proven to be an effective inhibitor of hyaluronidase, lipoxygenase, and xanthine oxidase enzymes. The experimental data suggest that A. viridis leaf extract is a source of potent antioxidant and anti-inflammatory agent and may modulate cholesterol metabolism by inhibition of HMG-CoA reductase. PMID:27051453

Resolution and partial characterization of two aldehyde reductases of mammalian liver.

PubMed

Tulsiani, D R; Touster

1977-04-25

Investigation of NADP-dependent aldehyde reductase activity in mouse liver led to the finding that two distinct reductases are separable by DE52 ion exchange chromatography. Aldehyde reductase I (AR I) appears in the effluent, while aldehyde reductase II (AR II) is eluted with a salt gradient. By several procedures AR II was purified over 1100-fold from liver supernatant fraction, but AR I could be pruified only 107-fold because of its instability. The two enzymes are different in regard to pH optimum, substrate specificity, response to inhibitors, and reactivity with antibody to AR II. While both enzymes utilize aromatic aldehydes well, only AR II ACTS ON D-glucuronate, indicating that it is the aldyhyde reductase recently reported to be identical to NADP-L-gulonate dehydrogenase. The presence of two NADP-linked aldehyde reductases in liver has apparently not heretofore been reported.

Evaluation of in vitro aldose reductase inhibitory potential of alkaloidal fractions of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera.

PubMed

Gupta, Sakshi; Singh, Nirmal; Jaggi, Amteshwar Singh

2014-05-01

Aldose reductase is primarily involved in development of long-term diabetic complications due to increased polyol pathway activity. The synthetic aldose reductase inhibitors are not very successful clinically. Therefore, the natural sources may be exploited for safer and effective aldose reductase inhibitors. In the present study, the aldose reductase inhibitory potential of hydroalcoholic and alkaloidal extracts of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera was evaluated. The hydroalcoholic and alkaloidal extracts of the selected plants were prepared. The different concentrations of hydroalcoholic and alkaloidal extracts of these plants were evaluated for their goat lens aldose reductase inhibitory activity using dl-glyceraldehyde as substrate. The aldose reductase inhibitory potential of extracts was assessed in terms of their IC50 value. Amongst the hydroalcoholic extracts, the highest aldose reductase inhibitory activity was shown by P. nigrum (IC50 value 35.64±2.7 μg/mL) followed by M. koenigii (IC50 value 45.67±2.57 μg/mL), A. mexicana (IC50 value 56.66±1.30 μg/mL), and N. nucifera (IC50 value 59.78±1.32 μg/mL). Among the alkaloidal extracts, highest inhibitory activity was shown by A. mexicana (IC50 value 25.67±1.25 μg/mL), followed by N. nucifera (IC50 value 28.82±1.85 μg/mL), P. nigrum (IC50 value 30.21±1.63 μg/mL), and M. koenigii (IC50 value 35.66±1.64 μg/mL). It may be concluded that the alkaloidal extracts of these plants possess potent aldose reductase inhibitory activity and may be therapeutically exploited in diabetes-related complications associated with increased activity of aldose reductase.

Off-label use of TNF-alpha inhibitors in a dermatological university department: retrospective evaluation of 118 patients.

PubMed

Sand, Freja Lærke; Thomsen, Simon Francis

2015-01-01

Tumor necrosis factor-alpha (TNF)-alpha inhibitors are licensed for patients with severe refractory psoriasis and psoriatic arthritis. However, TNF-alpha inhibitors have also been used off-label for various recalcitrant mucocutaneous diseases. This study aimed to evaluate the efficacy and safety of TNF-alpha inhibitors used for off-label dermatological indications. We retrospectively evaluated patient records of 118 patients treated off-label with TNF-alpha inhibitors in a dermatological university department. Patients presented with severe aphthous stomatitis/genital aphthous lesions (26), chronic urticaria (25), hidradenitis suppurativa (29), acne conglobata (11), dissecting cellulitis of the scalp (two), orofacial granulomatosis (four), sarcoidosis (four), granuloma annulare (two), granulomatous rosacea (one), granuloma faciale (one), subcorneal pustulosis (one), pyoderma gangrenosum (four), Sweet's syndrome (four), Well's syndrome (one), benign familial pemphigus (one), lichen planus (one), and folliculitis decalvans (one). A significant number of these patients went into remission during therapy with TNF-alpha inhibitors. A total of 11 patients (9%) experienced severe adverse effects during therapy. Off-label therapy with TNF-alpha inhibitors may be considered for selected patients with severe recalcitrant mucocutaneous diseases. The risk of severe adverse effects signals that a thorough benefit-risk assessment should be performed before initiating off-label treatment with TNF-alpha inhibitors for these conditions. © 2015 Wiley Periodicals, Inc.

[The effects of combination therapy with 5-reductase inhibitor and -blocker on the prognosis of BPH].

PubMed

Neimark, A I; Davydov, A V; Aliev, R T

2018-05-01

Benign prostatic hyperplasia (BPH) is a polyethological disease of elderly and old men. The symptomatic pharmacological treatment of BPH involves the use of drugs that reduce either the dynamic component of obstruction or the size of the prostate (a mechanical component of obstruction). 5-reductase inhibitors (5-ARI) and -blockers are considered first-line therapy in the management of prostate adenoma. To investigate the efficacy of combination therapy with Fokusin and Penester in BPH patients. The study is based on the analysis of medical records of 67 BPH patients aged over 50 years. All patients included in the study were randomized to 3 groups and had comparable age, sex, clinical manifestations and severity of the disease. Group 1 comprised 21 patients (mean age 63.8+/-9.7 years), who received a 5-reductase inhibitor (5-ARI) Pentester (Sanofi, France) 5 mg once daily. Group 2 included 22 patients (mean age 65.2+/-7.8 years), who received an -blocker Fokusin (Sanofi, France) 0.4 mg once a day. Group 3 comprised 24 patients (mean age 64.2+/-8.6 years) who received combination therapy with 5-reductase inhibitor (5-ARI) (Penester 5 mg once daily) and blocker (Fokusin 0.4 mg once daily). The study findings showed that in comparison with monotherapy, the concurrent administration of Fokusin and Penester was more effective in reducing the clinical manifestations of BPH, slowing the growth of adenomatous tissue thus reducing the size of the enlarged prostate. Combination therapy with Fokusin and Penester can be recommended to improve the treatment results of BPH patients.

[Status of phytotherapeutic drugs in treatment of benign prostatic hyperplasia].

PubMed

Dreikorn, K; Schönhöfer, P S

1995-03-01

Phytotherapeutic preparations are still commonly used for the treatment of symptomatic benign prostate hyperplasia (BPH) in Germany; in recent years there has even been an increase in their use, so that sales now amount to more than DM 220 millions per year. The preparations most frequently used are extracts of Hypoxis rooperi, the roots of the stinging nettle, the fruits of the saw palmetto, pumpkin seeds and rye pollen. The suggested mechanisms of action have not been documented by scientific observation. This applies especially to the blocking effect on 5 alpha-reductase postulated with the doses used. Moreover, a critical analysis of the data available suggests that the effects of phytotherapy are no better than those of placebo treatment. Further studies are urgently needed, to compare the effects of phytotherapy with those of chemically defined drugs (alpha 1-receptor antagonists, 5 alpha-reductase blocker) that seem to have a beneficial influence on the pathomechanism underlying symptomatic BPH.

Effect of beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitors and antioxidant vitamins on free radical lipid oxidation in rat liver.

PubMed

Lankin, V Z; Ivanova, M V; Konovalova, G G; Tikhaze, A K; Kaminnyi, A I; Kukharchuk, V V

2007-04-01

We studied the effects of two inhibitors of beta-hydroxy-beta-methylglutaryl coenzyme A reductase, simvastatin and lovastatin, on the lag phase of ascorbate-dependent lipid oxidation in rat liver. Oxidizability of liver biological membranes significantly increased in intact animals and rats with induced hypercholesterolemia after peroral administration of these statins. The lag phase of ascorbate-dependent lipid oxidation in liver biomembranes decreased by 2.1 times in hypercholesterolemic rats. In animals of the lovastatin group this parameter decreased by 4.4 times compared to the control. In intact rats receiving simvastatin, the lag phase of oxidation in biomembranes from the liver decreased practically by 2 times. At the same time, in animals receiving simvastatin in combination with antioxidant vitamins (vitamins E and C, provitamin A) and selenium, the period of induction of oxidation increased by 3.3 times. Our results indicate that beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitors produce a prooxidant effect on the liver, which can be prevented by administration of antioxidant agents.

Can HMG Co-A reductase inhibitors (“statins”) slow the progression of age-related macular degeneration? The Age-Related Maculopathy Statin Study (ARMSS)

PubMed Central

Guymer, Robyn H; Dimitrov, Peter N; Varsamidis, Mary; Lim, Lyndell L; Baird, Paul N; Vingrys, Algis J; Robman, Luba

2008-01-01

Age-related macular degeneration (AMD) is responsible for the majority of visual impairment in the Western world. The role of cholesterol-lowering medications, HMG Co-A reductase inhibitors or statins, in reducing the risk of AMD or of delaying its progression has not been fully investigated. A 3-year prospective randomized controlled trial of 40 mg simvastatin per day compared to placebo in subjects at high risk of AMD progression is described. This paper outlines the primary aims of the Age-Related Maculopathy Statin Study (ARMSS), and the methodology involved. Standardized clinical grading of macular photographs and comparison of serial macular digital photographs, using the International grading scheme, form the basis for assessment of primary study outcomes. In addition, macular function is assessed at each visit with detailed psychophysical measurements of rod and cone function. Information collected in this study will assist in the assessment of the potential value of HMG Co-A reductase inhibitors (statins) in reducing the risk of AMD progression. PMID:18982929

Comparison of the potency of different brands of Serenoa repens extract on 5alpha-reductase types I and II in prostatic co-cultured epithelial and fibroblast cells.

PubMed

Scaglione, Francesco; Lucini, Valeria; Pannacci, Marilou; Caronno, Alessia; Leone, Claude

2008-01-01

Serenoa repens extract is the phytotherapeutic agent most frequently used for the treatment of the urological symptoms caused by benign prostatic hyperplasia. There are many extracts in the market and each manufacturer uses different extraction processes; for this reason, it's possible that one product is not equivalent to another. The aim of this study was to compare the activity of different extracts of Serenoa repens marketed in Italy. The following extracts were tested on 10 day co-cultured epithelial and fibroblast cells by a 5alpha-reductase activity assay: Permixon, Saba, Serpens, Idiprost, Prostamev, Profluss and Prostil. In order to assess the variability in Serenoa repens products, 2 different batches for each brand were evaluated. All extracts tested, albeit variably, are able to inhibit both isoforms of 5alpha-reductase. However, the potency of the extracts appears to be very different, as well as the potencies of 2 different batches of the same extract. This is probably due to qualitative and quantitative differences in the active ingredients. So, the product of each company must be tested to evaluate the clinical efficacy and bioactivity. Copyright 2008 S. Karger AG, Basel.

New steroid 5alpha-reductase type I (SRD5A1) homologous sequences on human chromosomes 6 and 8.

PubMed

Eminović, I; Liović, M; Prezelj, J; Kocijancic, A; Rozman, D; Komel, R

2001-01-01

To date, two genes encoding 5alpha-reductase isoenzymes are known (type I, type II), and one type I pseudogene. The divergent localization of these genes and the still not fully understood function of the encoded enzymes as well as the perplexing results we obtained after sequencing PCR-amplified SRD5A1 gene fragments (out of genomic DNA), made us assume that, in addition to the known SRD5A1 gene, one or more different human 5alpha-reductase type I coding genes may exist. Our research provide the first evidence for the existence of two new SRD5A1 related, previously unidentified sequences in the human genome. These sequences which were localized to chromosomes 6 and 8 are highly homologous (> 99%) to SRD5A1, and also do not contain any deletions or insertions that are otherwise a characteristic of the SRD5API pseudogene. Our results imply that these sequences may be either coding parts of yet unknown, active SRD5A1 genes, and/or of previously unidentified pseudogenes. These findings additionally support data of Chen et al. who confirmed the existence of various SRD5A1 proteins in cultured human skin cells.

Brevetoxin-2, is a unique inhibitor of the C-terminal redox center of mammalian thioredoxin reductase-1.

PubMed

Chen, Wei; Tuladhar, Anupama; Rolle, Shantelle; Lai, Yanhao; Rodriguez Del Rey, Freddy; Zavala, Cristian E; Liu, Yuan; Rein, Kathleen S

2017-08-15

Karenia brevis, the Florida red tide dinoflagellate produces a suite of neurotoxins known as the brevetoxins. The most abundant of the brevetoxins PbTx-2, was found to inhibit the thioredoxin-thioredoxin reductase system, whereas the PbTx-3 has no effect on this system. On the other hand, PbTx-2 activates the reduction of small disulfides such as 5,5'-dithio-bis-(2-nitrobenzoic acid) by thioredoxin reductase. PbTx-2 has an α, β-unsaturated aldehyde moiety which functions as an efficient electrophile and selenocysteine conjugates are readily formed. PbTx-2 blocks the inhibition of TrxR by the inhibitor curcumin, whereas curcumin blocks PbTx-2 activation of TrxR. It is proposed that the mechanism of inhibition of thioredoxin reduction is via the formation of a Michael adduct between selenocysteine and the α, β-unsaturated aldehyde moiety of PbTx-2. PbTx-2 had no effect on the rates of reactions catalyzed by related enzymes such as glutathione reductase, glutathione peroxidase or glutaredoxin. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel class of α-glucosidase and HMG-CoA reductase inhibitors from Ganoderma leucocontextum and the anti-diabetic properties of ganomycin I in KK-Ay mice.

PubMed

Wang, Kai; Bao, Li; Ma, Ke; Zhang, Jinjin; Chen, Baosong; Han, Junjie; Ren, Jinwei; Luo, Huajun; Liu, Hongwei

2017-02-15

Three new meroterpenoids, ganoleucin A-C (1-3), together with five known meroterpenoids (4-8), were isolated from the fruiting bodies of Ganoderma leucocontextum. The structures of the new compounds were elucidated by extensive spectroscopic analysis, circular dichroism (CD) spectroscopy, and chemical transformation. The inhibitory effects of 1-8 on HMG-CoA reductase and α-glucosidase were tested in vitro. Ganomycin I (4), 5, and 8 showed stronger inhibitory activity against HMG-CoA reductase than the positive control atorvastatin. Compounds 1, and 3-8 presented potent noncompetitive inhibitory activity against α-glucosidase from both yeast and rat small intestinal mucosa. Ganomycin I (4), the most potent inhibitor against both α-glucosidase and HMG-CoA reductase, was synthesized and evaluated for its in vivo bioactivity. Pharmacological results showed that ganomycin I (4) exerted potent and efficacious hypoglycemic, hypolipidemic, and insulin-sensitizing effects in KK-A y mice. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Structure-Based Approach to the Development of Potent and Selective Inhibitors of Dihydrofolate Reductase from Cryptosporidium

PubMed Central

Bolstad, David B.; Bolstad, Erin S. D.; Frey, Kathleen M.; Wright, Dennis L.; Anderson, Amy C.

2008-01-01

Cryptosporidiosis is an emerging infectious disease that can be life-threatening in an immune-compromised individual and causes gastrointestinal distress lasting up to 2 weeks in an immune-competent individual. There are few therapeutics available for effectively treating this disease. We have been exploring dihydrofolate reductase (DHFR) as a potential target in Cryptosporidium. On the basis of the structure of the DHFR enzyme from C. hominis, we have developed a novel scaffold that led to the discovery of potent (38 nM) and efficient inhibitors of this enzyme. Recently, we have advanced these inhibitors to the next stage of development. Using the structures of both the protozoal and human enzymes, we have developed inhibitors with nanomolar potency (1.1 nM) against the pathogenic enzyme and high levels (1273-fold) of selectivity over the human enzyme. PMID:18834108

A facile synthesis of lanost-8-en-3 beta-ol-24-one (24-ketolanosterol). An inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase.

PubMed

Parish, E J; Honda, H; Chitrakorn, S; Taylor, F R

1988-10-01

A facile chemical synthesis of lanost-8-en-3 beta-ol-24-one (24-ketolanosterol) is described. This compound was found to be a potent inhibitor of 3-hydroxy-3-methylglutaryl (HMG) CoA reductase activity in cultured mouse L cells. The synthetic scheme developed in this study utilizes commercial lanosterol as a starting material and involves selective hydroboration of the C-24 double bond followed by oxidation of the carbon-boron bond at C-24 by pyridinium chlorochromate (PCC).

The Biochemical Basis of Hydroxymethylglutaryl-CoA Reductase Inhibitors as Neuroprotective Agents in Aneurysmal Subarachnoid Hemorrhage

PubMed Central

Wong, George Kwok Chu; Poon, Wai Sang

2010-01-01

Aneurysmal subarachnoid hemorrhage (SAH) has the highest morbidity and mortality rates of all types of stroke. Many aneurysmal SAH patients continue to suffer from significant neurological morbidity and mortality directly related to delayed cerebral ischemia. Pilot clinical studies of the use of Hydroxymethylglutaryl-CoA Reductase Inhibitors (statins) in aneurysmal SAH patients have reported a reduction in delayed cerebral ischemia and better clinical outcomes. We review the biochemical effects of statins on endothelium vascular function, glutamate-mediated neurotoxicity, inflammatory changes, and oxidative injuries, with reference to their possible neuroprotective effects in aneurysmal SAH.

Variants in the 5alpha-reductase type 1 and type 2 genes are associated with polycystic ovary syndrome and the severity of hirsutism in affected women.

PubMed

Goodarzi, Mark O; Shah, Nissar A; Antoine, Heath J; Pall, Marita; Guo, Xiuqing; Azziz, Ricardo

2006-10-01

Despite the importance of dihydrotestosterone in androgen action, polymorphisms in the genes for the two isoforms of 5alpha-reductase (SRD5A1 and SRD5A2) have not been evaluated as risk factors for polycystic ovary syndrome (PCOS). The objective of the study was to test the hypothesis that haplotypes in the SRD5A1 and SRD5A2 genes are risk factors for PCOS and the severity of hirsutism in affected women. PCOS and control subjects were genotyped for seven single-nucleotide polymorphisms in SRD5A1 and eight single-nucleotide polymorphisms in SRD5A2. Haplotypes were determined and tested for association with PCOS diagnosis and component phenotypes. Subjects were recruited from the reproductive endocrinology clinic at the University of Alabama at Birmingham; control subjects were recruited from the general surrounding community. Genotyping took place at Cedars-Sinai Medical Center in Los Angeles. A total of 287 White women with PCOS and 187 controls participated. SRD5A1 and SRD5A2 genotype, quantitative hirsutism score, and hormonal and metabolic phenotypes were assessed. Haplotypes within both genes were associated with PCOS risk. The Leu allele of the Val89Leu variant in SRD5A2 was associated with protection against PCOS; this allele is known to modestly reduce 5alpha-reductase activity. Haplotypes in SRD5A1 but not SRD5A2 were also associated with the degree of hirsutism in affected women. This study presents genetic evidence suggesting an important role of both isoforms of 5alpha-reductase in the pathogenesis of PCOS. That only SRD5A1 haplotypes were associated with hirsutism suggests that only this isoform is important in the hair follicle.

Androgens and alopecia.

PubMed

Kaufman, Keith D

2002-12-30

Androgens have profound effects on scalp and body hair in humans. Scalp hair grows constitutively in the absence of androgens, while body hair growth is dependent on the action of androgens. Androgenetic alopecia, referred to as male pattern hair loss (MPHL) in men and female pattern hair loss (FPHL) in women, is due to the progressive miniaturization of scalp hair. Observations in both eunuchs, who have low levels of testicular androgens, and males with genetic 5alpha-reductase (5alphaR) deficiency, who have low levels of dihydrotestosterone (DHT), implicate DHT as a key androgen in the pathogenesis of MPHL in men. The development of finasteride, a type 2-selective 5alphaR inhibitor, further advanced our understanding of the role of DHT in the pathophysiology of scalp alopecia. Controlled clinical trials with finasteride demonstrated improvements in scalp hair growth in treated men associated with reductions in scalp DHT content, and a trend towards reversal of scalp hair miniaturization was evident by histopathologic evaluation of scalp biopsies. In contrast to its beneficial effects in men, finasteride did not improve hair growth in postmenopausal women with FPHL. Histopathological evaluation of scalp biopsies confirmed that finasteride treatment produced no benefit on scalp hair in these women. These findings suggest that MPHL and FPHL are distinct clinical entities, with disparate pathophysiologies. Studies that elucidate the molecular mechanisms by which androgens regulate hair growth would provide greater understanding of these differences. Copyright 2002 Elsevier Science Ireland Ltd.

Dihydroquinazolines as a novel class of Trypanosoma brucei trypanothione reductase inhibitors: discovery, synthesis, and characterization of their binding mode by protein crystallography.

PubMed

Patterson, Stephen; Alphey, Magnus S; Jones, Deuan C; Shanks, Emma J; Street, Ian P; Frearson, Julie A; Wyatt, Paul G; Gilbert, Ian H; Fairlamb, Alan H

2011-10-13

Trypanothione reductase (TryR) is a genetically validated drug target in the parasite Trypanosoma brucei , the causative agent of human African trypanosomiasis. Here we report the discovery, synthesis, and development of a novel series of TryR inhibitors based on a 3,4-dihydroquinazoline scaffold. In addition, a high resolution crystal structure of TryR, alone and in complex with substrates and inhibitors from this series, is presented. This represents the first report of a high resolution complex between a noncovalent ligand and this enzyme. Structural studies revealed that upon ligand binding the enzyme undergoes a conformational change to create a new subpocket which is occupied by an aryl group on the ligand. Therefore, the inhibitor, in effect, creates its own small binding pocket within the otherwise large, solvent exposed active site. The TryR-ligand structure was subsequently used to guide the synthesis of inhibitors, including analogues that challenged the induced subpocket. This resulted in the development of inhibitors with improved potency against both TryR and T. brucei parasites in a whole cell assay.

Anti-neuroinflammatory efficacy of the aldose reductase inhibitor FMHM via phospholipase C/protein kinase C-dependent NF-κB and MAPK pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeng, Ke-Wu; Li, Jun; Dong, Xin

2013-11-15

Aldose reductase (AR) has a key role in several inflammatory diseases: diabetes, cancer and cardiovascular diseases. Therefore, AR inhibition seems to be a useful strategy for anti-inflammation therapy. In the central nervous system (CNS), microglial over-activation is considered to be a central event in neuroinflammation. However, the effects of AR inhibition in CNS inflammation and its underlying mechanism of action remain unknown. In the present study, we found that FMHM (a naturally derived AR inhibitor from the roots of Polygala tricornis Gagnep.) showed potent anti-neuroinflammatory effects in vivo and in vitro by inhibiting microglial activation and expression of inflammatory mediators.more » Mechanistic studies showed that FMHM suppressed the activity of AR-dependent phospholipase C/protein kinase C signaling, which further resulted in downstream inactivation of the IκB kinase/IκB/nuclear factor-kappa B (NF-κB) inflammatory pathway. Therefore, AR inhibition-dependent NF-κB inactivation negatively regulated the transcription and expression of various inflammatory genes. AR inhibition by FMHM exerted neuroprotective effects in lipopolysaccharide-induced neuron–microglia co-cultures. These findings suggested that AR is a potential target for neuroinflammation inhibition and that FMHM could be an effective agent for treating or preventing neuroinflammatory diseases. - Highlights: • FMHM is a natural-derived aldose reductase (AR) inhibitor. • FMHM inhibits various neuroinflammatory mediator productions in vitro and in vivo. • FMHM inhibits neuroinflammation via aldose reductase/PLC/PKC-dependent NF-κB pathway. • FMHM inhibits neuroinflammation via aldose reductase/PLC/PKC-dependent MAPK pathway. • FMHM protects neurons against inflammatory injury in microglia-neuron co-cultures.« less

A crystalline protein-proteinase inhibitor from pinto bean seeds.

PubMed

Wang, D

1975-06-26

A crystalline protein-proteinase inhibitor has been isolated from seeds of Pinto bean (Phaseolus vulgaris cultvar. Pinto). It has an average molecular weight of 19 000 as estimated by gel filtration. This crystalline inhibitor is highly active against both bovine pancreatic trypsin and alpha-chymotrypsin. Complexes of both trypsin-inhibitor and alpha-chymotrypsin-inhibitor have been isolated. The inhibitor which was derived from the dissociated trypsin-inhibitor complex was only 62% as effective as the original compound against either enzyme. In contrast, the inhibitor obtained from alpha-chymotrypsin-inhibitor complex retained its full original inhibitory activity for trypsin, but only 25% of its original activity against alpha-chymotrypsin. The dissociated inhibitor from alpha-chymotrypsin-inhibitor compex, despite its full inhibitory activity, had been modified to such an extent that it could no longer form any precipitable complex with trypsin. The crystalline protein-proteinase inhibitor is not homogeneous and has been resolved into two distinct inhibitors in terms of their physical and chemical properties. These two inhibitors are designated as Pinto bean proteinase inhibitor I and II and their respective minimum molecular weights are 9100 and 10 000. They differ most strikingly in their amino acid composition in that inhibitor II is void of both valine and methionine.

In silico screening for Plasmodium falciparum enoyl-ACP reductase inhibitors

NASA Astrophysics Data System (ADS)

Lindert, Steffen; Tallorin, Lorillee; Nguyen, Quynh G.; Burkart, Michael D.; McCammon, J. Andrew

2015-01-01

The need for novel therapeutics against Plasmodium falciparum is urgent due to recent emergence of multi-drug resistant malaria parasites. Since fatty acids are essential for both the liver and blood stages of the malarial parasite, targeting fatty acid biosynthesis is a promising strategy for combatting P. falciparum. We present a combined computational and experimental study to identify novel inhibitors of enoyl-acyl carrier protein reductase ( PfENR) in the fatty acid biosynthesis pathway. A small-molecule database from ChemBridge was docked into three distinct PfENR crystal structures that provide multiple receptor conformations. Two different docking algorithms were used to generate a consensus score in order to rank possible small molecule hits. Our studies led to the identification of five low-micromolar pyrimidine dione inhibitors of PfENR.

Gender identity of children and young adults with 5alpha-reductase deficiency.

PubMed

Praveen, E P; Desai, Ankush K; Khurana, M L; Philip, Jim; Eunice, Marumudi; Khadgawat, Rajesh; Kulshreshtha, Bindu; Kucheria, Kiran; Gupta, Devendra K; Seith, Ashu; Ammini, Ariachery C

2008-02-01

Male pseudohermaphroditism (46,XY DSD) due to 5alpha-reductase deficiency has been recognized for the last few decades. There is scant literature on this entity in India. We compiled data on five patients with this disorder. Four of our five patients were reared as females. Our assessment of these children reveals that they had male gender identity from childhood. Three of the four reared as females chose to change gender role at adolescence, while the fourth is still prepubertal. We conclude that all these patients had male gender identity from early childhood. The parents took note of this only after the appearance of male secondary sexual characteristics at puberty, thereby giving an impression of change in gender identity and gender role.

Combinations of ERK and p38 MAPK inhibitors ablate tumor necrosis factor-alpha (TNF-alpha ) mRNA induction. Evidence for selective destabilization of TNF-alpha transcripts.

PubMed

Rutault, K; Hazzalin, C A; Mahadevan, L C

2001-03-02

Tumor necrosis factor-alpha (TNF-alpha) is a potent proinflammatory cytokine whose synthesis and secretion are implicated in diverse pathologies. Hence, inhibition of TNF-alpha transcription or translation and neutralization of its protein product represent major pharmaceutical strategies to control inflammation. We have studied the role of ERK and p38 mitogen-activated protein (MAP) kinase in controlling TNF-alpha mRNA levels in differentiated THP-1 cells and in freshly purified human monocytes. We show here that it is possible to produce virtually complete inhibition of lipopolysaccharide-stimulated TNF-alpha mRNA accumulation by using a combination of ERK and p38 MAP kinase inhibitors. Furthermore, substantial inhibition is achievable using combinations of 1 microm of each inhibitor, whereas inhibitors used individually are incapable of producing complete inhibition even at high concentrations. Finally, addressing mechanisms involved, we show that inhibition of p38 MAP kinase selectively destabilizes TNF-alpha transcripts but does not affect degradation of c-jun transcripts. These results impinge on the controversy in the literature surrounding the mode of action of MAP kinase inhibitors on TNF-alpha mRNA and suggest the use of combinations of MAP kinase inhibitors as an effective anti-inflammatory strategy.

Prescribing Habits for Androgenic Alopecia Among Dermatologists in Spain in 2017: A Cross-Sectional Study.

PubMed

Pindado-Ortega, C; Saceda-Corralo, D; Buendía-Castaño, D; Fernández-González, P; Moreno-Arrones, Ó M; Fonda-Pascual, P; Alegre-Sánchez, A; Rodrigues-Barata, A R; Vañó-Galván, S

2018-04-12

Topical minoxidil and oral finasteride are the only drugs approved for the treatment of androgenetic alopecia (AGA) in Spain. However, the management of this condition is highly variable because numerous treatments are used off-label. The main aim of this study was to describe the prescribing habits of dermatologists in Spain for male AGA (MAGA) and female AGA (FAGA). Descriptive cross-sectional study using online questionnaires completed by dermatologists working in Spain. The responses of 241 dermatologists were analyzed. The most common treatments prescribed for MAGA were minoxidil (98%), oral finasteride (96%), nutricosmetics (44%), topical finasteride (37%), oral dutasteride (33%), platelet-rich plasma (14%), and low-level laser therapy (8%). For premenopausal FAGA, the most common treatments were topical minoxidil (98%), oral contraceptives (81%), nutricosmetics (72%), cyproterone acetate (58%), oral finasteride (39%), topical finasteride (39%), spironolactone (27%), platelet-rich plasma (20%), oral dutasteride (20%), oral flutamide (18%), and low-level laser therapy (7%). Finally, for postmenopausal FAGA, the most common treatments prescribed were topical minoxidil (98%), oral finasteride (84%), nutricosmetics (68%), topical finasteride (50%), oral dutasteride (35%), platelet-rich plasma (21%), spironolactone (16%), cyproterone acetate (16%), oral flutamide (9%), and low-level laser therapy (9%). A limitation of our study is that we did not analyze novel AGA treatments such as oral minoxidil and dutasteride mesotherapy. The most common treatments prescribed for AGA by dermatologists in Spain are topical minoxidil, oral finasteride, and nutricosmetics for MAGA and postmenopausal FAGA and topical minoxidil, oral contraceptives, and nutricosmetics for premenopausal FAGA. Copyright © 2018 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Post-finasteride syndrome and post-SSRI sexual dysfunction: two sides of the same coin?

PubMed

Giatti, Silvia; Diviccaro, Silvia; Panzica, Giancarlo; Melcangi, Roberto Cosimo

2018-04-19

Sexual dysfunction is a clinical condition due to different causes including the iatrogenic origin. For instance, it is well known that sexual dysfunction may occur in patients treated with antidepressants like selective serotonin reuptake inhibitors (SSRI). A similar side effect has been also reported during treatment with finasteride, an inhibitor of the enzyme 5alpha-reductase, for androgenetic alopecia. Interestingly, sexual dysfunction persists in both cases after drug discontinuation. These conditions have been named post-SSRI sexual dysfunction (PSSD) and post-finasteride syndrome (PFS). In particular, feeling of a lack of connection between the brain and penis, loss of libido and sex drive, difficulty in achieving an erection and genital paresthesia have been reported by patients of both conditions. It is interesting to note that the incidence of these diseases is probably so far underestimated and their etiopathogenesis is not sufficiently explored. To this aim, the present review will report the state of art of these two different pathologies and discuss, on the basis of the role exerted by three different neuromodulators such as dopamine, serotonin and neuroactive steroids, whether the persistent sexual dysfunction observed could be determined by common mechanisms.

Regulation of HMG-CoA reductase in MCF-7 cells by genistein, EPA, and DHA, alone and in combination with mevastatin.

PubMed

Duncan, Robin E; El-Sohemy, Ahmed; Archer, Michael C

2005-06-28

We investigated the regulation of HMG-CoA reductase in MCF-7 human breast cancer cells by genistein, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). All three compounds down-regulated reductase activity, primarily through post-transcriptional effects. In mevastatin-treated cells, only genistein and DHA abrogated the induction of reductase activity caused by this competitive inhibitor. Diets rich in soy isoflavones and fish oils, therefore, may exert anti-cancer effects through the inhibition of mevalonate synthesis in the breast. Genistein and DHA, in particular, may augment the efficacy of statins, increasing the potential for use of these drugs in adjuvant therapy for breast cancer.

1H and 13C NMR Chemical Shift Assignments and Conformational Analysis for the Two Diastereomers of the Vitamin K Epoxide Reductase Inhibitor Brodifacoum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cort, John R.; Cho, Herman M.

2009-10-01

Proton and 13C NMR chemical shift assignments and 1H-1H scalar couplings for the two diastereomers of the vitamin K epoxide reductase (VKOR) inhibitor brodifacoum have been determined from acetone solutions containing both diastereomers. Data were obtained from homo- and heteronuclear correlation spectra acquired at 1H frequencies of 750 and 900 MHz over a 268-303 K temperature range. Conformations inferred from scalar coupling and 1-D NOE measurements exhibit large differences between the diastereomers. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Inhibition of Mycobacterium tuberculosis dihydrodipicolinate synthase by alpha-ketopimelic acid and its other structural analogues

PubMed Central

Shrivastava, Priyanka; Navratna, Vikas; Silla, Yumnam; Dewangan, Rikeshwer P.; Pramanik, Atreyi; Chaudhary, Sarika; Rayasam, GeethaVani; Kumar, Anuradha; Gopal, Balasubramanian; Ramachandran, Srinivasan

2016-01-01

The Mycobacterium tuberculosis dihydrodipicolinate synthase (Mtb-dapA) is an essential gene. Mtb-DapA catalyzes the aldol condensation between pyruvate and L-aspartate-beta-semialdehyde (ASA) to yield dihydrodipicolinate. In this work we tested the inhibitory effects of structural analogues of pyruvate on recombinant Mtb-DapA (Mtb-rDapA) using a coupled assay with recombinant dihydrodipicolinate reductase (Mtb-rDapB). Alpha-ketopimelic acid (α-KPA) showed maximum inhibition of 88% and IC50 of 21 μM in the presence of pyruvate (500 μM) and ASA (400 μM). Competition experiments with pyruvate and ASA revealed competition of α-KPA with pyruvate. Liquid chromatography-mass spectrometry (LC-MS) data with multiple reaction monitoring (MRM) showed that the relative abundance peak of final product, 2,3,4,5-tetrahydrodipicolinate, was decreased by 50%. Thermal shift assays showed 1 °C Tm shift of Mtb-rDapA upon binding α-KPA. The 2.4 Å crystal structure of Mtb-rDapA-α-KPA complex showed the interaction of critical residues at the active site with α-KPA. Molecular dynamics simulations over 500 ns of pyruvate docked to Mtb-DapA and of α-KPA-bound Mtb-rDapA revealed formation of hydrogen bonds with pyruvate throughout in contrast to α-KPA. Molecular descriptors analysis showed that ligands with polar surface area of 91.7 Å2 are likely inhibitors. In summary, α-hydroxypimelic acid and other analogues could be explored further as inhibitors of Mtb-DapA. PMID:27501775

New Treatments for Hair Loss.

PubMed

Vañó-Galván, S; Camacho, F

2017-04-01

The treatment of hair loss is an important part of clinical dermatology given the prevalence of the problem and great impact on patients' quality of life. Many new treatments have been introduced in recent years. This review summarizes the main ones in 4 groups: a) For androgenetic alopecia, we discuss new excipients for oral minoxidil, dutasteride, and finasteride as well as new forms of topical application; prostaglandin agonists and antagonists; low-level laser therapy; and regenerative medicine with Wnt signaling activators and stem cell therapy. b) For alopecia areata, Janus kinase inhibitors are reviewed. c) For frontal fibrosing alopecia, we discuss the use of antiandrogens and, for some patients, pioglitazone. d) Finally, we mention new robotic devices for hair transplant procedures and techniques for optimal follicular unit extraction. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Discovery of Ecopladib, an indole inhibitor of cytosolic phospholipase A2alpha.

PubMed

Lee, Katherine L; Foley, Megan A; Chen, Lihren; Behnke, Mark L; Lovering, Frank E; Kirincich, Steven J; Wang, Weiheng; Shim, Jaechul; Tam, Steve; Shen, Marina W H; Khor, Soopeang; Xu, Xin; Goodwin, Debra G; Ramarao, Manjunath K; Nickerson-Nutter, Cheryl; Donahue, Frances; Ku, M Sherry; Clark, James D; McKew, John C

2007-03-22

The synthesis and structure-activity relationship of a series of indole inhibitors of cytosolic phospholipase A2alpha (cPLA2alpha, type IVA phospholipase) are described. Inhibitors of cPLA2alpha are predicted to be efficacious in treating asthma as well as the signs and symptoms of osteoarthritis, rheumatoid arthritis, and pain. The introduction of a benzyl sulfonamide substituent at C2 was found to impart improved potency of these inhibitors, and the SAR of these sulfonamide analogues is disclosed. Compound 123 (Ecopladib) is a sub-micromolar inhibitor of cPLA2alpha in the GLU micelle and rat whole blood assays. Compound 123 displayed oral efficacy in the rat carrageenan air pouch and rat carrageenan-induced paw edema models.

Comparative genomic and phylogenetic analysis of short-chain dehydrogenases/reductases with dual retinol/sterol substrate specificity.

PubMed

Belyaeva, Olga V; Kedishvili, Natalia Y

2006-12-01

Human short-chain dehydrogenases/reductases with dual retinol/sterol substrate specificity (RODH-like enzymes) are thought to contribute to the oxidation of retinol for retinoic acid biosynthesis and to the metabolism of androgenic and neuroactive 3alpha-hydroxysteroids. Here, we investigated the phylogeny and orthology of these proteins to understand better their origins and physiological roles. Phylogenetic and genomic analysis showed that two proteins (11-cis-RDH and RDHL) are highly conserved, and their orthologs can be identified in the lower taxa, such as amphibians and fish. Two other proteins (RODH-4 and 3alpha-HSD) are significantly less conserved. Orthologs for 3alpha-HSD are present in all mammals analyzed, whereas orthologs for RODH-4 can be identified in some mammalian species but not in others due to species-specific gene duplications. Understanding the evolution and divergence of RODH-like enzymes in various vertebrate species should facilitate further investigation of their in vivo functions using animal models.

Testosterone 5alpha-reductase inhibitory active constituents of Piper nigrum leaf.

PubMed

Hirata, Noriko; Tokunaga, Masashi; Naruto, Shunsuke; Iinuma, Munekazu; Matsuda, Hideaki

2007-12-01

Previously we reported that Piper nigrum leaf extract showed a potent stimulation effect on melanogenesis and that (-)-cubebin (1) and (-)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2) were isolated as active constituents. As a part of our continuous studies on Piper species for the development of cosmetic hair-care agents, testosterone 5alpha-reductase inhibitory activity of aqueous ethanolic extracts obtained from several different parts of six Piper species, namely Piper nigrum, P. methysticum, P. betle, P. kadsura, P. longum, and P. cubeba, were examined. Among them, the extracts of P. nigrum leaf, P. nigrum fruit and P. cubeba fruit showed potent inhibitory activity. Activity-guided fractionation of P. nigrum leaf extract led to the isolation of 1 and 2. Fruits of P. cubeba contain 1 as a major lignan, thus inhibitory activity of the fruit may be attributable to 1. As a result of further assay on other known constituents of the cited Piper species, it was found that piperine, a major alkaloid amide of P. nigrum fruit, showed potent inhibitory activity, thus a part of the inhibitory activity of P. nigrum fruit may depend on piperine. The 5alpha-reductase inhibitory activities of 1 and piperine were found for the first time. In addition, the P. nigrum leaf extract showed in vivo anti-androgenic activity using the hair regrowth assay in testosterone sensitive male C57Black/6CrSlc strain mice.

21 CFR 866.5890 - Inter-alpha trypsin inhibitor immunological test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... measure by immunochemical techniques the inter-alpha trypsin inhibitor (a protein) in serum and other body fluids. Measurement of inter-alpha trypsin inhibitor may aid in the diagnosis of acute bacterial...

21 CFR 866.5890 - Inter-alpha trypsin inhibitor immunological test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... measure by immunochemical techniques the inter-alpha trypsin inhibitor (a protein) in serum and other body fluids. Measurement of inter-alpha trypsin inhibitor may aid in the diagnosis of acute bacterial...

21 CFR 866.5890 - Inter-alpha trypsin inhibitor immunological test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... measure by immunochemical techniques the inter-alpha trypsin inhibitor (a protein) in serum and other body fluids. Measurement of inter-alpha trypsin inhibitor may aid in the diagnosis of acute bacterial...

21 CFR 866.5890 - Inter-alpha trypsin inhibitor immunological test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... measure by immunochemical techniques the inter-alpha trypsin inhibitor (a protein) in serum and other body fluids. Measurement of inter-alpha trypsin inhibitor may aid in the diagnosis of acute bacterial...

Potential role of recombinant secretory leucoprotease inhibitor in the prevention of neutrophil mediated matrix degradation.

PubMed

Llewellyn-Jones, C G; Lomas, D A; Stockley, R A

1994-06-01

Neutrophil elastase is able to degrade connective tissue matrices and is thought to be involved in the pathogenesis of destructive lung diseases. The ability of recombinant secretory leucoprotease inhibitor (rSLPI) to inhibit neutrophil mediated degradation of fibronectin in vitro is demonstrated and its efficacy compared with native alpha-1-proteinase inhibitor (n alpha 1-PI), recombinant alpha-1-proteinase inhibitor (r alpha 1-PI), and the chemical elastase inhibitor ICI 200,355. When preincubated with neutrophils both rSLPI and r alpha 1-PI were effective inhibitors of fibronectin degradation although n alpha 1-PI and ICI 200,355 were less effective. Recombinant SLPI was the most effective inhibitor when the cells were allowed to adhere to fibronectin before the addition of the inhibitors. Preincubation of rSLPI (0.1 mumol/l) with the fibronectin plate resulted in almost total inhibition of fibronectin degradation (reduced to 3.3 (SE 0.9)% of control). Pretreating the fibronectin plate with 1 mumol/l rSLPI, r alpha 1-PI and ICI 200,355 followed by thorough washing before the addition of cells resulted in no inhibition of fibronectin degradation with r alpha 1-PI and the ICI inhibitor, but rSLPI retained its inhibitory effect. This effect could be reduced by adding rSLPI in high pH buffer or 2 mol/1 NaCl. It is postulated that rSLPI binds to fibronectin to form a protective layer which prevents its degradation by neutrophil elastase. It may prove to be the most useful therapeutic agent in the prevention of neutrophil mediated lung damage.

Thioredoxin Inhibitors Attenuate Platelet Function and Thrombus Formation

PubMed Central

Metcalfe, Clive; Ramasubramoni, Anjana; Pula, Giordano; Harper, Matthew T.; Mundell, Stuart J.; Coxon, Carmen H.

2016-01-01

Thioredoxin (Trx) is an oxidoreductase with important physiological function. Imbalances in the NADPH/thioredoxin reductase/thioredoxin system are associated with a number of pathologies, particularly cancer, and a number of clinical trials for thioredoxin and thioredoxin reductase inhibitors have been carried out or are underway. Due to the emerging role and importance of oxidoreductases for haemostasis and the current interest in developing inhibitors for clinical use, we thought it pertinent to assess whether inhibition of the NADPH/thioredoxin reductase/thioredoxin system affects platelet function and thrombosis. We used small molecule inhibitors of Trx (PMX 464 and PX-12) to determine whether Trx activity influences platelet function, as well as an unbiased proteomics approach to identify potential Trx substrates on the surface of platelets that might contribute to platelet reactivity and function. Using LC-MS/MS we found that PMX 464 and PX-12 affected the oxidation state of thiols in a number of cell surface proteins. Key surface receptors for platelet adhesion and activation were affected, including the collagen receptor GPVI and the von Willebrand factor receptor, GPIb. To experimentally validate these findings we assessed platelet function in the presence of PMX 464, PX-12, and rutin (a selective inhibitor of the related protein disulphide isomerase). In agreement with the proteomics data, small molecule inhibitors of thioredoxin selectively inhibited GPVI-mediated platelet activation, and attenuated ristocetin-induced GPIb-vWF-mediated platelet agglutination, thus validating the findings of the proteomics study. These data reveal a novel role for thioredoxin in regulating platelet reactivity via proteins required for early platelet responses at sites of vessel injury (GPVI and GPIb). This work also highlights a potential opportunity for repurposing of PMX 464 and PX-12 as antiplatelet agents. PMID:27716777

Thioredoxin Inhibitors Attenuate Platelet Function and Thrombus Formation.

PubMed

Metcalfe, Clive; Ramasubramoni, Anjana; Pula, Giordano; Harper, Matthew T; Mundell, Stuart J; Coxon, Carmen H

2016-01-01

Thioredoxin (Trx) is an oxidoreductase with important physiological function. Imbalances in the NADPH/thioredoxin reductase/thioredoxin system are associated with a number of pathologies, particularly cancer, and a number of clinical trials for thioredoxin and thioredoxin reductase inhibitors have been carried out or are underway. Due to the emerging role and importance of oxidoreductases for haemostasis and the current interest in developing inhibitors for clinical use, we thought it pertinent to assess whether inhibition of the NADPH/thioredoxin reductase/thioredoxin system affects platelet function and thrombosis. We used small molecule inhibitors of Trx (PMX 464 and PX-12) to determine whether Trx activity influences platelet function, as well as an unbiased proteomics approach to identify potential Trx substrates on the surface of platelets that might contribute to platelet reactivity and function. Using LC-MS/MS we found that PMX 464 and PX-12 affected the oxidation state of thiols in a number of cell surface proteins. Key surface receptors for platelet adhesion and activation were affected, including the collagen receptor GPVI and the von Willebrand factor receptor, GPIb. To experimentally validate these findings we assessed platelet function in the presence of PMX 464, PX-12, and rutin (a selective inhibitor of the related protein disulphide isomerase). In agreement with the proteomics data, small molecule inhibitors of thioredoxin selectively inhibited GPVI-mediated platelet activation, and attenuated ristocetin-induced GPIb-vWF-mediated platelet agglutination, thus validating the findings of the proteomics study. These data reveal a novel role for thioredoxin in regulating platelet reactivity via proteins required for early platelet responses at sites of vessel injury (GPVI and GPIb). This work also highlights a potential opportunity for repurposing of PMX 464 and PX-12 as antiplatelet agents.

Taxonomy of the Streptomyces strain ZG0656 that produces acarviostatin alpha-amylase inhibitors and analysis of their effects on blood glucose levels in mammalian systems.

PubMed

Geng, P; Bai, G; Shi, Q; Zhang, L; Gao, Z; Zhang, Q

2009-02-01

To clarify the taxonomic status of strain ZG0656 and analyse the effects of its acarviostatin products on blood glucose levels in mammalian systems. Our program to screen for new alpha-amylase inhibitors led to the isolation of strain ZG0656. The polyphasic taxonomic study revealed that strain ZG0656 represents a novel variation of Streptomyces coelicoflavus, for which we propose the name S. coelicoflavus var. nankaiensis. Four chemically distinct alpha-amylase inhibitors, acarviostatins I03, II03, III03 and IV03, were isolated from strain ZG0656. Acarviostatins III03 and IV03 are both novel oligomers. All four acarviostatins are mixed noncompetitive porcine pancreas alpha-amylase inhibitors. Acarviostatin III03 is the most potent alpha-amylase inhibitor known to date. Moreover, in the in vitro and in vivo experiments, acarviostatins III03 showed significant inhibition of starch hydrolysis and glucose transfer to blood. Strain ZG0656 is a novel variation of S. coelicoflavus, whose products are novel effective alpha-amylase inhibitors. Among the products, acarviostatins III03 could significantly depress blood glucose levels in mammalian systems and be developed towards a possible therapeutic agent for diabetes. Acarviostatin III03 is the most potent alpha-amylase inhibitor known to date. The oligomer will benefit the research on the relationship between alpha-amylase and various inhibitors and will offer more choices in diabetes treatments.

Role of microsomal retinol/sterol dehydrogenase-like short-chain dehydrogenases/reductases in the oxidation and epimerization of 3alpha-hydroxysteroids in human tissues.

PubMed

Belyaeva, Olga V; Chetyrkin, Sergei V; Clark, Amy L; Kostereva, Natalia V; SantaCruz, Karen S; Chronwall, Bibie M; Kedishvili, Natalia Y

2007-05-01

Allopregnanolone (ALLO) and androsterone (ADT) are naturally occurring 3alpha-hydroxysteroids that act as positive allosteric regulators of gamma-aminobutyric acid type A receptors. In addition, ADT activates nuclear farnesoid X receptor and ALLO activates pregnane X receptor. At least with respect to gamma-aminobutyric acid type A receptors, the biological activity of ALLO and ADT depends on the 3alpha-hydroxyl group and is lost upon its conversion to either 3-ketosteroid or 3beta-hydroxyl epimer. Such strict structure-activity relationships suggest that the oxidation or epimerization of 3alpha-hydroxysteroids may serve as physiologically relevant mechanisms for the control of the local concentrations of bioactive 3alpha-hydroxysteroids. The exact enzymes responsible for the oxidation and epimerization of 3alpha-hydroxysteroids in vivo have not yet been identified, but our previous studies showed that microsomal nicotinamide adenine dinucleotide-dependent short-chain dehydrogenases/reductases (SDRs) with dual retinol/sterol dehydrogenase substrate specificity (RoDH-like group of SDRs) can oxidize and epimerize 3alpha-hydroxysteroids in vitro. Here, we present the first evidence that microsomal nicotinamide adenine dinucleotide-dependent 3alpha-hydroxysteroid dehydrogenase/epimerase activities are widely distributed in human tissues with the highest activity levels found in liver and testis and lower levels in lung, spleen, brain, kidney, and ovary. We demonstrate that RoDH-like SDRs contribute to the oxidation and epimerization of ALLO and ADT in living cells, and show that RoDH enzymes are expressed in tissues that have microsomal 3alpha-hydroxysteroid dehydrogenase/epimerase activities. Together, these results provide further support for the role of RoDH-like SDRs in human metabolism of 3alpha-hydroxysteroids and offer a new insight into the enzymology of ALLO and ADT inactivation.

The oxidation of apomorphine and other catechol compounds by horseradish peroxidase: relevance to the measurement of dihydropteridine reductase activity.

PubMed

Milstien, S; Kaufman, S

1987-03-19

It has been reported by Shen et al. (Shen, R.-S., Smith, R.V., Davis, P.J. and Abell, C.W. (1984) J. Biol. Chem. 259, 8894-9000) that apomorphine and dopamine are potent, non-competitive inhibitors of quinonoid dihydropteridine reductase. In this paper we show that apomorphine, dopamine and other catechol-containing compounds are oxidized rapidly to quinones by the horseradish peroxidase-H2O2 system which is used to generate the quinonoid dihydropterin substrate. These quinones react non-enzymatically with reduced pyridine nucleotides, depleting the other substrate of dihydropteridine reductase. When true initial rates of dihydropteridine reductase-dependent reduction of quinonoid dihydropterins are measured, neither apomorphine nor any other catechol-containing compound that has been tested has been found to inhibit dihydropteridine reductase.

21 CFR 866.5890 - Inter-alpha trypsin inhibitor immunological test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5890 Inter-alpha trypsin inhibitor immunological test system. (a) Identification. An inter... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Inter-alpha trypsin inhibitor immunological test...

Thioredoxin Reductase and its Inhibitors

PubMed Central

Saccoccia, Fulvio; Angelucci, Francesco; Boumis, Giovanna; Carotti, Daniela; Desiato, Gianni; Miele, Adriana E; Bellelli, Andrea

2014-01-01

Thioredoxin plays a crucial role in a wide number of physiological processes, which span from reduction of nucleotides to deoxyriboucleotides to the detoxification from xenobiotics, oxidants and radicals. The redox function of Thioredoxin is critically dependent on the enzyme Thioredoxin NADPH Reductase (TrxR). In view of its indirect involvement in the above mentioned physio/pathological processes, inhibition of TrxR is an important clinical goal. As a general rule, the affinities and mechanisms of binding of TrxR inhibitors to the target enzyme are known with scarce precision and conflicting results abound in the literature. A relevant analysis of published results as well as the experimental procedures is therefore needed, also in view of the critical interest of TrxR inhibitors. We review the inhibitors of TrxR and related flavoreductases and the classical treatment of reversible, competitive, non competitive and uncompetitive inhibition with respect to TrxR, and in some cases we are able to reconcile contradictory results generated by oversimplified data analysis. PMID:24875642

Screening alpha-glucosidase and alpha-amylase inhibitors from natural compounds by molecular docking in silico.

PubMed

Jhong, Chien-Hung; Riyaphan, Jirawat; Lin, Shih-Hung; Chia, Yi-Chen; Weng, Ching-Feng

2015-01-01

The alpha-glucosidase inhibitor is a common oral anti-diabetic drug used for controlling carbohydrates normally converted into simple sugars and absorbed by the intestines. However, some adverse clinical effects have been observed. The present study seeks an alternative drug that can regulate the hyperglycemia by down-regulating alpha-glucosidase and alpha-amylase activity by molecular docking approach to screen the hyperglycemia antagonist against alpha-glucosidase and alpha-amylase activities from the 47 natural compounds. The docking data showed that Curcumin, 16-hydroxy-cleroda-3,13-dine-16,15-olide (16-H), Docosanol, Tetracosanol, Antroquinonol, Berberine, Catechin, Quercetin, Actinodaphnine, and Rutin from 47 natural compounds had binding ability towards alpha-amylase and alpha-glucosidase as well. Curcumin had a better biding ability of alpha-amylase than the other natural compounds. Analyzed alpha-glucosidase activity reveals natural compound inhibitors (below 0.5 mM) are Curcumin, Actinodaphnine, 16-H, Quercetin, Berberine, and Catechin when compared to the commercial drug Acarbose (3 mM). A natural compound with alpha-amylase inhibitors (below 0.5 mM) includes Curcumin, Berberine, Docosanol, 16-H, Actinodaphnine/Tetracosanol, Catechin, and Quercetin when compared to Acarbose (1 mM). When taken together, the implication is that molecular docking is a fast and effective way to screen alpha-glucosidase and alpha-amylase inhibitors as lead compounds of natural sources isolated from medicinal plants. © 2015 International Union of Biochemistry and Molecular Biology.

[The primary structure of the alpha-amylase inhibitor Hoe 467A from Streptomyces tendae 4158. A new class of inhibitors].

PubMed

Aschauer, H; Vértesy, L; Nesemann, G; Braunitzer, G

1983-10-01

The native or modified alpha-amylase inhibitor Hoe 467A - isolated from the culture medium of Streptomyces tendae 4158 - and overlapping peptides were degraded by the automatic Edman technique. The oxidized or aminoethylated or oxidized and maleoylated inhibitor was digested with trypsin and the native inhibitor with pepsin. Further digestion with Staphylococcus aureus proteinase was also carried out. After peptic digestion two cystin peptides were isolated, which allowed the establishment of the disulfide bonds. The alpha-amylase inhibitor is a polypeptid consisting of 74 amino-acid residues with a molecular mass of 7958 Da. The inhibitor is composed of all naturally occurring amino acids except methionine and phenylalanine and shows no sequence homology to known inhibitors. The clinical and pharmacological importance in respect to the inhibitors ability for inactivation of human salivary and pancreatic alpha-amylase is discussed. Especially the proteinase resistance of the inhibitor enables a clinical application in human (e.g. Diabetes mellitus) per os.

Isolation and pharmacological characterization of fatty acids from saw palmetto extract.

PubMed

Abe, Masayuki; Ito, Yoshihiko; Suzuki, Asahi; Onoue, Satomi; Noguchi, Hiroshi; Yamada, Shizuo

2009-04-01

Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary-tract symptoms secondary to benign prostatic hyperplasia. The mechanisms of pharmacological effects of SPE include the inhibition of 5alpha-reductase, anti-androgenic effects, anti-proliferative effects, and anti-inflammatory effects. Previously, we showed that SPE bound actively to alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine calcium channel (1,4-DHP) receptors in the prostate and bladder of rats, whereas its active constituents have not been fully clarified. The present investigation is aimed to identify the main active components contained in hexane and diethyl ether extracts of SPE with the use of column chromatography and preparative HPLC. Based on the binding activity with alpha(1)-adrenergic, muscarinic, and 1,4-DHP receptors, both isolated oleic and lauric acids were deduced to be active components. Authentic samples of oleic and lauric acids also exhibited similar binding activities to these receptors as the fatty acids isolated from SPE, consistent with our findings. In addition, oleic and lauric acids inhibited 5alpha-reductase, possibly leading to therapeutic effects against benign prostatic hyperplasia and related lower urinary-tract symptoms.

Potential role of recombinant secretory leucoprotease inhibitor in the prevention of neutrophil mediated matrix degradation.

PubMed Central

Llewellyn-Jones, C. G.; Lomas, D. A.; Stockley, R. A.

1994-01-01

BACKGROUND--Neutrophil elastase is able to degrade connective tissue matrices and is thought to be involved in the pathogenesis of destructive lung diseases. METHODS--The ability of recombinant secretory leucoprotease inhibitor (rSLPI) to inhibit neutrophil mediated degradation of fibronectin in vitro is demonstrated and its efficacy compared with native alpha-1-proteinase inhibitor (n alpha 1-PI), recombinant alpha-1-proteinase inhibitor (r alpha 1-PI), and the chemical elastase inhibitor ICI 200,355. RESULTS--When preincubated with neutrophils both rSLPI and r alpha 1-PI were effective inhibitors of fibronectin degradation although n alpha 1-PI and ICI 200,355 were less effective. Recombinant SLPI was the most effective inhibitor when the cells were allowed to adhere to fibronectin before the addition of the inhibitors. Preincubation of rSLPI (0.1 mumol/l) with the fibronectin plate resulted in almost total inhibition of fibronectin degradation (reduced to 3.3 (SE 0.9)% of control). Pretreating the fibronectin plate with 1 mumol/l rSLPI, r alpha 1-PI and ICI 200,355 followed by thorough washing before the addition of cells resulted in no inhibition of fibronectin degradation with r alpha 1-PI and the ICI inhibitor, but rSLPI retained its inhibitory effect. This effect could be reduced by adding rSLPI in high pH buffer or 2 mol/1 NaCl. CONCLUSIONS--It is postulated that rSLPI binds to fibronectin to form a protective layer which prevents its degradation by neutrophil elastase. It may prove to be the most useful therapeutic agent in the prevention of neutrophil mediated lung damage. Images PMID:7912452

The metabolism of testosterone by dermal papilla cells cultured from human pubic and axillary hair follicles concurs with hair growth in 5 alpha-reductase deficiency.

PubMed

Hamada, K; Thornton, M J; Laing, I; Messenger, A G; Randall, V A

1996-05-01

Androgens regulate the growth of many human hair follicles, but only pubic, axillary, and scalp hair growth occur in men with 5 alpha-reductase deficiency. This suggests that 5 alpha-dihydrotestosterone is the active intracellular androgen in androgen-dependent follicles, except in the axilla and pubis. Since the dermal papilla plays a major regulatory role in hair follicles and may be the site of androgen action, we have investigated androgen metabolism in six primary lines of cultured dermal papilla cells from pubic and axillary hair follicles; previous studies have shown that beard cells take up and metabolize testosterone, retaining and secreting 5 alpha-dihydrotestosterone. After 24 h preincubation in serum-free Eagle's medium 199, 100-mm dishes of confluent cells were incubated for 2 h with 5 nM [1,2,6,7-3H]testosterone. Media were collected and the cells washed with phosphate-buffered saline and extracted with chloroform: methanol (2:1). After the addition of unlabeled and 14C-labeled marker steroids, the extracts were analyzed by a two-step thin-layer chromatography system; steroid identity was confirmed by recrystallization to a constant 3H/14C ratio. Beard and pubic dermal papilla cells were also incubated for 24 h, and the medium was analyzed at various times. The results from pubic and axillary primary cell lines were similar. In both cells and media the major steroid identified was testosterone, but significant amounts of androstenedione were present, indicating 17 beta-hydroxysteroid dehydrogenase activity; androstenedione was also identified within the cells, but a small amount of 5 alpha-dihydrotestosterone was only identified in one pubic cell line. Beard dermal papilla cells secreted large amounts of 5 alpha-dihydrotestosterone into the medium over 24 h in contrast to pubic cells, which produced only very small amounts. The pubic and axillary cell results contrasts with the observations of pronounced 5 alpha-dihydrotestosterone in beard cells and confirm that androgen metabolism in cultured dermal papilla cells reflects the parent follicle's ability to respond to androgen in the absence of 5 alpha-reductase type II in vivo. This supports our hypothesis that androgen acts on hair follicles via the dermal papilla and suggests that cultured dermal papilla cells may offer an important model system for studies of androgen action.

The beta-3 adrenoceptor agonist, mirabegron relaxes isolated prostate from human and rabbit: new therapeutic indication?

PubMed

Calmasini, Fabiano B; Candido, Tuany Z; Alexandre, Eduardo C; D'Ancona, Carlos A; Silva, Daniel; de Oliveira, Marco Antonio; De Nucci, Gilberto; Antunes, Edson; Mónica, Fabíola Z

2015-03-01

Alpha1 (α1)-blockers, 5-alpha reductase and phosphodiesterase type-5 inhibitors are pharmacological classes currently available for benign prostatic hyperplasia (BPH) treatment. Mirabegron, a beta-3 adrenoceptor (β3-AR) agonist has been approved for the therapy of overactive bladder and may constitute a new therapeutic option for BPH treatment. This study is aimed to evaluate the in vitro effects of mirabegron in human and rabbit prostatic smooth muscle. In rabbit prostate, electrical field stimulation (EFS)-induced contraction and concentration-response curve (CRC) to mirabegron in phenylephrine pre-contracted tissues were carried out. The potency (pEC50 ) and maximal response (Emax ) values were determined. In human prostate, CRC to phenylephrine was carried out in the absence and presence of mirabegron. Immunohistochemistry analysis for β3-AR was also carried out. In human prostate, immunohistochemistry analysis revealed the presence of β3-AR on the transition zone and mirabegron reduced by 42% the phenylephrine-induced contractions. In rabbit prostate, mirabegron produced concentration-dependent relaxations (pEC50 : 6.01 ± 0.12; Emax : 106 ± 3%), which were fully resistant to the blockade of β1-AR and β2-AR. The β3-AR blocker L748,337 caused a six-fold rightward shift in mirabegron-induced relaxations. Mirabegron (10 μM) reduced by 63% the EFS-induced contractions. Inhibitors of nitric oxide (L-NAME) and of soluble guanylate cyclase (ODQ) along with a cocktail of K+ channel blockers (apamin, charybdotoxin, glibenclamide, tetraethylammonium) all failed to significantly affect the mirabegron-induced rabbit relaxations. Mirabegron relaxes prostatic smooth muscle, providing an experimental support for the clinical investigation of its combination with an α1-blockers or PDE5 inhibitors in the treatment of BPH. Prostate 75:440-447, 2015. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Biological Evaluation and X-ray Co-crystal Structures of Cyclohexylpyrrolidine Ligands for Trypanothione Reductase, an Enzyme from the Redox Metabolism of Trypanosoma.

PubMed

De Gasparo, Raoul; Brodbeck-Persch, Elke; Bryson, Steve; Hentzen, Nina B; Kaiser, Marcel; Pai, Emil F; Krauth-Siegel, R Luise; Diederich, François

2018-05-08

The tropical diseases human African trypanosomiasis, Chagas disease, and the various forms of leishmaniasis are caused by parasites of the family of trypanosomatids. These protozoa possess a unique redox metabolism based on trypanothione and trypanothione reductase (TR), making TR a promising drug target. We report the optimization of properties and potency of cyclohexylpyrrolidine inhibitors of TR by structure-based design. The best inhibitors were freely soluble and showed competitive inhibition constants (K i ) against Trypanosoma (T.) brucei TR and T. cruzi TR and in vitro activities (half-maximal inhibitory concentration, IC 50 ) against these parasites in the low micromolar range, with high selectivity against human glutathione reductase. X-ray co-crystal structures confirmed the binding of the ligands to the hydrophobic wall of the "mepacrine binding site" with the new, solubility-providing vectors oriented toward the surface of the large active site. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibitor-bound complexes of dihydrofolate reductase-thymidylate synthase from Babesia bovis

PubMed Central

Begley, Darren W.; Edwards, Thomas E.; Raymond, Amy C.; Smith, Eric R.; Hartley, Robert C.; Abendroth, Jan; Sankaran, Banumathi; Lorimer, Donald D.; Myler, Peter J.; Staker, Bart L.; Stewart, Lance J.

2011-01-01

Babesiosis is a tick-borne disease caused by eukaryotic Babesia parasites which are morphologically similar to Plasmodium falciparum, the causative agent of malaria in humans. Like Plasmodium, different species of Babesia are tuned to infect different mammalian hosts, including rats, dogs, horses and cattle. Most species of Plasmodium and Babesia possess an essential bifunctional enzyme for nucleotide synthesis and folate metabolism: dihydrofolate reductase-thymidylate synthase. Although thymidylate synthase is highly conserved across organisms, the bifunctional form of this enzyme is relatively uncommon in nature. The structural characterization of dihydrofolate reductase-thymidylate synthase in Babesia bovis, the causative agent of babesiosis in livestock cattle, is reported here. The apo state is compared with structures that contain dUMP, NADP and two different antifolate inhibitors: pemetrexed and raltitrexed. The complexes reveal modes of binding similar to that seen in drug-resistant malaria strains and point to the utility of applying structural studies with proven cancer chemotherapies towards infectious disease research. PMID:21904052

Methyl-branched fatty acids, inhibitors of enoyl-ACP reductase with antibacterial activity from Streptomyces sp. A251.

PubMed

Zheng, Chang-Ji; Sohn, Mi-Jin; Chi, Seung-Wook; Kim, Won-Gon

2010-05-01

Bacterial enoyl-ACP reductase (FabI) has been demonstrated to be a novel antibacterial target. In the course of our screening for FabI inhibitors we isolated two methyl-branched fatty acids from Streptomyces sp. A251. They were identified as 14-methyl-9(Z)-pentadecenoic acid and 15-methyl-9(Z)-hexadecenoic acid by MS and NMR spectral data. These compounds inhibited Staphylococcus aureus FabI with IC50 of 16.0 and 16.3mu M, respectively, while didn't affect FabK, an enoyl-ACP reductase of Streptococcus pneumonia, at 100muM. Consistent with their selective inhibition for FabI, they blocked intracellular fatty acid synthesis as well as the growth of S. aureus, while didn't inhibit the growth of S. pneumonia. Additionally, these compounds showed reduced antibacterial activity against fabI-overexpressing S. aureus compared to the wild-type strain. These results demonstrate that the methyl-branched fatty acids showed antibacterial activity by inhibiting FabI in vivo.

Androgen Regulation of 5α-Reductase Isoenzymes in Prostate Cancer: Implications for Prostate Cancer Prevention

PubMed Central

Li, Jin; Ding, Zhiyong; Wang, Zhengxin; Lu, Jing-Fang; Maity, Sankar N.; Navone, Nora M.; Logothetis, Christopher J.; Mills, Gordon B.; Kim, Jeri

2011-01-01

The enzyme 5α-reductase, which converts testosterone to dihydrotestosterone (DHT), performs key functions in the androgen receptor (AR) signaling pathway. The three isoenzymes of 5α-reductase identified to date are encoded by different genes: SRD5A1, SRD5A2, and SRD5A3. In this study, we investigated mechanisms underlying androgen regulation of 5α-reductase isoenzyme expression in human prostate cells. We found that androgen regulates the mRNA level of 5α-reductase isoenzymes in a cell type–specific manner, that such regulation occurs at the transcriptional level, and that AR is necessary for this regulation. In addition, our results suggest that AR is recruited to a negative androgen response element (nARE) on the promoter of SRD5A3 in vivo and directly binds to the nARE in vitro. The different expression levels of 5α-reductase isoenzymes may confer response or resistance to 5α-reductase inhibitors and thus may have importance in prostate cancer prevention. PMID:22194926

Natural products with hypoglycemic, hypotensive, hypocholesterolemic, antiatherosclerotic and antithrombotic activities.

PubMed

Wang, H X; Ng, T B

1999-01-01

This article reviews compounds of botanical origin which are capable of lowering plasma levels of glucose and cholesterol and blood pressure, as well as compounds inhibiting atherosclerosis and thrombosis. Hypoglycemic natural products comprise flavonoids, xanthones, triterpenoids, alkaloids, glycosides, alkyldisulfides, aminobutyric acid derivatives, guanidine, polysaccharides and peptides. Hypotensive compounds include flavonoids, diterpenes, alkaloids, glycosides, polysaccharides and proteins. Among natural products with hypocholesterolemic activity are beta-carotene, lycopene, cycloartenol, beta-sitosterol, sitostanol, saponin, soybean protein, indoles, dietary fiber, propionate, mevinolin (beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitor) and polysaccharides. Heparins, flavonoids, tocotrienols, beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitors (statins), garlic compounds and fungal proteases exert antithrombotic action. Statins and garlic compounds also possess antiatherosclerotic activity.

Decursin and decursinol angelate selectively inhibit NADH-fumarate reductase of Ascaris suum.

PubMed

Shiomi, Kazuro; Hatano, Hiroko; Morimoto, Hiromi; Ui, Hideaki; Sakamoto, Kimitoshi; Kita, Kiyoshi; Tomoda, Hiroshi; Lee, Eun Woo; Heo, Tae Ryeon; Kawagishi, Hirokazu; Omura, Satoshi

2007-11-01

NADH-fumarate reductase (NFRD) is a key enzyme in many anaerobic helminths. Decursin and decursinol angelate have been isolated from the roots of ANGELICA GIGAS Nakai (Apiaceae) as NFRD inhibitors. They inhibited ASCARIS SUUM NFRD with IC (50) values of 1.1 and 2.7 microM, respectively. Their target is the electron transport enzyme complex I. Since the inhibitory activities of decursin against bovine heart complexes are weak, it is a selective inhibitor of the nematode complex I. In contrast, decursinol angelate moderately inhibits bovine heart complexes II and III. Decursinol inhibits A. SUUM NFRD to a similar extent, but its target is complex II. It also inhibits bovine heart complexes II and III.

Design, synthesis and biological evaluation of novel 3-oxo-4-oxa-5α-androst-17β-amide derivatives as dual 5α-reductase inhibitors and androgen receptor antagonists.

PubMed

Lao, Kejing; Sun, Jie; Wang, Chong; Wang, Ying; You, Qidong; Xiao, Hong; Xiang, Hua

2017-09-01

Prostate cancer (PCa) is the second leading cause of death in men. Recently, some researches have showed that 5α-reductase inhibitors were beneficial in PCa treatment as well. In this study, a series of novel 3-oxo-4-oxa-5α-androst-17β-amide derivatives have been designed and synthesized in a more simple and convenient method. Most of the synthesized compounds displayed good 5α-reductase inhibitory activities and androgen receptor binding affinities. Their anti-proliferation activities in PC-3 and LNCaP cell lines were also evaluated and the results indicated that most of the synthesized compounds exhibited potent anti-proliferative activities. It is obvious that the androgen-dependent cell line LNCaP was much more sensitive than the androgen-independent cell line PC-3. Among all the synthesized compounds, 11d and 11k displayed the best inhibition activity with 4-fold more sensitive toward LNCaP than PC-3, which was consistent with their high affinities observed in AR binding assay. Molecular modeling studies suggested that 11k could bind to AR in a manner similar to the binding of dihydrotestosterone to AR. Compared to the finasteride, 11k showed a longer plasma half-life (4h) and a better bioavailability. Overall, based on biological activities data, compound 11d and 11k can be identified as potential dual 5α-reductase inhibitors and AR antagonists which might be of therapeutic importance for prostate cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

A human fatty acid synthase inhibitor binds β-ketoacyl reductase in the keto-substrate site.

PubMed

Hardwicke, Mary Ann; Rendina, Alan R; Williams, Shawn P; Moore, Michael L; Wang, Liping; Krueger, Julie A; Plant, Ramona N; Totoritis, Rachel D; Zhang, Guofeng; Briand, Jacques; Burkhart, William A; Brown, Kristin K; Parrish, Cynthia A

2014-09-01

Human fatty acid synthase (hFAS) is a complex, multifunctional enzyme that is solely responsible for the de novo synthesis of long chain fatty acids. hFAS is highly expressed in a number of cancers, with low expression observed in most normal tissues. Although normal tissues tend to obtain fatty acids from the diet, tumor tissues rely on de novo fatty acid synthesis, making hFAS an attractive metabolic target for the treatment of cancer. We describe here the identification of GSK2194069, a potent and specific inhibitor of the β-ketoacyl reductase (KR) activity of hFAS; the characterization of its enzymatic and cellular mechanism of action; and its inhibition of human tumor cell growth. We also present the design of a new protein construct suitable for crystallography, which resulted in what is to our knowledge the first co-crystal structure of the human KR domain and includes a bound inhibitor.

Resistance Mechanisms and the Future of Bacterial Enoyl-Acyl Carrier Protein Reductase (FabI) Antibiotics

PubMed Central

Yao, Jiangwei; Rock, Charles O.

2016-01-01

Missense mutations leading to clinical antibiotic resistance are a liability of single-target inhibitors. The enoyl-acyl carrier protein reductase (FabI) inhibitors have one intracellular protein target and drug resistance is increased by the acquisition of single-base-pair mutations that alter drug binding. The spectrum of resistance mechanisms to FabI inhibitors suggests criteria that should be considered during the development of single-target antibiotics that would minimize the impact of missense mutations on their clinical usefulness. These criteria include high-affinity, fast on/off kinetics, few drug contacts with residue side chains, and no toxicity. These stringent criteria are achievable by structure-guided design, but this approach will only yield pathogen-specific drugs. Single-step acquisition of resistance may limit the clinical application of broad-spectrum, single-target antibiotics, but appropriately designed pathogen-specific antibiotics have the potential to overcome this liability. PMID:26931811

A Novel NADPH-Dependent Aldehyde Reductase Gene from Saccharomyces cerevisiae NRRL Y-12632 Involved in the Detoxification of Aldehyde Inhibitors Derived from Lignocellulosic Biomass Conversion

USDA-ARS?s Scientific Manuscript database

Aldehyde inhibitors such as furfural, 5-hydroxymethylfurfural (HMF), anisaldehyde, benzaldehyde, cinnamaldehyde, and phenylaldehyde are commonly generated during lignocellulosic biomass conversion process for low-cost cellulosic ethanol production that interferes with subsequent microbial growth and...

GRE2 from Scheffersomyces stipitis as an aldehyde reductase contributes tolerance to aldehyde inhibitors derived from lignocellulosic biomass

USDA-ARS?s Scientific Manuscript database

Scheffersomyces (Pichia) stipitis is one of the most promising yeasts for industrial bioethanol production from lignocellulosic biomass. S. stipitis is able to in situ detoxify aldehyde inhibitors [such as furfural and 5-hydroxymethylfurfural (HMF)] to less toxic corresponding alcohols. However, the...

Molecular structure, spectroscopic and docking analysis of 1,3-diphenylpyrazole-4-propionic acid: A good prostaglandin reductase inhibitor

NASA Astrophysics Data System (ADS)

Kavitha, T.; Velraj, G.

2018-03-01

The molecule 1,3-diphenylpyrazole-4-propionic acid (DPPA) was optimized to its minimum energy level using density functional theory (DFT) calculations. The vibrational frequencies of DPPA were calculated along with their potential energy distribution (PED) and the obtained values are validated with the help of experimental calculations. The reactivity nature of the molecule was investigated with the aid of various DFT methods such as global reactivity descriptors, local reactivity descriptors, molecular electrostatic potential (MEP), natural bond orbitals (NBOs), etc. The prediction of activity spectra for substances (PASS) result forecast that, DPPA can be more active as a prostaglandin (PG) reductase inhibitor. The PGs are biologically synthesized by the cyclooxygenase (COX) enzyme which exists in COX1 and COX2 forms. The PGs produced by COX2 enzyme induces inflammation and fungal infections and hence the inhibition of COX2 enzyme is indispensable in anti-inflammation and anti-fungal activities. The docking analysis of DPPA with COX enzymes (both COX1 and COX2) were carried out and eventually, it was found that DPPA can selectively inhibit COX2 enzyme and can serve as a PG reductase inhibitor thereby acting as a lead compound for the treatment of inflammation and fungal diseases.

Exploration of natural product ingredients as inhibitors of human HMG-CoA reductase through structure-based virtual screening.

PubMed

Lin, Shih-Hung; Huang, Kao-Jean; Weng, Ching-Feng; Shiuan, David

2015-01-01

Cholesterol plays an important role in living cells. However, a very high level of cholesterol may lead to atherosclerosis. HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase is the key enzyme in the cholesterol biosynthesis pathway, and the statin-like drugs are inhibitors of human HMG-CoA reductase (hHMGR). The present study aimed to virtually screen for potential hHMGR inhibitors from natural product to discover hypolipidemic drug candidates with fewer side effects and lesser toxicities. We used the 3D structure 1HWK from the PDB (Protein Data Bank) database of hHMGR as the target to screen for the strongly bound compounds from the traditional Chinese medicine database. Many interesting molecules including polyphenolic compounds, polisubstituted heterocyclics, and linear lipophilic alcohols were identified and their ADMET (absorption, disrtibution, metabolism, excretion, toxicity) properties were predicted. Finally, four compounds were obtained for the in vitro validation experiments. The results indicated that curcumin and salvianolic acid C can effectively inhibit hHMGR, with IC50 (half maximal inhibitory concentration) values of 4.3 µM and 8 µM, respectively. The present study also demonstrated the feasibility of discovering new drug candidates through structure-based virtual screening.

The bean. alpha. -amylase inhibitor is encoded by a lectin gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, J.; Altabella, T.; Chrispeels, M.J.

The common bean, Phaseolus vulgaris, contains an inhibitor of insect and mammalian {alpha}-amylases that does not inhibit plant {alpha}-amylase. This inhibitor functions as an anti-feedant or seed-defense protein. We purified this inhibitor by affinity chromatography and found that it consists of a series of glycoforms of two polypeptides (Mr 14,000-19,000). Partial amino acid sequencing was carried out, and the sequences obtained are identical with portions of the derived amino acid sequence of a lectin-like gene. This lectin gene encodes a polypeptide of MW 28,000, and the primary in vitro translation product identified by antibodies to the {alpha}-amylase inhibitor has themore » same size. Co- and posttranslational processing of this polypeptide results in glycosylated polypeptides of 14-19 kDa. Our interpretation of these results is that the bean lectins constitute a gene family that encodes diverse plant defense proteins, including phytohemagglutinin, arcelin and {alpha}-amylase inhibitor.« less

Lyme neuroborreliosis in a patient treated with TNF-alpha inhibitor.

PubMed

Merkac, Maja Ivartnik; Tomazic, Janez; Strle, Franc

2015-12-01

A 57-year-old woman, receiving TNF-alpha inhibitor adalimumab for psoriasis, presented with early Lyme neuroborreliosis (Bannwarth's syndrome). Discontinuation of adalimumab and 14-day therapy with ceftriaxone resulted in a smooth course and favorable outcome of Lyme borreliosis. This is the first report on Lyme neuroborreliosis in a patient treated with TNF-alpha inhibitor.

Molecular cloning of alpha-amylases from cotton boll weevil, Anthonomus grandis and structural relations to plant inhibitors: an approach to insect resistance.

PubMed

Oliveira-Neto, Osmundo B; Batista, João A N; Rigden, Daniel J; Franco, Octávio L; Falcão, Rosana; Fragoso, Rodrigo R; Mello, Luciane V; dos Santos, Roseane C; Grossi-de-Sá, Maria F

2003-01-01

Anthonomus grandis, the cotton boll weevil, causes severe cotton crop losses in North and South America. Here we demonstrate the presence of starch in the cotton pollen grains and young ovules that are the main A. grandis food source. We further demonstrate the presence of alpha-amylase activity, an essential enzyme of carbohydrate metabolism for many crop pests, in A. grandis midgut. Two alpha-amylase cDNAs from A. grandis larvae were isolated using RT-PCR followed by 5' and 3' RACE techniques. These encode proteins with predicted molecular masses of 50.8 and 52.7kDa, respectively, which share 58% amino acid identity. Expression of both genes is induced upon feeding and concentrated in the midgut of adult insects. Several alpha-amylase inhibitors from plants were assayed against A. grandis alpha-amylases but, unexpectedly, only the BIII inhibitor from rye kernels proved highly effective, with inhibitors generally active against other insect amylases lacking effect. Structural modeling of Amylag1 and Amylag2 showed that different factors seem to be responsible for the lack of effect of 0.19 and alpha-AI1 inhibitors on A. grandis alpha-amylase activity. This work suggests that genetic engineering of cotton to express alpha-amylase inhibitors may offer a novel route to A. grandis resistance.

Genetics Home Reference: 5-alpha reductase deficiency

MedlinePlus

... countries, including the Dominican Republic, Papua New Guinea, Turkey, and Egypt. Related Information What information about a ... Updated Pages Reviewed : April 2017 Published : June 19, 2018 The resources on this site should not be ...

Inhibitory spectrum of alpha 2-plasmin inhibitor.

PubMed Central

Saito, H; Goldsmith, G H; Moroi, M; Aoki, N

1979-01-01

alpha 2-Plasmin inhibitor (alpha 2PI) has been recently characterized as a fast-reacting inhibitor of plasmin in human plasma and appears to play an important role in the regulation of fibrinolysis in vivo. We have studied the effect of purified alpha 2PI upon various proteases participating in human blood coagulation and kinin generation. At physiological concentration (50 microgram/ml), alpha 2PI inhibited the clot-promoting and prekallikrein-activating activity of Hageman factor fragments, the amidolytic, kininogenase, and clot-promoting activities of plasma kallikrein, and the clot-promoting properties of activated plasma thromboplastin antecedent (PTA, Factor XIa) and thrombin. alpha 2PI had minimal inhibitory effect on surface-bound activated PTA and activated Stuart factor (Factor Xa). alpha 2PI did not inhibit the activity of activated Christmas factor (Factor IXa) or urinary kallikrein. Heparin (1.5-2.0 units/ml) did not enhance the inhibitory function of alpha 2PI. These results suggest that, like other plasma protease inhibitors, alpha 2PI possesses a broad in vitro spectrum of inhibitory properties. PMID:156364

Unique regional distribution of delta 4-3-ketosteroid-5 alpha-oxidoreductase and associated epididymal morphology in the marsupial, Didelphis virginiana.

PubMed

Kelce, W R; Krause, W J; Ganjam, V K

1987-09-01

The epididymal epithelial ultrastructure has been described in the adult male North American opossum, Didelphis virginiana. Morphological results have suggested that absorptive activity is prominent in the proximal epididymal region by virtue of numerous microvilli, an endocytotic complex, dense granules, and multivesicular bodies in the apical cytoplasm. In contrast, the middle and distal epididymal regions exhibit ultrastructural features indicative of protein synthesis such as large invaginated euchromatic nuclei, large nucleoli, and increased amounts of granular endoplasmic reticulum. It is in the middle and distal epididymal regions where sperm head rotation and sperm pairing take place. Epididymal delta 4-3-ketosteroid-5 alpha-oxidoreductase (5 alpha-reductase) activity also has been measured. It has been found that the level of enzyme activity differs significantly (p less than 0.01) between the proximal, middle, and distal epididymal regions. Enzyme-specific activity has been found to be highest in the middle region (47.6 +/- 5.4 picomoles 5 alpha-reduced androgens formed/b/mg protein), lower in the distal region (18.3 +/- 0.7 picomoles 5 alpha-reduced androgens formed/b/mg protein), with little activity (2.4 +/- 1.2 picomoles 5 alpha-reduced androgens formed/h/mg protein) found in the proximal epididymal region. This regional distribution of enzyme activity differs markedly from that reported for eutherian mammals. Both the suggested epididymal protein synthetic and secretory activity and the level of epididymal 5 alpha-reductase activity appear to correlate regionally with the morphological changes that occur in the opossum spermatozoa as they transit the epididymis.

Guinea-pig liver testosterone 17 beta-dehydrogenase (NADP+) and aldehyde reductase exhibit benzene dihydrodiol dehydrogenase activity.

PubMed Central

Hara, A; Hayashibara, M; Nakayama, T; Hasebe, K; Usui, S; Sawada, H

1985-01-01

We have kinetically and immunologically demonstrated that testosterone 17 beta-dehydrogenase (NADP+) isoenzymes (EC 1.1.1.64) and aldehyde reductase (EC 1.1.1.2) from guinea-pig liver catalyse the oxidation of benzene dihydrodiol (trans-1,2-dihydroxycyclohexa-3,5-diene) to catechol. One isoenzyme of testosterone 17 beta-dehydrogenase, which has specificity for 5 beta-androstanes, oxidized benzene dihydrodiol at a 3-fold higher rate than 5 beta-dihydrotestosterone, and showed a more than 4-fold higher affinity for benzene dihydrodiol and Vmax. value than did another isoenzyme, which exhibits specificity for 5 alpha-androstanes, and aldehyde reductase. Immunoprecipitation of guinea-pig liver cytosol with antisera against the testosterone 17 beta-dehydrogenase isoenzymes and aldehyde reductase indicated that most of the benzene dihydrodiol dehydrogenase activity in the tissue is due to testosterone 17 beta-dehydrogenase. PMID:2983661

A new strategy for strain improvement of Aurantiochytrium sp. based on heavy-ions mutagenesis and synergistic effects of cold stress and inhibitors of enoyl-ACP reductase.

PubMed

Cheng, Yu-Rong; Sun, Zhi-Jie; Cui, Gu-Zhen; Song, Xiaojin; Cui, Qiu

2016-11-01

Developing a strain with high docosahexaenoic acid (DHA) yield and stable fermenting-performance is an imperative way to improve DHA production using Aurantiochytrium sp., a microorganism with two fatty acid synthesis pathways: polyketide synthase (PKS) pathway and Type I fatty acid synthase (FAS) pathway. This study investigated the growth and metabolism response of Aurantiochytrium sp. CGMCC 6208 to two inhibitors of enoyl-ACP reductase of Type II FAS pathway (isoniazid and triclosan), and proposed a method of screening high DHA yield Aurantiochytrium sp. strains with heavy ion mutagenesis and pre-selection by synergistic usage of cold stress (4°C) and FAS inhibitors (triclosan and isoniazid). Results showed that (1) isoniazid and triclosan have positive effects on improving DHA level of cells; (2) mutants from irradiation dosage of 120Gy yielded more DHA compared with cells from 40Gy, 80Gy treatment and wild type; (3) DHA contents of mutants pre-selected by inhibitors of enoyl-ACP reductase of Type II FAS pathway (isoniazid and triclosan)at 4°C, were significantly higher than that of wild type; (4) compared to the wild type, the DHA productivity and yield of a mutant (T-99) obtained from Aurantiochytrium sp. CGMCC 6208 by the proposed method increased by 50% from 0.18 to 0.27g/Lh and 30% from 21 to 27g/L, respectively. In conclusion, this study developed a feasible method to screen Aurantiochytrium sp. with high DHA yield by a combination of heavy-ion mutagenesis and mutant-preselection by FAS inhibitors and cold stress. Copyright © 2016 Elsevier Inc. All rights reserved.

Inhibitory effect of rhetsinine isolated from Evodia rutaecarpa on aldose reductase activity.

PubMed

Kato, A; Yasuko, H; Goto, H; Hollinshead, J; Nash, R J; Adachi, I

2009-03-01

Aldose reductase inhibitors have considerable potential for the treatment of diabetic complications, without increased risk of hypoglycemia. Search for components inhibiting aldose reductase led to the discovery of active compounds contained in Evodia rutaecarpa Bentham (Rutaceae), which is the one of the component of Kampo-herbal medicine. The hot water extract from the E. rutaecarpa was subjected to distribution or gel filtration chromatography to give an active compound, N2-(2-methylaminobenzoyl)tetrahydro-1H-pyrido[3,4-b]indol-1-one (rhetsinine). It inhibited aldose reductase with IC(50) values of 24.1 microM. Furthermore, rhetsinine inhibited sorbitol accumulation by 79.3% at 100 microM. These results suggested that the E. rutaecarpa derived component, rhetsinine, would be potentially useful in the treatment of diabetic complications.

Potential of the bean alpha-amylase inhibitor alpha-AI-1 to inhibit alpha-amylase activity in true bugs(Hemiptera)

USDA-ARS?s Scientific Manuscript database

True bugs (Hemiptera) are an important pest complex not controlled by Bt crops. An alternative source of resistance includes inhibitors of digestive enzymes. aAI-1, an a-amylase inhibitor from the common bean, has been shown to inhibit a-amylases of bruchid pests of grain legumes. Here we quantify t...

Prospecting for Novel Plant-Derived Molecules of Rauvolfia serpentina as Inhibitors of Aldose Reductase, a Potent Drug Target for Diabetes and Its Complications

PubMed Central

Pathania, Shivalika; Randhawa, Vinay; Bagler, Ganesh

2013-01-01

Aldose Reductase (AR) is implicated in the development of secondary complications of diabetes, providing an interesting target for therapeutic intervention. Extracts of Rauvolfia serpentina, a medicinal plant endemic to the Himalayan mountain range, have been known to be effective in alleviating diabetes and its complications. In this study, we aim to prospect for novel plant-derived inhibitors from R. serpentina and to understand structural basis of their interactions. An extensive library of R. serpentina molecules was compiled and computationally screened for inhibitory action against AR. The stability of complexes, with docked leads, was verified using molecular dynamics simulations. Two structurally distinct plant-derived leads were identified as inhibitors: indobine and indobinine. Further, using these two leads as templates, 16 more leads were identified through ligand-based screening of their structural analogs, from a small molecules database. Thus, we obtained plant-derived indole alkaloids, and their structural analogs, as potential AR inhibitors from a manually curated dataset of R. serpentina molecules. Indole alkaloids reported herein, as a novel structural class unreported hitherto, may provide better insights for designing potential AR inhibitors with improved efficacy and fewer side effects. PMID:23613832

Prospecting for novel plant-derived molecules of Rauvolfia serpentina as inhibitors of Aldose Reductase, a potent drug target for diabetes and its complications.

PubMed

Pathania, Shivalika; Randhawa, Vinay; Bagler, Ganesh

2013-01-01

Aldose Reductase (AR) is implicated in the development of secondary complications of diabetes, providing an interesting target for therapeutic intervention. Extracts of Rauvolfia serpentina, a medicinal plant endemic to the Himalayan mountain range, have been known to be effective in alleviating diabetes and its complications. In this study, we aim to prospect for novel plant-derived inhibitors from R. serpentina and to understand structural basis of their interactions. An extensive library of R. serpentina molecules was compiled and computationally screened for inhibitory action against AR. The stability of complexes, with docked leads, was verified using molecular dynamics simulations. Two structurally distinct plant-derived leads were identified as inhibitors: indobine and indobinine. Further, using these two leads as templates, 16 more leads were identified through ligand-based screening of their structural analogs, from a small molecules database. Thus, we obtained plant-derived indole alkaloids, and their structural analogs, as potential AR inhibitors from a manually curated dataset of R. serpentina molecules. Indole alkaloids reported herein, as a novel structural class unreported hitherto, may provide better insights for designing potential AR inhibitors with improved efficacy and fewer side effects.

Analogues of methotrexate and aminopterin with gamma-methylene and gamma-cyano substitution of the glutamate side chain: synthesis and in vitro biological activity.

PubMed

Rosowsky, A; Bader, H; Freisheim, J H

1991-01-01

Analogues of methotrexate (MTX) and aminopterin (AMT) modified at the gamma-position of the glutamate side chain were synthesized and evaluated as dihydrofolate reductase (DHFR) inhibitors and tumor cell growth inhibitors. Condesations of 4-amino-4-deoxy-N10-methylpteroic acid (mAPA) with dimethyl DL-4-methyleneglutamate in the presence of diethyl phosphorocyanidate (DEPC) followed by alkaline hydrolysis yielded N-(4-amino-4-deoxy-N10-methylpteroyl)-DL-4-methyleneglutamic acid (gamma-methyleneMTX). Condensation of 4-amino-4-deoxy-N10-formylpteroic acid (fAPA) with dimethyl-DL-4-methyleneglutamate by the mixed carboxylic-carbonic anhydride method yielded N-4-amino-4-deoxypteroyl)-DL-4-methyleneglutamic acid (gamma-methyleneAMT). Also prepared via DEPC coupling was a mixture of the four possible diastereomers of N-(4-amino-4-deoxy-N10-methylpteroyl)-4-cyanoglutamic acid (gamma-cyanoMTX). The requisite intermediate gamma-tert-butyl alpha-methyl 4-cyanoglutamate, as a DL-threo/DL-erythro mixture, was prepared from methyl N alpha-Boc-O-tosyl-L-serinate by reaction with sodium tert-butyl cyanoacetate followed by mild trifluoroacetic treatment to selectively remove the Boc group. The gamma-methylene derivatives of MTX and AMT are attractive because of their potential to act as Michael acceptors within the DHFR active site. gamma-CyanoMTX may be viewed as a congener of the nonpolyglutamated MTX analogue gamma-fluoroMTX. In vitro bioassay data for the gamma-methylene and gamma-cyano compounds support the idea that the active site of DHFR, already known for its ability to tolerate modification of the gamma-carboxyl group of MTX and AMT, can likewise accommodate substitution on the gamma-carbon itself.

Structural basis for androgen specificity and oestrogen synthesis in human aromatase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Debashis; Griswold, Jennifer; Erman, Mary

2009-03-06

Aromatase cytochrome P450 is the only enzyme in vertebrates known to catalyse the biosynthesis of all oestrogens from androgens. Aromatase inhibitors therefore constitute a frontline therapy for oestrogen-dependent breast cancer. In a three-step process, each step requiring 1 mol of O{sub 2}, 1 mol of NADPH, and coupling with its redox partner cytochrome P450 reductase, aromatase converts androstenedione, testosterone and 16{alpha}-hydroxytestosterone to oestrone, 17{beta}-oestradiol and 17{beta},16{alpha}-oestriol, respectively. The first two steps are C19-methyl hydroxylation steps, and the third involves the aromatization of the steroid A-ring, unique to aromatase. Whereas most P450s are not highly substrate selective, it is the hallmarkmore » androgenic specificity that sets aromatase apart. The structure of this enzyme of the endoplasmic reticulum membrane has remained unknown for decades, hindering elucidation of the biochemical mechanism. Here we present the crystal structure of human placental aromatase, the only natural mammalian, full-length P450 and P450 in hormone biosynthetic pathways to be crystallized so far. Unlike the active sites of many microsomal P450s that metabolize drugs and xenobiotics, aromatase has an androgen-specific cleft that binds the androstenedione molecule snugly. Hydrophobic and polar residues exquisitely complement the steroid backbone. The locations of catalytically important residues shed light on the reaction mechanism. The relative juxtaposition of the hydrophobic amino-terminal region and the opening to the catalytic cleft shows why membrane anchoring is necessary for the lipophilic substrates to gain access to the active site. The molecular basis for the enzyme's androgenic specificity and unique catalytic mechanism can be used for developing next-generation aromatase inhibitors.« less

The inhibitor protein of phosphorylated nitrate reductase from spinach (Spinacia oleracea) leaves is a 14-3-3 protein.

PubMed

Bachmann, M; Huber, J L; Liao, P C; Gage, D A; Huber, S C

1996-06-03

The inhibitor protein (IP) that inactivates spinach leaf NADH:nitrate reductase (NR) has been identified for the first time as a member of the eukaryotic 14-3-3 protein family based on three lines of evidence. First, the sequence of an eight amino acid tryptic peptide, obtained from immunopurified IP, matched that of a highly conserved region of the 14-3-3 proteins. Second, an authentic member of the 14-3-3 family, recombinant Arabidopsis GF14omega, caused inactivation of phospho-NR in a magnesium-dependent manner identical to IP. Third, an anti-GF14 monoclonal antibody cross-reacted with IP and anti-IP monoclonal antibodies cross-reacted with GF14omega.

Differences in Grain Ultrastructure, Phytochemical and Proteomic Profiles between the Two Contrasting Grain Cd-Accumulation Barley Genotypes

PubMed Central

Sun, Hongyan; Cao, Fangbin; Wang, Nanbo; Zhang, Mian; Mosaddek Ahmed, Imrul; Zhang, Guoping; Wu, Feibo

2013-01-01

To reveal grain physio-chemical and proteomic differences between two barley genotypes, Zhenong8 and W6nk2 of high- and low- grain-Cd-accumulation, grain profiles of ultrastructure, amino acid and proteins were compared. Results showed that W6nk2 possesses significantly lower protein content, with hordein depicting the greatest genotypic difference, compared with Zhenong8, and lower amino acid contents with especially lower proportion of Glu, Tyr, Phe and Pro. Both scanning and transmission electron microscopy observation declared that the size of A-type starch molecule in W6nk2 was considerably larger than that of Zhenong8. Grains of Zhenong8 exhibited more protein-rich deposits around starch granules, with some A-type granules having surface pits. Seventeen proteins were identified in grains, using 2-DE coupled with mass spectrometry, with higher expression in Zhenong8 than that in W6nk2; including z-type serpin, serpin-Z7 and alpha-amylase/trypsin inhibitor CM, carbohydrate metabolism, protein synthesis and signal transduction related proteins. Twelve proteins were less expressed in Zhenong8 than that in W6nk2; including barley trypsin inhibitor chloroform/methanol-soluble protein (BTI-CMe2.1, BTI-CMe2.2), trypsin inhibitor, dehydroascorbate reductase (DHAR), pericentrin, dynein heavy chain and some antiviral related proteins. The data extend our understanding of mechanisms underlying Cd accumulation/tolerance and provides possible utilization of elite genetic resources in developing low-grain-Cd barley cultivars. PMID:24260165

Best practice in the management of storage symptoms in male lower urinary tract symptoms: a review of the evidence base

PubMed Central

Gacci, Mauro; Sebastianelli, Arcangelo; Spatafora, Pietro; Corona, Giovanni; Serni, Sergio; De Ridder, Dirk; Gravas, Stavros; Abrams, Paul

2017-01-01

Storage lower urinary tract symptoms (LUTS) are characterized by an altered bladder sensation, increased daytime frequency, nocturia, urgency and urgency incontinence. Some evidence underlines the role of metabolic factors, pelvic ischemia, prostatic chronic inflammation and associated comorbidities in the pathophysiology of storage LUTS. A detailed evaluation of the severity of storage LUTS, and the concomitance of these symptoms with voiding and postmicturition symptoms, is mandatory for improving the diagnosis and personalizing treatment. A detailed medical history with comorbidities and associated risk factors, a physical examination, a comprehensive analysis of all the features of LUTS, including their impact on quality of life, and a frequency–volume chart (FVC) or bladder diary, are recommended for men with storage LUTS. Several drugs are available for the treatment of LUTS secondary to benign prostatic obstruction (BPO). Alpha-blockers (α-blockers), 5-α-reductase inhibitors and phosphodiesterase type 5 inhibitors are commonly used to manage storage LUTS occurring with voiding symptoms associated with BPO. Muscarinic receptor antagonists and Beta 3-agonists (β3-agonists) alone, or in combination with α-blockers, represent the gold standard of treatment in men with predominant storage LUTS. There is no specific recommendation regarding the best treatment options for storage LUTS after prostatic surgery. PMID:29434675

Best practice in the management of storage symptoms in male lower urinary tract symptoms: a review of the evidence base.

PubMed

Gacci, Mauro; Sebastianelli, Arcangelo; Spatafora, Pietro; Corona, Giovanni; Serni, Sergio; De Ridder, Dirk; Gravas, Stavros; Abrams, Paul

2018-02-01

Storage lower urinary tract symptoms (LUTS) are characterized by an altered bladder sensation, increased daytime frequency, nocturia, urgency and urgency incontinence. Some evidence underlines the role of metabolic factors, pelvic ischemia, prostatic chronic inflammation and associated comorbidities in the pathophysiology of storage LUTS. A detailed evaluation of the severity of storage LUTS, and the concomitance of these symptoms with voiding and postmicturition symptoms, is mandatory for improving the diagnosis and personalizing treatment. A detailed medical history with comorbidities and associated risk factors, a physical examination, a comprehensive analysis of all the features of LUTS, including their impact on quality of life, and a frequency-volume chart (FVC) or bladder diary, are recommended for men with storage LUTS. Several drugs are available for the treatment of LUTS secondary to benign prostatic obstruction (BPO). Alpha-blockers (α-blockers), 5-α-reductase inhibitors and phosphodiesterase type 5 inhibitors are commonly used to manage storage LUTS occurring with voiding symptoms associated with BPO. Muscarinic receptor antagonists and Beta 3-agonists (β3-agonists) alone, or in combination with α-blockers, represent the gold standard of treatment in men with predominant storage LUTS. There is no specific recommendation regarding the best treatment options for storage LUTS after prostatic surgery.

The effect of prolonged ethanol administration on central alpha 2-adrenoceptors sensitivity.

PubMed

Szmigielski, A; Szmigielska, H; Wejman, I

1989-01-01

The response of an endogenous inhibitor of protein kinases (type II inhibitor) to clonidine was used as an index of sensitivity of central alpha 2-adrenoceptors. Low doses of clonidine (20-50 micrograms/kg) induced an increase in type II inhibitor activity in the nucleus accumbens, hippocampus and in the anterior and posterior hypothalamus by stimulating presynaptic alpha 2-adrenoceptors. Stimulation of postsynaptic alpha 2-adrenoceptors by high doses of clonidine 0.5-1.0 mg/kg resulted in a dose-dependent decrease in type II inhibitor activity. Prolonged treatment with ethanol (5 g/kg/day po for 21 days) greatly reduced the action of high doses of clonidine in all the examined brain areas, suggesting subsensitivity of postsynaptic alpha 2-adrenoceptors lasting for at least 48 h after the last ethanol administration. A single dose of ethanol induced a short lasting subsensitivity of postsynaptic alpha 2-adrenoceptors in the anterior hypothalamus. 12 h after administration of alcohol the response of type II inhibitor to high doses of clonidine in this brain area was the same as in untreated rats.

New Strategy for Prostate Cancer Prevention Based on Selenium Suppression of Androgen Receptor Signaling

DTIC Science & Technology

2010-04-01

reductase. The Prostate Cancer Prevention Trial (PCPT) demonstrated that treatment with finasteride , an inhibitor of 5α-reductase, reduced prostate...Statement of Work (SOW). B. BODY Task 1. Determine the optimal dose of finasteride to achieve growth inhibition of tumor xenografts in nude mice... finasteride and we found in the literature doses of finasteride effective in inhibiting the growth of LNCaP xenografts in nude mice inhibiting LNCaP

Complex formation between the protein components of methane monooxygenase from Methylosinus trichosporium OB3b. Identification of sites of component interaction.

PubMed

Fox, B G; Liu, Y; Dege, J E; Lipscomb, J D

1991-01-05

Kinetic, spectroscopic, and chemical evidence for the formation of specific catalytically essential complexes between the three protein components of the soluble form of methane monooxygenase from Methylosinus trichosporium OB3b is reported. The effects of the concentrations of the reductase and component B on the hydroxylation activity of the reconstituted enzyme system has been numerically simulated based on a kinetic model which assumes formation of multiple high affinity complexes with the hydroxylase component during catalysis. The formation of several of these complexes has been directly demonstrated. By using EPR spectroscopy, the binding of approximately 2 mol of component B/mol of hydroxylase (subunit structure (alpha beta gamma)2) is shown to significantly change the electronic environment of the mu-(H/R)-oxo-bridged binuclear iron cluster of the hydroxylase in both the mixed valent (Fe(II).Fe(III)) and fully reduced (Fe(II).Fe(II)) states. Protein-protein complexes between the reductase and component B as well as between the reductase and hydroxylase have been shown to form by monitoring quenching of the tryptophan fluorescence spectrum of either the component B (KD approximately 0.4 microM) or hydroxylase (two binding sites, KDa approximately 10 nM, KDb approximately 8 microM). The observed KD values are in agreement with the best fit values from the kinetic simulation. Through the use of the covalent zero length cross-linking reagent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC), the binding sites of the component B and reductase were shown to be on the hydroxylase alpha and beta subunits, respectively. The alpha and beta subunits of the hydroxylase are cross-linked by EDC suggesting that they are juxtaposed. EDC also caused the rapid loss of the ability of the monomeric component B to stimulate the hydroxylation reaction suggesting that cross-linking of reactive groups on the protein surface had occurred. This effect was inhibited by the presence of hydroxylase and was accompanied by a loss of the ability of the component B to bind to the hydroxylase. Thus, formation of a component B-hydroxylase complex is apparently required for effective catalysis linked to NADH oxidation. When present in concentrations greater than required to saturate the initial hydroxylase complex, component B inhibited both the rate of the enzymic reaction and the cross-linking of the reductase to the hydroxylase. This suggests that a second complex involving component B can form that negatively regulates catalysis by preventing formation of the reductase-hydroxylase complex.

Inhibition of the archaeal beta-class (Cab) and gamma-class (Cam) carbonic anhydrases.

PubMed

Zimmerman, Sabrina A; Ferry, James G; Supuran, Claudiu T

2007-01-01

Five independently evolved classes (alpha-, beta-, gamma-, delta-, zeta-) of carbonic anhydrases facilitate the reversible hydration of carbon dioxide to bicarbonate of which the alpha-class is the most extensively studied. Detailed inhibition studies of the alpha-class with the two main classes of inhibitors, sulfonamides and metal-complexing anions, revealed many inhibitors that are used as therapeutic agents to prevent and treat many diseases. Recent inhibitor studies of the archaeal beta-class (Cab) and the gamma-class (Cam) carbonic anhydrases show differences in inhibition response to sulfonamides and metal-complexing anions, when compared to the alpha-class carbonic anhydrases. In addition, inhibition between Cab and Cam differ. These inhibition patterns are consistent with the idea that although, alpha-, beta-, and gamma-class carbonic anhydrases participate in the same two-step isomechanism, diverse active site architecture among these classes predicts variations on the catalytic mechanism. These inhibitor studies of the archaeal beta- and gamma-class carbonic anhydrases give insight to new applications of current day carbonic anhydrase inhibitors, as well as direct research to develop new compounds that may be specific inhibitors of prokaryotic carbonic anhydrases.

Anxiolytic effect of Kami-Shoyo-San (TJ-24) in mice: possible mediation of neurosteroid synthesis.

PubMed

Mizowaki, M; Toriizuka, K; Hanawa, T

2001-09-21

We assessed the anxiolytic effect of Kami-Shoyo-San (Jia-wei-xiao-yao-san; TJ-24), one of a traditional Chinese herbal medicine used for the treatment of menopausal anxiety, by the social interaction (SI) test in male mice. Acute administration of TJ-24 (25-100 mg/kg, p.o.), as well as the gamma-amino-butyric acidA/benzodiazepine (GABA(A)/BZP) receptor agonist diazepam (1-3 mg/kg, i.p.), dose dependently increased the SI time, respectively. The GABA(A) receptor antagonist picrotoxin blocked the effects of TJ-24 and diazepam. TJ-24-induced SI behavior was significantly blocked by the GABA(A)/BZP receptor inverse agonist Ro 15-4513 and the GABA(A)/BZP receptor antagonist flumazenil. In addition, 5alpha-reductase inhibitor finasteride potently blocked the effect of TJ-24 without attenuating the basal level by itself. These findings suggest that TJ-24 shows the anxiolytic effect through the neurosteroid synthesis followed by GABA(A)/BDZ receptor stimulations.

Molecular profiles of finasteride effects on prostate carcinogenesis.

PubMed

Li, Jin; Kim, Jeri

2009-06-01

Our inability to distinguish between low-grade prostate cancers that pose no threat and those that can kill compels newly diagnosed early prostate cancer patients to make decisions that may negatively affect their lives needlessly for years afterward. To reliably stratify patients into different risk categories and apply appropriate treatment, we need a better molecular understanding of prostate cancer progression. Androgen ablation therapy and 5-alpha reductase inhibitors reduce dihydrotestosterone levels and increase apoptosis. Because of the differing biological potentials of tumor cells, however, these treatments may, in some cases, worsen outcome by selecting for or inducing adaptation of stronger androgen receptor signaling pathways. Reduced dihydrotestosterone also may be associated with altered survival pathways. Complicating treatment effects further, molecular adaptation may be accelerated by interactions between epithelial and stromal cells. The hypothesis that early prostate cancer cells with differing biological potential may respond differently to finasteride treatment is worth testing. Ongoing studies using a systems biology approach in a preoperative prostate cancer setting are testing this hypothesis toward developing more-rational clinical interventions.

Influence of temperature on flavour compound production from citrate by Lactobacillus rhamnosus ATCC 7469.

PubMed

De Figueroa, R M; Oliver, G; Benito de Cárdenas, I L

2001-03-01

The citrate utilization by Lactobacillus rhamnosus ATCC 7469 was found to be temperature-dependent. The maximum citrate utilization and incorporation of [1,5-14C]citrate rate were observed at 37 degreesC. At this temperature, maximum citrate lyase activity and specific diacetyl and acetoin production (Y(DA%)) were observed. The high levels of alpha-acetolactate synthase and low levels of diacetyl reductase, acetoin reductase and L-lactate dehydrogenase found at 37 degreesC led to an accumulation of diacetyl and acetoin. Optimum lactic acid production was observed at 45 degreesC, according to the high lactate dehydrogenase activity. The NADH oxidase activity increased with increasing culture temperature from 22 degreesC to 37 degreesC. Thus there are greater quantities of pyruvate available for the production of alpha-acetolactate, diacetyl and aceotin, and less diacetyl and acetoin are reduced.

Comparison of efficacies of a dipeptidyl peptidase IV inhibitor and alpha-glucosidase inhibitors in oral carbohydrate and meal tolerance tests and the effects of their combination in mice.

PubMed

Yamazaki, Kazuto; Inoue, Takashi; Yasuda, Nobuyuki; Sato, Yoshiaki; Nagakura, Tadashi; Takenaka, Osamu; Clark, Richard; Saeki, Takao; Tanaka, Isao

2007-05-01

E3024 (3-but-2-ynyl-5-methyl-2-piperazin-1-yl-3,5-dihydro-4H-imidazo[4,5-d]pyridazin-4-one tosylate) is a dipeptidyl peptidase IV (DPP-IV) inhibitor. Since the target of both DPP-IV inhibitors and alpha-glucosidase inhibitors is the lowering of postprandial hyperglycemia, we compared antihyperglycemic effects for E3024 and alpha-glucosidase inhibitors in various oral carbohydrate and meal tolerance tests using normal mice. In addition, we investigated the combination effects of E3024 and voglibose on blood glucose levels in a meal tolerance test using mice fed a high-fat diet. ER-235516-15 (the trifluoroacetate salt form of E3024, 1 mg/kg) lowered glucose excursions consistently, regardless of the kind of carbohydrate loaded. However, the efficacy of acarbose (10 mg/kg) and of voglibose (0.1 mg/kg) varied with the type of carbohydrate administered. The combination of E3024 (3 mg/kg) and voglibose (0.3 mg/kg) improved glucose tolerance additively, with the highest plasma active glucagon-like peptide-1 levels. This study shows that compared to alpha-glucosidase inhibitors, DPP-IV inhibitors may have more consistent efficacy to reduce postprandial hyperglycemia, independent of the types of carbohydrate contained in a meal, and that the combination of a DPP-IV inhibitor and an alpha-glucosidase inhibitor is expected to be a promising option for lowering postprandial hyperglycemia.

Crystallization of mitochondrial rhodoquinol-fumarate reductase from the parasitic nematode Ascaris suum with the specific inhibitor flutolanil

PubMed Central

Osanai, Arihiro; Harada, Shigeharu; Sakamoto, Kimitoshi; Shimizu, Hironari; Inaoka, Daniel Ken; Kita, Kiyoshi

2009-01-01

In adult Ascaris suum (roundworm) mitochondrial membrane-bound complex II acts as a rhodoquinol-fumarate reductase, which is the reverse reaction to that of mammalian complex II (succinate-ubiquinone reductase). The adult A. suum rhodoquinol-fumarate reductase was crystallized in the presence of octaethyleneglycol monododecyl ether and n-dodecyl-β-d-maltopyranoside in a 3:2 weight ratio. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 123.75, b = 129.08, c = 221.12 Å, and diffracted to 2.8 Å resolution using synchrotron radiation. The presence of two molecules in the asymmetric unit (120 kDa × 2) gives a crystal volume per protein mass (V M) of 3.6 Å3 Da−1. PMID:19724139

Purification and properties of a dissimilatory nitrate reductase from Haloferax denitrificans

NASA Technical Reports Server (NTRS)

Hochstein, L. I.; Lang, F.

1991-01-01

A membrane-bound nitrate reductase (nitrite:(acceptor) oxidoreductase, EC 1.7.99.4) from the extremely halophilic bacterium Haloferax denitrificans was solubilized by incubating membranes in buffer lacking NaCl and purified by DEAE, hydroxylapatite, and Sepharose 6B gel filtration chromatography. The purified nitrate reductase reduced chlorate and was inhibited by azide and cyanide. Preincubating the enzyme with cyanide increased the extent of inhibition which in turn was intensified when dithionite was present. Although cyanide was a noncompetitive inhibitor with respect to nitrate, nitrate protected against inhibition. The enzyme, as isolated, was composed of two subunits (Mr 116,000 and 60,000) and behaved as a dimer during gel filtration (Mr 380,000). Unlike other halobacterial enzymes, this nitrate reductase was most active, as well as stable, in the absence of salt.

Dissociation of branched-chain alpha-keto acid dehydrogenase kinase (BDK) from branched-chain alpha-keto acid dehydrogenase complex (BCKDC) by BDK inhibitors.

PubMed

Murakami, Taro; Matsuo, Masayuki; Shimizu, Ayako; Shimomura, Yoshiharu

2005-02-01

Branched-chain alpha-keto acid dehydrogenase kinase (BDK) phosphorylates and inactivates the branched-chain alpha-keto acid dehydrogenase complex (BCKDC), which is the rate-limiting enzyme in the branched-chain amino acid catabolism. BDK has been believed to be bound to the BCKDC. However, recent our studies demonstrated that protein-protein interaction between BDK and BCKDC is one of the factors to regulate BDK activity. Furthermore, only the bound form of BDK appears to have its activity. In the present study, we examined effects of BDK inhibitors on the amount of BDK bound to the BCKDC using rat liver extracts. The bound form of BDK in the extracts of liver from low protein diet-fed rats was measured by an immunoprecipitation pull down assay with or without BDK inhibitors. Among the BDK inhibitors. alpha-ketoisocaproate, alpha-chloroisocaproate, and a-ketoisovalerate released the BDK from the complex. Furthermore, the releasing effect of these inhibitors on the BDK appeared to depend on their inhibition constants. On the other hand, clofibric acid and thiamine pyrophosphate had no effect on the protein-protein interaction between two enzymes. These results suggest that the dissociation of the BDK from the BCKDC is one of the mechanisms responsible for the action of some inhibitors to BDK.

Structure based comprehensive modelling, spatial fingerprints mapping and ADME screening of curcumin analogues as novel ALR2 inhibitors

PubMed Central

Verma, Sant Kumar

2017-01-01

Aldose reductase (ALR2) inhibition is the most legitimate approach for the management of diabetic complications. The limited triumph in the drug development against ALR2 is mainly because of its close structural similarity with the other members of aldo-keto reductase (AKR) superfamily viz. ALR1, AKR1B10; and lipophilicity problem i.e. poor diffusion of synthetic aldose reductase inhibitors (ARIs) to target tissues. The literature evidenced that naturally occurring curcumin demonstrates relatively specific and non-competitive inhibition towards human recombinant ALR2 over ALR1 and AKR1B10; however β-diketone moiety of curcumin is a specific substrate for liver AKRs and accountable for it’s rapid in vivo metabolism. In the present study, structure based comprehensive modelling studies were used to map the pharmacophoric features/spatial fingerprints of curcumin analogues responsible for their ALR2 specificity along with potency on a data set of synthetic curcumin analogues and naturally occurring curcuminoids. The data set molecules were also screened for drug-likeness or ADME parameters, and the screening data strongly support that curcumin analogues could be proposed as a good drug candidate for the development of ALR2 inhibitors with improved pharmacokinetic profile compared to curcuminoids due to the absence of β-diketone moiety in their structural framework. PMID:28399135

Nitrate reductase and nitrite as additional components of defense system in pigeonpea (Cajanus cajan L.) against Helicoverpa armigera herbivory.

PubMed

Kaur, Rimaljeet; Gupta, Anil Kumar; Taggar, Gaurav Kumar

2014-10-01

Amylase inhibitors serve as attractive candidates of defense mechanisms against insect attack. Therefore, the impediment of Helicoverpa armigera digestion can be the effective way of controlling this pest population. Nitrite was found to be a potent mixed non-competitive competitive inhibitor of partially purified α-amylase of H. armigera gut. This observation impelled us to determine the response of nitrite and nitrate reductase (NR) towards H. armigera infestation in nine pigeonpea genotypes (four moderately resistant, three intermediate and two moderately susceptible). The significant upregulation of NR in moderately resistant genotypes after pod borer infestation suggested NR as one of the factors that determine their resistance status against insect attack. The pod borer attack caused greater reduction of nitrate and significant accumulation of nitrite in moderately resistant genotypes. The activity of nitrite reductase (NiR) was also enhanced more in moderately resistant genotypes than moderately susceptible genotypes on account of H. armigera herbivory. Expression of resistance to H. armigera was further revealed when significant negative association between NR, NiR, nitrite and percent pod damage was observed. This is the first report that suggests nitrite to be a potent inhibitor of H. armigera α-amylase and also the involvement of nitrite and NR in providing resistance against H. armigera herbivory. Copyright © 2014 Elsevier Inc. All rights reserved.

Genome sequence analysis of predicted polyprenol reductase gene from mangrove plant kandelia obovata

NASA Astrophysics Data System (ADS)

Basyuni, M.; Sagami, H.; Baba, S.; Oku, H.

2018-03-01

It has been previously reported that dolichols but not polyprenols were predominated in mangrove leaves and roots. Therefore, the occurrence of larger amounts of dolichol in leaves of mangrove plants implies that polyprenol reductase is responsible for the conversion of polyprenol to dolichol may be active in mangrove leaves. Here we report the early assessment of probably polyprenol reductase gene from genome sequence of mangrove plant Kandelia obovata. The functional assignment of the gene was based on a homology search of the sequences against the non-redundant (nr) peptide database of NCBI using Blastx. The degree of sequence identity between DNA sequence and known polyprenol reductase was confirmed using the Blastx probability E-value, total score, and identity. The genome sequence data resulted in three partial sequences, termed c23157 (700 bp), c23901 (960 bp), and c24171 (531 bp). The c23157 gene showed the highest similarity (61%) to predicted polyprenol reductase 2- like from Gossypium raimondii with E-value 2e-100. The second gene was c23901 to exhibit high similarity (78%) to the steroid 5-alpha-reductase Det2 from J. curcas with E-value 2e-140. Furthermore, the c24171 gene depicted highest similarity (79%) to the polyprenol reductase 2 isoform X1 from Jatropha curcas with E- value 7e-21.The present study suggested that the c23157, c23901, and c24171, genes may encode predicted polyprenol reductase. The c23157, c23901, c24171 are therefore the new type of predicted polyprenol reductase from K. obovata.

Structural and biological evaluation of a novel series of benzimidazole inhibitors of Francisella tularensis enoyl-ACP reductase (FabI)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehboob, Shahila; Song, Jinhua; Hevener, Kirk E.

Francisella tularensis, the causative agent of tularemia, presents a significant biological threat and is a Category A priority pathogen due to its potential for weaponization. In the bacterial FASII pathway we found it a viable target for the development of novel antibacterial agents treating Gram-negative infections. Here, we report the advancement of a promising series of benzimidazole FabI (enoyl-ACP reductase) inhibitors to a second-generation using a systematic, structure-guided lead optimization strategy, and the determination of several co-crystal structures that confirm the binding mode of designed inhibitors. Furthermore, these compounds display an improved low nanomolar enzymatic activity as well as promisingmore » low microgram/mL antibacterial activity against both F. tularensis and Staphylococcus aureus and its methicillin-resistant strain (MRSA). Finally, the improvements in activity accompanying structural modifications lead to a better understanding of the relationship between the chemical structure and biological activity that encompasses both enzymatic and whole-cell activity.« less

Structural and biological evaluation of a novel series of benzimidazole inhibitors of Francisella tularensis enoyl-ACP reductase (FabI)

DOE PAGES

Mehboob, Shahila; Song, Jinhua; Hevener, Kirk E.; ...

2015-01-29

Francisella tularensis, the causative agent of tularemia, presents a significant biological threat and is a Category A priority pathogen due to its potential for weaponization. In the bacterial FASII pathway we found it a viable target for the development of novel antibacterial agents treating Gram-negative infections. Here, we report the advancement of a promising series of benzimidazole FabI (enoyl-ACP reductase) inhibitors to a second-generation using a systematic, structure-guided lead optimization strategy, and the determination of several co-crystal structures that confirm the binding mode of designed inhibitors. Furthermore, these compounds display an improved low nanomolar enzymatic activity as well as promisingmore » low microgram/mL antibacterial activity against both F. tularensis and Staphylococcus aureus and its methicillin-resistant strain (MRSA). Finally, the improvements in activity accompanying structural modifications lead to a better understanding of the relationship between the chemical structure and biological activity that encompasses both enzymatic and whole-cell activity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schormann, Norbert; Velu, Sadanandan E.; Murugesan, Srinivasan

Dihydrofolate reductase (DHFR) of the parasite Trypanosoma cruzi (T. cruzi) is a potential target for developing drugs to treat Chagas disease. We have undertaken a detailed structure-activity study of this enzyme. We report here synthesis and characterization of six potent inhibitors of the parasitic enzyme. Inhibitory activity of each compound was determined against T. cruzi and human DHFR. One of these compounds, ethyl 4-(5-[(2,4-diamino-6-quinazolinyl)methyl]amino-2-methoxyphenoxy)butanoate (6b) was co-crystallized with the bifunctional dihydrofolate reductase-thymidylate synthase enzyme of T. cruzi and the crystal structure of the ternary enzyme:cofactor:inhibitor complex was determined. Molecular docking was used to analyze the potential interactions of all inhibitorsmore » with T. cruzi DHFR and human DHFR. Inhibitory activities of these compounds are discussed in the light of enzyme-ligand interactions. Binding affinities of each inhibitor for the respective enzymes were calculated based on the experimental or docked binding mode. An estimated 60-70% of the total binding energy is contributed by the 2,4-diaminoquinazoline scaffold.« less

Cinnamaldehyde inhibits the tumor necrosis factor-{alpha}-induced expression of cell adhesion molecules in endothelial cells by suppressing NF-{kappa}B activation: Effects upon I{kappa}B and Nrf2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, B.-C.; Hsieh, C.-W.; Liu, Y.-C.

The production of adhesion molecules and subsequent attachment of leukocytes to endothelial cells (ECs) are critical early events in atherogenesis. These adhesion molecules thus play an important role in the development of this disease. Recent studies have highlighted the chemoprotective and anti-inflammatory effects of cinnamaldehyde, a Cinnamomum cassia Presl-specific diterpene. In our current study, we have examined the effects of both cinnamaldehyde and extracts of C. cassia on cytokine-induced monocyte/human endothelial cell interactions. We find that these compounds inhibit the adhesion of TNF{alpha}-induced monocytes to endothelial cells and suppress the expression of the cell adhesion molecules, VCAM-1 and ICAM-1, atmore » the transcriptional level. Moreover, in TNF{alpha}-treated ECs, the principal downstream signal of VCAM-1 and ICAM-1, NF-{kappa}B, was also found to be abolished in a time-dependent manner. Interestingly, cinnamaldehyde exerts its anti-inflammatory effects by blocking the degradation of the inhibitory protein I{kappa}B-{alpha}, but only in short term pretreatments, whereas it does so via the induction of Nrf2-related genes, including heme-oxygenase-1 (HO-1), over long term pretreatments. Treating ECs with zinc protoporphyrin, a HO-1 inhibitor, partially blocks the anti-inflammatory effects of cinnamaldehyde. Elevated HO-1 protein levels were associated with the inhibition of TNF{alpha}-induced ICAM-1 expression. In addition to HO-1, we also found that cinnamaldehyde can upregulate Nrf2 in nuclear extracts, and can increase ARE-luciferase activity and upregulate thioredoxin reductase-1, another Nrf2-related gene. Moreover, cinnamaldehyde exposure rapidly reduces the cellular GSH levels in ECs over short term treatments but increases these levels after 9 h exposure. Hence, our present findings indicate that cinnamaldehyde suppresses TNF-induced singling pathways via two distinct mechanisms that are activated by different pretreatment periods.« less

The spectrum of low molecular weight alpha-amylase/protease inhibitor genes expressed in the US bread wheat cultivar Butte 86

PubMed Central

2011-01-01

Background Wheat grains accumulate a variety of low molecular weight proteins that are inhibitors of alpha-amylases and proteases and play an important protective role in the grain. These proteins have more balanced amino acid compositions than the major wheat gluten proteins and contribute important reserves for both seedling growth and human nutrition. The alpha-amylase/protease inhibitors also are of interest because they cause IgE-mediated occupational and food allergies and thereby impact human health. Results The complement of genes encoding alpha-amylase/protease inhibitors expressed in the US bread wheat Butte 86 was characterized by analysis of expressed sequence tags (ESTs). Coding sequences for 19 distinct proteins were identified. These included two monomeric (WMAI), four dimeric (WDAI), and six tetrameric (WTAI) inhibitors of exogenous alpha-amylases, two inhibitors of endogenous alpha-amylases (WASI), four putative trypsin inhibitors (CMx and WTI), and one putative chymotrypsin inhibitor (WCI). A number of the encoded proteins were identical or very similar to proteins in the NCBI database. Sequences not reported previously included variants of WTAI-CM3, three CMx inhibitors and WTI. Within the WDAI group, two different genes encoded the same mature protein. Based on numbers of ESTs, transcripts for WTAI-CM3 Bu-1, WMAI Bu-1 and WTAI-CM16 Bu-1 were most abundant in Butte 86 developing grain. Coding sequences for 16 of the inhibitors were unequivocally associated with specific proteins identified by tandem mass spectrometry (MS/MS) in a previous proteomic analysis of milled white flour from Butte 86. Proteins corresponding to WDAI Bu-1/Bu-2, WMAI Bu-1 and the WTAI subunits CM2 Bu-1, CM3 Bu-1 and CM16 Bu-1 were accumulated to the highest levels in flour. Conclusions Information on the spectrum of alpha-amylase/protease inhibitor genes and proteins expressed in a single wheat cultivar is central to understanding the importance of these proteins in both plant defense mechanisms and human allergies and facilitates both breeding and biotechnology approaches for manipulating the composition of these proteins in plants. PMID:21774824

Early Access Program Using Alpha 1 Antitrypsin Infusion for Patients With Steroid Refractory Acute GvHD After Hematopoietic Stem Cell Transplantation (HSCT)

ClinicalTrials.gov

2017-05-29

SR aGvHD; Acute-graft-versus-host Disease; Steroid Refractory Acute Graft Versus Host Disease; Graft-versus-host-disease; Graft Vs Host Disease; Alpha 1-Antitrypsin Deficiency; Alpha-1 Proteinase Inhibitor; Alpha-1 Protease Inhibitor Deficiency; Acute Graft-Versus-Host Reaction Following Bone Marrow Transplant

On the inhibitor effects of bergamot juice flavonoids binding to the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) enzyme.

PubMed

Leopoldini, Monica; Malaj, Naim; Toscano, Marirosa; Sindona, Giovanni; Russo, Nino

2010-10-13

Density functional theory was applied to study the binding mode of new flavonoids as possible inhibitors of the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), an enzyme that catalyzes the four-electron reduction of HMGCoA to mevalonate, the committed step in the biosynthesis of sterols. The investigated flavonoid conjugates brutieridin and melitidin were recently quantified in the bergamot fruit extracts and identified to be structural analogues of statins, lipids concentration lowering drugs that inhibit HMGR. Computations allowed us to perform a detailed analysis of the geometrical and electronic features affecting the binding of these compounds, as well as that of the excellent simvastatin drug, to the active site of the enzyme and to give better insight into the inhibition process.

Lactate oxidation coupled to energy production in mitochondria like particles from Setaria digitata, a filarial parasite.

PubMed

Sivan, V M; Raj, R K

1994-10-14

In the filarial parasite, Setaria digitata, the mitochondria like particles (MLP) show NAD reduction with sodium lactate. The MLP also reduces dye and ferricyanide with lactate. The ferricyanide reduction by lactate is found to be sensitive to the cytochrome o inhibitor orthohydroxy diphenyl (OHD) and complex I inhibitor rotenone, modulated by ADP (+) and ATP (-) and inhibited by pyruvate and oxaloacetate. MLP shows lactate oxidation sensitive to OHD, rotenone and sodium malonate. Thus, the lactate utilizing complex system, consisting of an NADH generating MLP bound lactate dehydrogenase and a lactate flavocytochrome reductase tightly linked to complex I and cytochrome o, produces ATP in functional association with fumarate reductase complex and other enzyme systems. Hence, this study provides new dimensions to the study of metabolism in filarial parasites.

The effect of low-carbohydrates calorie-restricted diet on visceral adipose tissue and metabolic status in psoriasis patients receiving TNF-alpha inhibitors: results of an open label controlled, prospective, clinical study.

PubMed

Campanati, A; Molinelli, E; Ganzetti, G; Giuliodori, K; Minetti, I; Taus, M; Catani, M; Martina, E; Conocchiari, L; Offidani, A

2017-05-01

TNF alpha inhibitors are usually associated with anthropometric changes over the time, however whether and how the visceral adipose tissue (VAT) is involved in this phenomenon, still remains unclear. Aim of the study is to evaluate if the increases in trunk fat percentage (TF%) and VAT are directly involved in anthropometric changes occurring during treatment, and whether and how a calorie restricted diet could prevent these changes. Twenty patients receiving TNF-alpha inhibitors for psoriasis was evaluated at baseline (T0) and after 24 weeks of therapy (T24), and then compared with 25 patients receiving a combined treatment based on TNF alpha inhibitors and low-carbohydrates calorie-restricted diet. TNF-alpha inhibitors do not influence the VAT expression. The combined treatment is associated with a significant decrease in body weight (kg) (p < .0001), BMI (p = .0001), WC (cm) (p < .0001), TF% (p < .0001), VAT (p < .0001), serum levels of triglycerides (mg/dL) (p = .0018) and total cholesterol (mg/dL) (p = .0005). The administration of TNF-alpha inhibitors can induce anthropometric changes after 24 weeks, but it does not cause an increase in VAT. The association between low-carbohydrates calorie-restricted diet and anti-TNF-alpha therapy seems to be able to improve the anthropometric profile of psoriasis patients.

9-Hydroxyprostaglandin dehydrogenase activity in the adult rat kidney. Regional distribution and sub-fractionation.

PubMed

Asciak, C P; Domazet, Z

1975-02-20

1. Catabolism of prostaglandin F2alpha in the adult rat kidney takes place by the following sequence of enzymatic steps: (1) 15-hydroxyprostaglandin dehydrogenase; (2) prostaglandin delta13-reductase; and (3) 9-hydroxyprostaglandin dehydrogenase. 2. 9-Hydroxyprostaglandin dehydrogenase activity was highest in the cortex with lesser amounts in the medulla and negligible activity detected in the papilla. A similar distribution was observed for 15-hydroxyprostaglandin dehydrogenase and prostaglandin delta13-reductase. 3. Most of the 9-hydroxyprostaglandin dehydrogenase activity in the homogenate was found in the high-speed supernatant as also observed for 15-hydroxyprostaglandin dehydrogenase and prostaglandin delta13-reductase. 4. These observations indicate that the rat kidney contains an abundance of prostaglandin-catabolising enzymes which favour formation of metabolites of the E-type.

Binding of [alpha, alpha]-Disubstituted Amino Acids to Arginase Suggests New Avenues for Inhibitor Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilies, Monica; Di Costanzo, Luigi; Dowling, Daniel P.

Arginase is a binuclear manganese metalloenzyme that hydrolyzes L-arginine to form L-ornithine and urea, and aberrant arginase activity is implicated in various diseases such as erectile dysfunction, asthma, atherosclerosis, and cerebral malaria. Accordingly, arginase inhibitors may be therapeutically useful. Continuing our efforts to expand the chemical space of arginase inhibitor design and inspired by the binding of 2-(difluoromethyl)-L-ornithine to human arginase I, we now report the first study of the binding of {alpha},{alpha}-disubstituted amino acids to arginase. Specifically, we report the design, synthesis, and assay of racemic 2-amino-6-borono-2-methylhexanoic acid and racemic 2-amino-6-borono-2-(difluoromethyl)hexanoic acid. X-ray crystal structures of human arginase Imore » and Plasmodium falciparum arginase complexed with these inhibitors reveal the exclusive binding of the L-stereoisomer; the additional {alpha}-substituent of each inhibitor is readily accommodated and makes new intermolecular interactions in the outer active site of each enzyme. Therefore, this work highlights a new region of the protein surface that can be targeted for additional affinity interactions, as well as the first comparative structural insights on inhibitor discrimination between a human and a parasitic arginase.« less

Cyclopiazonic acid biosynthesis in Aspergillus sp.: characterization of a reductase-like R* domain in cyclopiazonate synthetase that forms and releases cyclo-acetoacetyl-L-tryptophan.

PubMed

Liu, Xinyu; Walsh, Christopher T

2009-09-15

The fungal neurotoxin alpha-cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca2+-ATPase, has a pentacyclic indole tetramic acid scaffold that arises from one molecule of tryptophan, acetyl-CoA, malonyl-CoA, and dimethylallyl pyrophosphate by consecutive action of three enzymes, CpaS, CpaD, and CpaO. CpaS is a hybrid, two module polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) that makes and releases cyclo-acetoacetyl-L-tryptophan (cAATrp), the tetramic acid that serves as substrate for subsequent prenylation and oxidative cyclization to the five ring CPA scaffold. The NRPS module in CpaS has a predicted four-domain organization of condensation, adenylation, thiolation, and reductase* (C-A-T-R*), where R* lacks the critical Ser-Tyr-Lys catalytic triad of the short chain dehydrogenase/reductase (SDR) superfamily. By heterologous overproduction in Escherichia coli of the 56 kDa Aspergillus flavus CpaS TR* didomain and the single T and R* domains, we demonstrate that CpaS catalyzes a Dieckmann-type cyclization on the N-acetoacetyl-Trp intermediate bound in thioester linkage to the phosphopantetheinyl arm of the T domain to form and release cAATrp. This occurs without any participation of NAD(P)H, so R* does not function as a canonical SDR family member. Use of the T and R* domains in in trans assays enabled multiple turnovers and evaluation of specific mutants. Mutation of the D3803 residue in the R* domain, conserved in other fungal tetramate synthetases, abolished activity both in in trans and in cis (TR*) activity assays. It is likely that cyclization of beta-ketoacylaminoacyl-S-pantetheinyl intermediates to released tetramates represents a default cyclization/release route for redox-incompetent R* domains embedded in NRPS assembly lines.

IkappaB is a sensitive target for oxidation by cell-permeable chloramines: inhibition of NF-kappaB activity by glycine chloramine through methionine oxidation.

PubMed

Midwinter, Robyn G; Cheah, Fook-Choe; Moskovitz, Jackob; Vissers, Margret C; Winterbourn, Christine C

2006-05-15

Hypochlorous acid (HOCl) is produced by the neutrophil enzyme, myeloperoxidase, and reacts with amines to generate chloramines. These oxidants react readily with thiols and methionine and can affect cell-regulatory pathways. In the present study, we have investigated the ability of HOCl, glycine chloramine (Gly-Cl) and taurine chloramine (Tau-Cl) to oxidize IkappaBalpha, the inhibitor of NF-kappaB (nuclear factor kappaB), and to prevent activation of the NF-kappaB pathway in Jurkat cells. Glycine chloramine (Gly-Cl) and HOCl were permeable to the cells as determined by oxidation of intracellular GSH and inactivation of glyceraldehyde-3-phosphate dehydrogenase, whereas Tau-Cl showed no detectable cell permeability. Both Gly-Cl (20-200 muM) and HOCl (50 microM) caused oxidation of IkappaBalpha methionine, measured by a shift in electrophoretic mobility, when added to the cells in Hanks buffer. In contrast, a high concentration of Tau-Cl (1 mM) in Hanks buffer had no effect. However, Tau-Cl in full medium did modify IkappaBalpha. This we attribute to chlorine exchange with other amines in the medium to form more permeable chloramines. Oxidation by Gly-Cl prevented IkappaBalpha degradation in cells treated with TNFalpha (tumour necrosis factor alpha) and inhibited nuclear translocation of NF-kappaB. IkappaBalpha modification was reversed by methionine sulphoxide reductase, with both A and B forms required for complete reduction. Oxidized IkappaBalpha persisted intracellularly for up to 6 h. Reversion occurred in the presence of cycloheximide, but was prevented if thioredoxin reductase was inhibited, suggesting that it was due to endogenous methionine sulphoxide reductase activity. These results show that cell-permeable chloramines, either directly or when formed in medium, could regulate NF-kappaB activation via reversible IkappaBalpha oxidation.

Subcellular localization of the five members of the human steroid 5α-reductase family.

PubMed

Scaglione, Antonella; Montemiglio, Linda Celeste; Parisi, Giacomo; Asteriti, Italia Anna; Bruni, Renato; Cerutti, Gabriele; Testi, Claudia; Savino, Carmelinda; Mancia, Filippo; Lavia, Patrizia; Vallone, Beatrice

2017-06-01

In humans the steroid 5alpha-reductase (SRD5A) family comprises five integral membrane enzymes that carry out reduction of a double bond in lipidic substrates: Δ 4 -3-keto steroids, polyprenol and trans-enoyl CoA. The best-characterized reaction is the conversion of testosterone into the more potent dihydrotestosterone carried out by SRD5A1-2. Some controversy exists on their possible nuclear or endoplasmic reticulum localization. We report the cloning and transient expression in HeLa cells of the five members of the human steroid 5α-reductase family as both N- and C-terminus green fluorescent protein tagged protein constructs. Following the intrinsic fluorescence of the tag, we have determined that the subcellular localization of these enzymes is in the endoplasmic reticulum, upon expression in HeLa cells. The presence of the tag at either end of the polypeptide chain can affect protein expression and, in the case of trans enoyl-CoA reductase, it induces the formation of protein aggregates.

Alirocumab Injection

MedlinePlus

... injection is used along with diet and certain cholesterol-lowering medications (HMG-CoA reductase inhibitors [statins]) in ... familial heterozygous hypercholesterolemia (an inherited condition in which cholesterol cannot be removed from the body normally) or ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, Joshua P.; Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ; Mishin, Vladimir

Inhalation of vesicants including sulfur mustard can cause significant damage to the upper airways. This is the result of vesicant-induced modifications of proteins important in maintaining the integrity of the lung. Cytochrome P450s are the major enzymes in the lung mediating detoxification of sulfur mustard and its metabolites. NADPH cytochrome P450 reductase is a flavin-containing electron donor for cytochrome P450. The present studies demonstrate that the sulfur mustard analog, 2-chloroethyl ethyl sulfide (CEES), is a potent inhibitor of human recombinant cytochrome P450 reductase, as well as native cytochrome P450 reductase from liver microsomes of saline and {beta}-naphthoflavone-treated rats, and cytochromemore » P450 reductase from type II lung epithelial cells. Using rat liver microsomes from {beta}-naphthoflavone-treated rats, CEES was found to inhibit CYP 1A1 activity. This inhibition was overcome by microsomal cytochrome P450 reductase from saline-treated rats, which lack CYP 1A1 activity, demonstrating that the CEES inhibitory activity was selective for cytochrome P450 reductase. Cytochrome P450 reductase also generates reactive oxygen species (ROS) via oxidation of NADPH. In contrast to its inhibitory effects on the reduction of cytochrome c and CYP1A1 activity, CEES was found to stimulate ROS formation. Taken together, these data demonstrate that sulfur mustard vesicants target cytochrome P450 reductase and that this effect may be an important mechanism mediating oxidative stress and lung injury.« less

Hair loss

MedlinePlus

... that is applied to the scalp to stimulate hair growth. Other medicines, such as hormones, may be prescribed to decrease hair loss and promote hair growth. Drugs such as finasteride and dutasteride can be ...

Regulation of HSD17B1 and SRD5A1 in lymphocytes.

PubMed

Zhou, Z; Speiser, P W

1999-11-01

We previously reported lymphocyte expression of genes encoding enzymes required for steroid metabolism; however, only 17beta-HSD and 5alpha-reductase showed significant enzyme activity. We now investigate regulation of lymphocyte expression for genes encoding 17beta-HSD and 5alpha-reductase. Cultured human T and B lymphoid cell lines and peripheral blood mononuclear cells were treated with known regulators of steroidogenic gene expression including forskolin, PMA, ionomycin, various steroids, interleukin (IL)-4, and IL-6. Treatment with 10 or 50 microM forskolin resulted in a 20-60% reduction of expression for HSD17B1 (encoding 17beta-HSD I) in T and B lymphoid cell lines and peripheral blood mononuclear cells, although such a change was not observed in the expression of SRD5A1 (encoding 5alpha-reductase I). No significant changes were found when cells were treated for 24 h with various concentrations of PMA or ionomycin. Incubation with 10(-9) to 10(-7) M androstenedione or estradiol increased expression of HSD17B1, while testosterone decreased the expression of this gene. SRD5A1 expression was increased in the presence of 5alpha-DHT although no consistent changes were observed when the cells were treated with testosterone. Other steroids, including dexamethasone, progesterone, and 6-hydroxypregnanolone, produced no effects on expression of either HSD17B1 or SRD5A1. Treatment with 0.1-10 ng/ml of IL-4 or IL-6 also did not effect significant changes in gene expression. These data implicate the involvement of the cAMP-protein kinase signal transduction pathway in regulating lymphocyte expression of HSD17B1. Furthermore, it appears that lymphocyte HSD17B1 and SRD5A1 are regulated to some extent by specific steroids. Copyright 1999 Academic Press.

Characterization of a cultured human T-cell line with genetically altered ribonucleotide reductase activity. Model for immunodeficiency.

PubMed

Waddell, D; Ullman, B

1983-04-10

From human CCRF-CEM T-cells growing in continuous culture, we have selected, isolated, and characterized a clonal cell line, APHID-D2, with altered ribonucleotide reductase activity. In comparative growth rate experiments, the APHID-D2 cell line is less sensitive than the parental cell line to growth inhibition by deoxyadenosine in the presence of 10 microM erythro-9-(2-hydroxy-3-nonyl)adenine, an inhibitor of adenosine deaminase. The APHID-D2 cell line has elevated levels of all four dNTPs. The resistance of the APHID-D2 cell line to growth inhibition by deoxyadenosine and the abnormal dNTP levels can be explained by the fact that the APHID-D2 ribonucleotide reductase, unlike the parental ribonucleotide reductase, is not normally sensitive to inhibition by dATP. These results suggest that the allosteric site of ribonucleotide reductase which binds both dATP and ATP is altered in the APHID-D2 line. The isolation of a mutant clone of human T-cells which contains a ribonucleotide reductase that has lost its normal sensitivity to dATP and which is resistant to deoxyadenosine-mediated growth inhibition suggests that a primary pathogenic target of accumulated dATP in lymphocytes from patients with adenosine deaminase deficiency may be the cellular ribonucleotide reductase.

SRD5A1 and SRD5A2 are associated with treatment for benign prostatic hyperplasia with the combination of 5α-reductase inhibitors and α-adrenergic receptor antagonists.

PubMed

Gu, Xin; Na, Rong; Huang, Tao; Wang, Li; Tao, Sha; Tian, Lu; Chen, Zhuo; Jiao, Yang; Kang, Jian; Zheng, Siqun; Xu, Jianfeng; Sun, Jielin; Qi, Jun

2013-08-01

Common treatments for benign prostatic hyperplasia include 5α-reductase inhibitors and α-adrenergic receptor antagonists. However, these treatments can only partially decrease the risk of benign prostatic hyperplasia progression. SRD5A1 and SRD5A2 are 5α-reductase inhibitor targets. We investigated the association between drug efficacy and single nucleotide polymorphisms in the SRD5A1 and SRD5A2 genes in a Chinese population. We genotyped 11 tagging single nucleotide polymorphisms in the SRD5A1 and SRD5A2 genes in a total of 426 benign prostatic hyperplasia cases and 1,008 controls from Xinhua Hospital, Shanghai, People's Republic of China. Cases were treated with type II 5α-reductase inhibitors and α-adrenergic receptor antagonists. We tested the association of tagging single nucleotide polymorphisms with benign prostatic hyperplasia risk/progression, clinical characteristics at baseline, including the I-PSS (International Prostate Symptom Score) and total prostate volume, and changes in clinical characteristics after treatment. The 11 tagging single nucleotide polymorphisms were not significantly associated with benign prostatic hyperplasia risk or progression (each p >0.05). In the SRD5A1 gene rs6884552 and rs3797177 were significantly associated with baseline I-PSS (p = 0.04 and 0.003, respectively). In the SRD5A2 gene rs523349 (V89L) and rs9332975 were significantly associated with baseline total prostate volume (p = 0.01 and 0.001, respectively). In SRD5A1 rs166050 was significantly associated with the posttreatment change in total prostate volume (p = 0.04). In SRD5A2 rs523349 and rs612224 were significantly associated with the posttreatment I-PSS change (p = 0.03 and 0.009, respectively). SRD5A1 and SRD5A2 single nucleotide polymorphisms are significantly associated with the clinical characteristics of benign prostatic hyperplasia and the efficacy of benign prostatic hyperplasia treatment. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Evaluation of potent inhibitors of dihydrofolate reductase in a culture model for growth of Pneumocystis carinii.

PubMed

Bartlett, M S; Shaw, M; Navaran, P; Smith, J W; Queener, S F

1995-11-01

Many antifolates are known to inhibit dihydrofolate reductase from murine Pneumocystis carinii, with 50% inhibitory concentrations (IC50s) ranging from 10(-4) to 10(-11) M. The relationship of the potency against isolated enzyme to the potency against intact murine P. carinii cells was explored with 17 compounds that had proven selectivity for or potency against P. carinii dihydrofolate reductase. Pyrimethamine and one analog were inhibitory to P. carinii in culture at concentrations two to seven times the IC50s for the enzyme, suggesting that the compounds may enter P. carinii cells in culture. Methotrexate was a potent inhibitor of P. carinii dihydrofolate reductase, but the concentrations effective in culture were more than 1,000-fold higher than IC50s for the enzyme, since P. carinii lacks an uptake system for methotrexate. Analogs of methotrexate in which chlorine, bromine, or iodine was added to the phenyl ring had improved potency against the isolated enzyme but were markedly less effective in culture; polyglutamation also lowered the activity in culture but improved activity against the enzyme. Substitution of a naphthyl group for the phenyl group of methotrexate produced a compound with improved activity against the enzyme (IC50, 0.00019 microM) and excellent activity in culture (IC50, 0.1 microM). One trimetrexate analog in which an aspartate or a chlorine replaced two of the methoxy groups of trimetrexate was much more potent and was much more selective toward P. carinii dihydrofolate reductase than trimetrexate; this analog was also as active as trimetrexate in culture. These studies suggest that modifications of antifolate structures can be made that facilitate activity against intact organisms while maintaining the high degrees of potency and the selectivities of the agents can be made.

Medical and minimally invasive therapies for the treatment of benign prostatic hyperplasia.

PubMed

Harkaway, R C; Issa, M M

2006-01-01

Over the last decade, management of benign prostatic hyperplasia (BPH) has changed with a substantial decrease in the use of transurethral prostatectomy (TURP) and a simultaneous increase in the use of medical therapy and minimally invasive surgical therapy (MIST). The goal of management of this chronic progressive condition is not only to provide relief of lower urinary tract symptoms (LUTS) but also to reduce the lifetime risk of adverse outcomes. Recent clinical evidence has demonstrated a clear role for medical therapy, particularly with 5-alpha-reductase inhibitors (5ARIs) either alone or in combination with alpha-blockers, to reduce the risk of acute urinary retention and need for surgery and provide symptom relief. Clinical data on MISTs also indicate a more pronounced short-term effect; however, the long-term durability of these therapies remains uncertain. Minimally invasive surgical therapies confer treatment benefits in a single 1-h treatment session under local anesthesia. Recovery times and adverse events are improved compared with TURP, but issues such as hematuria, prolonged catheterization, urinary tract infection and retreatment remain commonly reported issues. Today, urologists are faced with the challenge of identifying the most appropriate treatment option for the long-term management of BPH. The initial choice for any given patient will depend on his presenting circumstances and the influence of treatment risks on these circumstances. Providing patients with informed treatment decisions is a key element of management.

Trypanothione reductase from Leishmania infantum: cloning, expression, purification, crystallization and preliminary X-ray data analysis.

PubMed

Baiocco, Paola; Franceschini, Stefano; Ilari, Andrea; Colotti, Gianni

2009-01-01

The most promising targets for Leishmania-specific drug design are two key enzymes involved in the unique thiol-based metabolism, common to all parasites of the Trypanosomatidae family: trypanothione synthetase (TryS) and trypanothione reductase (TR). Recently, new inhibitors of TR have been identified such as polyamines and tricyclic compounds. The knowledge of the three-dimensional structure of Leishmania TR will shed light on the mechanism of interaction of these inhibitors with TR and will be the starting point to design novel lead candidates to facilitate the development of new effective and affordable drugs. Trypanothione reductase from Leishmania infantum has been cloned, expressed in E. coli and purified. Crystals were obtained at 294 K by the hanging drop vapour diffusion method using ammonium sulfate as precipitant agent and diffract to better than 2.95 A resolution using a synchrotron radiation source. The crystals exhibit an unusually high solvent content of 74 %, belong to the tetragonal space group P41 with units cell parameters a=b=103.45 A, c=192.62 A and two molecules in the asymmetric unit. The protein X-ray structure has been solved by Molecular Replacement and the model is under construction.

The role of morphine on rat neural stem cells viability, neuro-angiogenesis and neuro-steroidgenesis properties.

PubMed

Abdyazdani, Nima; Nourazarian, Alireza; Nozad Charoudeh, Hojjatollah; Kazemi, Masoumeh; Feizy, Navid; Akbarzade, Maryam; Mehdizadeh, Amir; Rezaie, Jafar; Rahbarghazi, Reza

2017-01-01

A lack of comprehensive data exists on the effect of morphine on neural stem cell neuro-steroidogenesis and neuro-angiogenesis properties. We, herein, investigated the effects of morphine (100μM), naloxone (100μM) and their combination on rat neural stem cells viability, clonogenicity and Ki-67 expression over a period of 72h. Any alterations in the total fatty acids profile under treatment protocols were elucidated by direct transesterification method. We also monitored the expression of p53, aromatase and 5-alpha reductase by real-time PCR assay. To examine angiogenic capacity, in vitro tubulogenesis and the level of VE-cadherin transcript were investigated during neural to endothelial differentiation under the experimental procedure. Cells supplemented with morphine displayed reduced survival (p<0.01) and clonogenicity (p<0.001). Flow cytometric analysis showed a decrease in Ki-67 during 72h. Naloxone potentially blunted morphine-induced all effects. The normal levels of fatty acids, including saturated and unsaturated were altered by naloxone and morphine supplements. Following 48h, the up-regulation of p53, aromatase and 5-alpha reductase genes occurred in morphine-primed cells. Using three-dimensional culture models of angiogenesis and real time PCR assay, we showed morphine impaired the tubulogenesis properties of neural stem cells (p<0.001) by the inhibition of trans-differentiation into vascular cells and led to decrease of in VE-cadherin expression. Collectively, morphine strongly impaired the healthy status of neural stem cells by inducing p53 and concurrent elevation of aromatase and 5-alpha reductase activities especially during early 48h. Also, neural stem cells-being exposed to morphine lost their potency to elicit angiogenesis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

HMG-CoA reductase inhibitory activity and phytocomponent investigation of Basella alba leaf extract as a treatment for hypercholesterolemia.

PubMed

Baskaran, Gunasekaran; Salvamani, Shamala; Ahmad, Siti Aqlima; Shaharuddin, Noor Azmi; Pattiram, Parveen Devi; Shukor, Mohd Yunus

2015-01-01

The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases.

HMG-CoA reductase inhibitory activity and phytocomponent investigation of Basella alba leaf extract as a treatment for hypercholesterolemia

PubMed Central

Baskaran, Gunasekaran; Salvamani, Shamala; Ahmad, Siti Aqlima; Shaharuddin, Noor Azmi; Pattiram, Parveen Devi; Shukor, Mohd Yunus

2015-01-01

The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases. PMID:25609924

Plasmalemma Redox Activity and H+ Extrusion in Roots of Fe-Deficient Cucumber Plants 1

PubMed Central

Alcántara, Esteban; de la Guardia, Manuel D.; Romera, Francisco J.

1991-01-01

Cucumber plants (Cucumis sativus L.) with incipient Fe deficiency showed increased root capacity to reduce chelated Fe3+ compared to Fe-sufficient plants. When Fe-ethylenediaminete-traacetate was added to the root medium of the Fe-deficient plants, the reductase activity was associated with acidification of the medium and an increase in the net apparent K+ efflux. In the presence of the H+-ATPase inhibitor N,N′-dicyclohexylcarbodiimide the net apparent H+ efflux was completely suppressed, though some reductase activity was preserved, and the net apparent K+ efflux was significantly increased. The inhibition of the reductase activity by N,N′-dicyclohexylcarbodiimide was similar whether the pH of the medium was buffered or not. Anoxia and the protonophore carbonyl cyanide m-chlorophenyl hydrazone also caused a similar inhibition of the reductase activity. It is proposed that this redox system transports electrons only and that its activity is inhibited by plasmamembrane depolarization and anoxia. The H+ and K+ efflux associated with the reductase activity may be a result of the plasmamembrane depolarization it causes. PMID:16668294

The influence of vitamin B2 intake on the activation coefficient of erythrocyte glutation reductase in the elderly.

PubMed

López-Sobaler, A M; Ortega, R M; Quintas, M E; Navarro, A R; Aparicio, A; Gomez-Rodriguez, N; Cocho, M; Requejo, A M

2002-01-01

To evaluate the influence of dietetic vitamin B2 on the activation coefficient of erythrocyte glutation reductase (alpha-EGR) of a group of elderly people. The study subjects were 133, independently-living elderly people, between 65 and 90 years of age. A dietetic study was performed using a 7-day food record. Riboflavin status was measured by determining the alpha-EGR. Some 23.9% of subjects had riboflavin intakes lower than those recommended. At the biochemical level, 9.8% of subjects (7.7% of men and of 10.6% women) showed alpha-EGR>1.2. Those subjects with riboflavin intakes below 90% of those recommended showed significantly higher alpha-EGR levels (1.15+/-0.16), an indication of a poorer riboflavin status at the biochemical level. Those with greater intakes showed lower alpha-EGR values (1.05+/-0.10). Furthermore, the mean consumption of dairy products (an important source of this vitamin) by subjects is insuficiente (341.1+/-159.8 g/day, 2.1+/-1 servings/day). The data show that those with riboflavin intakes below those recommended took 204.7+/-89.4 g/day of milk products (1.3+/-0.5 servings/day) compared to the 384+/-153.1 g/day (2.4+/-1 servings/day) (p<0.001) consumed by those with higher riboflavin intakes. Although the mean riboflavin intake is acceptable, there remain some insufficiencies that require attention. It would seem advisable to recommend the elderly increase their intake of milk products. This would be especially important for subjects who take less than two rations per day.

Cancer cell death induced by phosphine gold(I) compounds targeting thioredoxin reductase.

PubMed

Gandin, Valentina; Fernandes, Aristi Potamitou; Rigobello, Maria Pia; Dani, Barbara; Sorrentino, Francesca; Tisato, Francesco; Björnstedt, Mikael; Bindoli, Alberto; Sturaro, Alberto; Rella, Rocco; Marzano, Cristina

2010-01-15

The thioredoxin system, composed of thioredoxin reductase (TrxR), thioredoxin (Trx), and NADPH (nicotinamide adenine dinucleotide phosphate), plays a central role in regulating cellular redox homeostasis and signaling pathways. TrxR, overexpressed in many tumor cells and contributing to drug resistance, has emerged as a new target for anticancer drugs. Gold complexes have been validated as potent TrxR inhibitors in vitro in the nanomolar range. In order to obtain potent and selective TrxR inhibitors, we have synthesized a series of linear, 'auranofin-like' gold(I) complexes all containing the [Au(PEt(3))](+) synthon and the ligands: Cl(-), Br(-), cyanate, thiocyanate, ethylxanthate, diethyldithiocarbamate and thiourea. Phosphine gold(I) complexes efficiently inhibited cytosolic and mitochondrial TrxR at concentrations that did not affect the two related oxidoreductases glutathione reductase (GR) and glutathione peroxidase (GPx). The inhibitory effect of the redox proteins was also observed intracellularly in cancer cells pretreated with gold(I) complexes. Gold(I) compounds were found to induce antiproliferative effects towards several human cancer cells some of which endowed with cisplatin or multidrug resistance. In addition, they were able to activate caspase-3 and induce apoptosis observed as nucleosome formation and sub-G1 cell accumulation. The complexes with thiocyanate and xanthate ligands were particularly effective in inhibiting thioredoxin reductase and inducing apoptosis. Pharmacodynamic studies in human ovarian cancer cells allowed for the correlation of intracellular drug accumulation with TrxR inhibition that leads to the induction of apoptosis via the mitochondrial pathway.

Conversion of Human Steroid 5[beta]-Reductase (AKR1D1) into 3[beta]-Hydroxysteroid Dehydrogenase by Single Point Mutation E120H: Example of Perfect Enzyme Engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Mo; Drury, Jason E.; Christianson, David W.

2012-10-10

Human aldo-keto reductase 1D1 (AKR1D1) and AKR1C enzymes are essential for bile acid biosynthesis and steroid hormone metabolism. AKR1D1 catalyzes the 5{beta}-reduction of {Delta}{sup 4}-3-ketosteroids, whereas AKR1C enzymes are hydroxysteroid dehydrogenases (HSDs). These enzymes share high sequence identity and catalyze 4-pro-(R)-hydride transfer from NADPH to an electrophilic carbon but differ in that one residue in the conserved AKR catalytic tetrad, His120 (AKR1D1 numbering), is substituted by a glutamate in AKR1D1. We find that the AKR1D1 E120H mutant abolishes 5{beta}-reductase activity and introduces HSD activity. However, the E120H mutant unexpectedly favors dihydrosteroids with the 5{alpha}-configuration and, unlike most of the AKR1Cmore » enzymes, shows a dominant stereochemical preference to act as a 3{beta}-HSD as opposed to a 3{alpha}-HSD. The catalytic efficiency achieved for 3{beta}-HSD activity is higher than that observed for any AKR to date. High resolution crystal structures of the E120H mutant in complex with epiandrosterone, 5{beta}-dihydrotestosterone, and {Delta}{sup 4}-androstene-3,17-dione elucidated the structural basis for this functional change. The glutamate-histidine substitution prevents a 3-ketosteroid from penetrating the active site so that hydride transfer is directed toward the C3 carbonyl group rather than the {Delta}{sup 4}-double bond and confers 3{beta}-HSD activity on the 5{beta}-reductase. Structures indicate that stereospecificity of HSD activity is achieved because the steroid flips over to present its {alpha}-face to the A-face of NADPH. This is in contrast to the AKR1C enzymes, which can invert stereochemistry when the steroid swings across the binding pocket. These studies show how a single point mutation in AKR1D1 can introduce HSD activity with unexpected configurational and stereochemical preference.« less

Effects of male sex hormones on gender identity, sexual behavior, and cognitive function.

PubMed

Zhu, Yuan-shan; Cai, Li-qun

2006-04-01

Androgens, the male sex hormones, play an essential role in male sexual differentiation and development. However, the influence of these sex hormones extends beyond their roles in sexual differentiation and development. In many animal species, sex hormones have been shown to be essential for sexual differentiation of the brain during development and for maintaining sexually dimorphic behavior throughout life. The principals of sex determination in humans have been demonstrated to be similar to other mammals. However, the hormonal influence on sexual dimorphic differences in the nervous system in humans, sex differences in behaviors, and its correlations with those of other mammals is still an emerging field. In this review, the roles of androgens in gender and cognitive function are discussed with the emphasis on subjects with androgen action defects including complete androgen insensitivity due to androgen receptor mutations and 5alpha-reductase-2 deficiency syndromes due to 5alpha-reductase-2 gene mutations. The issue of the complex interaction of nature versus nurture is addressed.

Pharmacy benefits management in the Veterans Health Administration: 1995 to 2003.

PubMed

Sales, Mariscelle M; Cunningham, Francesca E; Glassman, Peter A; Valentino, Michael A; Good, Chester B

2005-02-01

The Department of Veterans Affairs (VA) Pharmacy Benefits Management Strategic Healthcare Group (VA PBM) oversees the formulary for the entire VA system, which serves more than 4 million veterans and provides more than 108 million prescriptions per year. Since its establishment in 1995, the VA PBM has managed pharmaceuticals and pharmaceutical-related policies, including drug safety and efficacy evaluations, pharmacologic management algorithms, and criteria for drug use. These evidence-based practices promote, optimize, and assist VA providers with the safe and appropriate use of pharmaceuticals while allowing for formulary decisions that can result in substantial cost savings. The VA PBM also has utilized various contracting techniques to standardize generic agents as well as specific drugs and drug classes (eg, antihistamines, angiotensin-converting enzyme inhibitors, alpha-blockers, and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors [statins]). These methods have enabled the VA to save approximately dollar 1.5 billion since 1996 even as drug expenditures continued to rise from roughly dollar 1 billion in fiscal year (FY) 1996 to more than dollar 3 billion in FY 2003. Furthermore, the VA PBM has established an outcomes research section to undertake quality-improvement and safety initiatives that ultimately monitor and determine the clinical impact of formulary decisions on the VA system nationwide. The experiences of this pharmacy benefits program, including clinical and contracting processes/procedures and their impact on the VA healthcare system, are described.

Relative adrenal insufficiency in mice deficient in 5α-reductase 1

PubMed Central

Livingstone, Dawn E W; Di Rollo, Emma M; Yang, Chenjing; Codrington, Lucy E; Mathews, John A; Kara, Madina; Hughes, Katherine A; Kenyon, Christopher J; Walker, Brian R; Andrew, Ruth

2014-01-01

Patients with critical illness or hepatic failure exhibit impaired cortisol responses to ACTH, a phenomenon known as ‘relative adrenal insufficiency’. A putative mechanism is that elevated bile acids inhibit inactivation of cortisol in liver by 5α-reductases type 1 and type 2 and 5β-reductase, resulting in compensatory downregulation of the hypothalamic–pituitary–adrenal axis and adrenocortical atrophy. To test the hypothesis that impaired glucocorticoid clearance can cause relative adrenal insufficiency, we investigated the consequences of 5α-reductase type 1 deficiency in mice. In adrenalectomised male mice with targeted disruption of 5α-reductase type 1, clearance of corticosterone was lower after acute or chronic (eightfold, P<0.05) administration, compared with WT control mice. In intact 5α-reductase-deficient male mice, although resting plasma corticosterone levels were maintained, corticosterone responses were impaired after ACTH administration (26% lower, P<0.05), handling stress (2.5-fold lower, P<0.05) and restraint stress (43% lower, P<0.05) compared with WT mice. mRNA levels of Nr3c1 (glucocorticoid receptor), Crh and Avp in pituitary or hypothalamus were altered, consistent with enhanced negative feedback. These findings confirm that impaired peripheral clearance of glucocorticoids can cause ‘relative adrenal insufficiency’ in mice, an observation with important implications for patients with critical illness or hepatic failure, and for patients receiving 5α-reductase inhibitors for prostatic disease. PMID:24872577

Pharmacology of the lower urinary tract

PubMed Central

Hennenberg, Martin; Stief, Christian G.; Gratzke, Christian

2014-01-01

Pharmacology of the lower urinary tract provides the basis for medical treatment of lower urinary tract symptoms (LUTS). Therapy of LUTS addresses obstructive symptoms (frequently explained by increased prostate smooth muscle tone and prostate enlargement) in patients with benign prostate hyperplasia (BPH) and storage symptoms in patients with overactive bladder (OAB). Targets for medical treatment include G protein-coupled receptors (α1-adrenoceptors, muscarinic acetylcholine receptors, β3-adrenoceptors) or intracellular enzymes (5α-reductase; phosphodiesterase-5, PDE5). Established therapies of obstructive symptoms aim to induce prostate smooth muscle relaxation by α1-blockers or PDE5 inhibitors, or to reduce prostate growth and volume with 5α-reductase inhibitors. Available options for treatment of OAB comprise anitmuscarinics, β3-adrenoceptor agonists, and botulinum toxin A, which improve storage symptoms by inhibition of bladder smooth muscle contraction. With the recent approval of β3-antagonists, PDE inhibitors, and silodosin for therapy of LUTS, progress from basic research of lower urinary tract pharmacology was translated into new clinical applications. Further targets are in preclinical stages of examination, including modulators of the endocannabinoid system and transient receptor potential (TRP) channels. PMID:24744518

Lepidopteran HMG-CoA reductase is a potential selective target for pest control

PubMed Central

Li, Yuan-mei; Huang, Juan; Tobe, Stephen S.

2017-01-01

As a consequence of the negative impacts on the environment of some insecticides, discovery of eco-friendly insecticides and target has received global attention in recent years. Sequence alignment and structural comparison of the rate-limiting enzyme HMG-CoA reductase (HMGR) revealed differences between lepidopteran pests and other organisms, which suggested insect HMGR could be a selective insecticide target candidate. Inhibition of JH biosynthesis in vitro confirmed that HMGR inhibitors showed a potent lethal effect on the lepidopteran pest Manduca sexta, whereas there was little effect on JH biosynthesis in Apis mellifera and Diploptera punctata. The pest control application of these inhibitors demonstrated that they can be insecticide candidates with potent ovicidal activity, larvicidal activity and insect growth regulatory effects. The present study has validated that Lepidopteran HMGR can be a potent selective insecticide target, and the HMGR inhibitors (especially type II statins) could be selective insecticide candidates and lead compounds. Furthermore, we demonstrated that sequence alignment, homology modeling and structural comparison may be useful for determining potential enzymes or receptors which can be eco-friendly pesticide  targets. PMID:28133568

Lepidopteran HMG-CoA reductase is a potential selective target for pest control.

PubMed

Li, Yuan-Mei; Kai, Zhen-Peng; Huang, Juan; Tobe, Stephen S

2017-01-01

As a consequence of the negative impacts on the environment of some insecticides, discovery of eco-friendly insecticides and target has received global attention in recent years. Sequence alignment and structural comparison of the rate-limiting enzyme HMG-CoA reductase (HMGR) revealed differences between lepidopteran pests and other organisms, which suggested insect HMGR could be a selective insecticide target candidate. Inhibition of JH biosynthesis in vitro confirmed that HMGR inhibitors showed a potent lethal effect on the lepidopteran pest Manduca sexta , whereas there was little effect on JH biosynthesis in Apis mellifera and Diploptera punctata . The pest control application of these inhibitors demonstrated that they can be insecticide candidates with potent ovicidal activity, larvicidal activity and insect growth regulatory effects. The present study has validated that Lepidopteran HMGR can be a potent selective insecticide target, and the HMGR inhibitors (especially type II statins) could be selective insecticide candidates and lead compounds. Furthermore, we demonstrated that sequence alignment, homology modeling and structural comparison may be useful for determining potential enzymes or receptors which can be eco-friendly pesticide  targets.

Pharmacologic inhibition of squalene synthase and other downstream enzymes of the cholesterol synthesis pathway: a new therapeutic approach to treatment of hypercholesterolemia.

PubMed

Seiki, Stephanie; Frishman, William H

2009-01-01

Hypercholesterolemia is a major risk factor for the development of atherosclerotic vascular diseases. The most popular agents for cholesterol reduction are the statin drugs, which are competitive inhibitors of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, the primary rate-limiting enzyme in the hepatic biosynthesis of cholesterol. Although relatively safe and effective, the available statins can cause elevations in liver enzymes and myopathy. Squalene synthase is another enzyme that is downstream to HMG-CoA reductase in the cholesterol synthesis pathway and modulates the first committed step of hepatic cholesterol biosynthesis at the final branch point of the cholesterol biosynthetic pathway. Squalene epoxidase and oxidosqualene cyclase are other enzymes that act distally to squalene synthase. Pharmacologic inhibitors of these downstream enzymes have been developed, which may reduce low-density lipoprotein cholesterol and reduce the myopathy side effect seen with upstream inhibition of HMG-CoA. At this juncture, one squalene synthase inhibitor, lapaquistat (TAK-475) is in active clinical trials as a monotherapy, but there have been suggestions of increased hepatotoxicity with the drug.

2'-Deoxy-2'-methylenecytidine and 2'-deoxy-2',2'-difluorocytidine 5'-diphosphates: potent mechanism-based inhibitors of ribonucleotide reductase.

PubMed

Baker, C H; Banzon, J; Bollinger, J M; Stubbe, J; Samano, V; Robins, M J; Lippert, B; Jarvi, E; Resvick, R

1991-06-01

It has been found that 2'-deoxy-2'-methyleneuridine (MdUrd), 2'-deoxy-2'-methylenecytidine (MdCyd), and 2'-deoxy-2',2'-difluorocytidine (dFdCyd) 5'-diphosphates (MdUDP (1) MdCDP (2) and dFdCDP (3), respectively) function as irreversible inactivators of the Escherichia coli ribonucleoside diphosphate reductase (RDPR). 2 is a much more potent inhibitor than its uridine analogue 1. It is proposed that 2 undergoes abstraction of H3' to give an allylic radical that captures a hydrogen atom and decomposes to an active alkylating furanone species. RDPR also accepts 3 as an alternative substrate analogue and presumably executes an initial abstraction of H3' to initiate formation of a suicide species. Both 2 and 3 give inactivation results that differ from those of previously studied inhibitors. The potent anticancer activities of MdCyd and dFdCyd indicate a significant chemotherapeutic potential. The analogous RDPR of mammalian cells should be regarded as a likely target and/or activating enzyme for these novel mechanism-based inactivators.

Synthetic serine elastase inhibitor reduces cigarette smoke-induced emphysema in guinea pigs.

PubMed

Wright, Joanne L; Farmer, Stephen G; Churg, Andrew

2002-10-01

To test whether a serine elastase inhibitor could prevent or reduce emphysema, we exposed guinea pigs to cigarette smoke acutely, or daily for 6 months, and treated some animals with the neutrophil elastase inhibitor ZD0892. Acute smoke exposure increased lavage neutrophils and increased desmosine and hydroxyproline, measures of elastin and collagen breakdown; all these measures were reduced by ZD0892. Long-term smoke exposure produced emphysema and increases in lavage neutrophils, desmosine, hydroxyproline, and plasma tumor necrosis factor alpha (TNF-alpha). ZD0892 treatment returned lavage neutrophils, desmosine, and hydroxyproline levels to control values, and decreased airspace enlargement by 45% and TNF-alpha by 30%. Animals exposed to smoke for 4 months and then to smoke plus ZD0892 for 2 months were not protected against emphysema. Mice exposed to smoke showed increases in gene expression of neutrophil chemoattractant macrophage inflammatory protein-2, macrophage chemoattractant protein-1, and TNF-alpha at 2 hours along with increased plasma TNF-alpha; ZD0892 prevented the increases in macrophage inflammatory protein-2 and macrophage chemoattractant protein-1 expression and reduced plasma TNF-alpha levels to baseline. These data demonstrate that a serine elastase inhibitor ameliorates the inflammatory and destructive effects of cigarette smoke, and that these effects are mediated in part by neutrophils and by smoke-driven TNF-alpha production.

Potential risk of alpha-glucosidase inhibitor administration in prostate cancer external radiotherapy by exceptional rectal gas production: a case report.

PubMed

Nishimura, Takuya; Yamazaki, Hideya; Iwama, Kazuki; Oota, Yoshitaka; Aibe, Norihiro; Nakamura, Satoaki; Yoshida, Ken; Okabe, Haruumi; Yamada, Kei

2014-05-05

Radiotherapy is a standard treatment for prostate cancer, and image-guided radiotherapy is increasingly being used to aid precision of dose delivery to targeted tissues. However, precision during radiotherapy cannot be maintained when unexpected intrafraction organ motion occurs. We report our experience of internal organ motion caused by persistent gas production in a patient taking an alpha-glucosidase inhibitor. A 68-year-old Japanese man with prostate cancer visited our institution for treatment with helical tomotherapy. He suffered from diabetes mellitus and took an alpha-glucosidase inhibitor. Routine treatment planning computed tomography showed a large volume of rectal gas; an enema was given to void the rectum. Subsequent treatment planning computed tomography again showed a large volume of gas. After exercise (walking) to remove the intestinal gas, a third scan was performed as a test scan without tight fixation, which showed a sufficiently empty rectum for planning. However, after only a few minutes, treatment planning computed tomography again showed extreme accumulation of gas. Therefore, we postponed treatment planning computed tomography and consulted his doctor to suspend the alpha-glucosidase inhibitor, which was the expected cause of his persistent gas. Four days after the alpha-glucosidase inhibitor regimen was suspended, we took a fourth treatment planning computed tomography and made a treatment plan without gas accumulation. Thereafter, the absence of rectal gas accumulation was confirmed using daily megavolt computed tomography before treatment, and the patient received 37 fractions of intensity-modified radiotherapy at 74 Gy without rectal gas complications. In this case study, the alpha-glucosidase inhibitor induced the accumulation of intestinal gas, which may have caused unexpected organ motion, untoward reactions, and insufficient doses to clinical targets. We suggest that patients who are taking an alpha-glucosidase inhibitor for diabetes should discontinue use of that particular medicine prior to beginning radiotherapy.

Characterization of human DHRS4: an inducible short-chain dehydrogenase/reductase enzyme with 3beta-hydroxysteroid dehydrogenase activity.

PubMed

Matsunaga, Toshiyuki; Endo, Satoshi; Maeda, Satoshi; Ishikura, Shuhei; Tajima, Kazuo; Tanaka, Nobutada; Nakamura, Kazuo T; Imamura, Yorishige; Hara, Akira

2008-09-15

Human DHRS4 is a peroxisomal member of the short-chain dehydrogenase/reductase superfamily, but its enzymatic properties, except for displaying NADP(H)-dependent retinol dehydrogenase/reductase activity, are unknown. We show that the human enzyme, a tetramer composed of 27kDa subunits, is inactivated at low temperature without dissociation into subunits. The cold inactivation was prevented by a mutation of Thr177 with the corresponding residue, Asn, in cold-stable pig DHRS4, where this residue is hydrogen-bonded to Asn165 in a substrate-binding loop of other subunit. Human DHRS4 reduced various aromatic ketones and alpha-dicarbonyl compounds including cytotoxic 9,10-phenanthrenequinone. The overexpression of the peroxisomal enzyme in cultured cells did not increase the cytotoxicity of 9,10-phenanthrenequinone. While its activity towards all-trans-retinal was low, human DHRS4 efficiently reduced 3-keto-C(19)/C(21)-steroids into 3beta-hydroxysteroids. The stereospecific conversion to 3beta-hydroxysteroids was observed in endothelial cells transfected with vectors expressing the enzyme. The mRNA for the enzyme was ubiquitously expressed in human tissues and several cancer cells, and the enzyme in HepG2 cells was induced by peroxisome-proliferator-activated receptor alpha ligands. The results suggest a novel mechanism of cold inactivation and role of the inducible human DHRS4 in 3beta-hydroxysteroid synthesis and xenobiotic carbonyl metabolism.

Genomic structure of rat 3alpha-hydroxysteroid/dihydrodiol dehydrogenase (3alpha-HSD/DD, AKR1C9).

PubMed

Lin, H K; Hung, C F; Moore, M; Penning, T M

1999-11-01

Rat liver 3alpha-hydroxysteroid/dihydrodiol dehydrogenase (3alpha-HSD/DD) is a member of the aldo-keto reductase (AKR) superfamily. It is involved in the inactivation of steroid hormones and the metabolic activation of polycyclic aromatic hydrocarbons (PAH) by converting trans-dihydrodiols into reactive and redox-active o-quinones. The structure of the 5'-flanking region of the gene and factors involved in the constitutive and regulated expression of this gene have been reported [H.-K. Lin, T.M. Penning, Cloning, sequencing, and functional analysis of the 5'-flanking region of the rat 3alpha-hydroxysteroid/dihydrodiol dehydrogenase gene, Cancer Res. 55 (1995) 4105-4113]. We now describe the complete genomic structure of the rat type 1 3alpha-HSD/DD gene. Charon 4A and P1 genomic clones contained at least three rat genes (type 1, type 2 and type 3 3alpha-HSD/DD) each of which encoded for the same open reading frame (ORF) but differed in their exon-intron organization. 5'-RACE confirmed that the type 1 3alpha-HSD/DD gene encodes for the dominant transcript in rat liver and it was the regulation of this gene that was previously studied. The rat type 1 3alpha-HSD/DD gene is 30 kb in length and consists of nine exons and eight introns. Exon 9 encodes +931 to 966 bp of the ORF and the 1292 bp 3'-UTR implicated in mRNA stability. This genomic structure is nearly identical to the homologous human genes, type 1 3alpha-HSD (chlordecone reductase/DD4, AKR1C4), type 2 3alpha-HSD (AKR1C3) and type 3 3alpha-HSD (bile-acid binding protein, AKR1C2) genes. Three different cDNA's containing identical ORFs for 3alpha-HSD have been reported suggesting that all three genes may be expressed in rat liver. Using 5' primers corresponding to the 5'-UTR's of the three different cDNA's only one PCR fragment was obtained and corresponded to the type 1 3alpha-HSD/DD gene. These data suggested that the type 2 and type 3 3alpha-HSD/DD genes are not abundantly expressed in rat liver. It is unknown whether the type 2 and type 3 3alpha-HSD/DD genes represent pseudo-genes or whether they represent genes that are differentially expressed in other rat tissues.

Squalene synthase inhibitors: An update on the search for new antihyperlipidemic and antiatherosclerotic agents.

PubMed

Kourounakis, A P; Katselou, M G; Matralis, A N; Ladopoulou, E M; Bavavea, E

2011-01-01

Atherosclerosis and related heart disease is strongly associated with elevated blood levels of total (and LDL) cholesterol. Due to the widespread incidence as well as severity of this pathological condition, major efforts have been made for the discovery and development of hypocholesteroleamic agents. In the past few decades, HMG-CoA reductase inhibitors (statins) are being extensively used as lipid lowering drugs. These agents act predominantly by inhibiting the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) that is the rate limiting step of cholesterol biosynthesis. Both the success as well as drawbacks of HMGRIs, have led to the investigation and design of inhibitors of other (downstream) enzymes involved in the multistep cholesterol biosynthetic pathway. One such class of agents consists of the squalene sythase inhibitors which act at the first and solely committed step towards the biosynthesis of the cholesterol nucleus. This target is considered not to interfere with the biosynthesis of other biologically important molecules and thus a better side-effect profile is expected for these inhibitors. Several classes of squalene synthase inhibitors (SQSIs), such as substrate or transition-state analogues, zaragozic acids or 2,8- dioxabicyclo[3.2.1]octane derivatives, dicarboxylic acid and quinuclidine derivatives, 4,1-benzoxazepine as well as substituted morpholine derivatives, have been studied as potent inhibitors of squalene synthase. So far only one benzoxazepine derivative (TAK-475) has been evaluated in advanced clinical trials. In this article we review the up to date research and literature on the therapeutic potential of this relatively new class of compounds, the drug discovery efforts towards the development of active squalene synthase inhibitors, their activity profile and effectiveness, as well as their structure-activity relationships.

Bioactive constituents from Chinese natural medicines. XXXII. aminopeptidase N and aldose reductase inhibitors from Sinocrassula indica: structures of sinocrassosides B(4), B(5), C(1), and D(1)-D(3).

PubMed

Morikawa, Toshio; Xie, Haihui; Wang, Tao; Matsuda, Hisashi; Yoshikawa, Masayuki

2008-10-01

From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B(4) (1), B(5) (2), C(1) (3), D(1) (4), D(2) (5), and D(3) (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.

Differential protein acetylation induced by novel histone deacetylase inhibitors.

PubMed

Glaser, K B; Li, J; Pease, L J; Staver, M J; Marcotte, P A; Guo, J; Frey, R R; Garland, R B; Heyman, H R; Wada, C K; Vasudevan, A; Michaelides, M R; Davidsen, S K; Curtin, M L

2004-12-17

Histone deacetylase (HDAC) inhibitors induce the hyperacetylation of nucleosomal histones in carcinoma cells resulting in the expression of repressed genes that cause growth arrest, terminal differentiation, and/or apoptosis. In vitro selectivity of several novel hydroxamate HDAC inhibitors including succinimide macrocyclic hydroxamates and the non-hydroxamate alpha-ketoamide inhibitors was investigated using isolated enzyme preparations and cellular assays. In vitro selectivity for the HDAC isozymes (HDAC1/2, 3, 4/3, and 6) was not observed for these HDAC inhibitors or the reference HDAC inhibitors, MS-275 and SAHA. In T24 and HCT116 cells these compounds caused the accumulation of acetylated histones H3 and H4; however, the succinimide macrocyclic hydroxamates and the alpha-ketoamides did not cause the accumulation of acetylated alpha-tubulin. These data suggest "selectivity" can be observed at the cellular level with HDAC inhibitors and that the nature of the zinc-chelating moiety is an important determinant of activity against tubulin deacetylase.

Isoporphyrin intermediate in heme oxygenase catalysis. Oxidation of alpha-meso-phenylheme.

PubMed

Evans, John P; Niemevz, Fernando; Buldain, Graciela; de Montellano, Paul Ortiz

2008-07-11

Human heme oxygenase-1 (hHO-1) catalyzes the O2- and NADPH-dependent oxidation of heme to biliverdin, CO, and free iron. The first step involves regiospecific insertion of an oxygen atom at the alpha-meso carbon by a ferric hydroperoxide and is predicted to proceed via an isoporphyrin pi-cation intermediate. Here we report spectroscopic detection of a transient intermediate during oxidation by hHO-1 of alpha-meso-phenylheme-IX, alpha-meso-(p-methylphenyl)-mesoheme-III, and alpha-meso-(p-trifluoromethylphenyl)-mesoheme-III. In agreement with previous experiments (Wang, J., Niemevz, F., Lad, L., Huang, L., Alvarez, D. E., Buldain, G., Poulos, T. L., and Ortiz de Montellano, P. R. (2004) J. Biol. Chem. 279, 42593-42604), only the alpha-biliverdin isomer is produced with concomitant formation of the corresponding benzoic acid. The transient intermediate observed in the NADPH-P450 reductase-catalyzed reaction accumulated when the reaction was supported by H2O2 and exhibited the absorption maxima at 435 and 930 nm characteristic of an isoporphyrin. Product analysis by reversed phase high performance liquid chromatography and liquid chromatography electrospray ionization mass spectrometry of the product generated with H2O2 identified it as an isoporphyrin that, on quenching, decayed to benzoylbiliverdin. In the presence of H218O2, one labeled oxygen atom was incorporated into these products. The hHO-1-isoporphyrin complexes were found to have half-lives of 1.7 and 2.4 h for the p-trifluoromethyl- and p-methyl-substituted phenylhemes, respectively. The addition of NADPH-P450 reductase to the H2O2-generated hHO-1-isoporphyrin complex produced alpha-biliverdin, confirming its role as a reaction intermediate. Identification of an isoporphyrin intermediate in the catalytic sequence of hHO-1, the first such intermediate observed in hemoprotein catalysis, completes our understanding of the critical first step of heme oxidation.

The aldo-keto reductase superfamily homepage.

PubMed

Hyndman, David; Bauman, David R; Heredia, Vladi V; Penning, Trevor M

2003-02-01

The aldo-keto reductases (AKRs) are one of the three enzyme superfamilies that perform oxidoreduction on a wide variety of natural and foreign substrates. A systematic nomenclature for the AKR superfamily was adopted in 1996 and was updated in September 2000 (visit www.med.upenn.edu/akr). Investigators have been diligent in submitting sequences of functional proteins to the Web site. With the new additions, the superfamily contains 114 proteins expressed in prokaryotes and eukaryotes that are distributed over 14 families (AKR1-AKR14). The AKR1 family contains the aldose reductases, the aldehyde reductases, the hydroxysteroid dehydrogenases and steroid 5beta-reductases, and is the largest. Other families of interest include AKR6, which includes potassium channel beta-subunits, and AKR7 the aflatoxin aldehyde reductases. Two new families include AKR13 (yeast aldose reductase) and AKR14 (Escherichia coli aldehyde reductase). Crystal structures of many AKRs and their complexes with ligands are available in the PDB and accessible through the Web site. Each structure has the characteristic (alpha/beta)(8)-barrel motif of the superfamily, a conserved cofactor binding site and a catalytic tetrad, and variable loop structures that define substrate specificity. Although the majority of AKRs are monomeric proteins of about 320 amino acids in length, the AKR2, AKR6 and AKR7 family may form multimers. To expand the nomenclature to accommodate multimers, we recommend that the composition and stoichiometry be listed. For example, AKR7A1:AKR7A4 (1:3) would designate a tetramer of the composition indicated. The current nomenclature is recognized by the Human Genome Project (HUGO) and the Web site provides a link to genomic information including chromosomal localization, gene boundaries, human ESTs and SNPs and much more.

The peroxisome proliferator-activated receptor alpha agonist fenofibrate has no effect on insulin sensitivity compared to atorvastatin in type 2 diabetes mellitus; a randomised, double-blind controlled trial.

PubMed

Black, R Neil A; Ennis, Cieran N; Young, Ian S; Hunter, Steven J; Atkinson, A Brew; Bell, Patrick M

2014-01-01

Assess insulin sensitivity after treatment with a selective PPAR-alpha agonist compared to an HMG CoA reductase inhibitor in human subjects with type 2 diabetes mellitus. Thirteen subjects with Type 2 diabetes mellitus were studied in a double-blind crossover design with 4-week placebo run-in and washout and 12-week treatment periods, randomised to micronised fenofibrate 267 mg or atorvastatin 10mg daily followed by the alternate drug in the second period. Insulin resistance was measured using the isoglycaemic hyperinsulinaemic clamp method with isotope dilution. Weight, physical activity and other medications did not change. Total cholesterol (mean +/- standard error) was 4.60+/-0.21 versus 3.9+/-0.22 mmol/L after fenofibrate and atorvastatin respectively, p<0.05. LDL was 2.70+/-0.19 versus 1.95+/-0.23 mmol/L, p<0.05 and triglyceride 1.64+/-0.23 versus 1.84+/-0.26 mmol/L, p<0.05. Insulin-stimulated whole-body glucose disposal (35.4+/-3.1 versus 33.2+/-3.0 μmol/kg/min) and nadir endogenous glucose production (6.2+/-1.4 versus 7.0+/-1.1 μmol/kg/min) revealed no significant differences in effects of the treatments. In human subjects with Type 2 diabetes mellitus there were characteristic differences in lipid profile changes but no difference in insulin sensitivity after treatment with micronised fenofibrate compared to atorvastatin. This study finds no evidence of increased insulin sensitivity using this selective PPAR-alpha agonist over a commonly used statin at these doses. Copyright © 2014 Elsevier Inc. All rights reserved.

Identification of Non-nucleoside Human Ribonucleotide Reductase Modulators

DOE PAGES

Ahmad, Md. Faiz; Huff, Sarah E.; Pink, John; ...

2015-10-21

Ribonucleotide reductase (RR) catalyzes the rate-limiting step of dNTP synthesis and is an established cancer target. Drugs targeting RR are mainly nucleoside in nature. In this study, we sought to identify non-nucleoside small-molecule inhibitors of RR. Using virtual screening, binding affinity, inhibition, and cell toxicity, we have discovered a class of small molecules that alter the equilibrium of inactive hexamers of RR, leading to its inhibition. Several unique chemical categories, including a phthalimide derivative, show micromolar IC 50s and K Ds while demonstrating cytotoxicity. A crystal structure of an active phthalimide binding at the targeted interface supports the noncompetitive modemore » of inhibition determined by kinetic studies. Furthermore, the phthalimide shifts the equilibrium from dimer to hexamer. Finally, together, these data identify several novel non-nucleoside inhibitors of human RR which act by stabilizing the inactive form of the enzyme.« less

Human hydroxysteroid dehydrogenases and pre-receptor regulation: Insights into inhibitor design and evaluation

PubMed Central

Penning, Trevor M.

2011-01-01

Hydroxysteroid dehydrogenases (HSDs) represent a major class of NAD(P)(H) dependent steroid hormone oxidoreductases involved in the pre-receptor regulation of hormone action. This is achieved by HSDs working in pairs so that they can interconvert ketosteroids with hydroxysteroids resulting in a change in ligand potency for nuclear receptors. HSDs belong to two protein superfamilies the aldo-keto reductases and the short-chain dehydrogenase/reductases. In humans, many of the important enzymes have been thoroughly characterized including the elucidation of their three-dimensional structures. Because these enzymes play fundamental roles in steroid hormone action they can be considered to be drug targets for a variety of steroid driven diseases: e.g. metabolic syndrome and obesity, inflammation, and hormone dependent malignancies of the endometrium, prostate and breast. This article will review how fundamental knowledge of these enzymes can be exploited in the development of isoform specific HSD inhibitors from both protein superfamilies. PMID:21272640

Manumycin A Is a Potent Inhibitor of Mammalian Thioredoxin Reductase-1 (TrxR-1).

PubMed

Tuladhar, Anupama; Rein, Kathleen S

2018-04-12

The anticancer effect of manumycin A (Man A) has been attributed to the inhibition of farnesyl transferase (FTase), an enzyme that is responsible for post-translational modification of Ras proteins. However, we have discovered that Man A inhibits mammalian cytosolic thioredoxin reductase 1 (TrxR-1) in a time-dependent manner, with an IC 50 of 272 nM with preincubation and 1586 nM without preincubation. The inhibition of TrxR-1 by Man A is irreversible and is the result of a covalent interaction between Man A and TrxR-1. Evidence presented herein demonstrates that Man A forms a Michael adduct with the selenocysteine residue, which is located in the C-terminal redox center of TrxR-1. Inhibitors of TrxR-1, which act through this mechanism, convert TrxR-1 into a SecTRAP, which utilizes NADPH to reduce oxygen to superoxide radical anion (O 2 -• ).

The 5α-reductase inhibitor finasteride is not associated with alterations in sleep spindles in men referred for polysomnography

PubMed Central

Goldstein, Michael R.; Cook, Jesse D.; Plante, David T.

2015-01-01

Objective Endogenous neurosteroids that potentiate the GABAA receptor are thought to enhance the generation of sleep spindles. This study tested the hypothesis that the 5α-reductase inhibitor finasteride, an agent associated with reductions in neurosteroids, would be associated with reduced sleep spindles in men referred for polysomnography. Methods Spectral analysis and spindle waveform detection were performed on electroencephalographic (EEG) sleep data in the 11–16Hz sigma band, as well as several subranges, from 27 men taking finasteride and 27 matched comparison patients (ages 18 to 81 years). Results No significant differences between groups were observed for spectral power or sleep spindle morphology measures, including spindle density, amplitude, duration, and integrated spindle activity. Conclusions Contrary to our hypothesis, these findings demonstrate that finasteride is not associated with alterations in sleep spindle range activity or spindle morphology parameters. PMID:26494125

Design, synthesis, and evaluation of inhibitors of trypanosomal and leishmanial dihydrofolate reductase.

PubMed

Chowdhury, S F; Villamor, V B; Guerrero, R H; Leal, I; Brun, R; Croft, S L; Goodman, J M; Maes, L; Ruiz-Perez, L M; Pacanowska, D G; Gilbert, I H

1999-10-21

This paper concerns the design, synthesis, and evaluation of inhibitors of leishmanial and trypanosomal dihydrofolate reductase. Initially study was made of the structures of the leishmanial and human enzyme active sites to see if there were significant differences which could be exploited for selective drug design. Then a series of compounds were synthesized based on 5-benzyl-2, 4-diaminopyrimidines. These compounds were assayed against the protozoan and human enzymes and showed selectivity for the protozoan enzymes. The structural data was then used to rationalize the enzyme assay data. Compounds were also tested against the clinically relevant forms of the intact parasite. Activity was seen against the trypanosomes for a number of compounds. The compounds were in general less active against Leishmania. This latter result may be due to uptake problems. Two of the compounds also showed some in vivo activity in a model of African trypanosomiasis.

Rational Design of Broad Spectrum Antibacterial Activity Based on a Clinically Relevant Enoyl-Acyl Carrier Protein (ACP) Reductase Inhibitor*

PubMed Central

Schiebel, Johannes; Chang, Andrew; Shah, Sonam; Lu, Yang; Liu, Li; Pan, Pan; Hirschbeck, Maria W.; Tareilus, Mona; Eltschkner, Sandra; Yu, Weixuan; Cummings, Jason E.; Knudson, Susan E.; Bommineni, Gopal R.; Walker, Stephen G.; Slayden, Richard A.; Sotriffer, Christoph A.; Tonge, Peter J.; Kisker, Caroline

2014-01-01

Determining the molecular basis for target selectivity is of particular importance in drug discovery. The ideal antibiotic should be active against a broad spectrum of pathogenic organisms with a minimal effect on human targets. CG400549, a Staphylococcus-specific 2-pyridone compound that inhibits the enoyl-acyl carrier protein reductase (FabI), has recently been shown to possess human efficacy for the treatment of methicillin-resistant Staphylococcus aureus infections, which constitute a serious threat to human health. In this study, we solved the structures of three different FabI homologues in complex with several pyridone inhibitors, including CG400549. Based on these structures, we rationalize the 65-fold reduced affinity of CG400549 toward Escherichia coli versus S. aureus FabI and implement concepts to improve the spectrum of antibacterial activity. The identification of different conformational states along the reaction coordinate of the enzymatic hydride transfer provides an elegant visual depiction of the relationship between catalysis and inhibition, which facilitates rational inhibitor design. Ultimately, we developed the novel 4-pyridone-based FabI inhibitor PT166 that retained favorable pharmacokinetics and efficacy in a mouse model of S. aureus infection with extended activity against Gram-negative and mycobacterial organisms. PMID:24739388

Computer simulation of protein systems

NASA Technical Reports Server (NTRS)

Osguthorpe, D. J.; Dauber-Osguthorpe, P.; Wolff, J.; Kitson, D. H.; Hagler, A. T.

1984-01-01

Ligand binding to dihydrofolate reductase (DHFR) is discussed. This is an extremely important enzyme, as it is the target of several drugs (inhibitors) which are used clinically as antibacterials, antiprotozoals and in cancer chemotherapy. DHFR catalyzes the NADPH (reduced nicotinamide adenine dinucleotide phosphate) dependent reduction of dihydrofolate to tetrahydrofolate, which is used in several pathways of purine and pyrimidine iosynthesis, including that of thymidylate. Since DNA synthesis is dependent on a continuing supply of thymidylate, a blockade of DHFR resulting in a depletion of thymidylate can lead to the cessation of growth of a rapidly proliferating cell line. DHFR exhibits a significant species to species variability in its sensitivity to various inhibitors. For example, trimethoprim, an inhibitor of DHFR, binds to bacterial DHFR's 5 orders of magnitude greater than to vertebrate DHFR's. The structural mechanics, dynamics and energetics of a family of dihydrofolate reductases are studied to rationalize the basis for the inhibitor of these enyzmes and to understand the molecular basis of the difference in the binding constants between the species. This involves investigating the conformational changes induced in the protein on binding the ligand, the internal strain imposed by the enzyme on the ligand, the restriction of fluctuations in atom positions due to binding and the consequent change in entropy.

HMG-CoA Reductase inhibitors: an updated review of patents of novel compounds and formulations (2011-2015).

PubMed

Oliveira, Eduardo Filipe; Santos-Martins, Diogo; Ribeiro, António Meireles; Brás, Natércia Fernandes; Cerqueira, Nuno Sousa; Sousa, Sérgio Filipe; Ramos, Maria João; Fernandes, Pedro Alexandrino

2016-11-01

Statins are remarkably safe and efficient medications that are the mainstay of hypercholesterolemia treatment and have proven to be an invaluable tool to lower the risk of acute cardiovascular events. These compounds are inhibitors of 3-hydroxy-methylglutaryl CoA reductase (HMG-R), the rate-limiting enzyme in cholesterol biosynthesis. In spite of their success, they present undesirable side effects and are now loosing patent protection, which provides a great opportunity for the development of new and improved statins. Areas covered: This review summarizes the new patents for HMG-R inhibitors for the 2011-2015 period. Combinations of existing statins with other drugs are also addressed, as well as novel applications of existing statins. Expert opinion: Recent efforts for the discovery of HMG-CoA-R inhibitors has resulted in several new molecules. Most of these are based on commercially available statins, including sterol and terpenoid derivatives. A few peptides have also been patented. However, the origin of the side effects caused by previous statins continues to be, to a large extent, unknown. Although the patents published in the past 5 years are promising, and might result in new drugs, there is still no way to know if they will present reduced toxicity. Only future clinical trials will answer this question.

Rational design of broad spectrum antibacterial activity based on a clinically relevant enoyl-acyl carrier protein (ACP) reductase inhibitor.

PubMed

Schiebel, Johannes; Chang, Andrew; Shah, Sonam; Lu, Yang; Liu, Li; Pan, Pan; Hirschbeck, Maria W; Tareilus, Mona; Eltschkner, Sandra; Yu, Weixuan; Cummings, Jason E; Knudson, Susan E; Bommineni, Gopal R; Walker, Stephen G; Slayden, Richard A; Sotriffer, Christoph A; Tonge, Peter J; Kisker, Caroline

2014-06-06

Determining the molecular basis for target selectivity is of particular importance in drug discovery. The ideal antibiotic should be active against a broad spectrum of pathogenic organisms with a minimal effect on human targets. CG400549, a Staphylococcus-specific 2-pyridone compound that inhibits the enoyl-acyl carrier protein reductase (FabI), has recently been shown to possess human efficacy for the treatment of methicillin-resistant Staphylococcus aureus infections, which constitute a serious threat to human health. In this study, we solved the structures of three different FabI homologues in complex with several pyridone inhibitors, including CG400549. Based on these structures, we rationalize the 65-fold reduced affinity of CG400549 toward Escherichia coli versus S. aureus FabI and implement concepts to improve the spectrum of antibacterial activity. The identification of different conformational states along the reaction coordinate of the enzymatic hydride transfer provides an elegant visual depiction of the relationship between catalysis and inhibition, which facilitates rational inhibitor design. Ultimately, we developed the novel 4-pyridone-based FabI inhibitor PT166 that retained favorable pharmacokinetics and efficacy in a mouse model of S. aureus infection with extended activity against Gram-negative and mycobacterial organisms. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Polymorphisms of steroid 5-alpha-reductase type I (SRD5A1) gene are associated to peripheral arterial disease.

PubMed

Signorelli, S S; Barresi, V; Musso, N; Anzaldi, M; Croce, E; Fiore, V; Condorelli, D F

2008-12-01

Although animal studies support the hypothesis that androgenic biological actions may affect experimental atherosclerosis progression, evidence for a relationship between androgen effects and peripheral arterial disease (PAD), a common clinical form of atherosclerosis, is weak or contradictory. Testosterone, the main androgen hormone, is converted in a 5alpha-reduced form by enzymatic activities in the target cells and some specific actions are mediated by such metabolites. Steroid 5-alpha reductase isoenzymes (SRD5A1 and SRD5A2) catalyze the conversion to the bioactive potent androgen dihydrotestosterone and other reduced metabolites and represent relevant regulators of local hormonal actions. In the present study we tested for the association of selected single nucleotide polymorphisms (SNP) of SRD5A1 and SRD5A2 with symptomatic PAD patients. Two different SNP in the SRD5A1 were significantly associated which the PAD phenotype (p<0.03, odds ratio 1.73), while no association was found between PAD phenotypes and SRD5A2. Since the examined SRDA1 gene variant was previously associated with a low enzymatic activity, we suggest that a decreased local enzymatic conversion of testosterone may contribute to PAD genetic susceptibility.

The development of novel inhibitors of tumor necrosis factor-alpha production based on substituted [5,5]-bicyclic pyrozolones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laufersweiler, Matthew; Brugel, Todd; Clark, Michael

Novel substituted [5,5]-bicyclic pyrzazolones are presented as inhibitors of tumor necrosis factor-{alpha} (TNF-{alpha}) production. Many of these compounds show low nanomolar activity against lipopolysaccaride (LPS)-induced TNF-{alpha} production in THP-1 cells. This class of molecules was co-crystallized with mutated p38, and several analogs showed good oral bioavailability in the rat. Oral activity of these compounds in the rat iodoacetate model for osteoarthritis is discussed.

The discovery of novel tartrate-based TNF-[alpha] converting enzyme (TACE) inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosner, Kristin E.; Guo, Zhuyan; Orth, Peter

2010-09-17

A novel series of TNF-{alpha} convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.

Molecular modelling and synthesis of spiroimidazolidine-2,4-diones with dual activities as hypoglycemic agents and selective inhibitors of aldose reductase.

PubMed

Salem, Manar G; Abdel Aziz, Yasmine M; Elewa, Marwa; Elshihawy, Hosam A; Said, Mohamed M

2018-05-02

Novel derivatives of spiroimidazolidinedione were synthesized and evaluated as hypoglycemic agents through binding to sulfonylurea receptor 1 (SUR1) in pancreatic beta-cells. Their selectivity index was calculated against both aldehyde reductase (ALR1) and aldose reductase (ALR2). Aldehyde reductase is a key enzyme in the polyol pathway that is involved in the etiology of the secondary diabetic complications. All structures were confirmed by microanalysis and by IR, 1 H NMR, 13 C NMR and EI-MS spectroscopy. The investigated compounds were subjected to molecular docking and an in silico prediction study to determine their free energy of binding (ΔG) values and predict their physicochemical properties and drug-likeness scores. Compound 1'-(5-chlorothiophene-2-ylsulfonyl)spiro[cyclohexane-1,5'-imidazolidine]-2',4'-dione showed IC 50 0.47 µM and 79% reduction in blood glucose level with a selectivity index 127 for ALR2. Copyright © 2018 Elsevier Inc. All rights reserved.

Mitogen-activated protein kinase inhibitors suppress prostaglandin F(2alpha)-induced myosin-light chain phosphorylation and contraction in iris sphincter smooth muscle.

PubMed

Yousufzai, S Y; Gao, G; Abdel-Latif, A A

2000-10-27

The purpose of this study was to investigate the potential role of mitogen-activated protein (MAP) kinase in contraction by monitoring MAP kinase phosphorylation (activation) and contraction during agonist stimulation of cat iris sphincter smooth muscle. Changes in tension in response to prostaglandin F(2alpha), latanoprost, a prostaglandin F(2alpha) analog used as an anti-glaucoma drug, and carbachol were recorded isometrically, and MAP kinase activation was monitored by Western blot using a phosphospecific p42/p44 MAP kinase antibody. We found that treatment of the muscle with 2'-Amino-3'-methoxyflavone (PD98059) (10 microM), a specific inhibitor of MAP kinase kinase (MEK), inhibited significantly prostaglandin F(2alpha)- and latanoprost-induced phosphorylation and contraction, but had little effect on those evoked by carbachol. Prostaglandin F(2alpha) increased MAP kinase phosphorylation in a concentration-dependent manner with EC(50) value of 1.1 x 10(-8) M and increased contraction with EC(50) of 0.92 x 10(-9) M. The MAP kinase inhibitors PD98059, Apigenin and 1,4-Diamino-2,3-dicyano-1, 4bis(2-aminophenylthio)butadiene (UO126) inhibited prostaglandin F(2alpha)-induced contraction in a concentration-dependent manner with IC(50) values of 2.4, 3.0 and 4.8 microM, respectively. PD98059 had no effect on prostaglandin F(2alpha)- or on carbachol-stimulated inositol-1,4,5-trisphosphate (IP(3)) production. In contrast, the MAP kinase inhibitor inhibited prostaglandin F(2alpha)-induced myosin-light chain (MLC) phosphorylation, but had no effect on that of carbachol. N-[2-(N-(4-Chloro-cinnamyl)-N-methylaminomethyl)phenyl]-N-[2- hydroxyethyl]-4-methoxybenzenesulfonamide (KN-93) (10 microM), a Ca(2+)-calmodulin-dependent protein kinase inhibitor, and Wortmannin (10 microM), an MLC kinase inhibitor, inhibited significantly (by 80%) prostaglandin F(2alpha)- and carbachol-induced contraction. It can be concluded that in this smooth muscle p42/p44 MAP kinases are involved in the mechanism of prostaglandin F(2alpha)-, but not in that of carbachol, induced contraction. In addition, these data clearly indicate that the stimulation of the iris sphincter with prostaglandin F(2alpha) and carbachol activate two distinct pathways, the MAP kinase pathway and the Ca(2+) mobilization pathway.

Finasteride treatment of patterned hair loss in normoandrogenic postmenopausal women.

PubMed

Trüeb, Ralph M

2004-01-01

Finasteride, an inhibitor of type 2 5alpha-reductase, inhibits conversion of testosterone to dihydrotestosterone, resulting in a decrease in serum and scalp dihydrotestosterone levels believed to be pathogenic in androgenetic alopecia. Oral finasteride has been shown to be effective in the treatment of hair loss in men, while its efficacy in women has remained controversial. 5 postmenopausal women without clinical or laboratory signs of hyperandrogenism were given 2.5 or 5 mg/day oral finasteride for the treatment of pattern hair loss. Efficacy was evaluated by patient and investigator assessments, and review of photographs taken at baseline and at months 6, 12 and 18 by an expert panel. Finasteride treatment improved scalp hair by all evaluation techniques. The patients' self-assessment demonstrated that finasteride treatment decreased hair loss, increased hair growth and improved appearance of hair. These improvements were confirmed by investigator assessment and assessments of photographs. No adverse effects were noted. Oral finasteride in a dosage of 2.5 mg/day or more may be effective for the treatment of pattern hair loss in postmenopausal women in the absence of clinical or laboratory signs of hyperandrogenism.

Switch control pocket inhibitors of p38-MAP kinase. Durable type II inhibitors that do not require binding into the canonical ATP hinge region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, Yu Mi; Clare, Michael; Ensinger, Carol L.

Switch control pocket inhibitors of p38-alpha kinase are described. Durable type II inhibitors were designed which bind to arginines (Arg67 or Arg70) that function as key residues for mediating phospho-threonine 180 dependant conformational fluxing of p38-alpha from an inactive type II state to an active type I state. Binding to Arg70 in particular led to potent inhibitors, exemplified by DP-802, which also exhibited high kinase selectivity. Binding to Arg70 obviated the requirement for binding into the ATP Hinge region. X-ray crystallography revealed that DP-802 and analogs induce an enhanced type II conformation upon binding to either the unphosphorylated or themore » doubly phosphorylated form of p38-alpha kinase.« less

Discovery of 4-(5-(Cyclopropylcarbamoyl)-2-methylphenylamino)-5-methyl-N-propylpyrrolo[1,2-f][1,2,4]triazine-6-carboxamide (BMS-582949), a Clinical p38[alpha] MAP Kinase Inhibitor for the Treatment of Inflammatory Diseases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Chunjian; Lin, James; Wrobleski, Stephen T.

The discovery and characterization of 7k (BMS-582949), a highly selective p38{alpha} MAP kinase inhibitor that is currently in phase II clinical trials for the treatment of rheumatoid arthritis, is described. A key to the discovery was the rational substitution of N-cyclopropyl for N-methoxy in 1a, a previously reported clinical candidate p38{alpha} inhibitor. Unlike alkyl and other cycloalkyls, the sp{sup 2} character of the cyclopropyl group can confer improved H-bonding characteristics to the directly substituted amide NH. Inhibitor 7k is slightly less active than 1a in the p38{alpha} enzymatic assay but displays a superior pharmacokinetic profile and, as such, was moremore » effective in both the acute murine model of inflammation and pseudoestablished rat AA model. The binding mode of 7k with p38{alpha} was confirmed by X-ray crystallographic analysis.« less

Novel benzofuran-3-one indole inhibitors of PI3 kinase-alpha and the mammalian target of rapamycin: hit to lead studies.

PubMed

Bursavich, Matthew G; Brooijmans, Natasja; Feldberg, Lawrence; Hollander, Irwin; Kim, Stephen; Lombardi, Sabrina; Park, Kaapjoo; Mallon, Robert; Gilbert, Adam M

2010-04-15

A series of benzofuran-3-one indole phosphatidylinositol-3-kinases (PI3K) inhibitors identified via HTS has been prepared. The optimized inhibitors possess single digit nanomolar activity against p110alpha (PI3K-alpha), good pharmaceutical properties, selectivity versus p110gamma (PI3K-gamma), and tunable selectivity versus the mammalian target of rapamycin (mTOR). Modeling of compounds 9 and 32 in homology models of PI3K-alpha and mTOR supports the proposed rationale for selectivity. Compounds show activity in multiple cellular proliferation assays with signaling through the PI3K pathway confirmed via phospho-Akt inhibition in PC-3 cells. Copyright 2010 Elsevier Ltd. All rights reserved.

Tobacco plants transformed with the bean. alpha. ai gene express an inhibitor of insect. alpha. -amylase in their seeds. [Nicotiana tabacum; Tenebrio molitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Altabella, T.; Chrispeels, M.J.

Bean (Phaseolus vulgaris L.) seeds contain a putative plant defense protein that inhibits insect and mammalian but not plant {alpha}-amylases. We recently presented strong circumstantial evidence that this {alpha}-amylase inhibitor ({alpha}Al) is encoded by an already-identified lectin gene whose product is referred to as lectin-like-protein (LLP). We have now made a chimeric gene consisting of the coding sequence of the lectin gene that encodes LLP and the 5{prime} and 3{prime} flanking sequences of the lectin gene that encodes phytohemagglutinin-L. When this chimeric gene was expressed in transgenic tobacco (Nicotiana tabacum), we observed in the seeds a series of polypeptides (M{submore » r} 10,000-18,000) that cross-react with antibodies to the bean {alpha}-amylase inhibitor. Most of these polypeptides bind to a pig pancreas {alpha}-amylase affinity column. An extract of the seeds of the transformed tobacco plants inhibits pig pancreas {alpha}-amylase activity as well as the {alpha}-amylase present in the midgut of Tenebrio molitor. We suggest that introduction of this lectin gene (to be called {alpha}ai) into other leguminous plants may be a strategy to protect the seeds from the seed-eating larvae of Coleoptera.« less

Differential cytokine modulation and T cell activation by two distinct classes of thalidomide analogues that are potent inhibitors of TNF-alpha.

PubMed

Corral, L G; Haslett, P A; Muller, G W; Chen, R; Wong, L M; Ocampo, C J; Patterson, R T; Stirling, D I; Kaplan, G

1999-07-01

TNF-alpha mediates both protective and detrimental manifestations of the host immune response. Our previous work has shown thalidomide to be a relatively selective inhibitor of TNF-alpha production in vivo and in vitro. Additionally, we have recently reported that thalidomide exerts a costimulatory effect on T cell responses. To develop thalidomide analogues with increased anti-TNF-alpha activity and reduced or absent toxicities, novel TNF-alpha inhibitors were designed and synthesized. When a selected group of these compounds was examined for their immunomodulatory activities, different patterns of cytokine modulation were revealed. The tested compounds segregated into two distinct classes: one class of compounds, shown to be potent phosphodiesterase 4 inhibitors, inhibited TNF-alpha production, increased IL-10 production by LPS-induced PBMC, and had little effect on T cell activation; the other class of compounds, similar to thalidomide, were not phosphodiesterase 4 inhibitors and markedly stimulated T cell proliferation and IL-2 and IFN-gamma production. These compounds inhibited TNF-alpha, IL-1beta, and IL-6 and greatly increased IL-10 production by LPS-induced PBMC. Similar to thalidomide, the effect of these agents on IL-12 production was dichotomous; IL-12 was inhibited when PBMC were stimulated with LPS but increased when cells were stimulated by cross-linking the TCR. The latter effect was associated with increased T cell CD40 ligand expression. The distinct immunomodulatory activities of these classes of thalidomide analogues may potentially allow them to be used in the clinic for the treatment of different immunopathological disorders.

Comparative cost-effectiveness of HMG-CoA reductase inhibitors in secondary prevention of acute myocardial infarction.

PubMed

Elliott, W J; Weir, D R

1999-09-01

The cost-effectiveness of each of the six hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors currently available was studied. For a cohort of patients between the ages of 60 and 85 years with coronary heart disease (CHD) who were taking atorvastatin, cerivastatin, fluvastatin, lovastatin, pravastatin, or simvastatin, the number of survivors, the annual direct cost per survivor, and the annual indirect cost saving per survivor associated with the predicted reduction in the rate of nonfatal myocardial infarction recurrences were projected. Percent reductions in excess mortality due to CHD were derived from the relative risks of cardiac mortality in treatment versus control groups in the Scandinavian Simvastatin Survival Study (4S). Doses necessary to provide a long-term 35.57% reduction in low-density- lipoprotein (LDL) cholesterol, as seen in 4S, were estimated. One-way sensitivity analyses were performed to assess the importance of the baseline assumptions. The cost per year of life saved ranged from $5,421 with atorvastatin to $15,073 with lovastatin. The patient's age at time of diagnosis of CHD had a major impact on the cost-effectiveness of the drugs; cost-effectiveness per year of life saved was higher for older patients than younger patients. The six currently marketed HMG-CoA reductase inhibitors varied widely in cost and effectiveness in producing reductions in the LDL-cholesterol concentrations that have been shown to prevent recurrent MI; there was an approximately threefold difference in the cost per year of life saved between the most cost-effective and least cost-effective agents.

Inhibition of botulinum neurotoxins interchain disulfide bond reduction prevents the peripheral neuroparalysis of botulism.

PubMed

Zanetti, Giulia; Azarnia Tehran, Domenico; Pirazzini, Marcon; Binz, Thomas; Shone, Clifford C; Fillo, Silvia; Lista, Florigio; Rossetto, Ornella; Montecucco, Cesare

2015-12-01

Botulinum neurotoxins (BoNTs) form a growing family of metalloproteases with a unique specificity either for VAMP, SNAP25 or syntaxin. The BoNTs are grouped in seven different serotypes indicated by letters from A to G. These neurotoxins enter the cytosol of nerve terminals via a 100 kDa chain which binds to the presynaptic membrane and assists the translocation of a 50 kDa metalloprotease chain. These two chains are linked by a single disulfide bridge which plays an essential role during the entry of the metalloprotease chain in the cytosol, but thereafter it has to be reduced to free the proteolytic activity. Its reduction is mediated by thioredoxin which is continuously regenerated by its reductase. Here we show that inhibitors of thioredoxin reductase or of thioredoxin prevent the specific proteolysis of VAMP by the four VAMP-specific BoNTs: type B, D, F and G. These compounds are effective not only in primary cultures of neurons, but also in preventing the in vivo mouse limb neuroparalysis. In addition, one of these inhibitors, Ebselen, largely protects mice from the death caused by a systemic injection. Together with recent results obtained with BoNTs specific for SNAP25 and syntaxin, the present data demonstrate the essential role of the thioredoxin-thioredoxin reductase system in reducing the interchain disulfide during the nerve intoxication mechanism of all serotypes. Therefore its inhibitors should be considered for a possible use to prevent botulism and for treating infant botulism. Copyright © 2015 Elsevier Inc. All rights reserved.

Structure-activity relationship for enantiomers of potent inhibitors of B. anthracis dihydrofolate reductase

PubMed Central

Bourne, Christina R.; Wakeham, Nancy; Nammalwar, Baskar; Tseitin, Vladimir; Bourne, Philip C.; Barrow, Esther W.; Mylvaganam, Shankari; Ramnarayan, Kal; Bunce, Richard A.; Berlin, K. Darrell; Barrow, William W.

2012-01-01

Background Bacterial resistance to antibiotic therapies is increasing and new treatment options are badly needed. There is an overlap between these resistant bacteria and organisms classified as likely bioterror weapons. For example, Bacillus anthracis is innately resistant to the anti-folate trimethoprim due to sequence changes found in the dihydrofolate reductase enzyme. Development of new inhibitors provides an opportunity to enhance the current arsenal of anti-folate antibiotics while also expanding the coverage of the anti-folate class. Methods We have characterized inhibitors of Bacillus anthracis dihydrofolate reductase by measuring the Ki and MIC values and calculating the energetics of binding. This series contains a core diaminopyrimidine ring, a central dimethoxybenzyl ring, and a dihydrophthalazine moiety. We have altered the chemical groups extended from a chiral center on the dihydropyridazine ring of the phthalazine moiety. The interactions for the most potent compounds were visualized by X-ray structure determination. Results We find that the potency of individual enantiomers is divergent with clear preference for the S-enantiomer, while maintaining a high conservation of contacts within the binding site. The preference for enantiomers seems to be predicated largely by differential interactions with protein residues Leu29, Gln30 and Arg53. Conclusions These studies have clarified the activity of modifications and of individual enantiomers, and highlighted the role of the less-active R-enantiomer in effectively diluting the more active S-enantiomer in racemic solutions. This directly contributes to the development of new antimicrobials, combating trimethoprim resistance, and treatment options for potential bioterrorism agents. PMID:22999981

Ketopantoyl-lactone reductase from Candida parapsilosis: purification and characterization as a conjugated polyketone reductase.

PubMed

Hata, H; Shimizu, S; Hattori, S; Yamada, H

1989-02-24

Ketopantoyl-lactone reductase (2-dehydropantoyl-lactone reductase, EC 1.1.1.168) was purified and crystallized from cells of Candida parapsilosis IFO 0708. The enzyme was found to be homogeneous on ultracentrifugation, high-performance gel-permeation liquid chromatography and SDS-polyacrylamide gel electrophoresis. The relative molecular mass of the native and SDS-treated enzyme is approximately 40,000. The isoelectric point of the enzyme is 6.3. The enzyme was found to catalyze specifically the reduction of a variety of natural and unnatural polyketones and quinones other than ketopantoyl lactone in the presence of NADPH. Isatin and 5-methylisatin are rapidly reduced by the enzyme, the Km and Vmax values for isatin being 14 microM and 306 mumol/min per mg protein, respectively. Ketopantoyl lactone is also a good substrate (Km = 333 microM and Vmax = 481 mumol/min per mg protein). Reverse reaction was not detected with pantoyl lactone and NADP+. The enzyme is inhibited by quercetin, several polyketones and SH-reagents. 3,4-Dihydroxy-3-cyclobutene-1,2-dione, cyclohexenediol-1,2,3,4-tetraone and parabanic acid are uncompetitive inhibitors for the enzyme, the Ki values being 1.4, 0.2 and 3140 microM, respectively, with isatin as substrate. Comparison of the enzyme with the conjugated polyketone reductase of Mucor ambiguus (S. Shimizu, H. Hattori, H. Hata and H. Yamada (1988) Eur. J. Biochem. 174, 37-44) and ketopantoyl-lactone reductase of Saccharomyces cerevisiae suggested that ketopantoyl-lactone reductase is a kind of conjugated polyketone reductase.

Zinc oxide nanoparticles as novel alpha-amylase inhibitors

NASA Astrophysics Data System (ADS)

Dhobale, Sandip; Thite, Trupti; Laware, S. L.; Rode, C. V.; Koppikar, Soumya J.; Ghanekar, Ruchika-Kaul; Kale, S. N.

2008-11-01

Amylase inhibitors, also known as starch blockers, contain substances that prevent dietary starches from being absorbed by the body via inhibiting breakdown of complex sugars to simpler ones. In this sense, these materials are projected as having potential applications in diabetes control. In this context, we report on zinc oxide nanoparticles as possible alpha-amylase inhibitors. Zinc oxide nanoparticles have been synthesized using soft-chemistry approach and 1-thioglycerol was used as a surfactant to yield polycrystalline nanoparticles of size ˜18 nm, stabilized in wurtzite structure. Conjugation study and structural characterization have been done using x-ray diffraction technique, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and transmission electron microscopy. Cytotoxicity studies on human fibrosarcoma (HT-1080) and skin carcinoma (A-431) cell lines as well as mouse primary fibroblast cells demonstrate that up to a dose of 20 μg/ml, ZnO nanoparticles are nontoxic to the cells. We report for the first time the alpha-amylase inhibitory activity of ZnO nanoparticles wherein an optimum dose of 20 μg/ml was sufficient to exhibit 49% glucose inhibition at neutral pH and 35 °C temperature. This inhibitory activity was similar to that obtained with acarbose (a standard alpha-amylase inhibitor), thereby projecting ZnO nanoparticles as novel alpha-amylase inhibitors.

The mitochondrial pyruvate carrier. Kinetics and specificity for substrates and inhibitors.

PubMed

Halestrap, A P

1975-04-01

1. Studies on the kinetics of pyruvate transport into mitochondria by an 'inhibitor-stop' technique were hampered by the decarboxylation of pyruvate by mitochondria even in the presence of rotenone. Decarboxylation was minimal at 6 degrees C. At this temperature the Km for pyruvate was 0.15 mM and Vmax. was 0.54nmol/min per mg of protein; alpha-cyano-4-hydroxycinnamate was found to be a non-competitive inhibitor, Ki 6.3 muM, and phenyl-pyruvate a competitive inhibitor, Ki 1.8 mM. 2. At 100 muM concentration, alpha-cyano-4-hydroxycinnamate rapidly and almost totally inhibited O2 uptake by rat heart mitochondria oxidizing pyruvate. Inhibition could be detected at concentrations of inhibitor as low as 1 muM although inhibition took time to develop at this concentration. Inhibition could be reversed by diluting out the inhibitor. 3. Various analogues of alpha-cyano-4-hydroxycinnamate were tested on rat liver and heart mitochondria. The important structural features appeared to be the alpha-cyanopropenoate group and the hydrophobic aromatic side chain. Alpha-Cyanocinnamate, alpha-cyano-5-phenyl-2,4-pentadienoate and compound UK 5099 [alpha-cyano-beta-(2-phenylindol-3-yl)acrylate] were all more powerful inhibitors than alpha-cyano-4-hydroxycinnamate showing 50% inhibition of pyruvate-dependent O2 consumption by rat heart mitochondria at concentrations of 200, 200 and 50 nM respectively. 4. The specificity of the carrier for its substrate was studied by both influx and efflux experiments. Oxamate, 2-oxobutyrate, phenylpyruvate, 2-oxo-4-methyl-pentanoate, chloroacetate, dichloroacetate, difluoroacetate, 2-chloropropionate, 3-chloropropionate and 2,2-dichloropropionate all exchanged with pyruvate, whereas acetate, lactate and trichloroacetate did not. 5. Pyruvate entry into the mitochondria was shown to be accompanied by the transport of a proton (or by exchange with an OH-ion). This proton flux was inhibited by alpha-cyano-4-hydroxycinnamate and allowed measurements of pyruvate transport at higher temperatures to be made. The activation energy of mitochondrial pyruvate transport was found to be 113 kJ (27 kcal)/mol and by extrapolation the rate of transport of pyruvate at 37 degrees C to be 42 nmol/min per mg of protein. The possibility that pyruvate transport into mitochondria may be rate limiting and involved in the regulation of gluconegenesis is discussed. 6. The transport of various monocarboxylic acids into mitochondria was studied by monitoring proton influx. The transport of dichloroacetate, difluoroacetate and oxamate appeared to be largely dependent on the pyruvate carrier and could be inhibited by pyruvate-transport inhibitors. However, many other halogenated and 2-oxo acids which could exchange with pyruvate on the carrier entered freely even in the presence of inhibitor.

The serine proteinase inhibitory proteins of the chondrodystrophoid (beagle) and non-chondrodystrophoid (greyhound) canine intervertebral disc.

PubMed

Melrose, J; Taylor, T K; Ghosh, P

1997-06-01

Trypsin inhibitory proteins of low buoyant density (p < or = 1.35 g/mL) fractions were prepared by CsCl density gradient ultracentrifugation of 4 M guanidinium hydrochloride extracts of lumbar beagle and greyhound annulus fibrosus and nucleus pulposus from animals aged 1 to 6 years. Affinity blotting with biotinylated trypsin was used to identify active trypsin inhibitory protein species; these species were also identified immunologically by Western blotting using antibodies against bovine pancreatic trypsin inhibitor (BPTI), and human inter-alpha-trypsin inhibitor (ITI). None of the trypsin inhibitory species evident in Western blots were reactive with anti-human alpha1-proteinase inhibitor (alpha-1-PI), alpha2-macroglobulin or secretory leucocyte proteinase inhibitor. The greyhound intervertebral disc samples generally had higher levels of active trypsin inhibitor species per unit weight of tissue extracted, and a more extensive range of inhibitor species. Inhibitor species of 30, 32, 34 kDa were identified in both beagle and greyhound intervertebral disc samples; these species were generally most prominent in the annulus fibrosus samples. In contrast, the nucleus pulposus samples contained relatively large trypsin inhibitor species; the anti-BPTI detected an inhibitor species of approximately 85-90 kDa; anti-ITI detected species of 120-250 kDa; biotinylated trypsin detected species of 60-110 kDa. A small molecular mass trypsin inhibitor species of 6 kDa, which was of similar mobility to BPTI, was also detected in annulus fibrosus samples; however, this species did not react with anti-BPTI.

H2AX foci in late S/G2- and M-phase cells after hydroxyurea- and aphidicolin-induced DNA replication stress in Vicia.

PubMed

Rybaczek, Dorota; Bodys, Aleksandra; Maszewski, Janusz

2007-09-01

Immunocytochemistry using alpha-phospho-H2AX antibodies shows that hydroxyurea (HU), an inhibitor of ribonucleotide reductase, and aphidicolin (APH), an inhibitor of DNA-polymerases alpha and delta, may promote formation of phospho-H2AX foci in late S/G2-phase cells in root meristems of Vicia faba. Although fluorescent foci spread throughout the whole area of nucleoplasm, large phospho-H2AX aggregates in HU-treated cells allocate mainly in perinucleolar regions. A strong tendency of ATR/ATM-dependent phospho-Chk1S317 kinase to focus in analogous compartments, as opposed to phospho-Chk2T68 and to both effector kinases in APH-treated cells, may suggest that selected elements of the intra-S-phase cell cycle checkpoints share overlapping locations with DNA repair factors known to concentrate in phospho-H2AX aggregates. APH-induced phosphorylation of H2AX exhibits little or no overlap with the areas positioned close to nucleoli. Following G2-M transition of the HU- and APH-pretreated cells, altered chromatin structures are still discernible as large phospho-H2AX foci in the vicinity of chromosomes. Both in HU- and APH-treated roots, immunofluorescence analysis revealed a dominant fraction of small foci and a less frequent population of large phospho-H2AX aggregates, similar to those observed in animal cells exposed to ionizing radiation. The extent of H2AX phosphorylation has been found considerably reduced in root meristem cells treated with HU and caffeine. The frequencies of phospho-H2AX foci observed during mitosis and caffeine-mediated premature chromosome condensation (PCC) suggest that there may be functional links between the checkpoint mechanisms that control genome integrity and those activities which operate throughout the unperturbed mitosis in plants.

Secretion of alpha 2-plasmin inhibitor is impaired by amino acid deletion in a small region of the molecule.

PubMed

Toyota, S; Hirosawa, S; Aoki, N

1994-02-01

Alpha 2-plasmin inhibitor (alpha 2PI) deficiency Okinawa results from defective secretion of the inhibitor from the liver and appears to be a direct consequence of the deletion of Glu137 in the amino acid sequence of alpha 2PI. To examine the effects of replacing the amino acid occupying position 137 or deleting its neighboring amino acid on alpha 2PI secretion, we used oligonucleotide-directed mutagenesis of alpha 2PI cDNA to change the codon specifying Glu137 or delete a codon specifying its neighboring amino acid. The effects were determined by pulse-chase experiments and by enzyme-linked immunosorbent assay of media from transiently transfected COS-7 cells. Replacement of Glu137 with an amino acid other than Cys had little effect on alpha 2PI secretion. In contrast, deletion of an amino acid in a region spanning a sequence of less than 30 amino acids including positions 127 and 137 severely impaired the secretion. The results suggest that structural integrity of the region, rather than its component amino acids, is important for the intracellular transport and secretion of alpha 2PI.

Synthesis of organic nitrates of luteolin as a novel class of potent aldose reductase inhibitors.

PubMed

Wang, Qi-Qin; Cheng, Ning; Zheng, Xiao-Wei; Peng, Sheng-Ming; Zou, Xiao-Qing

2013-07-15

Aldose reductase (AR) plays an important role in the design of drugs that prevent and treat diabetic complications. Aldose reductase inhibitors (ARIs) have received significant attentions as potent therapeutic drugs. Based on combination principles, three series of luteolin derivatives were synthesised and evaluated for their AR inhibitory activity and nitric oxide (NO)-releasing capacity in vitro. Eighteen compounds were found to be potent ARIs with IC50 values ranging from (0.099±0.008) μM to (2.833±0.102) μM. O(7)-Nitrooxyethyl-O(3'),O(4')-ethylidene luteolin (La1) showed the most potent AR inhibitory activity [IC50=(0.099±0.008) μM]. All organic nitrate derivatives released low concentrations of NO in the presence of l-cysteine. Structure-activity relationship studies suggested that introduction of an NO donor, protection of the catechol structure, and the ether chain of a 2-carbon spacer as a coupling chain on the luteolin scaffold all help increase the AR inhibitory activity of the resulting compound. This class of NO-donor luteolin derivatives as efficient ARIs offer a new concept for the development and design of new drug for preventive and therapeutic drugs for diabetic complications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Crystal Structures of Human Choline Kinase Isoforms in Complex with Hemicholinium-3 Single Amino Acid near the Active Site Influences Inhibitor Sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Bum Soo; Allali-Hassani, Abdellah; Tempel, Wolfram

2010-07-06

Human choline kinase (ChoK) catalyzes the first reaction in phosphatidylcholine biosynthesis and exists as ChoK{alpha} ({alpha}1 and {alpha}2) and ChoK{beta} isoforms. Recent studies suggest that ChoK is implicated in tumorigenesis and emerging as an attractive target for anticancer chemotherapy. To extend our understanding of the molecular mechanism of ChoK inhibition, we have determined the high resolution x-ray structures of the ChoK{alpha}1 and ChoK{beta} isoforms in complex with hemicholinium-3 (HC-3), a known inhibitor of ChoK. In both structures, HC-3 bound at the conserved hydrophobic groove on the C-terminal lobe. One of the HC-3 oxazinium rings complexed with ChoK{alpha}1 occupied the choline-bindingmore » pocket, providing a structural explanation for its inhibitory action. Interestingly, the HC-3 molecule co-crystallized with ChoK{beta} was phosphorylated in the choline binding site. This phosphorylation, albeit occurring at a very slow rate, was confirmed experimentally by mass spectroscopy and radioactive assays. Detailed kinetic studies revealed that HC-3 is a much more potent inhibitor for ChoK{alpha} isoforms ({alpha}1 and {alpha}2) compared with ChoK{beta}. Mutational studies based on the structures of both inhibitor-bound ChoK complexes demonstrated that Leu-401 of ChoK{alpha}2 (equivalent to Leu-419 of ChoK{alpha}1), or the corresponding residue Phe-352 of ChoK{beta}, which is one of the hydrophobic residues neighboring the active site, influences the plasticity of the HC-3-binding groove, thereby playing a key role in HC-3 sensitivity and phosphorylation.« less

Reactive oxygen species-generating mitochondrial DNA mutation up-regulates hypoxia-inducible factor-1alpha gene transcription via phosphatidylinositol 3-kinase-Akt/protein kinase C/histone deacetylase pathway.

PubMed

Koshikawa, Nobuko; Hayashi, Jun-Ichi; Nakagawara, Akira; Takenaga, Keizo

2009-11-27

Lewis lung carcinoma-derived high metastatic A11 cells constitutively overexpress hypoxia-inducible factor (HIF)-1alpha mRNA compared with low metastatic P29 cells. Because A11 cells exclusively possess a G13997A mutation in the mitochondrial NADH dehydrogenase subunit 6 (ND6) gene, we addressed here a causal relationship between the ND6 mutation and the activation of HIF-1alpha transcription, and we investigated the potential mechanism. Using trans-mitochondrial cybrids between A11 and P29 cells, we found that the ND6 mutation was directly involved in HIF-1alpha mRNA overexpression. Stimulation of HIF-1alpha transcription by the ND6 mutation was mediated by overproduction of reactive oxygen species (ROS) and subsequent activation of phosphatidylinositol 3-kinase (PI3K)-Akt and protein kinase C (PKC) signaling pathways. The up-regulation of HIF-1alpha transcription was abolished by mithramycin A, an Sp1 inhibitor, but luciferase reporter and chromatin immunoprecipitation assays indicated that Sp1 was necessary but not sufficient for HIF-1alpha mRNA overexpression in A11 cells. On the other hand, trichostatin A, a histone deacetylase (HDAC) inhibitor, markedly suppressed HIF-1alpha transcription in A11 cells. In accordance with this, HDAC activity was high in A11 cells but low in P29 cells and in A11 cells treated with the ROS scavenger ebselene, the PI3K inhibitor LY294002, and the PKC inhibitor Ro31-8220. These results suggest that the ROS-generating ND6 mutation increases HIF-1alpha transcription via the PI3K-Akt/PKC/HDAC pathway, leading to HIF-1alpha protein accumulation in hypoxic tumor cells.

Biodegradable braided poly(lactic-co-glycolic acid) urethral stent combined with dutasteride in the treatment of acute urinary retention due to benign prostatic enlargement: a pilot study.

PubMed

Kotsar, Andres; Isotalo, Taina; Juuti, Hanne; Mikkonen, Joonas; Leppiniemi, Jenni; Hänninen, Venla; Kellomäki, Minna; Talja, Martti; Tammela, Teuvo L J

2009-03-01

To evaluate, in a pilot study, the efficacy and safety of combining a braided poly(lactic-co-glycolic acid) (PLGA, a copolymer of l-lactide and glycolide) urethral stent and dutasteride in the treatment of acute urinary retention (AUR) due to benign prostatic enlargement (BPE). Ten men with AUR due to BPE were treated as outpatients. A biodegradable braided PLGA urethral stent was inserted into the prostatic urethra, using a specially designed insertion device under visual control. Dutasteride treatment was started and the patients were followed up for 3 months after insertion of the stents. In all patients the stents were placed successfully with the new insertion device. All men were able to void after inserting the stent. At 1 month five patients voided freely with a low residual urine volume (<150 mL), two voided but had a high residual urine volume and a suprapubic catheter was placed, and three needed a suprapubic or an indwelling catheter before 1 month, due to AUR or comorbidities. At 3 months five patients were voiding with no problems. We have developed a new and effective insertion device for biodegradable braided prostatic stents. The new braided-pattern stent overcomes the earlier problems of migration and sudden breakage into large particles associated with biodegradable spiral stents. However, the mechanical properties of the new stent need to be improved and tested in a longer follow-up. We consider that this new biodegradable braided-pattern urethral stent could provide a new option in the future treatment of AUR.

Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases and their relationship to isoflavone reductases

NASA Technical Reports Server (NTRS)

Min, Tongpil; Kasahara, Hiroyuki; Bedgar, Diana L.; Youn, Buhyun; Lawrence, Paulraj K.; Gang, David R.; Halls, Steven C.; Park, HaJeung; Hilsenbeck, Jacqueline L.; Davin, Laurence B.;

Rational Design of Novel Allosteric Dihydrofolate Reductase Inhibitors Showing Antibacterial Effects on Drug-Resistant Escherichia coli Escape Variants.

PubMed

Srinivasan, Bharath; Rodrigues, João V; Tonddast-Navaei, Sam; Shakhnovich, Eugene; Skolnick, Jeffrey

2017-07-21

In drug discovery, systematic variations of substituents on a common scaffold and bioisosteric replacements are often used to generate diversity and obtain molecules with better biological effects. However, this could saturate the small-molecule diversity pool resulting in drug resistance. On the other hand, conventional drug discovery relies on targeting known pockets on protein surfaces leading to drug resistance by mutations of critical pocket residues. Here, we present a two-pronged strategy of designing novel drugs that target unique pockets on a protein's surface to overcome the above problems. Dihydrofolate reductase, DHFR, is a critical enzyme involved in thymidine and purine nucleotide biosynthesis. Several classes of compounds that are structural analogues of the substrate dihydrofolate have been explored for their antifolate activity. Here, we describe 10 novel small-molecule inhibitors of Escherichia coli DHFR, EcDHFR, belonging to the stilbenoid, deoxybenzoin, and chalcone family of compounds discovered by a combination of pocket-based virtual ligand screening and systematic scaffold hopping. These inhibitors show a unique uncompetitive or noncompetitive inhibition mechanism, distinct from those reported for all known inhibitors of DHFR, indicative of binding to a unique pocket distinct from either substrate or cofactor-binding pockets. Furthermore, we demonstrate that rescue mutants of EcDHFR, with reduced affinity to all known classes of DHFR inhibitors, are inhibited at the same concentration as the wild-type. These compounds also exhibit antibacterial activity against E. coli harboring the drug-resistant variant of DHFR. This discovery is the first report on a novel class of inhibitors targeting a unique pocket on EcDHFR.

Synthesis and Evaluation of Novel RSK Inhibitors in a Living Human Breast Model

DTIC Science & Technology

2012-07-01

surprising. However, MCF7 cells express aldo-keto reductases ( AKRs ), well known to be Phase I metabolizing enzymes for a variety of drugs bearing...Inhibitors in a Living Human Breast Model PRINCIPAL INVESTIGATOR: Dr. Michael Hilinski CONTRACTING ORGANIZATION: The University of...that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it

An innovative strategy for dual inhibitor design and its application in dual inhibition of human thymidylate synthase and dihydrofolate reductase enzymes.

PubMed

Arooj, Mahreen; Sakkiah, Sugunadevi; Cao, Guang ping; Lee, Keun Woo

2013-01-01

Due to the diligence of inherent redundancy and robustness in many biological networks and pathways, multitarget inhibitors present a new prospect in the pharmaceutical industry for treatment of complex diseases. Nevertheless, to design multitarget inhibitors is concurrently a great challenge for medicinal chemists. We have developed a novel computational approach by integrating the affinity predictions from structure-based virtual screening with dual ligand-based pharmacophore to discover potential dual inhibitors of human Thymidylate synthase (hTS) and human dihydrofolate reductase (hDHFR). These are the key enzymes in folate metabolic pathway that is necessary for the biosynthesis of RNA, DNA, and protein. Their inhibition has found clinical utility as antitumor, antimicrobial, and antiprotozoal agents. A druglike database was utilized to perform dual-target docking studies. Hits identified through docking experiments were mapped over a dual pharmacophore which was developed from experimentally known dual inhibitors of hTS and hDHFR. Pharmacophore mapping procedure helped us in eliminating the compounds which do not possess basic chemical features necessary for dual inhibition. Finally, three structurally diverse hit compounds that showed key interactions at both active sites, mapped well upon the dual pharmacophore, and exhibited lowest binding energies were regarded as possible dual inhibitors of hTS and hDHFR. Furthermore, optimization studies were performed for final dual hit compound and eight optimized dual hits demonstrating excellent binding features at target systems were also regarded as possible dual inhibitors of hTS and hDHFR. In general, the strategy used in the current study could be a promising computational approach and may be generally applicable to other dual target drug designs.

An Innovative Strategy for Dual Inhibitor Design and Its Application in Dual Inhibition of Human Thymidylate Synthase and Dihydrofolate Reductase Enzymes

PubMed Central

Arooj, Mahreen; Sakkiah, Sugunadevi; Cao, Guang ping; Lee, Keun Woo

2013-01-01

Due to the diligence of inherent redundancy and robustness in many biological networks and pathways, multitarget inhibitors present a new prospect in the pharmaceutical industry for treatment of complex diseases. Nevertheless, to design multitarget inhibitors is concurrently a great challenge for medicinal chemists. We have developed a novel computational approach by integrating the affinity predictions from structure-based virtual screening with dual ligand-based pharmacophore to discover potential dual inhibitors of human Thymidylate synthase (hTS) and human dihydrofolate reductase (hDHFR). These are the key enzymes in folate metabolic pathway that is necessary for the biosynthesis of RNA, DNA, and protein. Their inhibition has found clinical utility as antitumor, antimicrobial, and antiprotozoal agents. A druglike database was utilized to perform dual-target docking studies. Hits identified through docking experiments were mapped over a dual pharmacophore which was developed from experimentally known dual inhibitors of hTS and hDHFR. Pharmacophore mapping procedure helped us in eliminating the compounds which do not possess basic chemical features necessary for dual inhibition. Finally, three structurally diverse hit compounds that showed key interactions at both active sites, mapped well upon the dual pharmacophore, and exhibited lowest binding energies were regarded as possible dual inhibitors of hTS and hDHFR. Furthermore, optimization studies were performed for final dual hit compound and eight optimized dual hits demonstrating excellent binding features at target systems were also regarded as possible dual inhibitors of hTS and hDHFR. In general, the strategy used in the current study could be a promising computational approach and may be generally applicable to other dual target drug designs. PMID:23577115

Switch control pocket inhibitors of p38-MAP kinase. Durable type II inhibitors that do not require binding into the canonical ATP hinge region.

PubMed

Ahn, Yu Mi; Clare, Michael; Ensinger, Carol L; Hood, Molly M; Lord, John W; Lu, Wei-Ping; Miller, David F; Patt, William C; Smith, Bryan D; Vogeti, Lakshminarayana; Kaufman, Michael D; Petillo, Peter A; Wise, Scott C; Abendroth, Jan; Chun, Lawrence; Clark, Robin; Feese, Michael; Kim, Hidong; Stewart, Lance; Flynn, Daniel L

2010-10-01

Switch control pocket inhibitors of p38-alpha kinase are described. Durable type II inhibitors were designed which bind to arginines (Arg67 or Arg70) that function as key residues for mediating phospho-threonine 180 dependant conformational fluxing of p38-alpha from an inactive type II state to an active type I state. Binding to Arg70 in particular led to potent inhibitors, exemplified by DP-802, which also exhibited high kinase selectivity. Binding to Arg70 obviated the requirement for binding into the ATP Hinge region. X-ray crystallography revealed that DP-802 and analogs induce an enhanced type II conformation upon binding to either the unphosphorylated or the doubly phosphorylated form of p38-alpha kinase. Copyright © 2010 Elsevier Ltd. All rights reserved.

Inhibition of CHK1 sensitizes Ewing sarcoma cells to the ribonucleotide reductase inhibitor gemcitabine

PubMed Central

Goss, Kelli L; Koppenhafer, Stacia L; Harmoney, Kathryn M; Terry, William W; Gordon, David J

2017-01-01

Ewing sarcoma is a bone and soft tissue sarcoma that occurs in children and young adults. The EWS-FLI1 gene fusion is the driver mutation in most Ewing sarcoma tumors and functions, in part, as an aberrant transcription factor. We recently identified that Ewing sarcoma cells are sensitive to inhibition of ribonucleotide reductase (RNR), which catalyzes the formation of deoxyribonucleotides from ribonucleotides. In this report, we show that Ewing sarcoma cells are sensitive to treatment with clofarabine, which is a nucleoside analogue and allosteric inhibitor of RNR. However, clofarabine is a reversible inhibitor of RNR and we found that the effect of clofarabine is limited when using a short (6-hour) drug treatment. Gemcitabine, on the other hand, is an irreversible inhibitor of the RRM1 subunit of RNR and this drug induces apoptosis in Ewing sarcoma cells when used in both 6-hour and longer drug treatments. Treatment of Ewing sarcoma cells with gemcitabine also results in activation of checkpoint kinase 1 (CHK1), which is a critical mediator of cell survival in the setting of impaired DNA replication. Notably, inhibition of CHK1 function in Ewing sarcoma cells using a small-molecule CHK1 inhibitor, or siRNA knockdown, in combination with gemcitabine results in increased toxicity both in vitro and in vivo in a mouse xenograft experiment. Overall, our results provide insight into Ewing sarcoma biology and identify a candidate therapeutic target, and drug combination, in Ewing sarcoma. PMID:29152060

Trypanosoma brucei DHFR-TS Revisited: Characterisation of a Bifunctional and Highly Unstable Recombinant Dihydrofolate Reductase-Thymidylate Synthase.

PubMed

Gibson, Marc W; Dewar, Simon; Ong, Han B; Sienkiewicz, Natasha; Fairlamb, Alan H

2016-05-01

Bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) is a chemically and genetically validated target in African trypanosomes, causative agents of sleeping sickness in humans and nagana in cattle. Here we report the kinetic properties and sensitivity of recombinant enzyme to a range of lipophilic and classical antifolate drugs. The purified recombinant enzyme, expressed as a fusion protein with elongation factor Ts (Tsf) in ThyA- Escherichia coli, retains DHFR activity, but lacks any TS activity. TS activity was found to be extremely unstable (half-life of 28 s) following desalting of clarified bacterial lysates to remove small molecules. Stability could be improved 700-fold by inclusion of dUMP, but not by other pyrimidine or purine (deoxy)-nucleosides or nucleotides. Inclusion of dUMP during purification proved insufficient to prevent inactivation during the purification procedure. Methotrexate and trimetrexate were the most potent inhibitors of DHFR (Ki 0.1 and 0.6 nM, respectively) and FdUMP and nolatrexed of TS (Ki 14 and 39 nM, respectively). All inhibitors showed a marked drop-off in potency of 100- to 1,000-fold against trypanosomes grown in low folate medium lacking thymidine. The most potent inhibitors possessed a terminal glutamate moiety suggesting that transport or subsequent retention by polyglutamylation was important for biological activity. Supplementation of culture medium with folate markedly antagonised the potency of these folate-like inhibitors, as did thymidine in the case of the TS inhibitors raltitrexed and pemetrexed.

Inhibition of α-glucosidase, α-amylase, and aldose reductase by potato polyphenolic compounds

PubMed Central

Kalita, Diganta; Holm, David G.; LaBarbera, Daniel V.; Petrash, J. Mark

2018-01-01

Diabetes mellitus is a chronic disease that is becoming a serious global health problem. Diabetes has been considered to be one of the major risks of cataract and retinopathy. Synthetic and natural product inhibitors of carbohydrate degrading enzymes are able to reduce type 2 diabetes and its complications. For a long time, potatoes have been portrayed as unhealthy for diabetic patients by some nutritionist due to their high starch content. However, purple and red potato cultivars have received considerable attention from consumers because they have high levels of polyphenolic compounds that have potent antioxidant activities. In this study, we screened the total phenolics (TP) and total anthocyanins (TA) and analyzed the phenolic and anthocyanin compounds in selected potato cultivars and advanced selections with distinct flesh colors (purple, red, yellow and white). Purple and red potato cultivars had higher levels of TP and TA than tubers with other flesh colors. Chlorogenic acid is the predominant phenolic acid, and major anthocyanin is composed of the derivatives of petunidin, peonidin, malvidin and pelargonidin. We tested the potential inhibitory effect of potato extracts on the activities of α-amylase and α-glucosidase, which were targeted to develop antidiabetic therapeutic agents. We also measured inhibitory effect of potato extracts on aldose reductase (AR) which is a key enzyme that has been a major drug target for the development of therapies to treat diabetic complications. Purple flesh tubers extract showed the most effective inhibition of α-amylase, α-glucosidase, and aldose reductase with IC50 values 25, 42, and 32 μg/ml, respectively. Kinetic studies showed that anthocyanins are noncompetitive inhibitors of these enzymes, whereas phenolic acids behaved as mixed inhibitors for α-amylase and α-glucosidase and noncompetitive inhibitors for AR. This study supports the development of a positive and healthful image of potatoes, which is an important issue for consumers. PMID:29370193

Inhibition of α-glucosidase, α-amylase, and aldose reductase by potato polyphenolic compounds.

PubMed

Kalita, Diganta; Holm, David G; LaBarbera, Daniel V; Petrash, J Mark; Jayanty, Sastry S

2018-01-01

Diabetes mellitus is a chronic disease that is becoming a serious global health problem. Diabetes has been considered to be one of the major risks of cataract and retinopathy. Synthetic and natural product inhibitors of carbohydrate degrading enzymes are able to reduce type 2 diabetes and its complications. For a long time, potatoes have been portrayed as unhealthy for diabetic patients by some nutritionist due to their high starch content. However, purple and red potato cultivars have received considerable attention from consumers because they have high levels of polyphenolic compounds that have potent antioxidant activities. In this study, we screened the total phenolics (TP) and total anthocyanins (TA) and analyzed the phenolic and anthocyanin compounds in selected potato cultivars and advanced selections with distinct flesh colors (purple, red, yellow and white). Purple and red potato cultivars had higher levels of TP and TA than tubers with other flesh colors. Chlorogenic acid is the predominant phenolic acid, and major anthocyanin is composed of the derivatives of petunidin, peonidin, malvidin and pelargonidin. We tested the potential inhibitory effect of potato extracts on the activities of α-amylase and α-glucosidase, which were targeted to develop antidiabetic therapeutic agents. We also measured inhibitory effect of potato extracts on aldose reductase (AR) which is a key enzyme that has been a major drug target for the development of therapies to treat diabetic complications. Purple flesh tubers extract showed the most effective inhibition of α-amylase, α-glucosidase, and aldose reductase with IC50 values 25, 42, and 32 μg/ml, respectively. Kinetic studies showed that anthocyanins are noncompetitive inhibitors of these enzymes, whereas phenolic acids behaved as mixed inhibitors for α-amylase and α-glucosidase and noncompetitive inhibitors for AR. This study supports the development of a positive and healthful image of potatoes, which is an important issue for consumers.

Amelioration in secretion of hyperthermostable and Ca2+ -independent alpha-amylase of Geobacillus thermoleovorans by some polyamines and their biosynthesis inhibitor methylglyoxal-bis-guanylhydrazone.

PubMed

Uma Maheswar Rao, J L; Satyanarayana, T

2004-01-01

Effect of polyamines and their biosynthesis inhibitors on the production of hyperthermostable and Ca2+ -independent alpha-amylase by Geobacillus thermoleovorans MTCC 4220. The alpha-amylase was produced in starch-yeast extract-tryptone (SYT) broth with different polyamines (PA) and polyamine biosynthesis inhibitors, methylglyoxal-bis-guanylhydrazone (MGBG) and cyclohexylammonium sulphate (CHA) at 70 degrees C. The bacterial pellets were obtained after growing G. thermoleovorans at different temperatures, and used in determining total PA. The cell-free culture filtrates were used in alpha-amylase assays. During growth, total polyamines in biomass increased till 2 h, and thereafter, decreased gradually. The total polyamine content was very high in the biomass cultivated at 55 degrees C when compared with that of higher temperatures. Enzyme titre enhanced up to 70 degrees C, and thereafter declined. Extracellular enzyme and protein levels declined in the presence of exogenously added PA. The intracellular enzyme titres, however, were higher in putrescine (put) and spermidine (spd) than in spermine (spm). Polyamine biosynthesis inhibitor, MGBG enhanced secretion of alpha-amylase in a laboratory fermentor as well as shake flasks, although CHA did not affect it. The intracellular accumulation of put in the presence of MGBG appeared to enhance synthesis and secretion of alpha-amylase. Extracellular enzyme and protein levels were low in the presence of exogenously added PA, but their intracellular levels, however, were higher in put and spd than in spm. A substantial increase in the synthesis and secretion of alpha-amylase was attained in G. thermoleovorans in the presence of polyamine biosynthesis inhibitor MGBG.

Molecular rationale delineating the role of lycopene as a potent HMG-CoA reductase inhibitor: in vitro and in silico study.

PubMed

Alvi, Sahir Sultan; Iqbal, Danish; Ahmad, Saheem; Khan, M Salman

2016-09-01

This study initially aimed to depict the molecular rationale evolving the role of lycopene in inhibiting the enzymatic activity of β-hydroxy-β-methylglutaryl-CoA (HMG-CoA) reductase via in vitro and in silico analysis. Our results illustrated that lycopene exhibited strong HMG-CoA reductase inhibitory activity (IC50 value of 36 ng/ml) quite better than pravastatin (IC50 = 42 ng/ml) and strong DPPH free radical scavenging activity (IC50 value = 4.57 ± 0.23 μg/ml) as compared to ascorbic acid (IC50 value = 9.82 ± 0.42 μg/ml). Moreover, the Ki value of lycopene (36 ng/ml) depicted via Dixon plot was well concurred with an IC50 value of 36 ± 1.8 ng/ml. Moreover, molecular informatics study showed that lycopene exhibited binding energy of -5.62 kcal/mol indicating high affinity for HMG-CoA reductase than HMG-CoA (ΔG: -5.34 kcal/mol). Thus, in silico data clearly demonstrate and support the in vitro results that lycopene competitively inhibit HMG-CoA reductase activity by binding at the hydrophobic portion of HMG-CoA reductase.

A simple whole cell based high throughput screening protocol using Mycobacterium bovis BCG for inhibitors against dormant and active tubercle bacilli.

PubMed

Khan, Arshad; Sarkar, Dhiman

2008-04-01

This study aimed at developing a whole cell based high throughput screening protocol to identify inhibitors against both active and dormant tubercle bacilli. A respiratory type of nitrate reductase (NarGHJI), which was induced during dormancy, could reflect the viability of dormant bacilli of Mycobacterium bovis BCG in microplate adopted model of in vitro dormancy. Correlation between reduction in viability and nitrate reductase activity was seen clearly when dormant stage inhibitor metronidazole and itaconic anhydride were applied in this in vitro microplate model. Active replicating stage could also be monitored in the same assay by measuring the A(620) of the culture. MIC values of 0.08, 0.075, 0.3 and 3.0 microg/ml, determined through monitoring A(620) in this assay for rifampin, isoniazid, streptomycin and ethambutol respectively, were well in agreement with previously reported by BACTEC and Bio-Siv assays. S/N ratio and Z' factor for the assay were 8.5 and 0.81 respectively which indicated the robustness of the protocol. Altogether the assay provides an easy, inexpensive, rapid, robust and high content screening tool to search novel antitubercular molecules against both active and dormant bacilli.

Identification of Novel Aldose Reductase Inhibitors from Spices: A Molecular Docking and Simulation Study.

PubMed

Antony, Priya; Vijayan, Ranjit

2015-01-01

Hyperglycemia in diabetic patients results in a diverse range of complications such as diabetic retinopathy, neuropathy, nephropathy and cardiovascular diseases. The role of aldose reductase (AR), the key enzyme in the polyol pathway, in these complications is well established. Due to notable side-effects of several drugs, phytochemicals as an alternative has gained considerable importance for the treatment of several ailments. In order to evaluate the inhibitory effects of dietary spices on AR, a collection of phytochemicals were identified from Zingiber officinale (ginger), Curcuma longa (turmeric) Allium sativum (garlic) and Trigonella foenum graecum (fenugreek). Molecular docking was performed for lead identification and molecular dynamics simulations were performed to study the dynamic behaviour of these protein-ligand interactions. Gingerenones A, B and C, lariciresinol, quercetin and calebin A from these spices exhibited high docking score, binding affinity and sustained protein-ligand interactions. Rescoring of protein ligand interactions at the end of MD simulations produced binding scores that were better than the initially docked conformations. Docking results, ligand interactions and ADMET properties of these molecules were significantly better than commercially available AR inhibitors like epalrestat, sorbinil and ranirestat. Thus, these natural molecules could be potent AR inhibitors.

Identification of Novel Aldose Reductase Inhibitors from Spices: A Molecular Docking and Simulation Study

PubMed Central

Antony, Priya; Vijayan, Ranjit

2015-01-01

Hyperglycemia in diabetic patients results in a diverse range of complications such as diabetic retinopathy, neuropathy, nephropathy and cardiovascular diseases. The role of aldose reductase (AR), the key enzyme in the polyol pathway, in these complications is well established. Due to notable side-effects of several drugs, phytochemicals as an alternative has gained considerable importance for the treatment of several ailments. In order to evaluate the inhibitory effects of dietary spices on AR, a collection of phytochemicals were identified from Zingiber officinale (ginger), Curcuma longa (turmeric) Allium sativum (garlic) and Trigonella foenum graecum (fenugreek). Molecular docking was performed for lead identification and molecular dynamics simulations were performed to study the dynamic behaviour of these protein-ligand interactions. Gingerenones A, B and C, lariciresinol, quercetin and calebin A from these spices exhibited high docking score, binding affinity and sustained protein-ligand interactions. Rescoring of protein ligand interactions at the end of MD simulations produced binding scores that were better than the initially docked conformations. Docking results, ligand interactions and ADMET properties of these molecules were significantly better than commercially available AR inhibitors like epalrestat, sorbinil and ranirestat. Thus, these natural molecules could be potent AR inhibitors. PMID:26384019

Discovery of Fungal Denitrification Inhibitors by Targeting Copper Nitrite Reductase from Fusarium oxysporum.

PubMed

Matsuoka, Masaki; Kumar, Ashutosh; Muddassar, Muhammad; Matsuyama, Akihisa; Yoshida, Minoru; Zhang, Kam Y J

2017-02-27

The efficient application of nitrogenous fertilizers is urgently required, as their excessive and inefficient use is causing substantial economic loss and environmental pollution. A significant amount of applied nitrogen in agricultural soils is lost as nitrous oxide (N 2 O) in the environment due to the microbial denitrification process. The widely distributed fungus Fusarium oxysporum is a major denitrifier in agricultural soils and its denitrification activity could be targeted to reduce nitrogen loss in the form of N 2 O from agricultural soils. Here, we report the discovery of first small molecule inhibitors of copper nitrite reductase (NirK) from F. oxysporum, which is a key enzyme in the fungal denitrification process. The inhibitors were discovered by a hierarchical in silico screening approach consisting of pharmacophore modeling and molecular docking. In vitro evaluation of F. oxysporum NirK activity revealed several pyrimidone and triazinone based compounds with potency in the low micromolar range. Some of these compounds suppressed the fungal denitrification in vivo as well. The compounds reported here could be used as starting points for the development of nitrogenous fertilizer supplements and coatings as a means to prevent nitrogen loss by targeting fungal denitrification.

Identification of some novel pyrazolo[1,5-a]pyrimidine derivatives as InhA inhibitors through pharmacophore-based virtual screening and molecular docking.

PubMed

Modi, Palmi; Patel, Shivani; Chhabria, Mahesh T

2018-05-04

The InhA inhibitors play key role in mycolic acid synthesis by preventing the fatty acid biosynthesis pathway. In this present article, Pharmacophore modelling and molecular docking study followed by in silico virtual screening could be considered as effective strategy to identify newer enoyl-ACP reductase inhibitors. Pyrrolidine carboxamide derivatives were opted to generate pharmacophore models using HypoGen algorithm in Discovery studio 2.1. Further it was employed to screen Zinc and Minimaybridge databases to identify and design newer potent hit molecules. The retrieved newer hits were further evaluated for their drug likeliness and docked against enoyl acyl carrier protein reductase. Here, novel pyrazolo[1,5-a]pyrimidine analogues were designed and synthesized with good yields. Structural elucidation of synthesized final molecules was perform through IR, MASS, 1 H-NMR, 13 C-NMR spectroscopy and further tested for its in vitro anti-tubercular activity against H37Rv strain using Microplate Alamar blue assay (MABA) method. Most of the synthesized compounds displayed strong anti-tubercular activities. Further, these potent compounds were gauged for MDR-TB, XDR-TB and cytotoxic study.

Cell death in response to antimetabolites directed at ribonucleotide reductase and thymidylate synthase

PubMed Central

Asuncion Valenzuela, Malyn M; Castro, Imilce; Gonda, Amber; Diaz Osterman, Carlos J; Jutzy, Jessica M; Aspe, Jonathan R; Khan, Salma; Neidigh, Jonathan W; Wall, Nathan R

2015-01-01

New agent development, mechanistic understanding, and combinatorial partnerships with known and novel modalities continue to be important in the study of pancreatic cancer and its improved treatment. In this study, known antimetabolite drugs such as gemcitabine (ribonucleotide reductase inhibitor) and 5-fluorouracil (thymidylate synthase inhibitor) were compared with novel members of these two drug families in the treatment of a chemoresistant pancreatic cancer cell line PANC-1. Cellular survival data, along with protein and messenger ribonucleic acid expression for survivin, XIAP, cIAP1, and cIAP2, were compared from both the cell cytoplasm and from exosomes after single modality treatment. While all antimetabolite drugs killed PANC-1 cells in a time- and dose-dependent manner, neither family significantly altered the cytosolic protein level of the four inhibitors of apoptosis (IAPs) investigated. Survivin, XIAP, cIAP1, and cIAP2 were found localized to exosomes where no significant difference in expression was recorded. This inability for significant and long-lasting expression may be a reason why pancreatic cancer lacks responsiveness to these and other cancer-killing agents. Continued investigation is required to determine the responsibilities of these IAPs in their role in chemoresistance in pancreatic adenocarcinoma. PMID:25767396

Discovery of novel aldose reductase inhibitors using a protein structure-based approach: 3D-database search followed by design and synthesis.

PubMed

Iwata, Y; Arisawa, M; Hamada, R; Kita, Y; Mizutani, M Y; Tomioka, N; Itai, A; Miyamoto, S

2001-05-24

Aldose reductase (AR) has been implicated in the etiology of diabetic complications. Due to the limited number of currently available drugs for the treatment of diabetic complications, we have carried out structure-based drug design and synthesis in an attempt to find new types of AR inhibitors. With the ADAM&EVE program, a three-dimensional database (ACD3D) was searched using the ligand binding site of the AR crystal structure. Out of 179 compounds selected through this search followed by visual inspection, 36 compounds were purchased and subjected to a biological assay. Ten compounds showed more than 40% inhibition of AR at a 15 microg/mL concentration. In a subsequent lead optimization, a series of analogues of the most active compound were synthesized based on the docking mode derived by ADAM&EVE. Many of these congeners exhibited higher activities compared to the mother compound. Indeed, the most potent, synthesized compound showed an approximately 20-fold increase in inhibitory activity (IC(50) = 0.21 vs 4.3 microM). Furthermore, a hydrophobic subsite was newly inferred, which would be useful for the design of inhibitors with improved affinity for AR.

Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat Part 2: Effects on reproductive parameters, on sex behavior, on memory retention and on hypothalamic expression of aromatase and 5alpha-reductases in the offspring.

PubMed

Colciago, A; Casati, L; Mornati, O; Vergoni, A V; Santagostino, A; Celotti, F; Negri-Cesi, P

2009-08-15

The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A reconstituted mixture of four indicator congeners (PCB 126, 138, 153 and 180) was injected subcutaneously to dams at the dose of 10 mg/kg daily from GD15 to GD19 and then twice a week till weanling. The results indicated that developmental PCB exposure produced important changes in the dimorphic hypothalamic expression of both aromatase and the 5alpha-Rs, which were still evident in adult animals. We observed that female puberty onset occurs earlier than in control animals without cycle irregularity, while testicular descent in males was delayed. A slight but significant impairment of sexual behavior and an important alteration in memory retention were also noted specifically in males. We conclude that PCBs might affect the dimorphic neuroendocrine control of reproductive system and of other neurobiological processes.

Subatomic and atomic crystallographic studies of aldose reductase: implications for inhibitor binding.

PubMed

Podjarny, A; Cachau, R E; Schneider, T; Van Zandt, M; Joachimiak, A

2004-04-01

The determination of several of aldose reductase-inhibitor complexes at subatomic resolution has revealed new structural details, including the specific interatomic contacts involved in inhibitor binding. In this article, we review the structures of the complexes of ALR2 with IDD 594 (resolution: 0.66 angstrom, IC50 (concentration of the inhibitor that produced half-maximal effect): 30 nM, space group: P2(1)), IDD 393 (resolution: 0.90 angstrom, IC50: 6 nM, space group: P1), fidarestat (resolution: 0.92 angstrom, IC50: 9 nM, space group: P2(1)) and minalrestat (resolution: 1.10 angstrom, IC50: 73 nM, space group: P1). The structures are compared and found to be highly reproductible within the same space group (root mean square (RMS) deviations: 0.15 approximately 0.3 angstrom). The mode of binding of the carboxylate inhibitors IDD 594 and IDD 393 is analysed. The binding of the carboxylate head can be accurately determined by the subatomic resolution structures, since both the protonation states and the positions of the atoms are very precisely known. The differences appear in the binding in the specificity pocket. The high-resolution structures explain the differences in IC50, which are confirmed both experimentally by mass spectrometry measures of VC50 and theoretically by free energy perturbation calculations. The binding of the cyclic imide inhibitors fidarestat and minalrestat is also described, focusing on the observation of a Cl(-) ion which binds simultaneously with fidarestat. The presence of this anion, binding also to the active site residue His110, leads to a mechanism in which the inhibitor can bind in a neutral state and then become charged inside the active site pocket. This mechanism can explain the excellent in vivo properties of cyclic imide inhibitors. In summary, the complete and detailed information supplied by the subatomic resolution structures can explain the differences in binding energy of the different inhibitors.

Mobilization of tissue cadmium in mice and calves and reversal of cadmium induced tissue damage in calves by zinc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddy, C.S.; Mohammad, F.K.; Ganjam, V.K.

1987-08-01

Earlier studies demonstrated that simultaneous dietary Zn supplementation to calves fed Cd, significantly decreased the accumulation of Cd in liver, kidney and muscle. However, studies are lacking in evaluating the effectiveness of zinc in reducing Cd-burden in animals with pre-existing tissue Cd-load, a situation encountered in chronic Cd intoxication. This study examined the effects of oral Zn (AnO) on tissue Cd levels in mice. N-acetylcysteine (NAC) and sodium sulfate (SS) were also used to evaluate the effects of providing organic and inorganic sources of sulfur on tissue Cd levels. Following demonstration of reduced Cd levels in tissues of mice receivingmore » antidotal Zn, subsequent investigation was aimed at studying the reversal of Cd-induced changes by Zn. The authors also examined whether Cd-induced reduction in epididymal 5 ..cap alpha..-reductase activity could explain previously reported low levels of circulating dihydrotestosterone (DHT) following Cd treatment. The ability of Zn to reverse the inhibition of 5 ..cap alpha..-reductase activity by Cd was also examined.« less

Gene analysis of steroid 5 alpha-reductase 1 in hyperandrogenic women.

PubMed

Eminović, Izet; Komel, Radovan; Prezelj, Janez; Karamehić, Jasenko; Gavrankapetanović, Faris; Heljić, Becir

2005-08-01

To examine the gene encoding for 5alpha-reductase type 1 in hyperandrogenic women, and assess the association of its eventual mutations or polymorphisms with the development of the hyperandrogenic female pattern. Sixteen hyperandrogenic women were included in the study. Single-stranded conformation polymorphism analysis (SSCP) and DNA sequencing were performed after polymerase chain reaction amplification of each of the 5 exons of the SRD5A1 gene in both hyperandrogenic and control group (16 participants). Sequence analysis identified the existence of many polymorphisms; in codon 24 of exon 1, GGC (Gly) into GAC (Asp); in codon 30 of exon 1, CGG (Arg) into CGC (Arg); in exon 3 codon 169, ACA to ACG (both encoding for threonine); in exon 5, AGA to AGG (both encoding for arginine, codon 260); and T/C polymorphism in intron 2. Polymorphisms were found in both groups. Polymorphisms of SRD5A1 gene were the same in both hyperandrogenic and healthy women, indicating no significant associations of genetic polymorphisms/variations of SRD5A1 gene with clinical manifestations of hyperandrogenic disorders in women.

Staphylococcus Alpha-Toxin Action on the Rabbit Iris: Toxic Effects and Their Inhibition.

PubMed

Arana, Angela M; Bierdeman, Michael A; Balzli, Charles L; Tang, Aihua; Caballero, Armando R; Patel, Rupesh; O'Callaghan, Richard J

2015-01-01

Staphylococcus aureus infection of the anterior chamber can occur after cataract surgery, causing inflammation and extensive damage to the iris. Alpha-toxin, the most potent S. aureus corneal toxin, was tested as a possible mediator of damage to the iris, and alpha-toxin anti-serum and a chemical toxin inhibitor were tested as potential pathology-reducing agents. The hemolytic activity of alpha-toxin and its inhibition by a chemical inhibitor or anti-serum were quantified in vitro. Purified alpha-toxin, heat-inactivated toxin, or alpha-toxin plus normal serum, alpha-toxin anti-serum, or the chemical inhibitor, methyl-β-cyclodextrin-cholesterol (CD-cholesterol), was injected into the rabbit anterior chamber. Pathological changes were photographed, quantified by slit-lamp examination (SLE) scoring, and further documented by histopathological analysis. At five hours post-injection, eyes injected with alpha-toxin or heat-inactivated toxin had a mean SLE score of 7.3 ± 0.59 or 0.84 ± 0.19, respectively. Active toxin caused moderate to severe iris edema, severe erosion of the iris, and mild to moderate fibrin accumulation in the anterior chamber. Alpha-toxin plus anti-serum or CD-cholesterol, in contrast to alpha-toxin alone, caused less iris edema and epithelium sloughing as well as significantly lower SLE scores than eyes receiving alpha-toxin alone (p ≤ 0.019). Alpha-toxin caused extensive iris damage and inflammation, and either anti-alpha-toxin anti-serum or CD-cholesterol was able to significantly reduce toxin-mediated damage and inflammation.

Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone.

PubMed

Murata, J; Ayukawa, K; Ogasawara, M; Watanabe, H; Saiki, I

1999-03-15

We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).

Alpha-amylase inhibitor-1 gene from Phaseolus vulgaris expressed in Coffea arabica plants inhibits alpha-amylases from the coffee berry borer pest.

PubMed

Barbosa, Aulus E A D; Albuquerque, Erika V S; Silva, Maria C M; Souza, Djair S L; Oliveira-Neto, Osmundo B; Valencia, Arnubio; Rocha, Thales L; Grossi-de-Sa, Maria F

2010-06-17

Coffee is an important crop and is crucial to the economy of many developing countries, generating around US$70 billion per year. There are 115 species in the Coffea genus, but only two, C. arabica and C. canephora, are commercially cultivated. Coffee plants are attacked by many pathogens and insect-pests, which affect not only the production of coffee but also its grain quality, reducing the commercial value of the product. The main insect-pest, the coffee berry borer (Hypotheneumus hampei), is responsible for worldwide annual losses of around US$500 million. The coffee berry borer exclusively damages the coffee berries, and it is mainly controlled by organochlorine insecticides that are both toxic and carcinogenic. Unfortunately, natural resistance in the genus Coffea to H. hampei has not been documented. To overcome these problems, biotechnological strategies can be used to introduce an alpha-amylase inhibitor gene (alpha-AI1), which confers resistance against the coffee berry borer insect-pest, into C. arabica plants. We transformed C. arabica with the alpha-amylase inhibitor-1 gene (alpha-AI1) from the common bean, Phaseolus vulgaris, under control of the seed-specific phytohemagglutinin promoter (PHA-L). The presence of the alpha-AI1 gene in six regenerated transgenic T1 coffee plants was identified by PCR and Southern blotting. Immunoblotting and ELISA experiments using antibodies against alpha-AI1 inhibitor showed a maximum alpha-AI1 concentration of 0.29% in crude seed extracts. Inhibitory in vitro assays of the alpha-AI1 protein against H. hampei alpha-amylases in transgenic seed extracts showed up to 88% inhibition of enzyme activity. This is the first report showing the production of transgenic coffee plants with the biotechnological potential to control the coffee berry borer, the most important insect-pest of crop coffee.

Reflection on design and testing of pancreatic alpha-amylase inhibitors: an in silico comparison between rat and rabbit enzyme models

PubMed Central

2012-01-01

Background Inhibitors of pancreatic alpha-amylase are potential drugs to treat diabetes and obesity. In order to find compounds that would be effective amylase inhibitors, in vitro and in vivo models are usually used. The accuracy of models is limited, but these tools are nonetheless valuable. In vitro models could be used in large screenings involving thousands of chemicals that are tested to find potential lead compounds. In vivo models are still used as preliminary mean of testing compounds behavior in the whole organism. In the case of alpha-amylase inhibitors, both rats and rabbits could be chosen as in vivo models. The question was which animal could present more accuracy with regard to its pancreatic alpha-amylase. Results As there is no crystal structure of these enzymes, a molecular modeling study was done in order to compare the rabbit and rat enzymes with the human one. The overall result is that rabbit enzyme could probably be a better choice in this regard, but in the case of large ligands, which could make putative interactions with the −4 subsite of pancreatic alpha-amylase, interpretation of results should be made cautiously. Conclusion Molecular modeling tools could be used to choose the most suitable model enzyme that would help to identify new enzyme inhibitors. In the case of alpha-amylase, three-dimensional structures of animal enzymes show differences with the human one which should be taken into account when testing potential new drugs. PMID:23352052

Geometric Restraint Drives On- and Off-pathway Catalysis by the Escherichia coli Menaquinol:Fumarate Reductase*

PubMed Central

Tomasiak, Thomas M.; Archuleta, Tara L.; Andréll, Juni; Luna-Chávez, César; Davis, Tyler A.; Sarwar, Maruf; Ham, Amy J.; McDonald, W. Hayes; Yankovskaya, Victoria; Stern, Harry A.; Johnston, Jeffrey N.; Maklashina, Elena; Cecchini, Gary; Iverson, Tina M.

2011-01-01

Complex II superfamily members catalyze the kinetically difficult interconversion of succinate and fumarate. Due to the relative simplicity of complex II substrates and their similarity to other biologically abundant small molecules, substrate specificity presents a challenge in this system. In order to identify determinants for on-pathway catalysis, off-pathway catalysis, and enzyme inhibition, crystal structures of Escherichia coli menaquinol:fumarate reductase (QFR), a complex II superfamily member, were determined bound to the substrate, fumarate, and the inhibitors oxaloacetate, glutarate, and 3-nitropropionate. Optical difference spectroscopy and computational modeling support a model where QFR twists the dicarboxylate, activating it for catalysis. Orientation of the C2–C3 double bond of activated fumarate parallel to the C(4a)–N5 bond of FAD allows orbital overlap between the substrate and the cofactor, priming the substrate for nucleophilic attack. Off-pathway catalysis, such as the conversion of malate to oxaloacetate or the activation of the toxin 3-nitropropionate may occur when inhibitors bind with a similarly activated bond in the same position. Conversely, inhibitors that do not orient an activatable bond in this manner, such as glutarate and citrate, are excluded from catalysis and act as inhibitors of substrate binding. These results support a model where electronic interactions via geometric constraint and orbital steering underlie catalysis by QFR. PMID:21098488

A [32P]-NAD+-based method to identify and quantitate long residence time enoyl-ACP reductase inhibitors

PubMed Central

Yu, Weixuan; Neckles, Carla; Chang, Andrew; Bommineni, Gopal Reddy; Spagnuolo, Lauren; Zhang, Zhuo; Liu, Nina; Lai, Christina; Truglio, James; Tonge, Peter J.

2015-01-01

The classical methods for quantifying drug-target residence time (tR) use loss or regain of enzyme activity in progress curve kinetic assays. However, such methods become imprecise at very long residence times, mitigating the use of alternative strategies. Using the NAD(P)H-dependent FabI enoyl-ACP reductase as a model system, we developed a Penefsky column-based method for direct measurement of tR, where the off-rate of the drug was determined with radiolabeled [adenylate-32P] NAD(P+) cofactor. Twenty-three FabI inhibitors were analyzed and a mathematical model was used to estimate limits to the tR values of each inhibitor based on percent drug-target complex recovery following gel filtration. In general, this method showed good agreement with the classical steady state kinetic methods for compounds with tR values of 10-100 min. In addition, we were able to identify seven long tR inhibitors (100-1500 min) and to accurately determine their tR values. The method was then used to measure tR as a function of temperature, an analysis not previously possible using the standard kinetic approach due to decreased NAD(P)H stability at elevated temperatures. In general, a 4-fold difference in tR was observed when the temperature was increased from 25 °C to 37 °C . PMID:25684450

Geometric Restraint Drives On- and Off-pathway Catalysis by the Escherichia coli Menaquinol:Fumarate Reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomasiak, Thomas M.; Archuleta, Tara L.; Andréll, Juni

2012-01-05

Complex II superfamily members catalyze the kinetically difficult interconversion of succinate and fumarate. Due to the relative simplicity of complex II substrates and their similarity to other biologically abundant small molecules, substrate specificity presents a challenge in this system. In order to identify determinants for on-pathway catalysis, off-pathway catalysis, and enzyme inhibition, crystal structures of Escherichia coli menaquinol:fumarate reductase (QFR), a complex II superfamily member, were determined bound to the substrate, fumarate, and the inhibitors oxaloacetate, glutarate, and 3-nitropropionate. Optical difference spectroscopy and computational modeling support a model where QFR twists the dicarboxylate, activating it for catalysis. Orientation of themore » C2-C3 double bond of activated fumarate parallel to the C(4a)-N5 bond of FAD allows orbital overlap between the substrate and the cofactor, priming the substrate for nucleophilic attack. Off-pathway catalysis, such as the conversion of malate to oxaloacetate or the activation of the toxin 3-nitropropionate may occur when inhibitors bind with a similarly activated bond in the same position. Conversely, inhibitors that do not orient an activatable bond in this manner, such as glutarate and citrate, are excluded from catalysis and act as inhibitors of substrate binding. These results support a model where electronic interactions via geometric constraint and orbital steering underlie catalysis by QFR.« less

Inhibition effects of chlorogenic acid on benign prostatic hyperplasia in mice.

PubMed

Huang, Ya; Chen, Huaguo; Zhou, Xin; Wu, Xingdong; Hu, Enming; Jiang, Zhengmeng

2017-08-15

This study aimed to evaluate the inhibitory effects and explore mechanisms of chlorogenic acid against testosterone-induced benign prostatic hyperplasia (BPH) in mice. Benign prostatic hyperplasia model was induced in experimental groups by daily subcutaneous injections of testosterone propionate (7.5mg/kg/d) consecutively for 14 d. A total of 60 mice were randomly divided into six groups: (Group 1) normal control group, (Group 2) benign prostatic hyperplasia model control group, (Group 3) benign prostatic hyperplasia mice treated with finasteride at a dose of 1mg/kg, (Group 4) benign prostatic hyperplasia mice treated with chlorogenic acid at dose levels of 0.8mg/kg (low dose group), (Group 5) benign prostatic hyperplasia mice treated with chlorogenic acid at dose levels of 1.6mg/kg (medium dose group) and (Group 6) benign prostatic hyperplasia mice treated with chlorogenic acid at dose levels of 3.2mg/kg (high dose group). Animals were sacrificed on the scheduled termination, pick out the eyeball to get blood, then prostates were weighed and prostatic index were determined. Then the serum acid phosphatase (ACP), prostatic acid phosphatase (PACP) and typeⅡ5-alpha-reductase (SRD5A2) levels were measured and observed morphological changes of the prostate. Comparing with benign prostatic hyperplasia model group, the high and medium dose of chlorogenic acid could significantly reduce prostate index and levels of acid phosphatase, prostatic acid phosphatase and typeⅡ5-alpha-reductase (P<0.05 or P<0.01). These findings were supported by histopathological observations of prostate tissues. Histopathological examination also indicated that chlorogenic acid treatment at the high and medium doses inhibited testosterone-induced prostatic hyperplasia. The results indicated that chlorogenic acid exhibited restraining effect on benign prostatic hyperplasia model animals, and its mechanism might be related to inhibit typeⅡ5-alpha reductase activity. Copyright © 2017. Published by Elsevier B.V.

Aromatase, steroid-5-alpha-reductase type 1 and type 2 mRNA expression in gonads and in brain of Xenopus laevis during ontogeny.

PubMed

Urbatzka, R; Lutz, I; Kloas, W

2007-01-01

The key enzymes involved in the production of endogenous sex steroids are steroid-5-alpha-reductase and aromatase converting testosterone (T) into dihydrotestosterone (DHT) and into estradiol (E2), respectively. To gain more insights into the molecular mechanisms of sexual differentiation of amphibians, we determined the mRNA expression of steroid-5-alpha-reductase type1 (Srd5a1), type2 (Srd5a2) and aromatase (Aro) during ontogeny starting from the egg and ending after completion of metamorphosis in Xenopus laevis. Expression of all three enzymes was measured by means of semi-quantitative RT-PCR, determining for the first time Srd5a1 and Srd5a2 mRNA expression in amphibians. mRNA was analyzed in whole body homogenates from stage 12 to 48, while brain and gonads with kidney were studied separately from stage 48 to 66. Different ontogenetic mRNA expression patterns were observed for all genes analyzed, revealing early mRNA expression of Srd5a1 already in the egg at stage 12 whereas Srd5a2 and Aro was detected at stage 39. Sex-specific mRNA expressions of Srd5a2 and of Aro were determined in the gonads with kidney but not in brain. Srd5a2 was two-fold higher expressed in testes than in ovaries while Aro mRNA was ten-fold higher in ovaries. No gender-specific mRNA expression was observed for Srd5a1 in gonads and in brain. The ontogenetic patterns of Aro, Srd5a1 and Srd5a2 suggest that these genes are involved in sexual differentiation of gonads and brain already in early developmental stages. Especially in gonads Srd5a2 seems to be important for physiological regulation of testis development while Aro is associated with the development of ovaries.

Long-term clinical effects of epalrestat, an aldose reductase inhibitor, on diabetic peripheral neuropathy: the 3-year, multicenter, comparative Aldose Reductase Inhibitor-Diabetes Complications Trial.

PubMed

Hotta, Nigishi; Akanuma, Yasuo; Kawamori, Ryuzo; Matsuoka, Kempei; Oka, Yoshitomo; Shichiri, Motoaki; Toyota, Takayoshi; Nakashima, Mitsuyoshi; Yoshimura, Isao; Sakamoto, Nobuo; Shigeta, Yukio

2006-07-01

We sought to evaluate the long-term efficacy and safety of epalrestat, an aldose reductase inhibitor, on diabetic peripheral neuropathy. Subjects with diabetic neuropathy, median motor nerve conduction velocity (MNCV) >or=40 m/s, and HbA(1c)

DD-RT-PCR identifies 7-dehydrocholesterol reductase as a key marker of early Leydig cell steroidogenesis.

PubMed

Anbalagan, M; Yashwanth, R; Jagannadha Rao, A

2004-04-30

Postnatal Leydig cell development in rat involves an initial phase of proliferation of progenitor Leydig cells (PLCs) and subsequent differentiation of these cells into immature Leydig cells (ILCs) and adult Leydig cells (ALCs). With an objective to identify the molecular changes associated with Leydig cell differentiation, the mRNA population in PLCs and ILCs were analyzed by the technique of differential display reverse transcription polymerase chain reaction (DD-RT-PCR). Results revealed differential expression of several transcripts in PLCs and ILCs. Of the several differentially expressed transcripts, the expression of transcripts corresponding to collagen IV alpha6 (Col IV alpha6) and ribosomal protein L 41 (RpL41) decreased during the differentiation of PLC to ILC. Also there was an increase in the expression of transcripts encoding enzymes such as microsomal glutathione-S-transferase (mGST 1) and 7-dehydrocholesterol reductase (7-DHCR) during this process. While Col IV alpha6 and RpL41 are known to be involved in cellular proliferation, mGST 1 and 7-DHCR are essential for normal Leydig cell steroidogenesis. A detailed study on 7-DHCR expression in Leydig cells revealed that this enzyme plays a crucial role in steroidogenesis. Interestingly expression of this enzyme is not under acute regulation by Luteinizing hormone (LH). Copyright 2004 Elsevier Ireland Ltd.

Effects of dietary saw palmetto on the prostate of transgenic adenocarcinoma of the mouse prostate model (TRAMP).

PubMed

Wadsworth, Teri L; Worstell, Teresa R; Greenberg, Norman M; Roselli, Charles E

2007-05-01

Several of the proposed mechanisms for the actions of the liposterolic extract of saw palmetto (SPE) are exerted on known risk factors for prostate cancer (CaP). This study investigated whether SPE could prevent the progression of CaP in a transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Two different doses of SPE designed to deliver 50 mg/kg/day SPE and 300 mg/kg/day SPE were administered in a custom diet to TRAMP mice for 12 or 24 weeks. Body and organ weights were used to evaluate toxicity, and radioimmunoassay was used to measure plasma and tissue androgen levels to monitor effects of SPE on 5alpha reductase activity. Prostate tissues were evaluated histologically to determine the effect of treatment on tumor grade, cell proliferation, and apoptosis. Treatment with 300 mg/kg/day SPE from 4 to 24 weeks of age significantly reduced the concentration of 5alpha-dihydrotestosterone (DHT) in the prostate and resulted in a significant increase in apoptosis and significant decrease in pathological tumor grade and frank tumor incidence. Dietary supplementation with SPE may be effective in controlling CaP tumorigenesis. SPE suppression of prostatic DHT levels lends support to the hypothesis that inhibition of the enzyme 5alpha-reductase is a mechanism of action of this substance. (c) 2007 Wiley-Liss, Inc.

Leishmania donovani pteridine reductase 1: comparative protein modeling and protein-ligand interaction studies of the leishmanicidal constituents isolated from the fruits of Piper longum.

PubMed

Sahi, Shakti; Tewatia, Parul; Ghosal, Sabari

2012-12-01

Visceral leishmaniasis or kala-azar is caused by the dimorphic parasite Leishmania donovani in the Indian subcontinent. Treatment options for kala-azar are currently inadequate due to various limitations. Currently, drug discovery for leishmaniases is oriented towards rational drug design; the aim is to identify specific inhibitors that target particular metabolic activities as a possible means of controlling the parasites without affecting the host. Leishmania salvages pteridin from its host and reduces it using pteridine reductase 1 (PTR1, EC 1.5.1.33), which makes this reductase an excellent drug target. Recently, we identified six alkamides and one benzenoid compound from the n-hexane fraction of the fruit of Piper longum that possess potent leishmanicidal activity against promastigotes as well as axenic amastigotes. Based on a homology model derived for recombinant pteridine reductase isolated from a clinical isolate of L. donovani, we carried out molecular modeling and docking studies with these compounds to evaluate their binding affinity. A fairly good agreement between experimental data and the results of molecular modeling investigation of the bioactive and inactive compounds was observed. The amide group in the conjugated alkamides and the 3,4-methylenedioxystyrene moiety in the benzenoid compound acts as heads and the long aliphatic chain acts as a tail, thus playing important roles in the binding of the inhibitor to the appropriate position at the active site. The remarkably high activity of a component containing piperine and piperine isomers (3.36:1) as observed by our group prompted us to study the activities of all four isomers of piperine-piperine (2E,4E), isopiperine (2Z,4E), isochavicine (2E,4Z), and chavicine (2Z,4Z)-against LdPTR1. The maximum inhibitory effect was demonstrated by isochavicine. The identification of these predicted inhibitors of LdPTR1 allowed us to build up a stereoview of the structure of the binding site in relation to activity, affording significant information that should prove useful during the structure-based design of leishmanicidal drugs.

Bean alpha-amylase inhibitors in transgenic peas inhibit development of pea weevil larvae.

PubMed

de Sousa-Majer, Maria José; Hardie, Darryl C; Turner, Neil C; Higgins, Thomas J V

2007-08-01

This glasshouse study used an improved larval measurement procedure to evaluate the impact of transgenic pea, Pisum sativum L., seeds expressing a-amylase inhibitor (AI)-1 or -2 proteins on pea weevil, Bruchus pisorum L. Seeds of transgenic 'Laura' and 'Greenfeast' peas expressing alpha-(AI)-1 reduced pea weevil survival by 93-98%. Larval mortality occurred at an early instar. Conversely, in nontransgenic cultivars, approximately 98-99% of the pea weevils emerged as adults. By measuring the head capsule size, we determined that larvae died at the first to early third instar in alpha-(AI)-1 transgenic peas, indicating that this inhibitor is highly effective in controlling this insect. By contrast, transgenic Laura and 'Dundale' expressing alpha-(AI)-2 did not affect pea weevil survival, but they did delay larval development. After 77 d of development, the head capsule size indicated that the larvae were still at the third instar stage in transgenic alpha-(AI)-2 peas, whereas adult bruchids had developed in the nontransgenic peas.

A 1,536-Well-Based Kinetic HTS Assay for Inhibitors of Schistosoma mansoni Thioredoxin Glutathione Reductase

PubMed Central

Lea, Wendy A.; Jadhav, Ajit; Rai, Ganesha; Sayed, Ahmed A.; Cass, Cynthia L.; Inglese, James; Williams, David L.; Austin, Christopher P.

2008-01-01

Abstract Schistosomiasis is a major neglected tropical disease that currently affects over 200 million people and leads to over 200,000 annual deaths. Schistosoma mansoni parasites survive in humans in part because of a set of antioxidant enzymes that continuously degrade reactive oxygen species produced by the host. A principal component of this defense system has been recently identified as thioredoxin glutathione reductase (TGR), a parasite-specific enzyme that combines the functions of two human counterparts, glutathione reductase and thioredoxin reductase, and as such this enzyme presents an attractive new target for anti-schistosomiasis drug development. Herein, we present the development of a highly miniaturized and robust screening assay for TGR. The 5-μl final volume assay is based on the Ellman reagent [5,5′-dithiobis(2-nitrobenzoic acid) (DTNB)] and utilizes a high-speed absorbance kinetic read to minimize the effect of dust, absorbance interference, and meniscus variation. This assay is further applicable to the testing of other redox enzymes that utilize DTNB as a model substrate. PMID:18665782

Aldose Reductase Inhibitory Activity of Compounds from  Zea mays L.

PubMed Central

Kim, Tae Hyeon; Kim, Jin Kyu; Kang, Young-Hee; Lee, Jae-Yong; Kang, Il Jun; Lim, Soon Sung

2013-01-01

Aldose reductase (AR) inhibitors have a considerable therapeutic potential against diabetes complications and do not increase the risk of hypoglycemia. Through bioassay-guided fractionation of an EtOH extract of the kernel from purple corn (Zea mays L.), 7 nonanthocyanin phenolic compounds (compound 1–7) and 5 anthocyanins (compound 8–12) were isolated. These compounds were investigated by rat lens aldose reductase (RLAR) inhibitory assays. Kinetic analyses of recombinant human aldose reductase (rhAR) were performed, and intracellular galactitol levels were measured. Hirsutrin, one of 12 isolated compounds, showed the most potent RLAR inhibitory activity (IC50, 4.78 μM). In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/substrate concentration, hirsutrin showed competitive inhibition against rhAR. Furthermore, hirsutrin inhibited galactitol formation in rat lens and erythrocytes sample incubated with a high concentration of galactose; this finding indicates that hirsutrin may effectively prevent osmotic stress in hyperglycemia. Therefore, hirsutrin derived from Zea mays L. may be a potential therapeutic agent against diabetes complications. PMID:23586057

Activation of bean (Phaseolus vulgaris) [alpha]-amylase inhibitor requires proteolytic processing of the proprotein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pueyo, J.J.; Hunt, D.C.; Chrispeels, M.J.

Seeds of the common bean (Phaseolus vulgaris) contain a plant defense protein that inhibits the [alpha]-amylases of mammals and insects. This [alpha]-amylase inhibitor ([alpha]Al) is synthesized as a proprotein on the endoplasmic reticulum and is proteolytically processed after arrival in the protein storage vacuoles to polypeptides of relative molecular weight (M[sub r]) 15,000 to 18,000. The authors report two types of evidence that proteolytic processing is linked to activation of the inhibitory activity. First, by surveying seed extracts of wild accessions of P. vulgaris and other species in the genus Phaseolus, they found that antibodies to [alpha]Al recognize large (M[submore » r] 30,000-35,000) polypeptides as well as typical [alpha]Al processing products (M[sub r] 15,000-18,000). [alpha]Al activity was found in all extracts that had the typical [alpha]Al processed polypeptides, but was absent from seed extracts that lacked such polypeptides. Second, they made a mutant [alpha]Al in which asparagine-77 is changed to aspartic acid-77. This mutation slows down the proteolytic processing of pro-[alpha]Al when the gene is expressed in tobacco. When pro-[alpha]Al was separated from mature [alpha]Al by gel filtration, pro-[alpha]Al was found not to have [alpha]-amylase inhibitory activity. The authors interpret these results to mean that formation of the active inhibitor is causally related to proteolytic processing of the proprotein. They suggest that the polypeptide cleavage removes a conformation constraint on the precursor to produce the biochemically active molecule. 43 refs., 5 figs., 1 tab.« less

Structure of the detoxification catalyst mercuric ion reductase from Bacillus sp. strain RC607

NASA Astrophysics Data System (ADS)

Schiering, N.; Kabsch, W.; Moore, M. J.; Distefano, M. D.; Walsh, C. T.; Pai, E. F.

1991-07-01

SEVERAL hundred million tons of toxic mercurials are dispersed in the biosphere1. Microbes can detoxify organo-mercurials and mercury salts through sequential action of two enzymes, organomercury lyase2 and mercuric ion reductase (MerA) 3-5. The latter, a homodimer with homology to the FAD-dependent disulphide oxidoreductases6, catalyses the reaction NADPH + Hg(II) --> NADP+ + H+Hg(0), one of the very rare enzymic reactions with metal substrates. Human glutathione reductase7,8 serves as a reference molecule for FAD-dependent disulphide reductases and between its primary structure9 and that of MerA from Tn501 (Pseudomonas), Tn21 (Shigella), pI258 (Staphylococcus) and Bacillus, 25-30% of the residues have been conserved10,11. All MerAs have a C-terminal extension about 15 residues long but have very varied N termini. Although the enzyme from Streptomyces lividans has no addition, from Pseudomonas aeruginosa Tn5Ol and Bacillus sp. strain RC607 it has one and two copies respectively of a domain of 80-85 residues, highly homologous to MerP, the periplasmic component of proteins encoded by the mer operon11. These domains can be proteolytically cleaved off without changing the catalytic efficiency3. We report here the crystal structure of MerA from the Gram-positive bacterium Bacillus sp. strain RC607. Analysis of its complexes with nicotinamide dinucleotide substrates and the inhibitor Cd(II) reveals how limited structural changes enable an enzyme to accept as substrate what used to be a dangerous inhibitor. Knowledge of the mode of mercury ligation is a prerequisite for understanding this unique detoxification mechanism.

Effects of indomethacin, NS-398 (a selective prostaglandin H synthase-2 inhibitor) and protein synthesis inhibitors on prostaglandin production by the guinea-pig placenta.

PubMed

Aitken, H; Poyser, N L

2001-01-01

The outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)were similar from the day 22 guinea-pig placenta and sub-placenta in culture, except for PGE2 output from the sub-placenta which was lower. Between days 22 and 29 of pregnancy, the outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)during the initial 2 h culture period increased 6.9-, 1.1- and 3.2-fold, respectively, from the placenta, and 2.1-, 1.4- and 2.2-fold, respectively, from the sub-placenta. Therefore, there was a relatively specific increase in PGF(2 alpha)production by the guinea-pig placenta between days 22 and 29 of pregnancy. The output of PGFM from the cultured placenta also increased between days 22 and 29, indicating that the increase in PGF(2 alpha)output was due to increased synthesis rather than to decreased metabolism. By comparing the amounts of prostaglandins produced by tissue homogenates during a 1 h incubation period, it appears that there is approximately a 2-fold increase in the amount of prostaglandin H synthase (PGHS) present in the guinea-pig placenta between days 22 and 29. NS-398 (a specific inhibitor of PGHS-2) and indomethacin (an inhibitor of both PGHS-1 and PGHS-2) both inhibited prostaglandin production by homogenates of day 22 and day 29 placenta. Indomethacin was more effective than NS-398, except for their actions on PGF(2 alpha)production by the day 29 placenta where indomethacin and NS-398 were equiactive. Indomethacin and NS-398 were both very effective at inhibiting the outputs of PGF(2 alpha), PGE2 and 6-keto-PGF(1 alpha)from the day 22 and day 29 placenta and sub-placenta in culture, indicating that prostaglandin production by the guinea-pig placenta and sub-placenta in culture is largely dependent upon the activity of PGHS-2. The high production of PGF(2 alpha)by the day 29 placenta is not dependent on the continual synthesis of fresh protein(s), as inhibitors of protein synthesis did not reduce PGF(2 alpha)output from the day 29 guinea-pig placenta in culture. Copyright 2001 Harcourt Publishers Ltd.

Stimulatory effect of insulin on 5alpha-reductase type 1 (SRD5A1) expression through an Akt-dependent pathway in ovarian granulosa cells.

PubMed

Kayampilly, Pradeep P; Wanamaker, Brett L; Stewart, James A; Wagner, Carrie L; Menon, K M J

2010-10-01

Elevated levels of 5α-reduced androgens have been shown to be associated with hyperandrogenism and hyperinsulinemia, the leading causes of ovulatory dysfunction in women. 5α-Dihydrotestosterone reduces ovarian granulosa cell proliferation by inhibiting FSH-mediated mitogenic signaling pathways. The present study examined the effect of insulin on 5α-reductase, the enzyme that catalyses the conversion of androgens to their 5α-derivatives. Granulosa cells isolated from immature rat ovaries were cultured in serum-free, phenol red-free DMEM-F12 media and treated with different doses of insulin (0, 0.1, 1.0, and 10.0 μg/ml) for different time intervals up to 12 h. The expression of 5α-reductase type 1 mRNA, the predominant isoform found in granulosa cells, showed a significant (P<0.05) increase in response to the insulin treatment up to 12 h compared with control. The catalytic activity of 5α-reductase enzyme was also stimulated in a dose-depended manner (P<0.05). Inhibiting the Akt-dependent signaling pathway abolished the insulin-mediated increase in 5α-reductase mRNA expression, whereas inhibition of the ERK-dependent pathway had no effect. The dose-dependent increase in 5α-reductase mRNA expression as well as catalytic activity seen in response to insulin treatment was also demonstrated in the human granulosa cell line (KGN). In addition to increased mRNA expression, a dose-dependent increase in 5α-reductase protein expression in response to insulin was also seen in KGN cells, which corroborated well with that of mRNA expression. These results suggest that elevated levels of 5α-reduced androgens seen in hyperinsulinemic conditions might be explained on the basis of a stimulatory effect of insulin on 5α-reductase in granulosa cells. The elevated levels of these metabolites, in turn, might adversely affect growth and proliferation of granulosa cells, thereby impairing follicle growth and ovulation.

Ribonucleotide reductase activity is regulated by proliferating cell nuclear antigen (PCNA)

PubMed Central

Salguero, Israel; Guarino, Estrella; Shepherd, Marianne; Deegan, Tom; Havens, Courtney G.; MacNeill, Stuart A.; Walter, Johannes C.; Kearsey, Stephen E.

2014-01-01

Summary Synthesis of dNTPs is required for both DNA replication and DNA repair and is catalyzed by ribonucleotide reductases (RNR), which convert ribonucleotides to their deoxy forms [1, 2]. Maintaining the correct levels of dNTPs for DNA synthesis is important for minimising the mutation rate [3-7], and this is achieved by tight regulation of ribonucleotide reductase [2, 8, 9]. In fission yeast, ribonucleotide reductase is regulated in part by a small protein inhibitor, Spd1, which is degraded in S phase and after DNA damage to allow up-regulation of dNTP supply [10-12]. Spd1 degradation is mediated by the activity of the CRL4Cdt2 ubiquitin ligase complex [5, 13, 14]. This has been reported to be dependent on modulation of Cdt2 levels which are cell cycle regulated, peaking in S phase, and which also increase after DNA damage in a checkpoint-dependent manner [7, 13]. We show here that Cdt2 levels fluctuations are not sufficient to regulate Spd1 proteolysis and that the key step in this event is the interaction of Spd1 with the polymerase processivity factor PCNA, complexed onto DNA. This mechanism thus provides a direct link between DNA synthesis and ribonucleotide reductase regulation. PMID:22464192

Natural Inhibitors of HMG-CoA Reductase-An Insilico Approach Through Molecular Docking and Simulation Studies.

PubMed

Suganya, Subramanian; Nandagopal, Balaji; Anbarasu, Anand

2017-01-01

Plant products have always been considered for many important metabolic disorders due to its abundant medicinal properties. Alarming adverse effects of overuse of statins has been reported for patients with dyslipidemia. This study was aimed to identify compounds with potent anti-dyslipidemic property from selected plants and analyze them for their efficiency in binding with HMG-CoA reductase, a key enzyme in lipid metabolism. The docking studies indicate rutin as the best compound that can inhibit HMG-CoA reductase as it had strong binding affinity to the enzyme. The molecular dynamics simulation studies confirmed the stability of the HMG-CoA reductase-rutin complex. RMSD, RMSF, Rg, H-bond results indicated that the HMG-CoA reductase-rutin complex is highly stable. Presently, statins are not preferred for individuals with pre-existing liver disease. Our study identified rutin as a promising lead compound which could be further developed into an anti-dyslipidemic molecule. Our results will be a good starting point for future experimental and clinical studies and if the results from such studies match international standards plant derived rutin might emerge as a good alternative to statins. J. Cell. Biochem. 118: 52-57, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Inhibition of Mutation: A Novel Approach to Preventing and Treating Cancer

DTIC Science & Technology

2007-06-01

Hydroxyurea (HU) is a small molecule chemotherapeutic that is thought to slow tumor growth by inhibiting RNR and thus reducing dNTP...Identification of hydroxyurea as an inhibitor of induced mutation that presumably acts by inhibiting ribonucleotide reductase and thereby decreasing the

Polyol pathway, 2,3-diphosphoglycerate in erythrocytes and diabetic neuropathy in rats.

PubMed

Nakamura, J; Koh, N; Sakakibara, F; Hamada, Y; Wakao, T; Hara, T; Mori, K; Nakashima, E; Naruse, K; Hotta, N

1995-12-27

The relationship between the 2,3-diphosphoglycerate concentration in red blood cells as a biological indicator of tissue hypoxia and diabetic neuropathy, and the effect of a potent aldose reductase inhibitor, (2S,4S)-6-fluoro-2'5'-dioxospiro [chroman-4,4'-imidazolidine]-2-carboxamide (SNK-860), on both were investigated in streptozotocin-induced diabetic rats. Diabetic rats demonstrated significantly delayed motor nerve conduction velocity and reduced sciatic nerve blood flow. Altered biochemical features in the sciatic nerves, including a marked accumulation of sorbitol and fructose, myo-inositol depletion and decreased Na+/K(+)-ATPase activity were also detected in diabetic rats. These defects were accompanied by a decrease in the red blood cell 2,3-diphosphoglycerate concentration. Treatment with SNK-860 partially or completely ameliorated these abnormalities. These observations suggest that a decrease in the red blood cell 2,3-diphosphoglycerate concentration is one of the factors contributing to tissue hypoxia, which results in diabetic neuropathy, and that this decrease is mediated through an aldose reductase inhibitor-sensitive pathway.

The potential behavioral and economic impacts of widespread HMG-CoA reductase inhibitor (statin) use.

PubMed

Gendle, Mathew H

2016-12-01

Dyslipidemia is a common pathology throughout the industrialized world, and HMG-CoA reductase inhibitors (statins) are often administered to treat elevated lipid levels. Substantial concern has been raised regarding the aggressive clinical lowering of cholesterol, particularly in light of a growing body of research linking low circulating lipid levels with negative behavioral outcomes in both human samples and non-human primate models. In 2009, Goldstein and colleagues tentatively speculated that the greed, impulsiveness, and lack of foresight that lead to the worldwide economic collapse in 2007-2008 could have been caused (in part) by depressed population cholesterol levels resulting from the widespread use of statins by workers in the financial services industry. This paper reviews the literature that links low circulating lipid levels with neurobehavioral dysfunction, develops Goldstein and colleagues' initial speculation into a formal hypothesis, and proposes several specific studies that could rigorously empirically evaluate this hypothesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation*

PubMed Central

Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

2015-01-01

Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. PMID:25998127

Severe Rhabdomyolysis Associated with the Cerivastatin-Gemfibrozil Combination Therapy

PubMed Central

Lau, Theodore K.; Leachman, D. Richard; Lufschanowski, Roberto

2001-01-01

Cerivastatin is the new 3rd-generation of the synthetic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, the 1st drugs of choice for treating hypercholesterolemia. A potent inhibitor of HMG-CoA reductase, it possesses a high affinity for liver tissue and decreases plasma low-density lipoprotein cholesterol at microgram doses. Cerivastatin produces reductions in low-density lipoprotein cholesterol of 31.3% and 36.1% at doses of 0.3 and 0.4 mg/day, respectively. It is an uncomplicated agent with regard to its pharmacokinetic profile, low potential for interaction with other drugs, and suitability for use in those with impaired renal function. Most other statins have been implicated in causing rhabdomyolysis, either as mono-therapy or in combination with other agents. We report what to our knowledge is the most profound case yet in the literature of rhabdomyolysis in association with ceriva-statin-gemfibrozil combination therapy, in regard both to the extreme elevation in serum creatinine kinase and to the patient's near-paralytic weakness. PMID:11453128

[Adverse drug reactions of hydroxymethylglutaryl-CoA reductase inhibitors reported to agency for medicinal products and medical devices].

PubMed

Skvrce, Nikica Mirosević; Bozina, Nada; Sarinić, Viola Macolić; Tomić, Sinisa

2010-01-01

Hydroxymethylglutaryl-CoA reductase inhibitors (statins) are drugs used in the treatment of chronic diseases and frequently in concomitant therapy with many other drugs. Therefore, the risk of adverse drug reactions (ADRs), especially those caused by interactions is high. Aim of the study was to describe and analyze ADRs caused by statins reported to Croatian Agency from March 2005 to December 2008, and to emphasize reasons of their occurrence. 136 of statin ADRs were reported. 12 % of all reported statins' ADRs were caused by interactions, which is higher than percent (5.6%) of interactions caused by all other drugs in 2005 and 2006. Proportion of serious ADRs related to administered dose and thus preventable was higher than proportion of all ADRs caused by statins (p = 0.003). Most serious ADRs could have been prevented with better understanding of interactions and by use of pharmacogenomics in identifying patients that are because of genetic predisposition more sensitive to standard doses.

Novel Inhibitors of Mycobacterium tuberculosis dTDP-6-deoxy-L-lyxo-4-hexulose Reductase (RmlD) Identified by Virtual Screening

PubMed Central

Wang, Yi; Hess, Tamara Noelle; Jones, Victoria; Zhou, Joe Zhongxiang; McNeil, Michael R.; McCammon, J. Andrew

2011-01-01

The complex and highly impermeable cell wall of Mycobacterium tuberculosis (Mtb) is largely responsible for the ability of the mycobacterium to resist the action of chemical therapeutics. An L-rhamnosyl residue, which occupies an important anchoring position in the Mtb cell wall, is an attractive target for novel anti-tuberculosis drugs. In this work, we report a virtual screening (VS) study targeting Mtb dTDP-deoxy-L-lyxo-4-hexulose reductase (RmlD), the last enzyme in the L-rhamnosyl synthesis pathway. Through two rounds of VS, we have identified four RmlD inhibitors with half inhibitory concentrations of 0.9-25 μM, and whole-cell minimum inhibitory concentrations of 20-200 μg/ml. Compared with our previous high throughput screening targeting another enzyme involved in L-rhamnosyl synthesis, virtual screening produced higher hit rates, supporting the use of computational methods in future anti-tuberculosis drug discovery efforts. PMID:22014548

Ultrahigh resolution drug design I: details of interactions in human aldose reductase-inhibitor complex at 0.66 A.

PubMed

Howard, E I; Sanishvili, R; Cachau, R E; Mitschler, A; Chevrier, B; Barth, P; Lamour, V; Van Zandt, M; Sibley, E; Bon, C; Moras, D; Schneider, T R; Joachimiak, A; Podjarny, A

2004-06-01

The first subatomic resolution structure of a 36 kDa protein [aldose reductase (AR)] is presented. AR was cocrystallized at pH 5.0 with its cofactor NADP+ and inhibitor IDD 594, a therapeutic candidate for the treatment of diabetic complications. X-ray diffraction data were collected up to 0.62 A resolution and treated up to 0.66 A resolution. Anisotropic refinement followed by a blocked matrix inversion produced low standard deviations (<0.005 A). The model was very well ordered overall (CA atoms' mean B factor is 5.5 A2). The model and the electron-density maps revealed fine features, such as H-atoms, bond densities, and significant deviations from standard stereochemistry. Other features, such as networks of hydrogen bonds (H bonds), a large number of multiple conformations, and solvent structure were also better defined. Most of the atoms in the active site region were extremely well ordered (mean B approximately 3 A2), leading to the identification of the protonation states of the residues involved in catalysis. The electrostatic interactions of the inhibitor's charged carboxylate head with the catalytic residues and the charged coenzyme NADP+ explained the inhibitor's noncompetitive character. Furthermore, a short contact involving the IDD 594 bromine atom explained the selectivity profile of the inhibitor, important feature to avoid toxic effects. The presented structure and the details revealed are instrumental for better understanding of the inhibition mechanism of AR by IDD 594, and hence, for the rational drug design of future inhibitors. This work demonstrates the capabilities of subatomic resolution experiments and stimulates further developments of methods allowing the use of the full potential of these experiments. Copyright 2004 Wiley-Liss, Inc.

Molecular design and structure--activity relationships leading to the potent, selective, and orally active thrombin active site inhibitor BMS-189664.

PubMed

Das, Jagabandhu; Kimball, S David; Hall, Steven E; Han, Wen Ching; Iwanowicz, Edwin; Lin, James; Moquin, Robert V; Reid, Joyce A; Sack, John S; Malley, Mary F; Chang, Chiehying Y; Chong, Saeho; Wang-Iverson, David B; Roberts, Daniel G M; Seiler, Steven M; Schumacher, William A; Ogletree, Martin L

2002-01-07

A series of structurally novel small molecule inhibitors of human alpha-thrombin was prepared to elucidate their structure-activity relationships (SARs), selectivity and activity in vivo. BMS-189664 (3) is identified as a potent, selective, and orally active reversible inhibitor of human alpha-thrombin which is efficacious in vivo in a mouse lethality model, and at inhibiting both arterial and venous thrombosis in cynomolgus monkey models.

Prostate Cancer Characteristics Associated with Response to Pre-Receptor Targeting of the Androgen Axis

PubMed Central

Mostaghel, Elahe A.; Morgan, Andrew; Zhang, Xiaotun; Marck, Brett T.; Xia, Jing; Hunter-Merrill, Rachel; Gulati, Roman; Plymate, Stephen; Vessella, Robert L.; Corey, Eva; Higano, Celestia S.; Matsumoto, Alvin M.; Montgomery, R. Bruce; Nelson, Peter S.

2014-01-01

Background Factors influencing differential responses of prostate tumors to androgen receptor (AR) axis-directed therapeutics are poorly understood, and predictors of treatment efficacy are needed. We hypothesized that the efficacy of inhibiting DHT ligand synthesis would associate with intra-tumoral androgen ratios indicative of relative dependence on DHT-mediated growth. Methods We characterized two androgen-sensitive prostate cancer xenograft models after androgen suppression by castration in combination with the SRD5A inhibitor, dutasteride, as well as a panel of castration resistant metastases obtained via rapid autopsy. Results In LuCaP35 tumors (intra-tumoral T:DHT ratio 2∶1) dutasteride suppressed DHT to 0.02 ng/gm and prolonged survival vs. castration alone (337 vs.152 days, HR 2.8, p = 0.0015). In LuCaP96 tumors (T:DHT 10∶1), survival was not improved despite similar DHT reduction (0.02 ng/gm). LuCaP35 demonstrated higher expression of steroid biosynthetic enzymes maintaining DHT levels (5-fold higher SRD5A1, 41 fold higher, 99-fold higher RL-HSD, p<0.0001 for both), reconstitution of intra-tumoral DHT (to ∼30% of untreated tumors), and ∼2 fold increased expression of full length AR. In contrast, LuCaP96 demonstrated higher levels of steroid catabolizing enzymes (6.9-fold higher AKR1C2, 3000-fold higher UGT2B15, p = 0.002 and p<0.0001 respectively), persistent suppression of intra-tumoral DHT, and 6–8 fold induction of full length AR and the ligand independent V7 AR splice variant. Human metastases demonstrated bio-active androgen levels and AR full length and AR splice-variant expression consistent with the range observed in xenografts. Conclusions Intrinsic differences in basal steroidogenesis, as well as variable expression of full length and splice-variant AR, associate with response and resistance to pre-receptor AR ligand suppression. Expression of steroidogenic enzymes and AR isoforms may serve as potential biomarkers of sensitivity to potent AR-axis inhibition and should be validated in additional models. PMID:25356728

Prostate cancer characteristics associated with response to pre-receptor targeting of the androgen axis.

PubMed

Mostaghel, Elahe A; Morgan, Andrew; Zhang, Xiaotun; Marck, Brett T; Xia, Jing; Hunter-Merrill, Rachel; Gulati, Roman; Plymate, Stephen; Vessella, Robert L; Corey, Eva; Higano, Celestia S; Matsumoto, Alvin M; Montgomery, R Bruce; Nelson, Peter S

2014-01-01

Factors influencing differential responses of prostate tumors to androgen receptor (AR) axis-directed therapeutics are poorly understood, and predictors of treatment efficacy are needed. We hypothesized that the efficacy of inhibiting DHT ligand synthesis would associate with intra-tumoral androgen ratios indicative of relative dependence on DHT-mediated growth. We characterized two androgen-sensitive prostate cancer xenograft models after androgen suppression by castration in combination with the SRD5A inhibitor, dutasteride, as well as a panel of castration resistant metastases obtained via rapid autopsy. In LuCaP35 tumors (intra-tumoral T:DHT ratio 2:1) dutasteride suppressed DHT to 0.02 ng/gm and prolonged survival vs. castration alone (337 vs.152 days, HR 2.8, p = 0.0015). In LuCaP96 tumors (T:DHT 10:1), survival was not improved despite similar DHT reduction (0.02 ng/gm). LuCaP35 demonstrated higher expression of steroid biosynthetic enzymes maintaining DHT levels (5-fold higher SRD5A1, 41 fold higher, 99-fold higher RL-HSD, p<0.0001 for both), reconstitution of intra-tumoral DHT (to ∼30% of untreated tumors), and ∼2 fold increased expression of full length AR. In contrast, LuCaP96 demonstrated higher levels of steroid catabolizing enzymes (6.9-fold higher AKR1C2, 3000-fold higher UGT2B15, p = 0.002 and p<0.0001 respectively), persistent suppression of intra-tumoral DHT, and 6-8 fold induction of full length AR and the ligand independent V7 AR splice variant. Human metastases demonstrated bio-active androgen levels and AR full length and AR splice-variant expression consistent with the range observed in xenografts. Intrinsic differences in basal steroidogenesis, as well as variable expression of full length and splice-variant AR, associate with response and resistance to pre-receptor AR ligand suppression. Expression of steroidogenic enzymes and AR isoforms may serve as potential biomarkers of sensitivity to potent AR-axis inhibition and should be validated in additional models.

Prostaglandin F(2alpha) stimulates tyrosine phosphorylation of phospholipase C-gamma1.

PubMed

Husain, Shahid; Jafri, Farahdiba

2002-10-11

In this study, we investigated the ability of prostaglandin F(2alpha) (PGF(2alpha)) to induce tyrosine phosphorylation of phospholipase C-gamma1 (PLC-gamma1) in cat iris sphincter smooth muscle (CISM) cells. PGF(2alpha)(1 microM) stimulated PLC-gamma1 tyrosine phosphorylation in a time- and dose-dependent manner with a maximum increase of 3-fold at 0.5min. The protein tyrosine kinase inhibitors, genistein, and tyrphostin A-25, blocked the stimulatory effects of PGF(2alpha), suggesting involvement of protein tyrosine kinase activity in the physiological actions of the PGF(2alpha). Furthermore, PGF(2alpha)-induced p42/p44 MAP kinase activation was also completely blocked by protein tyrosine kinase inhibitors. In summary, these findings show that PGF(2alpha) stimulates tyrosine phosphorylation of PLC-gamma1 in CISM cells and indicate that PGF(2alpha)-stimulated tyrosine phosphorylation is responsible for an early signal transduction event.

Comparison between testosterone enanthate-induced azoospermia and oligozoospermia in a male contraceptive study. V. Localization of higher 5 alpha-reductase activity to the reproductive tract in oligozoospermic men administered supraphysiological doses of testosterone.

PubMed

Anderson, R A; Kelly, R W; Wu, F C

1997-01-01

Sex steroid contraceptive regimes result in incomplete suppression of spermatogenesis in 30-45% of Caucasian men. The basis for this is unclear, but differences in the activity of 5 alpha-reductase (5 alpha R) have been demonstrated. Two isoforms of 5 alpha R have been described: 5 alpha R1 is found in skin, whereas the predominant from in reproductive tissues is 5 alpha R2. To investigate possible contributions of these isoenzymes, we have investigated androgen-dependent changes in seminal plasma androgens (5 alpha R2) and sebum production (5 alpha 1) during administration of a supraphysiological dose (200 mg IM weekly) of testosterone enanthate (TE) to 33 normal men. Eighteen men rapidly (< 20 weeks treatment) became azoospermic, the remainder having a mean sperm density of 2.0 +/- 0.6 x 10(6) at that time. The concentrations of testosterone and 3 alpha, 17 beta-androstanediol glucuronide (AdiolG) were lower in seminal plasma than in blood but rose by a similar degree (100%) after 16 weeks TE treatment in both groups. There were no differences in seminal-plasma concentration of testosterone or AdiolG between azoospermic and oligozoospermic responders, either pretreatment or after 16 weeks TE treatment. Although the concentrations of dihydrotestosterone (DHT) were similar in seminal plasma and blood pre- and posttreatment, there was a selective increase in seminal plasma DHT concentration in the oligozoospermic responders from 2.12 +/- 0.29 to 2.94 +/- 0.33 nmol/L (P < 0.05), while there was no significant change in the azoospermic responders (2.18 +/- 0.31-2.54 +/- 0.27 nmol/L) after 16 weeks of TE treatment. Dihydrotestosterone in seminal plasma is primarily derived from 5 alpha R activity in the epididymis. The concentration of prostaglandin E2 (PGE2) in seminal plasma was unchanged during TE treatment. Sebum excretion was increased during TE treatment, but there were no difference between azoospermic and oligozoospermic responders pretreatment or after 16 weeks TE treatment. These results are consistent with the hypothesis that incomplete suppression of spermatogenesis during TE treatment is associated with a relatively higher 5 alpha R activity in the reproductive tract (epididymis and/or testis) during TE treatment. As the predominant form of 5 alpha R in the reproductive tract is 5 alpha R2 (type 2), we conclude that the increase in activity derives from this form of the enzyme, rather than the type 1 form (5 alpha R1) predominantly found in nongenital skin.

Gateways to clinical trials.

PubMed

Tomillero, A; Moral, M A

2009-06-01

(+)-Dapoxetine hydrochloride; Abatacept, Adalimumab, Agalsidase beta, Alemtuzumab, Alglucosidase alfa, Aliskiren fumarate, Ambrisentan, Amlodipine, Aripiprazole, Atrasentan, Azacitidine, Azelnidipine; Belotecan hydrochloride, Bevacizumab, Bilastine, Biphasic insulin aspart, Bortezomib, Bosentan; Caspofungin acetate, CG-100649, Cinacalcet hydrochloride, Clindamycin phosphate/ benzoyl peroxide; Dasatinib, Denosumab, Duloxetine hydrochloride, Dutasteride, Dutasteride/tamsulosin; Ecogramostim, Eculizumab, Eltrombopag olamine, EndoTAG-1, Erlotinib hydrochloride, Everolimus, Exenatide, Ezetimibe; FAHF-2, Fondaparinux sodium; Gefitinib, Golimumab; HEV-239, HSV-TK; Imatinib mesylate, Indium 111 ((111)In) ibritumomab tiuxetan, Influenza vaccine(surface antigen, inactivated, prepared in cell culture), Insulin glargine; Kisspeptin-54; Lidocaine/prilocaine, Lomitapide; Maraviroc, Mirodenafil hydrochloride, MK-8141, MVA-Ag85A; Nilotinib hydrochloride monohydrate; Olmesartan medoxomil; Paclitaxel-eluting stent, Pegfilgrastim, Peginterferon alfa-2a, Peginterferon alfa-2b, Pemetrexed disodium, Pitavastatin calcium, Prasugrel; Recombinant human relaxin H2, RHAMM R3 peptide, Rivaroxaban, Rosuvastatin calcium, RRz2; Sagopilone, Salinosporamide A, SB-509, Serlopitant, Sirolimus-eluting stent, Sorafenib, Sunitinib malate; Tadalafil, Temsirolimus, Teriparatide, TG-4010, Tositumomab/iodine (I131) tositumomab; Velusetrag Hydrochloride; Ximelagatran; Yttrium 90 (90Y) ibritumomab tiuxetan. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.

Purification and properties of an alpha-amylase protein-inhibitor from Arachis hypogaea seeds.

PubMed

Irshad, M; Sharma, C B

1981-06-15

A protein showing highly specific inhibitory activity towards hog pancreatic and human salivary alpha-amylases (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1), but not towards plant and bacterial alpha-amylases, has been purified 197-fold from an aqueous extract of peanut cotyledons using heat treatment, (NH4)2SO4 precipitation and ion-exchange chromatography on DEAE- and CM-cellulose. The purified inhibitor was homogeneous by polyacrylamide gel electrophoresis. Its molecular weight, as determined by Sephadex G-100 gel-filtration, and its electrophoretic mobility at pH 8 relative to bromophenol blue, were 25 000 and 0.14, respectively. The inhibitory activity was relatively resistant to thermal treatment and markedly increased when the inhibitor was preincubated with the enzyme before the addition of starch. Further, the inhibition was found to be pH-dependent and non-competitive in nature.

Triclosan Derivatives: Towards Potent Inhibitors of Drug-Sensitive and Drug-Resistant Mycobacterium tuberculosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freundlich, Joel S.; Wang, Feng; Vilchèze, Catherine

Isoniazid (INH) is a frontline antitubercular drug that inhibits the enoyl acyl carrier protein reductase InhA. Novel inhibitors of InhA that are not cross-resistant to INH represent a significant goal in antitubercular chemotherapy. The design, synthesis, and biological activity of a series of triclosan-based inhibitors is reported, including their promising efficacy against INH-resistant strains of M. tuberculosis. Triclosan has been previously shown to inhibit InhA, an essential enoyl acyl carrier protein reductase involved in mycolic acid biosynthesis, the inhibition of which leads to the lysis of Mycobacterium tuberculosis. Using a structure-based drug design approach, a series of 5-substituted triclosan derivativesmore » was developed. Two groups of derivatives with alkyl and aryl substituents, respectively, were identified with dramatically enhanced potency against purified InhA. The most efficacious inhibitor displayed an IC{sub 50} value of 21 nM, which was 50-fold more potent than triclosan. X-ray crystal structures of InhA in complex with four triclosan derivatives revealed the structural basis for the inhibitory activity. Six selected triclosan derivatives were tested against isoniazid-sensitive and resistant strains of M. tuberculosis. Among those, the best inhibitor had an MIC value of 4.7 {mu}g mL{sup -1} (13 {mu}M), which represents a tenfold improvement over the bacteriocidal activity of triclosan. A subset of these triclosan analogues was more potent than isoniazid against two isoniazid-resistant M. tuberculosis strains, demonstrating the significant potential for structure-based design in the development of next generation antitubercular drugs.« less

NAD(P)H-dependent aldose reductase from the xylose-assimilating yeast Candida tenuis. Isolation, characterization and biochemical properties of the enzyme.

PubMed Central

Neuhauser, W; Haltrich, D; Kulbe, K D; Nidetzky, B

1997-01-01

During growth on d-xylose the yeast Candida tenuis produces one aldose reductase that is active with both NADPH and NADH as coenzyme. This enzyme has been isolated by dye ligand and anion-exchange chromatography in yields of 76%. Aldose reductase consists ofa single 43 kDa polypeptide with an isoelectric point of 4.70. Initial velocity, product inhibition and binding studies are consistent with a compulsory-ordered, ternary-complex mechanism with coenzyme binding first and leaving last. The catalytic efficiency (kcat/Km) in d-xylose reduction at pH 7 is more than 60-fold higher than that in xylitol oxidation and reflects significant differences in the corresponding catalytic centre activities as well as apparent substrate-binding constants. The enzyme prefers NADP(H) approx. 2-fold to NAD(H), which is largely due to better apparent binding of the phosphorylated form of the coenzyme. NADP+ is a potent competitive inhibitor of the NADH-linked aldehyde reduction (Ki 1.5 microM), whereas NAD+ is not. Unlike mammalian aldose reductase, the enzyme from C. tenuis is not subject to oxidation-induced activation. Evidence of an essential lysine residue located in or near the coenzyme binding site has been obtained from chemical modification of aldose reductase with pyridoxal 5'-phosphate. The results are discussed in the context of a comparison of the enzymic properties of yeast and mammalian aldose reductase. PMID:9307017

New Aldehyde Reductase Genes of Saccharomyces cerevisiae Contribute In Situ Detoxification of Lignocellulose-to-Ethanol Conversion Inhibitiors

USDA-ARS?s Scientific Manuscript database

Furfural and 5-hydroxymethylfurfural (HMF) are inhibitory compounds commonly encountered during lignocellulose-to-ethanol conversion for cleaner transportation fuels. It is possible to in situ detoxify the aldehyde inhibitors by tolerant ethanologenic yeast strains. Multiple gene-mediated reductio...

Toxicological Findings of Pilots Involved in Aviation Accidents Operated under 14 CFR Part 135

DTIC Science & Technology

2009-08-01

metoprolol (Lopressor® or Toprol XL®), pravas- tatin (Pravachol®), atorvastatin (Lipitor®), rosuvastatin (Crestor®), amlodipine (Norvasc®), benazepril... atorvastatin , and rosuvastatin are hy- droxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors used in the treatment of high blood cholesterol

Polyhydroxylated alkaloids isolated from mulberry trees (Morusalba L.) and silkworms (Bombyx mori L.).

PubMed

Asano, N; Yamashita, T; Yasuda, K; Ikeda, K; Kizu, H; Kameda, Y; Kato, A; Nash, R J; Lee, H S; Ryu, K S

2001-09-01

New polyhydroxylated alkaloids, (2R,3R,4R)-2-hydroxymethyl-3,4-dihydroxypyrrolidine-N-propionamide from the root bark of Morus alba L., and 4-O-alpha-D-galactopyranosyl-calystegine B(2) and 3 beta,6 beta-dihydroxynortropane from the fruits, were isolated by column chromatography using a variety of ion-exchange resins. Fifteen other polyhydroxylated alkaloids were also isolated. 1-Deoxynojirimycin, a potent alpha-glucosidase inhibitor, was concentrated 2.7-fold by silkworms feeding on mulberry leaves. Some alkaloids contained in mulberry leaves were potent inhibitors of mammalian digestive glycosidases but not inhibitors of silkworm midgut glycosidases, suggesting that the silkworm has enzymes specially adapted to enable it to feed on mulberry leaves. The possibility of preventing the onset of diabetes and obesity using natural dietary supplements containing 1-deoxynojirimycin and other alpha-glucosidase inhibitors in high concentration is of great potential interest.

Insight into the interactions of proteinase inhibitor-alpha-2-macroglobulin with hypochlorite-thermal analysis and biophysical approach.

PubMed

Siddiqui, Tooba; Zia, Mohammad Khalid; Ali, Syed Saqib; Ahsan, Haseeb; Khan, Fahim Halim

2018-05-17

Hypochlorous acid, an active bleaching agent is one of the major oxidants produced by neutrophils under physiological conditions. It is a potent reactive oxygen species (ROS) which causes oxidation of biomolecules. Treatment of proteins with hypochlorite results in direct oxidative damage to proteins. Alpha-2-macroglobulin is a major proteinase inhibitor and it can inhibit proteinase of any kind regardless of specificity and catalytic mechanism. The proteinase-antiproteinase balance plays an important role in mediating inflammation associated tissue destruction. In this paper, we have studied hypochlorite induced modifications in proteinase inhibitor-alpha-2-macroglobulin via biophysical techniques such as absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD), fourier transform infrared spectrometery (FTIR) and isothermal titration calorimetry (ITC). It was found that hypochlorite decreases the anti-proteolytic potential and causes inactivation of sheep alpha-2-macroglobulin. It also causes structural and functional change in alpha-2-macroglobulin as evident by absorption spectroscopy and fluorescence spectroscopy. Change in secondary structure of alpha-2-macroglobulin was confirmed by CD and FTIR. Thermodynamics parameters such as entropy (ΔS), enthalpy (ΔH) and Gibb's free energy changes (ΔG). The number of binding sites (N) of alpha-2-macroglobulin-HOCl binding in solution was determined by isothermal titration calorimetry and it was found that binding of hypochlorite with alpha-2-macroglobulin was exothermic in nature. Copyright © 2017. Published by Elsevier B.V.

Revisiting choline alphoscerate profile: a new, perspective, role in dementia?

PubMed

Scapicchio, Pier Luigi

2013-07-01

Choline alphoscerate (alpha-glyceryl-phosphorylcholine, alpha-GPC) is a semisynthetic derivative of phosphatidylcholine with central parasympathomimetic action. This action is, on the basis of its use in pathologies, characterized by cognitive deficits of neurodegenerative or vascular nature. In a number of clinical studies, alpha-GPC demonstrated benefit in patients with cognitive dysfunction. In light of the limited therapeutical results obtained in the past decades by the use of cholinesterase inhibitors in dementia, and of the relevance of their side effects in long-lasting therapies, it is desirable to reconsider alpha-GPC in larger carefully controlled studies not only as monotherapy but also in association with cholinesterase inhibitor drugs.

Identification of novel targets for PGC-1{alpha} and histone deacetylase inhibitors in neuroblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowell, Rita M.; Department of Neurology, University of Michigan, Ann Arbor, MI 48109; Talati, Pratik

2009-02-06

Recent evidence suggests that the transcriptional coactivator peroxisome proliferator activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) is involved in the pathology of Huntington's Disease (HD). While animals lacking PGC-1{alpha} express lower levels of genes involved in antioxidant defense and oxidative phosphorylation in the brain, little is known about other targets for PGC-1{alpha} in neuronal cells and whether there are ways to pharmacologically target PGC-1{alpha} in neurons. Here, PGC-1{alpha} overexpression in SH-SY5Y neuroblastoma cells upregulated expression of genes involved in mitochondrial function, glucose transport, fatty acid metabolism, and synaptic function. Overexpression also decreased vulnerability to hydrogen peroxide-induced cell death and caspase 3more » activation. Treatment of cells with the histone deacetylase inhibitors (HDACi's) trichostatin A and valproic acid upregulated PGC-1{alpha} and glucose transporter 4 (GLUT4). These results suggest that PGC-1{alpha} regulates multiple pathways in neurons and that HDACi's may be good candidates to target PGC-1{alpha} and GLUT4 in HD and other neurological disorders.« less

Potent, selective, orally bioavailable inhibitors of tumor necrosis factor-alpha converting enzyme (TACE): discovery of indole, benzofuran, imidazopyridine and pyrazolopyridine P1' substituents.

PubMed

Lu, Zhonghui; Ott, Gregory R; Anand, Rajan; Liu, Rui-Qin; Covington, Maryanne B; Vaddi, Krishna; Qian, Mingxin; Newton, Robert C; Christ, David D; Trzaskos, James; Duan, James J-W

2008-03-15

Potent and selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with several new heterocyclic P1' groups in conjunction with cyclic beta-amino hydroxamic acid scaffolds. Among them, the pyrazolopyridine provided the best overall profile when combined with tetrahydropyran beta-amino hydroxamic acid scaffold. Specifically, inhibitor 49 showed IC(50) value of 1 nM against porcine TACE and 170 nM in the suppression of LPS-induced TNF-alpha of human whole blood. Compound 49 also displayed excellent selectivity over a wide panel of MMPs as well as excellent oral bioavailability (F%>90%) in rat n-in-1 PK studies.

Sequence of the cDNA of a human dihydrodiol dehydrogenase isoform (AKR1C2) and tissue distribution of its mRNA.

PubMed Central

Shiraishi, H; Ishikura, S; Matsuura, K; Deyashiki, Y; Ninomiya, M; Sakai, S; Hara, A

1998-01-01

Human liver contains three isoforms (DD1, DD2 and DD4) of dihydrodiol dehydrogenase with 20alpha- or 3alpha-hydroxysteroid dehydrogenase activity; the dehydrogenases belong to the aldo-oxo reductase (AKR) superfamily. cDNA species encoding DD1 and DD4 have been identified. However, four cDNA species with more than 99% sequence identity have been cloned and are compatible with a partial amino acid sequence of DD2. In this study we have isolated a cDNA clone encoding DD2, which was confirmed by comparison of the properties of the recombinant and hepatic enzymes. This cDNA showed differences of one, two, four and five nucleotides from the previously reported four cDNA species for a dehydrogenase of human colon carcinoma HT29 cells, human prostatic 3alpha-hydroxysteroid dehydrogenase, a human liver 3alpha-hydroxysteroid dehydrogenase-like protein and chlordecone reductase-like protein respectively. Expression of mRNA species for the five similar cDNA species in 20 liver samples and 10 other different tissue samples was examined by reverse transcriptase-mediated PCR with specific primers followed by diagnostic restriction with endonucleases. All the tissues expressed only one mRNA species corresponding to the newly identified cDNA for DD2: mRNA transcripts corresponding to the other cDNA species were not detected. We suggest that the new cDNA is derived from the principal gene for DD2, which has been named AKR1C2 by a new nomenclature for the AKR superfamily. It is possible that some of the other cDNA species previously reported are rare allelic variants of this gene. PMID:9716498

Enduring effects of severe developmental adversity, including nutritional deprivation, on cortisol metabolism in aging Holocaust survivors.

PubMed

Yehuda, Rachel; Bierer, Linda M; Andrew, Ruth; Schmeidler, James; Seckl, Jonathan R

2009-06-01

In animal models, early life exposure to major environmental challenges such as malnutrition and stress results in persisting cardiometabolic, neuroendocrine and affective effects. While such effects have been associated with pathogenesis, the widespread occurrence of 'developmental programming' suggests it has adaptive function. Glucocorticoids may mediate 'programming' and their metabolism is known to be affected by early life events in rodents. To examine these relationships in humans, cortisol metabolism and cardiometabolic disease manifestations were examined in Holocaust survivors in relation to age at exposure and affective dysfunction, notably lifetime posttraumatic stress disorder (PTSD). Fifty-one Holocaust survivors and 22 controls without Axis I disorder collected 24-h urine samples and were evaluated for psychiatric disorders and cardiometabolic diagnoses. Corticosteroids and their metabolites were assayed by gas chromatography-mass spectroscopy (GC-MS); cortisol was also measured by radioimmunoassay (RIA). Holocaust survivors showed reduced cortisol by RIA, and decreased levels of 5alpha-tetrahydrocortisol (5alpha-THF) and total glucocorticoid production by GC-MS. The latter was associated with lower cortisol metabolism by 5alpha-reductase and 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type-2. The greatest decrements were associated with earliest age of Holocaust exposure and less severe PTSD symptomatology. Cardiometabolic manifestations were associated with decreased 11beta-HSD-2 activity. In controls, 5alpha-reductase was positively associated with trauma-related symptoms (i.e., to traumatic exposures unrelated to the Holocaust). Extreme malnutrition and related stress during development is associated with long-lived alterations in specific pathways of glucocorticoid metabolism. These effects may be adaptive and link with lower risks of cardiometabolic and stress-related disorders in later life.

The structural basis of the inhibition of human alpha-mannosidases by azafuranose analogues of mannose.

PubMed Central

Winchester, B; al Daher, S; Carpenter, N C; Cenci di Bello, I; Choi, S S; Fairbanks, A J; Fleet, G W

1993-01-01

Eight pyrrolidine, five pyrrolizidine and one indolizidine analogue(s) of the known alpha-mannosidase inhibitor, the azafuranose, 1,4-dideoxy-1,4-imino-D-mannitol (DIM), have been tested for inhibition of the multiple forms of alpha-mannosidase in human liver in vitro. Substitution of the ring nitrogen markedly decreased or abolished inhibition, but loss of the C-6 hydroxy group, as in 6-deoxy-DIM and 6-deoxy-6-fluoro-DIM, enhanced inhibition, particularly of the lysosomal alpha-mannosidase. Addition of the anomeric substituent-CH2OH decreased inhibition. To be a potent inhibitor of the lysosomal, Golgi II and neutral alpha-mannosidases, a polyhydroxylated pyrrolidine must have the same substituents and chirality as mannofuranose at C-2, C-3, C-4 and C-5. These four chiral centres can also be part of a polyhydroxylated indolizidine, e.g. swainsonine, but not of a pyrrolizidine, e.g. cyclized DIM, ring-contracted swainsonine or 1,7-diepi-australine. DIM did not inhibit lysosomal alpha-mannosidase intracellularly, but both 6-deoxy-DIM and 6-deoxy-6-fluoro-DIM caused accumulation of partially catabolized glycans in normal human fibroblasts. Analysis of these induced storage products by h.p.l.c. showed that both compounds also inhibited Golgi alpha-mannosidase II and that 6-deoxy-6-fluoro-DIM was also a good inhibitor of the endoplasmic reticulum alpha-mannosidase and specific lysosomal alpha (1-6)-mannosidase. None of the mannofuranose analogues appeared to inhibit Golgi alpha-mannosidase I. Images Figure 2 Figure 3 PMID:8457203

[Comparison of Physico-chemical Aspects between E. coli and Human Dihydrofolate Reductase: an Equilibrium Unfolding Study].

PubMed

Thapliyal, Charu; Jain, Neha; Chaudhuri, Pratima

2015-01-01

A protein, differing in origin, may exhibit variable physicochemical behaviour, difference in sequence homology, fold and function. Thus studying structure-function relationship of proteins from altered sources is meaningful in the sense that it may give rise to comparative aspects of their sequence-structure-function relationship. Dihydrofolate reductase is an enzyme involved in cell cycle regulation. It is a significant enzyme as.a target for developing anticancer drugs. Hence, detailed understanding of structure-function relationships of wide variants of the enzyme dihydrofolate reductase would be important for developing an inhibitor or an antagonist against the enzyme involved in the cellular developmental processes. In this communication, we have reported the comparative structure-function relationship between E. coli and human dihydrofolate reductase. The differences in the unfolding behaviour of these two proteins have been investigated to understand various properties of these two proteins like relative' stability differences and variation in conformational changes under identical denaturing conditions. The equilibrium unfolding mechanism of dihydrofolate reductase proteins using guanidine hydrochloride as a denaturant in the presence of various types of osmolytes has been monitored using loss in enzymatic activity, intrinsic tryptophan fluorescence and an extrinsic fluorophore 8-anilino-1-naphthalene-sulfonic acid as probes. It has been observed that osmolytes, such as 1M sucrose, and 30% glycerol, provided enhanced stability to both variants of dihydrofolate reductase. Their level of stabilisation has been observed to be dependent on intrinsic protein stability. It was observed that 100 mM proline does not show any 'significant stabilisation to either of dihydrofolate reductases. In the present study, it has been observed that the human protein is relatively less stable than the E.coli counterpart.

Rational design of nitrofuran derivatives: Synthesis and valuation as inhibitors of Trypanosoma cruzi trypanothione reductase.

PubMed

Arias, D G; Herrera, F E; Garay, A S; Rodrigues, D; Forastieri, P S; Luna, L E; Bürgi, M D L M; Prieto, C; Iglesias, A A; Cravero, R M; Guerrero, S A

2017-01-05

The rational design and synthesis of a series of 5-nitro-2-furoic acid analogues are presented. The trypanocidal activity against epimastigote forms of Trypanosoma cruzi and the toxic effects on human HeLa cells were tested. Between all synthetic compounds, three of thirteen had an IC 50 value in the range of Nfx, but compound 13 exhibited an improved effect with an IC 50 of 1.0 ± 0.1 μM and a selective index of 70 in its toxicity against HeLa cells. We analyzed the activity of compounds 8, 12 and 13 to interfere in the central redox metabolic pathway in trypanosomatids, which is dependent of reduced trypanothione as the major pivotal thiol. The three compounds behaved as better inhibitors of trypanothione reductase than Nfx (Ki values of 118 μM, 61 μM and 68 μM for 8, 12 and 13, respectively, compared with 245 μM for Nfx), all following an uncompetitive enzyme inhibition pattern. Docking analysis predicted a binding of inhibitors to the enzyme-substrate complex with binding energy calculated in-silico that supports such molecular interaction. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Interactions between cycloguanil derivatives and wild type and resistance-associated mutant Plasmodium falciparum dihydrofolate reductases

NASA Astrophysics Data System (ADS)

Maitarad, Phornphimon; Kamchonwongpaisan, Sumalee; Vanichtanankul, Jarunee; Vilaivan, Tirayut; Yuthavong, Yongyuth; Hannongbua, Supa

2009-04-01

Comparative molecular field analysis (CoMFA) and quantum chemical calculations were performed on cycloguanil (Cyc) derivatives of the wild type and the quadruple mutant (Asn51Ile, Cys59Arg, Ser108Asn, Ile164Leu) of Plasmodium falciparum dihydrofolate reductase ( PfDHFR). The represented CoMFA models of wild type ( r_{{cv}}2 = 0.727 and r 2 = 0.985) and mutant type ( r_{{cv}}2 = 0.786 and r 2 = 0.979) can describe the differences of the Cyc structural requirements for the two types of PfDHFR enzymes and can be useful to guide the design of new inhibitors. Moreover, the obtained particular interaction energies between the Cyc and the surrounding residues in the binding pocket indicated that Asn108 of mutant enzyme was the cause of Cyc resistance by producing steric clash with p-Cl of Cyc. Consequently, comparing the energy contributions with the potent flexible WR99210 inhibitor, it was found that the key mutant residue, Asn108, demonstrates attractive interaction with this inhibitor and some residues, Leu46, Ile112, Pro113, Phe116, and Leu119, seem to perform as second binding site with WR99210. Therefore, quantum chemical calculations can be useful for investigating residue interactions to clarify the cause of drug resistance.

Mechanisms of chromium (VI)-induced apoptosis in anterior pituitary cells.

PubMed

Quinteros, Fernanda A; Machiavelli, Leticia I; Miler, Eliana A; Cabilla, Jimena P; Duvilanski, Beatriz H

2008-07-30

Hexavalent chromium (Cr (VI)) is a highly toxic metal. Exposure to Cr (VI) compounds may affect reproductive functions. Due to the importance of anterior pituitary hormones on reproductive physiology we have studied the effects of Cr (VI) on anterior pituitary. We previously demonstrated that, after in vivo Cr (VI) administration, Cr accumulates in the pituitary gland and affects prolactin secretion. In vitro, Cr (VI) causes apoptosis in anterior pituitary cells due to oxidative stress generation. To better understand the mechanisms involved in Cr (VI)-induced apoptosis we studied: (a) whether Cr (VI) affects the intracellular antioxidant response and (b) which of the apoptotic factors participates in Cr (VI) effect. Our results show that Cr (VI) treatment induces a decrease in catalase and glutathione peroxidase (GPx) activity but does not modify glutathione reductase (GR) activity. Cr (VI) exposure causes an increase of GSH levels. p53 and Bax mRNA are also upregulated by the metal. Pifithrin alpha, a p53 transcriptional inhibitor, increases Cr (VI) cytotoxicity, suggesting a role of p53 as a survival molecule. The antioxidant N-acetyl-cysteine (NAC) could prevent Bax mRNA increase and caspase 3 activation, confirming that Cr (VI)-induced apoptosis involves oxidative stress generation.

The role of prostate-specific antigen in light of new scientific evidence.

PubMed

Hernández, C; Morote, J; Miñana, B; Cózar, J M

2013-06-01

Review the scientific evidence acquired in recent years on Prostate-Specific Antigen (PSA). Analysis of the available evidence on the current role of PSA, according to a panel of experts who recorded their experience on the subject. Currently, PSA cannot be considered solely an indicator of the presence or absence of prostate cancer. Rather, the determination of PSA assists the urologist in indicating the most appropriate treatment for a patient with benign prostatic hypertrophic (BPH), as well as in suspecting a prostatic tumour when the PSA reading increases >0,3 ng/ml, in patients treated with 5-alpha-reductase inhibitor, over the reading achieved at six months of having initiated this treatment. Moreover, PSA is a key factor in the follow-up of patients with prostate adenocarcinoma who undergo surgery, radiation therapy or minimally invasive techniques. PSA helps to define biochemical recurrence, suggest the existence of a local or distal recurrence and propose or rule out adjuvant therapies. New data on the current role of PSA in the management of patients treated for BPH and/or prostate cancer should be taken into account. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

Regulation of interleukin-4 signaling by extracellular reduction of intramolecular disulfides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curbo, Sophie; Gaudin, Raphael; Carlsten, Mattias

2009-12-25

Interleukin-4 (IL-4) contains three structurally important intramolecular disulfides that are required for the bioactivity of the cytokine. We show that the cell surface of HeLa cells and endotoxin-activated monocytes can reduce IL-4 intramolecular disulfides in the extracellular space and inhibit binding of IL-4 to the IL-4R{alpha} receptor. IL-4 disulfides were in vitro reduced by thioredoxin 1 (Trx1) and protein disulfide isomerase (PDI). Reduction of IL-4 disulfides by the cell surface of HeLa cells was inhibited by auranofin, an inhibitor of thioredoxin reductase that is an electron donor to both Trx1 and PDI. Both Trx1 and PDI have been shown tomore » be located at the cell surface and our data suggests that these enzymes are involved in catalyzing reduction of IL-4 disulfides. The pro-drug N-acetylcysteine (NAC) that promotes T-helper type 1 responses was also shown to mediate the reduction of IL-4 disulfides. Our data provides evidence for a novel redox dependent pathway for regulation of cytokine activity by extracellular reduction of intramolecular disulfides at the cell surface by members of the thioredoxin enzyme family.« less

Regulation of the Mevalonate Pathway for the Prevention of Breast Cancer

DTIC Science & Technology

2003-08-01

eicosapentaenoic acid (EPA) as well as the dietary isoprenoid geraniol that inhibit cell proliferation, are inhibitors of HMG-CoA reductase activity in...breast cancer cells. The inhibitory effects of EPA and geraniol on cell proliferation, however, are independent of mevalonate. DHA, on the other hand

Slow-Onset Inhibition of the FabI Enoyl Reductase from Francisella Tularensis: Residence Time and In Vivo Activity

PubMed Central

Lu, Hao; England, Kathleen; Ende, Christopher am; Truglio, James J.; Luckner, Sylvia; Reddy, B. Gopal; Marlenee, Nikki; Knudson, Susan E.; Knudson, Dennis L.; Bowen, Richard A.; Kisker, Caroline; Slayden, Richard A.; Tonge, Peter J.

2009-01-01

Francisella tularensis is a highly virulent and contagious gram-negative intracellular bacterium that causes the disease tularemia in mammals. The high infectivity and the ability of the bacterium to survive for weeks in a cool, moist environment have raised the possibility that this organism could be exploited deliberately as a potential biological weapon. Fatty acid biosynthesis (FAS-II) is essential for bacterial viability and has been validated as a target for the discovery of novel antibacterials. The FAS-II enoyl reductase ftuFabI has been cloned and expressed, and a series of diphenyl ethers have been identified that are subnanomolar inhibitors of the enzyme with MIC90 values as low as 0.00018 μg/ml. The existence of a linear correlation between the Ki and MIC values strongly suggests that the antibacterial activity of the diphenyl ethers results from direct inhibition of ftuFabI within the cell. The compounds are slow onset inhibitors of ftuFabI, and the residence time of the inhibitors on the enzyme correlates with their in vivo activity in a mouse model of tularemia infection. Significantly, the rate of breakdown of the enzyme-inhibitor complex is a better predictor of in vivo activity than the overall thermodynamic stability of the complex, a concept that has important implications for the discovery of novel chemotherapeutics that normally rely on equilibrium measurements of potency. PMID:19206187

Structure Guided Chemical Modifications of Propylthiouracil Reveal Novel Small Molecule Inhibitors of Cytochrome b5 Reductase 3 That Increase Nitric Oxide Bioavailability*

PubMed Central

Rahaman, Md. Mizanur; Reinders, Fabio G.; Koes, David; Nguyen, Anh T.; Mutchler, Stephanie M.; Sparacino-Watkins, Courtney; Alvarez, Roger A.; Miller, Megan P.; Cheng, Dongmei; Chen, Bill B.; Jackson, Edwin K.; Camacho, Carlos J.; Straub, Adam C.

2015-01-01

NADH cytochrome b5 reductase 3 (CYB5R3) is critical for reductive reactions such as fatty acid elongation, cholesterol biosynthesis, drug metabolism, and methemoglobin reduction. Although the physiological and metabolic importance of CYB5R3 has been established in hepatocytes and erythrocytes, emerging investigations suggest that CYB5R3 is critical for nitric oxide signaling and vascular function. However, advancement toward fully understanding CYB5R3 function has been limited due to a lack of potent small molecule inhibitors. Because of this restriction, we modeled the binding mode of propylthiouracil, a weak inhibitor of CYB5R3 (IC50 = ∼275 μm), and used it as a guide to predict thiouracil-biased inhibitors from the set of commercially available compounds in the ZINC database. Using this approach, we validated two new potent derivatives of propylthiouracil, ZINC05626394 (IC50 = 10.81 μm) and ZINC39395747 (IC50 = 9.14 μm), both of which inhibit CYB5R3 activity in cultured cells. Moreover, we found that ZINC39395747 significantly increased NO bioavailability in renal vascular cells, augmented renal blood flow, and decreased systemic blood pressure in response to vasoconstrictors in spontaneously hypertensive rats. These compounds will serve as a new tool to examine the biological functions of CYB5R3 in physiology and disease and also as a platform for new drug development. PMID:26001785

Slow-Onset Inhibition of the FabI Enoyl Reductase from Francisella tularensis: Residence Time and in Vivo Activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, H.; England, K; Ende, C

2009-01-01

Francisella tularensis is a highly virulent and contagious Gram-negative intracellular bacterium that causes the disease tularemia in mammals. The high infectivity and the ability of the bacterium to survive for weeks in a cool, moist environment have raised the possibility that this organism could be exploited deliberately as a potential biological weapon. Fatty acid biosynthesis (FAS-II) is essential for bacterial viability and has been validated as a target for the discovery of novel antibacterials. The FAS-II enoyl reductase ftuFabI has been cloned and expressed, and a series of diphenyl ethers have been identified that are subnanomolar inhibitors of the enzymemore » with MIC90 values as low as 0.00018 ?g mL-1. The existence of a linear correlation between the Ki and MIC values strongly suggests that the antibacterial activity of the diphenyl ethers results from direct inhibition of ftuFabI within the cell. The compounds are slow-onset inhibitors of ftuFabI, and the residence time of the inhibitors on the enzyme correlates with their in vivo activity in a mouse model of tularemia infection. Significantly, the rate of breakdown of the enzyme-inhibitor complex is a better predictor of in vivo activity than the overall thermodynamic stability of the complex, a concept that has important implications for the discovery of novel chemotherapeutics that normally rely on equilibrium measurements of potency.« less

Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in human myocytes.

PubMed

Nishimoto, Tomoyuki; Tozawa, Ryuichi; Amano, Yuichiro; Wada, Takeo; Imura, Yoshimi; Sugiyama, Yasuo

2003-12-01

TAK-475 is a squalene synthase inhibitor, rapidly metabolized to T-91485 in vivo. We investigated the myotoxicities of T-91485 and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in a human rhabdomyosarcoma cell line, RD, and in human skeletal myocytes. In differentiated RD cells, T-91485, atorvastatin (ATV) and simvastatin acid (SIM) inhibited cholesterol biosynthesis, with IC(50) values of 36, 2.8 and 3.8 nM, respectively. ATV and SIM decreased the intracellular ATP content, with IC(25) values (concentrations giving a 25% decrease in intracellular ATP content) of 0.61 and 0.44 microM, respectively. Although T-91485 potently inhibited cholesterol synthesis in RD cells, the IC(25) value exceeded 100 microM. In human skeletal myocytes, T-91485, ATV and SIM concentration-dependently inhibited cholesterol biosynthesis, with IC(50) values of 45, 8.6 and 8.4 nM, respectively. ATV and SIM decreased intracellular ATP content, with IC(25) values of 2.1 and 0.72 microM, respectively. Although T-91485 potently inhibited cholesterol synthesis, the IC(25) value exceeded 100 microM. Myotoxicity induced by ATV was prevented by mevalonate or geranylgeranyl-PP, but not by squalene in skeletal cells. Furthermore, T-91485 attenuated the myotoxicity of ATV. These findings suggest that TAK-475 and T-91485 may not only be far from myotoxic, they may also decrease statin-induced myotoxicity in lipid-lowering therapy.

Mannostatin A, a new glycoprotein-processing inhibitor.

PubMed

Tropea, J E; Kaushal, G P; Pastuszak, I; Mitchell, M; Aoyagi, T; Molyneux, R J; Elbein, A D

1990-10-30

Mannostatin A is a metabolite produced by the microorganism Streptoverticillium verticillus and reported to be a potent competitive inhibitor of rat epididymal alpha-mannosidase. When tested against a number of other arylglycosidases, mannostatin A was inactive toward alpha- and beta-glucosidase and galactosidase as well as beta-mannosidase, but it was a potent inhibitor of jack bean, mung bean, and rat liver lysosomal alpha-mannosidases, with estimated IC50's of 70 nM, 450 nM, and 160 nM, respectively. The type of inhibition was competitive in nature. This compound also proved to be an effective competitive inhibitor of the glycoprotein-processing enzyme mannosidase II (IC50 of about 10-15 nM with p-nitrophenyl alpha-D-mannopyranoside as substrate, and about 90 nM with [3H]mannose-labeled GlcNAc-Man5GlcNAc as substrate). However, it was virtually inactive toward mannosidase I. The N-acetylated derivative of mannostatin A had no inhibitory activity. In cell culture studies, mannostatin A also proved to be a potent inhibitor of glycoprotein processing. Thus, in influenza virus infected Madin Darby canine kidney (MDCK) cells, mannostatin A blocked the normal formation of complex types of oligosaccharides on the viral glycoproteins and caused the accumulation of hybrid types of oligosaccharides. This observation is in keeping with other data which indicate that the site of action of mannostatin A is mannosidase II. Thus, mannostatin A represents the first nonalkaloidal processing inhibitor and adds to the growing list of chemical structures that can have important biological activity.

Role of vitamin C transporters and biliverdin reductase in the dual pro-oxidant and anti-oxidant effect of biliary compounds on the placental-fetal unit in cholestasis during pregnancy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez, Maria J.; Castano, Beatriz; Jimenez, Silvia

Maternal cholestasis causes oxidative damage to the placental-fetal unit that may challenge the outcome of pregnancy. This has been associated with the accumulation of biliary compounds able to induce oxidative stress. However, other cholephilic compounds such as ursodeoxycholic acid (UDCA) and bilirubin have direct anti-oxidant properties. In the present study we investigated whether these compounds exert a protective effect on cholestasis-induced oxidative stress in placenta as compared to maternal and fetal livers, and whether this is due in part to the activation of anti-oxidant mechanisms involving vitamin C uptake and biliverdin/bilirubin recycling. In human placenta (JAr) and liver (HepG2) cells,more » deoxycholic acid (DCA) similar rates of free radical generation. In JAr (not HepG2), the mitochondrial membrane potential and cell viability were impaired by low DCA concentrations; this was partly prevented by bilirubin and UDCA. In HepG2, taurocholic acid (TCA) and UDCA up-regulated biliverdin-IX{alpha} reductase (BVR{alpha}) and the vitamin C transporter SVCT2 (not SVCT1), whereas bilirubin up-regulated both SVCT1 and SVCT2. In JAr, TCA and UDCA up-regulated BVR{alpha}, SVCT1 and SVCT2, whereas bilirubin up-regulated only SVCT2. A differential response to these compounds of nuclear receptor expression (SXR, CAR, FXR and SHP) was found in both cell types. When cholestasis was induced in pregnant rats, BVR{alpha}, SVCT1 and SVCT2 expression in maternal and fetal livers was stimulated, and this was further enhanced by UDCA treatment. In placenta, only BVR{alpha} was up-regulated. In conclusion, bilirubin accumulation and UDCA administration may directly and indirectly protect the placental-fetal unit from maternal cholestasis-induced oxidative stress.« less

The impact of protease inhibitors on maternal serum screening analyte levels in pregnant women who are HIV positive.

PubMed

Einstein, Francine H; Wright, Rodney L; Trentacoste, Stephanie; Gross, Susan; Merkatz, Irwin R; Bernstein, Peter S

2004-09-01

The purpose of this study was to compare alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol levels in women who take protease inhibitors and those women who do not. This retrospective review from August 2000 to May 2003 was performed for maternal serum screen results, medication use, pregnancy, and perinatal outcomes. Thirty-nine women met study criteria. Sixteen women were treated with protease inhibitors, and 23 women were not treated with protease inhibitors. There was no difference in initial viral load or initial CD4 count between the groups. No difference was found for human chorionic gonadotropin and estriol levels; significantly lower alpha-fetoprotein multiples of the median were found for the women who were treated with protease inhibitors compared with the women who were not (0.97 +/- 0.32 [SD] MoM vs 1.2 +/- 0.4 MoM, respectively; P = .04). Six of 39 women (15%) had positive maternal serum screens. All the babies were normal at birth, and there were no cases of perinatal transmission of human immunodeficiency virus. Protease inhibitors are associated with lower alpha-fetoprotein levels in women who are infected with human immunodeficiency virus.

Improving BPH symptoms and sexual dysfunctions with a saw palmetto preparation? Results from a pilot trial.

PubMed

Suter, Andreas; Saller, Reinhard; Riedi, Eugen; Heinrich, Michael

2013-02-01

In elderly men, benign prostatic hyperplasia (BPH) is a major risk factor for sexual dysfunctions (SDys). Additionally, the standard treatments for BPH symptoms, alpha blockers and 5-alpha-reductase inhibitors, cause SDys themselves. Preparations from saw palmetto berries are an efficacious and well-tolerated symptomatic treatment for mild to moderate BPH and have traditionally been used to treat SDys. We conducted an open multicentric clinical pilot trial to investigate whether the saw palmetto berry preparation Prostasan® influenced BPH symptoms and SDys. Eighty-two patients participated in the 8-week trial, taking one capsule of 320 mg saw palmetto extract daily. At the end of the treatment, the International Prostate Symptom Score was reduced from 14.4 ± 4.7 to 6.9 ± 5.2 (p < 0.0001); SDys measured with the brief Sexual Function Inventory improved from 22.4 ± 7.2 to 31.4 ± 9.2 (p < 0.0001), and the Urolife BPH QoL-9 sex total improved from 137.3 ± 47.9 to 195.0 ± 56.3 (p < 0.0001). Investigators' and patients' assessments confirmed the good efficacy, and treatment was very well tolerated and accepted by the patients. Correlation analyses confirmed the relationship between improved BPH symptoms and reduced SDys. This was the first trial with saw palmetto to show improvement in BPH symptoms and SDys as well. [Corrections made here after initial online publication.] Copyright © 2012 John Wiley & Sons, Ltd.

Monoamine uptake inhibitors block alpha7-nAChR-mediated cerebral nitrergic neurogenic vasodilation.

PubMed

Long, Cheng; Chen, Mei-Fang; Sarwinski, Susan J; Chen, Po-Yi; Si, Minliang; Hoffer, Barry J; Evans, M Steven; Lee, Tony J F

2006-07-01

We have proposed that activation of cerebral perivascular sympathetic alpha7-nicotinic acetylcholine receptors (alpha7-nAChRs) by nicotinic agonists releases norepinephrine, which then acts on parasympathetic nitrergic nerves, resulting in release of nitric oxide and vasodilation. Using patch-clamp electrophysiology, immunohistochemistry, and in vitro tissue bath myography, we tested this axo-axonal interaction hypothesis further by examining whether blocking norepinephrine reuptake enhanced alpha7-nAChR-mediated cerebral nitrergic neurogenic vasodilation. The results indicated that choline- and nicotine-induced alpha7-nAChR-mediated nitrergic neurogenic relaxation in endothelium-denuded isolated porcine basilar artery rings was enhanced by desipramine and imipramine at lower concentrations (0.03-0.1 microM) but inhibited at higher concentrations (0.3-10 microM). In cultured superior cervical ganglion (SCG) neurons of the pig and rat, choline (0.1-30 mM)-evoked inward currents were reversibly blocked by 1-30 microM mecamylamine, 1-30 microM methyllycaconitine, 10-300 nM alpha-bungarotoxin, and 0.1-10 microM desipramine and imipramine, providing electrophysiological evidence for the presence of similar functional alpha7-nAChRs in cerebral perivascular sympathetic neurons of pigs and rats. In alpha7-nAChR-expressing Xenopus oocytes, choline-elicited inward currents were attenuated by alpha-bungarotoxin, imipramine, and desipramine. These monoamine uptake inhibitors appeared to directly block the alpha7-nAChR, resulting in diminished nicotinic agonist-induced cerebral nitrergic vasodilation. The enhanced nitrergic vasodilation by lower concentrations of monoamine uptake inhibitors is likely due to a greater effect on monoamine uptake than on alpha7-nAChR blockade. These results further support the hypothesis of axo-axonal interaction in nitrergic regulation of cerebral vascular tone.

Aldo-keto reductase family 1 B10 protein detoxifies dietary and lipid-derived alpha, beta-unsaturated carbonyls at physiological levels.

PubMed

Zhong, Linlin; Liu, Ziwen; Yan, Ruilan; Johnson, Stephen; Zhao, Yupei; Fang, Xiubin; Cao, Deliang

2009-09-18

Alpha, beta-unsaturated carbonyls are highly reactive mutagens and carcinogens to which humans are exposed on a daily basis. This study demonstrates that aldo-keto reductase family 1 member B10 (AKR1B10) is a critical protein in detoxifying dietary and lipid-derived unsaturated carbonyls. Purified AKR1B10 recombinant protein efficiently catalyzed the reduction to less toxic alcohol forms of crotonaldehyde at 0.90 microM, 4-hydroxynonenal (HNE) at 0.10 microM, trans-2-hexanal at 0.10 microM, and trans-2,4-hexadienal at 0.05 microM, the concentrations at or lower than physiological exposures. Ectopically expressed AKR1B10 in 293T cells eliminated immediately HNE at 1 (subtoxic) or 5 microM (toxic) by converting to 1,4-dihydroxynonene, protecting the cells from HNE toxicity. AKR1B10 protein also showed strong enzymatic activity toward glutathione-conjugated carbonyls. Taken together, our study results suggest that AKR1B10 specifically expressed in the intestine is physiologically important in protecting the host cell against dietary and lipid-derived cytotoxic carbonyls.

Aldo-keto reductase family 1 B10 protein detoxifies dietary and lipid-derived alpha, beta-unsaturated carbonyls at physiological levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Linlin; Department of Neurobiology and Anatomy, China Medical University, Shenyang 110001; Liu, Ziwen

2009-09-18

Alpha, beta-unsaturated carbonyls are highly reactive mutagens and carcinogens to which humans are exposed on a daily basis. This study demonstrates that aldo-keto reductase family 1 member B10 (AKR1B10) is a critical protein in detoxifying dietary and lipid-derived unsaturated carbonyls. Purified AKR1B10 recombinant protein efficiently catalyzed the reduction to less toxic alcohol forms of crotonaldehyde at 0.90 {mu}M, 4-hydroxynonenal (HNE) at 0.10 {mu}M, trans-2-hexanal at 0.10 {mu}M, and trans-2,4-hexadienal at 0.05 {mu}M, the concentrations at or lower than physiological exposures. Ectopically expressed AKR1B10 in 293T cells eliminated immediately HNE at 1 (subtoxic) or 5 {mu}M (toxic) by converting to 1,4-dihydroxynonene,more » protecting the cells from HNE toxicity. AKR1B10 protein also showed strong enzymatic activity toward glutathione-conjugated carbonyls. Taken together, our study results suggest that AKR1B10 specifically expressed in the intestine is physiologically important in protecting the host cell against dietary and lipid-derived cytotoxic carbonyls.« less

Selected variants of the steroid-5-alpha-reductase isoforms SRD5A1 and SRD5A2 and the sex steroid hormone receptors ESR1, ESR2 and PGR: no association with female pattern hair loss identified.

PubMed

Redler, Silke; Tazi-Ahnini, Rachid; Drichel, Dmitriy; Birch, Mary P; Brockschmidt, Felix F; Dobson, Kathy; Giehl, Kathrin A; Refke, Melanie; Kluck, Nadine; Kruse, Roland; Lutz, Gerhard; Wolff, Hans; Böhm, Markus; Becker, Tim; Nöthen, Markus M; Betz, Regina C; Messenger, Andrew

2012-05-01

Female pattern hair loss (FPHL) is a common disorder with a complex mode of inheritance. Although understanding of its etiopathogenesis is incomplete, an interaction between genetic and hormonal factors is assumed to be important. The involvement of an androgen-dependent pathway and sex steroid hormones is the most likely hypothesis. We therefore selected a total of 21 variants from the steroid-5-alpha-reductase isoforms SRD5A1 and SRD5A2, the sex steroid hormone receptors ESR1, ESR2 (oestrogen receptor) and PGR (progesterone receptor) and genotyped these in a case-control sample of 198 patients (145 UK; 53 German patients) and 329 controls (179 UK; 150 German). None of these variants showed any significant association, either in the overall UK and German samples or in the subgroup analyses. In summary, the present results, while based on a limited selection of gene variants, do not point to the involvement of SRD5A1, SRD5A2, ESR1, ESR2 or PGR in FPHL. © 2012 John Wiley & Sons A/S.

Biochemical characterization of a recombinant short-chain NAD(H)-dependent dehydrogenase/reductase from Sulfolobus acidocaldarius.

PubMed

Pennacchio, Angela; Giordano, Assunta; Pucci, Biagio; Rossi, Mosè; Raia, Carlo A

2010-03-01

The gene encoding a novel alcohol dehydrogenase that belongs to the short-chain dehydrogenases/reductases (SDRs) superfamily was identified in the aerobic thermoacidophilic crenarchaeon Sulfolobus acidocaldarius strain DSM 639. The saadh gene was heterologously overexpressed in Escherichia coli, and the protein (SaADH) was purified to homogeneity and characterized. SaADH is a tetrameric enzyme consisting of identical 28,978-Da subunits, each composed of 264 amino acids. The enzyme has remarkable thermophilicity and thermal stability, displaying activity at temperatures up to 75 degrees C and a 30-min half-inactivation temperature of ~90 degrees C, and shows good tolerance to common organic solvents. SaADH has a strict requirement for NAD(H) as the coenzyme, and displays a preference for the reduction of alicyclic, bicyclic and aromatic ketones and alpha-keto esters, but is poorly active on aliphatic, cyclic and aromatic alcohols, and shows no activity on aldehydes. The enzyme catalyses the reduction of alpha-methyl and alpha-ethyl benzoylformate, and methyl o-chlorobenzoylformate with 100% conversion to methyl (S)-mandelate [17% enantiomeric excess (ee)], ethyl (R)-mandelate (50% ee), and methyl (R)-o-chloromandelate (72% ee), respectively, with an efficient in situ NADH-recycling system which involves glucose and a thermophilic glucose dehydrogenase. This study provides further evidence supporting the critical role of the D37 residue in discriminating NAD(H) from NAD(P)H in members of the SDR superfamily.

X-ray Crystallographic Analysis of [alpha]-Ketoheterocycle Inhibitors Bound to a Humanized Variant of Fatty Acid Amide Hydrolase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mileni, Mauro; Garfunkle, Joie; Ezzili, Cyrine

2010-11-03

Three cocrystal X-ray structures of the {alpha}-ketoheterocycle inhibitors 3-5 bound to a humanized variant of fatty acid amide hydrolase (FAAH) are disclosed and comparatively discussed alongside those of 1 (OL-135) and its isomer 2. These five X-ray structures systematically probe each of the three active site regions key to substrate or inhibitor binding: (1) the conformationally mobile acyl chain-binding pocket and membrane access channel responsible for fatty acid amide substrate and inhibitor acyl chain binding, (2) the atypical active site catalytic residues and surrounding oxyanion hole that covalently binds the core of the {alpha}-ketoheterocycle inhibitors captured as deprotonated hemiketals mimickingmore » the tetrahedral intermediate of the enzyme-catalyzed reaction, and (3) the cytosolic port and its uniquely important imbedded ordered water molecules and a newly identified anion binding site. The detailed analysis of their key active site interactions and their implications on the interpretation of the available structure-activity relationships are discussed providing important insights for future design.« less

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

PubMed Central

Giachetti, Daniela; Biagi, Marco; Manetti, Fabrizio; De Vico, Luca

2016-01-01

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. PMID:27904805

The endogenous adrenodoxin reductase-like flavoprotein arh1 supports heterologous cytochrome P450-dependent substrate conversions in Schizosaccharomyces pombe.

PubMed

Ewen, Kerstin M; Schiffler, Burkhard; Uhlmann-Schiffler, Heike; Bernhardt, Rita; Hannemann, Frank

2008-05-01

Mitochondrial cytochromes P450 are essential for biosynthesis of steroid hormones, vitamin D and bile acids. In mammals, the electrons needed for these reactions are provided via adrenodoxin and adrenodoxin reductase (AdR). Recently, Schizosaccharomyces pombe was introduced as a new host for the functional expression of human mitochondrial steroid hydroxylases without the coexpression of their natural redox partners. This fact qualifies S. pombe for the biotechnological production of steroids and for application as inhibitor test organism of heterologously expressed cytochromes P450. In this paper, we present evidence that the S. pombe ferredoxin reductase, arh1, and ferredoxin, etp1fd provide mammalian class I cytochromes P450 with reduction equivalents. The recombinant reductase showed an unusual weak binding of flavin adenine dinucleotide (FAD), which was mastered by modifying the FAD-binding region by site-directed mutagenesis yielding a stable holoprotein. The modified reductase arh1_A18G displayed spectroscopic characteristics similar to AdR and was shown to be capable of accepting electrons with no evident preference for NADH or NADPH, respectively. Arh1_A18G can substitute for AdR by interacting not only with its natural redox partner etp1fd but also with the mammalian homolog adrenodoxin. Cytochrome P450-dependent substrate conversion with all combinations of the mammalian and yeast redox proteins was evaluated in a reconstituted system.

The nuclear protein PH5P of the inter-alpha-inhibitor superfamily: a missing link between poly(ADP-ribose)polymerase and the inter-alpha-inhibitor family and a novel actor of DNA repair?

PubMed

Jean, L; Risler, J L; Nagase, T; Coulouarn, C; Nomura, N; Salier, J P

1999-03-05

Poly(ADP-ribose)polymerase is a nuclear NAD-dependent enzyme and an essential nick sensor involved in cellular processes where nicking and rejoining of DNA strands are required. The inter-alpha-inhibitor family is comprized of several plasma proteins that all harbor one or more so-called heavy chains designated H1-H4. The latter originate from precursor polypeptides H1P-H4P whose upper two thirds are highly homologous. We now describe a novel protein that includes (i) a so-called BRCT domain found in many proteins involved in DNA repair, (ii) an area that is homologous to the NAD-dependent catalytic domain of poly(ADP-ribose)polymerase, (iii) an area that is homologous to the upper two thirds of precursor polypeptides H1P-H4P and (iv) a proline-rich region with a potential nuclear localization signal. This protein now designated PH5P points to as yet unsuspected links between poly(ADP-ribose)polymerase and the inter-alpha-inhibitor family and is likely to be involved in DNA repair.

Ectodomain shedding of TNF receptor 1 induced by protein synthesis inhibitors regulates TNF-{alpha}-mediated activation of NF-{kappa}B and caspase-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogura, Hirotsugu; Tsukumo, Yoshinori; Department of Bioengineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501

2008-04-01

The transcription factor nuclear factor {kappa}B (NF-{kappa}B) plays a major role in the inducible resistance to death receptor-mediated apoptosis. It has been established that the protein synthesis inhibitor cycloheximide (CHX) sensitizes many types of cells to tumor necrosis factor (TNF)-{alpha}-induced apoptosis, mainly due to its ability to block de novo synthesis of cellular FLICE-inhibitory protein (c-FLIP). Nevertheless, we have surprisingly found that CHX, as well as its structural analogue acetoxycycloheximide (Ac-CHX), prevents TNF-{alpha}-mediated activation of NF-{kappa}B and caspase-8 in human lung carcinoma A549 cells. Both CHX and Ac-CHX reduced the expression of cell surface TNF receptor 1 (TNF-R1) in amore » dose-dependent manner, while Ac-CHX was approximately 100-fold more effective than CHX. Consistent with this observation, Ac-CHX induced the proteolytic cleavage of TNF-R1 and its release into the culture medium. CHX and Ac-CHX profoundly decreased constitutive and inducible expression of c-FLIP, whereas these compounds potentiated TNF-{alpha}-induced caspase-8 activation only when metalloprotease inhibitors were present. Thus, our results indicate that ectodomain shedding of TNF-R1 induced by protein synthesis inhibitors regulates TNF-{alpha}-mediated activation of NF-{kappa}B and caspase-8.« less

Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun.

PubMed

De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

2015-10-01

Tulsi, Banyan, and Jamun are popular Indian medicinal plants with notable hypoglycemic potentials. Now the work reports chemo-profiling of the three species with in-vitro screening approach for natural enzyme inhibitors (NEIs) against enzymes pathogenic for type 2 diabetes. Further along with the chemometrics optimized extraction process technology, phyto-synergistic studies of the composite polyherbal blends have also been reported. Chemometrically optimized extraction procedures, ratios of polyherbal composites to achieve phyto-synergistic actions, and in-vitro screening of NEIs amongst leaves of Tulsi, Banyan, and Jamun. The extraction process parameters of the leaves of three plant species (Ficus benghalensis, Syzigium cumini and Ocimum sanctum) were optimized by rotatable central composite design of chemometrics so as to get maximal yield of bio-actives. Phyto-blends of three species were prepared so as to achieve synergistic antidiabetic and antioxidant potentials and the ratios were optimized by chemometrics. Next, for in vitro screening of natural enzyme inhibitors the individual leaf extracts as well as composite blends were subjected to assay procedures to see their inhibitory potentials against the enzymes pathogenic in type 2 diabetes. The antioxidant potentials were also estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Considering response surface methodology studies and from the solutions obtained using desirability function, it was found that hydro-ethanolic or methanolic solvent ratio of 52.46 ± 1.6 and at a temperature of 20.17 ± 0.6 gave an optimum yield of polyphenols with minimal chlorophyll leaching. The species also showed the presence of glycosides, alkaloids, and saponins. Composites in the ratios of 1:1:1 and 1:1:2 gave synergistic effects in terms of polyphenol yield and anti-oxidant potentials. All composites (1:1:1, 1:2:1, 2:1:1, 1:1:2) showed synergistic anti-oxidant actions. Inhibitory activities against the targeted enzymes expressed in terms of IC50 values have shown that hydro-ethanolic extracts in all cases whether individual species or composites in varying ratios gave higher IC50 values thus showing greater effectivity. Current research provides the state-of-the-art of search of NEIs amongst three species by in-vitro assays which can be further utilized for bioactivity-guided isolations of such enzyme inhibitors. Further, it reports the optimized phyto-blend ratios so as to achieve synergistic anti-oxidative actions. The current research work focuses on the optimization of the extraction process parameters and the ratios of phyto-synergistic blends of the leaves of three common medicinal plants viz. banyan, jamun and tulsi by chemometrics. Qualitative and quantitative chemo profiling of the extracts were done by different phytochemical tests and UV spectrophotometric methods. Enzymes like alpha amylase, alpha glucosidase, aldose reductase, dipeptidyl peptidase 4, angiotensin converting enzymes are found to be pathogenic in type 2 diabetes. In vitro screening of natural enzyme inhibitors amongst individual extracts and composite blends were carried out by different assay procedures and the potency expressed in terms of IC50 values. Antioxidant potentials were estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Hydroalcoholic solvent (50:50) gave maximal yield of bio-actives with minimal chlorophyll leaching. Hydroethanolic extract of tulsi showed maximal antioxidant effect. Though all composites showed synergism, maximal effects were shown by the composite (1:1:2) in terms of polyphenol yield, antioxidant effect and inhibitory actions against the targeted enzymes. Abbreviations used: DPP4- dipeptidyl peptidase 4; AR- aldose reductase; ACE- angiotensin converting enzyme; PPAR-γ- peroxisome proliferator activated receptor-γ; NEIs- natural enzyme inhibitors; BE- binding energy; GLP-1- Glucagon like peptide -1; ROS- Reactive oxygen species; CAT- catalase; GSH-Px- glutathione per-oxidase; SOD- superoxide dismutase; pNPG- para-nitro phenyl-α-D-gluco-pyranoside solution; DPPH- 1,1-diphenyl-2-picrylhydrazyl; RSM- Response surface methodology; CCD- central composite design; DMSO- dimethyl sulfoxide; HHL- hippuryl-L-histidyl-L-leucine; GPN-Tos- Gly-Pro p-nitroanilide toluenesulfonate salt; ESC- experimental scavenging capacity; TSC- theoretical scavenging capacity; FRAP- Ferric Reducing Assay Procedure; ABTS- 2, 2'- azinobis (3-ethylbenzothiazoline-6 - sulfonic acid.

Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun

PubMed Central

De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K.; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

2015-01-01

Background: Tulsi, Banyan, and Jamun are popular Indian medicinal plants with notable hypoglycemic potentials. Now the work reports chemo-profiling of the three species with in-vitro screening approach for natural enzyme inhibitors (NEIs) against enzymes pathogenic for type 2 diabetes. Further along with the chemometrics optimized extraction process technology, phyto-synergistic studies of the composite polyherbal blends have also been reported. Objective: Chemometrically optimized extraction procedures, ratios of polyherbal composites to achieve phyto-synergistic actions, and in-vitro screening of NEIs amongst leaves of Tulsi, Banyan, and Jamun. Materials and Methods: The extraction process parameters of the leaves of three plant species (Ficus benghalensis, Syzigium cumini and Ocimum sanctum) were optimized by rotatable central composite design of chemometrics so as to get maximal yield of bio-actives. Phyto-blends of three species were prepared so as to achieve synergistic antidiabetic and antioxidant potentials and the ratios were optimized by chemometrics. Next, for in vitro screening of natural enzyme inhibitors the individual leaf extracts as well as composite blends were subjected to assay procedures to see their inhibitory potentials against the enzymes pathogenic in type 2 diabetes. The antioxidant potentials were also estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Results: Considering response surface methodology studies and from the solutions obtained using desirability function, it was found that hydro-ethanolic or methanolic solvent ratio of 52.46 ± 1.6 and at a temperature of 20.17 ± 0.6 gave an optimum yield of polyphenols with minimal chlorophyll leaching. The species also showed the presence of glycosides, alkaloids, and saponins. Composites in the ratios of 1:1:1 and 1:1:2 gave synergistic effects in terms of polyphenol yield and anti-oxidant potentials. All composites (1:1:1, 1:2:1, 2:1:1, 1:1:2) showed synergistic anti-oxidant actions. Inhibitory activities against the targeted enzymes expressed in terms of IC50 values have shown that hydro-ethanolic extracts in all cases whether individual species or composites in varying ratios gave higher IC50 values thus showing greater effectivity. Conclusion: Current research provides the state-of-the-art of search of NEIs amongst three species by in-vitro assays which can be further utilized for bioactivity-guided isolations of such enzyme inhibitors. Further, it reports the optimized phyto-blend ratios so as to achieve synergistic anti-oxidative actions. SUMMARY The current research work focuses on the optimization of the extraction process parameters and the ratios of phyto-synergistic blends of the leaves of three common medicinal plants viz. banyan, jamun and tulsi by chemometrics. Qualitative and quantitative chemo profiling of the extracts were done by different phytochemical tests and UV spectrophotometric methods. Enzymes like alpha amylase, alpha glucosidase, aldose reductase, dipeptidyl peptidase 4, angiotensin converting enzymes are found to be pathogenic in type 2 diabetes. In vitro screening of natural enzyme inhibitors amongst individual extracts and composite blends were carried out by different assay procedures and the potency expressed in terms of IC50 values. Antioxidant potentials were estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Hydroalcoholic solvent (50:50) gave maximal yield of bio-actives with minimal chlorophyll leaching. Hydroethanolic extract of tulsi showed maximal antioxidant effect. Though all composites showed synergism, maximal effects were shown by the composite (1:1:2) in terms of polyphenol yield, antioxidant effect and inhibitory actions against the targeted enzymes. Abbreviations used: DPP4- dipeptidyl peptidase 4; AR- aldose reductase; ACE- angiotensin converting enzyme; PPAR-γ- peroxisome proliferator activated receptor-γ; NEIs- natural enzyme inhibitors; BE- binding energy; GLP-1- Glucagon like peptide -1; ROS- Reactive oxygen species; CAT- catalase; GSH-Px- glutathione per-oxidase; SOD- superoxide dismutase; pNPG- para-nitro phenyl-α-D-gluco-pyranoside solution; DPPH- 1,1-diphenyl-2-picrylhydrazyl; RSM- Response surface methodology; CCD- central composite design; DMSO- dimethyl sulfoxide; HHL- hippuryl-L-histidyl-L-leucine; GPN-Tos- Gly-Pro p-nitroanilide toluenesulfonate salt; ESC- experimental scavenging capacity; TSC- theoretical scavenging capacity; FRAP- Ferric Reducing Assay Procedure; ABTS- 2, 2’- azinobis (3-ethylbenzothiazoline-6 – sulfonic acid. PMID:27013789

Amide-based inhibitors of p38alpha MAP kinase. Part 2: design, synthesis and SAR of potent N-pyrimidyl amides.

PubMed

Tester, Richland; Tan, Xuefei; Luedtke, Gregory R; Nashashibi, Imad; Schinzel, Kurt; Liang, Weiling; Jung, Joon; Dugar, Sundeep; Liclican, Albert; Tabora, Jocelyn; Levy, Daniel E; Do, Steven

2010-04-15

Optimization of a tri-substituted N-pyridyl amide led to the discovery of a new class of potent N-pyrimidyl amide based p38alpha MAP kinase inhibitors. Initial SAR studies led to the identification of 5-dihydrofuran as an optimal hydrophobic group. Additional side chain modifications resulted in the introduction of hydrogen bond interactions. Through extensive SAR studies, analogs bearing free amino groups and alternatives to the parent (S)-alpha-methyl benzyl moiety were identified. These compounds exhibited improved cellular activities and maintained balance between p38alpha and CYP3A4 inhibition. Copyright 2010 Elsevier Ltd. All rights reserved.

Tyrosine kinase inhibitors suppress prostaglandin F2alpha-induced phosphoinositide hydrolysis, Ca2+ elevation and contraction in iris sphincter smooth muscle.

PubMed

Yousufzai, S Y; Abdel-Latif, A A

1998-11-06

We investigated the effects of the protein tyrosine kinase inhibitors, genistein, tyrphostin 47, and herbimycin on prostaglandin F2alpha- and carbachol-induced inositol-1,4,5-trisphosphate (IP3) production, [Ca2+]i mobilization and contraction in cat iris sphincter smooth muscle. Prostaglandin F2alpha and carbachol induced contraction in a concentration-dependent manner with EC50 values of 0.92 x 10(-9) and 1.75 x 10(-8) M, respectively. The protein tyrosine kinase inhibitors blocked the stimulatory effects of prostaglandin F2alpha, but not those evoked by carbachol, on IP3 accumulation, [Ca2+]i mobilization and contraction, suggesting involvement of protein tyrosine kinase activity in the physiological actions of the prostaglandin. Daidzein and tyrphostin A, inactive negative control compounds for genistein and tyrphostin 47, respectively, were without effect. Latanoprost, a prostaglandin F2alpha analog used as an antiglaucoma drug, induced contraction and this effect was blocked by genistein. Genistein (10 microM) markedly reduced (by 67%) prostaglandin F2alpha-stimulated increase in [Ca2+]i but had little effect on that of carbachol in cat iris sphincter smooth muscle cells. Vanadate, a potent inhibitor of protein tyrosine phosphatase, induced a slow gradual muscle contraction in a concentration-dependent manner with an EC50 of 82 microM and increased IP3 generation in a concentration-dependent manner with an EC50 of 90 microM. The effects of vanadate were abolished by genistein (10 microM). Wortmannin, a myosin light chain kinase inhibitor, reduced prostaglandin F2alpha- and carbachol-induced contraction, suggesting that the involvement of protein tyrosine kinase activity may lie upstream of the increases in [Ca2+]i evoked by prostaglandin F2alpha. Further studies aimed at elucidating the role of protein tyrosine kinase activity in the coupling mechanism between prostaglandin F2alpha receptor activation and increases in intracellular Ca2+ mobilization and identifying the tyrosine-phosphorylated substrates will provide important information about the role of protein tyrosine kinase in the mechanism of smooth muscle contraction, as well as about the mechanism of the intraocular pressure lowering effect of the prostaglandin in glaucoma patients.

Studies on the synergistic effect of androgen on the stimulation of progestin secretion by FSH in cultured rat granulosa cells: progesterone metabolism and the effect of androgens.

PubMed

Nimrod, A

1977-09-01

Metabolic transformations of progesterone in cultures of granulosa cells from immature hypophysectomized rats treated with diethylstilbestrol were studied in relation to the synergistic action of exogenous androgen and FSH on progestin (progesterone and 20alpha-dihydroprogesterone) accumulation. Androstenedione (Ad; 10 ng/ml) enhanced the sensitivity of rat granulosa cells to this steroidogenic action of FSH, lowering the threshold of the response from greater than 4 ng/ml (FSH alone) to 0.8 ng/ml in the presence of Ad. A synergistic effect with FSH was also shown by various 5alpha-androstane derivatives. They were, however, less effective than the parent delta4-3 keto androstenes. Progesterone underwent extensive 5alpha-reduction during culture, leading to accumulation of endogenous 5alpha-pregnane compounds, and to transformation of labelled progesterone into 5 alpha-reduced radiometabolites. These compounds corresponded in gas-liquid and thin-layer chromatographic behaviour to 3alpha-hydroxy-5alpha-pregnan-20-one, 20alpha-hydroxy-5alpha-pregnan-3-one and 5alpha-pregnane-3alpha,20alpha-diol. The rate of 5alpha-reduction of progestins was not affected by the presence of exogenous Ad (1 microgram/ml), ruling out the possibility that the effect of androgen on progestin accumulation depends on competitive inhibition of 5alpha-reductase. An involvement of androgen of thecal origin in the enhancement of the sensitivity of the FSH-responsive mechanism in granulosa cells is suggested.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saji, Chiaki; Higashi, Chizuka; Niinaka, Yasufumi

Highlights: Black-Right-Pointing-Pointer Constitutive NF-{kappa}B signaling is essential for the survival and growth of PEL cells. Black-Right-Pointing-Pointer NF-{kappa}B signaling is upregulated by the proteasome-dependent degradation of I{kappa}B{alpha}. Black-Right-Pointing-Pointer Proteasome inhibitors suppress NF-{kappa}B signaling and induce apoptosis in PEL cells through stabilization of I{kappa}B{alpha}. Black-Right-Pointing-Pointer Proteasome inhibitors suppress viral replication in PEL cells during lytic KSHV infection. -- Abstract: Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi's sarcoma-associated herpesvirus (KSHV). This study provides evidence that proteasomal activity is required for both survival of PEL cells stably harboring the KSHV genome and viral replication of KSHV. We evaluated the cytotoxicmore » effects of proteasome inhibitors on PEL cells. The proteasome inhibitors MG132, lactacystin, and proteasome inhibitor I dramatically inhibited cell proliferation and induced apoptosis of PEL cells through the accumulation of p21 and p27. Furthermore, proteasome inhibitors induced the stabilization of NF-{kappa}B inhibitory molecule (I{kappa}B{alpha}) and suppressed the transcriptional activity of NF-{kappa}B in PEL cells. The NF-{kappa}B specific inhibitor BAY11-7082 also induced apoptosis in PEL cells. The constitutive activation of NF-{kappa}B signaling is essential for the survival and growth of B cell lymphoma cells, including PEL cells. NF-{kappa}B signaling is upregulated by proteasome-dependent degradation of I{kappa}B{alpha}. The suppression of NF-{kappa}B signaling by proteasome inhibitors may contribute to the induction of apoptosis in PEL cells. In addition, proteasome activity is required for KSHV replication in KSHV latently infected PEL cells. MG132 reduced the production of progeny virus from PEL cells at low concentrations, which do not affect PEL cell growth. These findings suggest that proteasome inhibitors may represent a novel strategy for the treatment of KSHV infection and KSHV-associated lymphomas.« less

Seasonal changes in testicular steroidogenesis in the toad Bufo arenarum H.

PubMed

Canosa, L F; Ceballos, N R

2002-02-15

The biosynthesis of androgens in Bufo arenarum takes place through the 5-ene pathway that includes 5-androstane-3beta,17beta-diol as intermediate in testosterone biosynthesis. Besides testosterone and 5alpha-dihydrotestosterone, testes are able to synthesize 5alpha-pregnan-3,20-dione and several 3alpha- and 20alpha-reduced derivatives. Steroid biosynthesis changes during the breeding period (spring and early summer), turning from androgen to C21 steroid production. During the reproductive season, the production of progesterone, 5alpha-pregnan-3alpha,20alpha-diol, 3alpha-hydroxy-5alpha-pregnan-20-one, and 5alpha-pregnan-3,20-dione increases significantly. The function of most of these steroids in amphibians remains unknown. However, 5alpha-androstan-3alpha,17beta-diol and 3alpha-hydroxy-5alpha-pregnan-20-one were shown to be neuroactive in mammals, modulating sexual behavior. Thus, 5alpha/3alpha-reduced steroids could be involved in the regulation of the reproductive behavior in B. arenarum, a species with a dissociated reproductive pattern. Percentage contribution of each enzymes to the total metabolism reveals that neither 3beta-hydroxysteroid dehydrogenase/isomerase nor 5alpha-reductase change throughout the reproductive cycle. However, a strong reduction in 17-hydroxylase-C(17-20) lyase activity occurs in the reproductive season, suggesting that this enzyme could represent a key enzyme in the regulation of the seasonal change of steroidogenesis. Also, 3alpha-hydroxysteroid dehydrogenase and 20-hydroxysteroid dehydrogenase activities increase during the reproductive period, implying that steroid metabolism is clearly focused on C21-reduced steroids. (C)2002 Elsevier Science (USA).

Mitochondrial fumarate reductase as a target of chemotherapy: from parasites to cancer cells.

PubMed

Sakai, Chika; Tomitsuka, Eriko; Esumi, Hiroyasu; Harada, Shigeharu; Kita, Kiyoshi

2012-05-01

Recent research on respiratory chain of the parasitic helminth, Ascaris suum has shown that the mitochondrial NADH-fumarate reductase system (fumarate respiration), which is composed of complex I (NADH-rhodoquinone reductase), rhodoquinone and complex II (rhodoquinol-fumarate reductase) plays an important role in the anaerobic energy metabolism of adult parasites inhabiting hosts. The enzymes in these parasite-specific pathways are potential target for chemotherapy. We isolated a novel compound, nafuredin, from Aspergillus niger, which inhibits NADH-fumarate reductase in helminth mitochondria at nM order. It competes for the quinone-binding site in complex I and shows high selective toxicity to the helminth enzyme. Moreover, nafuredin exerts anthelmintic activity against Haemonchus contortus in in vivo trials with sheep indicating that mitochondrial complex I is a promising target for chemotherapy. In addition to complex I, complex II is a good target because its catalytic direction is reverse of succinate-ubiquionone reductase in the host complex II. Furthermore, we found atpenin and flutolanil strongly and specifically inhibit mitochondrial complex II. Interestingly, fumarate respiration was found not only in the parasites but also in some types of human cancer cells. Analysis of the mitochondria from the cancer cells identified an anthelminthic as a specific inhibitor of the fumarate respiration. Role of isoforms of human complex II in the hypoxic condition of cancer cells and fetal tissues is a challenge. This article is part of a Special Issue entitled Biochemistry of Mitochondria, Life and Intervention 2010. Copyright © 2011 Elsevier B.V. All rights reserved.

Kinetic alteration of a human dihydrodiol/3alpha-hydroxysteroid dehydrogenase isoenzyme, AKR1C4, by replacement of histidine-216 with tyrosine or phenylalanine.

PubMed Central

Ohta, T; Ishikura, S; Shintani, S; Usami, N; Hara, A

2000-01-01

Human dihydrodiol dehydrogenase with 3alpha-hydroxysteroid dehydrogenase activity exists in four forms (AKR1C1-1C4) that belong to the aldo-keto reductase (AKR) family. Recent crystallographic studies on the other proteins in this family have indicated a role for a tyrosine residue (corresponding to position 216 in these isoenzymes) in stacking the nicotinamide ring of the coenzyme. This tyrosine residue is conserved in most AKR family members including AKR1C1-1C3, but is replaced with histidine in AKR1C4 and phenylalanine in some AKR members. In the present study we prepared mutant enzymes of AKR1C4 in which His-216 was replaced with tyrosine or phenylalanine. The two mutations decreased 3-fold the K(m) for NADP(+) and differently influenced the K(m) and k(cat) for substrates depending on their structures. The kinetic constants for bile acids with a 12alpha-hydroxy group were decreased 1.5-7-fold and those for the other substrates were increased 1.3-9-fold. The mutation also yielded different changes in sensitivity to competitive inhibitors such as hexoestrol analogues, 17beta-oestradiol, phenolphthalein and flufenamic acid and 3,5,3', 5'-tetraiodothyropropionic acid analogues. Furthermore, the mutation decreased the stimulatory effects of the enzyme activity by sulphobromophthalein, clofibric acid and thyroxine, which increased the K(m) for the coenzyme and substrate of the mutant enzymes more highly than those of the wild-type enzyme. These results indicate the importance of this histidine residue in creating the cavity of the substrate-binding site of AKR1C4 through the orientation of the nicotinamide ring of the coenzyme, as well as its involvement in the conformational change by binding non-essential activators. PMID:11104674

A Negative Finding from a Single Center Study Led to Re-Design of a Large-Scale Clinical Trial of Phytotherapy for Benign Prostatic Hyperplasia: the CAMUS study

PubMed Central

Lee, Jeannette Y.; Andriole, Gerald; Avins, Andrew; Crawford, E. David; Foster, Harris; Kaplan, Steven; Kreder, Karl; Kusek, John W.; McCullough, Andrew; McVary, Kevin; Meleth, Sreelatha; Naslund, Michael; Nickel, J. Curtis; Nyberg, Leroy M.; Roehrborn, Claus; Williams, O. Dale; Barry, Michael J.

2010-01-01

Background Benign prostatic hyperplasia (BPH), a common condition among older men, confers its morbidity through potentially bothersome lower urinary tract symptoms. Treatments for BPH include drugs such as alpha adrenergic receptor blockers and 5-alpha reductase inhibitors, minimally invasive therapies that use heat to damage or destroy prostate tissue, and surgery including transurethral resection of the prostate. Complementary and alternative medicines are gaining popularity in the U.S. Two phytotherapies commonly used for BPH are extracts of the fruit of Serenoa repens, the Saw palmetto dwarf palm that grows in the Southeastern U.S., and extracts of the bark of Pygeum africanum, the African plum tree. Purpose The objective of the Complementary and Alternative Medicines for Urological Symptoms (CAMUS) clinical trial is to determine if phytotherapy is superior to placebo in the treatment of BPH. Methods CAMUS was originally designed as a 3300-participant, four-arm trial of Serenoa repens, Pygeum africanum, an alpha adrenergic blocking drug, and placebo with time to clinical progression of BPH, a measure of long-term efficacy, as the primary endpoint. Before enrollment started, a randomized, double-blind, placebo-controlled, single institution clinical trial showed that Serenoa repens at the usual dose did not demonstrate any benefit over placebo with respect to symptom relief at one year. Consequently, the focus of CAMUS shifted from evaluating long-term efficacy to determining if any short-term (6-18 month) symptom relief could be achieved with increasing doses of Serenoa repens, the phytotherapy most commonly used in the U.S. for BPH. Results Results are anticipated in 2011. Conclusions Trial design occurs in an environment of continually evolving information. In this case, emerging results from another trial suggested that a study of long-term efficacy was premature, and that an effective dose and preparation of Serenoa repens had to be established before proceeding to a long-term clinical trial. PMID:20007408

Characterization of a Novel Dithiocarbamate Glutathione Reductase Inhibitor and Its Use as a Tool to Modulate Intracellular Glutathione*

PubMed Central

Seefeldt, Teresa; Zhao, Yong; Chen, Wei; Raza, Ashraf S.; Carlson, Laura; Herman, Jocqueline; Stoebner, Adam; Hanson, Sarah; Foll, Ryan; Guan, Xiangming

2009-01-01

Thiol redox state (TRS) is an important parameter to reflect intracellular oxidative stress and is associated with various normal and abnormal biochemical processes. Agents that can be used to increase intracellular TRS will be valuable tools in TRS-related research. Glutathione reductase (GR) is a critical enzyme in the homeostasis of TRS. The enzyme catalyzes the reduction of GSSG to GSH to maintain a high GSH:GSSG ratio. Inhibition of the enzyme can be used to increase TRS. Despite the reports of various GR inhibitors, N,N-bis(2-chloroethyl)-N-nitrosourea, an anticancer drug with IC50 = 647 μm against yeast GR, remains the most commonly used GR inhibitor in the literature. However, the toxicity caused by nonspecific interactions, as well as inhibition of DNA synthesis, complicates the use of N,N-bis(2-chloroethyl)-N-nitrosourea as a GR inhibitor. We report 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylthiocarbonylamino)phenylthiocarbamoylsulfanyl]propionic acid (2-AAPA) as a novel irreversible GR inhibitor. 2-AAPA was prepared by one-step synthesis from commercially available reagents. The Ki and kinact of 2-AAPA against yeast GR were determined to be 56 μm and 0.1 min–1, respectively. At the concentration that produced >80% yeast GR inhibition, 2-AAPA showed no inhibition against glutamylcysteine synthetase, glutathione synthetase, catalase, and superoxide dismutase, but minimal inhibition against glutathione S-transferase and glutathione peroxidase. In CV-1 cells, 2-AAPA (0.1 mm) produced 97% GR inhibition, 25% GSH reduction, and a 5-fold increase in GSSG in 20 min. The compound can be a useful tool in TRS-related research. PMID:19049979

[Patients with inherited trombophilia and recurrent pregnancy loss: incidence].

PubMed

Flores-Alatriste, José Daniel; Jacobo-Nájera, Sara; Segura-Rodríguez, Rubén; Stern-Colin y Nunes, Jorge Jaroslav

2014-06-01

Inherited thrombophilia is a genetic tendency to suffer thrombotic events clinically evident at an early age, with frequent re- currences without apparent cause. In recent years thrombophilia has earned a place as a primary risk factor for abnormal pregnancy. To determine the incidence of hereditary thrombophilia in patients with recurrent pregnancy loss. A retrospective, linear and descriptive study was conducted at Clinic of Reproduction IMMUNOREP with patients treated from January 2007 to December 2012. The study included patients with a diagnosis of recurrent pregnancy loss and inherited thrombophilia with laboratory studies of thrombophilia including different genes: G1619A (factor V Leiden), R2 H1299R (factor V polymorphism), C677T (methylenetetrahydrofolate reductase enzyme polymorphism), A1298C (methylenetetrahydrofolate reductase enzyme mutation), G20210A (mutation of the prothrombin gene), V34L (factor XIII polymorphism), 455G > A (fibrinogen gene mutation), 4G/5G (plasminogen activator inhibitor) and a/b L33P (ribosomal polymorphism of methylenetetrahydrofolate reductase enzyme). 211 files were reviewed and only 10.4% of patients were negative for hereditary thrombophilia, a percentage that is consistent with the results of different series of studies in patients with unexplained recurrent pregnancy loss. The most prevalent genetic condition was 4G/5G (plasminogen activator inhibitor, 85.5%) in homozygous and heterozygous with 63.4% (120) and 22.4% (42), respectively. It was demonstrated the direct relationship between thrombophilia and recurrent pregnancy loss depending on whether the patient is heterozygous or homozygous for the disease.

Expression, purification and enzymatic characterization of Brugia malayi dihydrofolate reductase.

PubMed

Perez-Abraham, Romy; Sanchez, Karla Garabiles; Alfonso, Melany; Gubler, Ueli; Siekierka, John J; Goodey, Nina M

2016-12-01

Brugia malayi (B. malayi) is one of the three causative agents of lymphatic filariasis, a neglected parasitic disease. Current literature suggests that dihydrofolate reductase is a potential drug target for the elimination of B. malayi. Here we report the recombinant expression and purification of a ∼20 kDa B. malayi dihydrofolate reductase (BmDHFR). A His6-tagged construct was expressed in E. coli and purified by affinity chromatography to yield active and homogeneous enzyme for steady-state kinetic characterization and inhibition studies. The catalytic activity kcat was found to be 1.4 ± 0.1 s(-1), the Michaelis Menten constant KM for dihydrofolate 14.7 ± 3.6 μM, and the equilibrium dissociation constant KD for NADPH 25 ± 24 nM. For BmDHFR, IC50 values for a six DHFR inhibitors were determined to be 3.1 ± 0.2 nM for methotrexate, 32 ± 22 μM for trimethoprim, 109 ± 34 μM for pyrimethamine, 154 ± 46 μM for 2,4-diaminoquinazoline, 771 ± 44 μM for cycloguanil, and >20,000 μM for 2,4-diaminopyrimidine. Our findings suggest that antifolate compounds can serve as inhibitors of BmDHFR. Copyright © 2016 Elsevier Inc. All rights reserved.

Synthesis and evaluation of 1,4-naphthoquinone ether derivatives as SmTGR inhibitors and new antischistosomal drugs

PubMed Central

Johann, Laure; Belorgey, Didier; Huang, Hsin-Hung; Day, Latasha; Chessé, Matthieu; Becker, Katja; Williams, David L.; Davioud-Charvet, Elisabeth

2016-01-01

Investigations on the chemistry and mechanism of action of 2-methyl-1,4-naphthoquinone (or menadione) derivatives, revealed 3-phenoxymethyl menadiones as a novel antischistosomal series. These newly synthesized compounds 1–7 and their difluoromethylmenadione counterparts 8–9 were found to be potent and specific inhibitors of Schistosoma mansoni thioredoxin-glutathione reductase (SmTGR) identified as a potential target. The compounds were also tested in enzymic assays using both human flavoenzymes, i.e. the glutathione reductase (hGR) and the selenium-dependent human thioredoxin reductase (hTrxR) to evaluate the specificity of the inhibition. Structure-activity relationships as well as physico- and electro-chemical studies showed a high potential for the 3-phenoxymethyl menadiones to inhibit SmTGR selectively versus hGR and hTrxR enzymes, in particular those bearing α-fluorophenol methyl ether moieties to improve antischistosomal action. In particular, the (substituted phenoxy)methyl menadione derivative 7 displayed time-dependent SmTGR inactivation, correlating with unproductive NADPH-dependent redox-cycling of SmTGR, and potent antischistosomal action in ex vivo worms. In contrast, the difluoromethylmenadione analogue 9, which inactivates SmTGR through an irreversible non-consuming NADPH-dependent process, has little killing effect in cultured ex vivo worms. Because none of the compounds tested in vivo was active, a limited bioavailability might compromise compound activity and future studies will be directed toward improving pharmacokinetics properties. PMID:26111549

Therapeutic Modalities in Diabetic Nephropathy: Future Approaches*

PubMed Central

Reeves, William Brian; Rawal, Bishal B.; Abdel-Rahman, Emaad M.; Awad, Alaa S.

2012-01-01

Diabetes mellitus is the leading cause of end stage renal disease and is responsible for more than 40% of all cases in the United States. Several therapeutic interventions for the treatment of diabetic nephropathy have been developed and implemented over the past few decades with some degree of success. However, the renal protection provided by these therapeutic modalities is incomplete. More effective approaches are therefore urgently needed. Recently, several novel therapeutic strategies have been explored in treating DN patients including Islet cell transplant, Aldose reductase inhibitors, Sulodexide (GAC), Protein Kinase C (PKC) inhibitors, Connective tissue growth factor (CTGF) inhibitors, Transforming growth factor-beta (TGF-β) inhibitors and bardoxolone. The benefits and risks of these agents are still under investigation. This review aims to summarize the utility of these novel therapeutic approaches. PMID:23293752

Recent Advances in Drug Design and Drug Discovery for Androgen- Dependent Diseases.

PubMed

Cabeza, Marisa; Sánchez-Márquez, Araceli; Garrido, Mariana; Silva, Aylín; Bratoeff, Eugene

2016-01-01

This article summarizes the importance of different targets such as 5α-reductase, 17β-HSD, CYP17A, androgen receptor and protein kinase A for the treatment of prostate cancer and benign prostatic hyperplasia. It is a well known fact that dihydrotestosterone (DHT) is associated with the development of androgen-dependent afflictions. At the present time, several research groups are attempting to develop new steroidal and non-steroidal molecules with the purpose of inhibiting the synthesis and biological response of DHT. This review also discusses the most recent studies reported in the literature that describe the therapeutic potential of novel compounds, as well as the new drugs, principally inhibitors of 5α-reductase.

Persistent elastase/proteinase inhibitor imbalance during prolonged ventilation of infants with bronchopulmonary dysplasia: evidence for the role of nosocomial infections.

PubMed

Walti, H; Tordet, C; Gerbaut, L; Saugier, P; Moriette, G; Relier, J P

1989-10-01

Acute imbalance between elastase and alpha-1-proteinase inhibitor (alpha 1Pi) may contribute to the development of bronchopulmonary dysplasia (BPD). The question of whether such an imbalance persists in BPD infants still requiring mechanical ventilation after 4 wk of life has not been previously addressed. We studied 14 infants still on mechanical ventilation at 4 wk of age: nine had BPD and five did not. Weekly (4 to 9 wk) serum and bronchoalveolar lavage (BAL) specimens were taken. alpha 1Pi and alpha-2-macroglobulin were measured in serum and BAL by immunoturbidimetric assay. BAL elastase activity was measured by cleavage of a synthetic substrate and expressed as ng of porcine pancreatic elastase equivalent. Infants with BPD had higher levels of serum alpha 1Pi and alpha-2-macroglobulin than those without BPD. In contrast, the corresponding BAL levels were either similar or even decreased (alpha 1Pi). Moreover, there was a 3-fold increase in elastase-1Pi imbalance expressed as the BAL ng of porcine pancreatic elastase equivalent/2 alpha 1Pi ratio. The role of nosocomial infections was evident in a subgroup of 11 infected BAL aspirates in BPD infants. In such cases we found a 3-fold increase in the BAL ng of porcine pancreatic elastase equivalent/alpha 1Pi ratio as compared to 35 noninfected BAL in BPD infants. These data suggest a persistent alveolitis with imbalance between elastase and proteinase inhibitors in prolonged severe BPD. Such an imbalance is, in part, explained by a local destruction and/or inactivation of alpha 1Pi. Our results also emphasize the increase in proteolysis with nosocomial pneumonia.

The biological activity of alpha-mangostin, a larvicidal botanic mosquito sterol carrier protein-2 inhibitor.

PubMed

Larson, Ryan T; Lorch, Jeffrey M; Pridgeon, Julia W; Becnel, James J; Clark, Gary G; Lan, Que

2010-03-01

alpha-Mangostin derived from mangosteen was identified as a mosquito sterol carrier protein-2 inhibitor via high throughput insecticide screening, alpha-Mangostin was tested for its larvicidal activity against third instar larvae of six mosquito species, and the median lethal concentration values range from 0.84 to 2.90 ppm. The residual larvicidal activity of alpha-mangostin was examined under semifield conditions. The results indicated that alpha-mangostin was photolytic with a half-life of 53 min in water under full sunlight exposure. The effect of alpha-mangostin on activities of major detoxification enzymes such as P450, glutathione S-transferase, and esterase was investigated. The results showed that alpha-mangostin significantly elevated activities of P450 and glutathione S-transferase in larvae, whereas it suppressed esterase activity. Toxicity of alpha-mangostin against young rats was studied, and there was no detectable adverse effect at dosages as high as 80 mg/kg. This is the first multifaceted study of the biological activity of alpha-mangostin in mosquitoes. The results suggest that alpha-mangostin may be a lead compound for the development of a new organically based mosquito larvicide.

Effect of statin use on mobility disability and its prevention in at-risk older adults: the LIFE study

USDA-ARS?s Scientific Manuscript database

BACKGROUND: HMG-CoA reductase inhibitors (statins) are among the most commonly prescribed classes of medications. Although their cardiovascular benefits and myalgia risks are well documented, their effects on older adults initiating an exercise training program are less understood. METHODS: 1,635 s...

A PHARMACOKINETIC-PHARMACODYNAMIC MODEL FOR GENE-REGULATED PROSTATE MAINTENANCE: COMPARING THE EFFECTS OF CASTRATION WITH ANTIANDROGEN EXPOSURE IN THE RAT

EPA Science Inventory

Antiandrogens affect prostate maintenance in two ways. Androgen antagonists, such as the fungicide vinclozolin, act as competitive ligands for the androgen receptor (AR). Enzyme inhibitors, such as the therapeutic drug Finasteride, inhibit the enzyme 5 -reductase (5 R) from metab...

INTER-ALPHA INHIBITOR PROTEINS: A NOVEL THERAPEUTIC STRATEGY FOR EXPERIMENTAL ANTHRAX INFECTION

PubMed Central

Opal, Steven M.; Lim, Yow-Pin; Cristofaro, Patricia; Artenstein, Andrew W.; Kessimian, Noubar; DelSesto, David; Parejo, Nicolas; Palardy, John E.; Siryaporn, Edward

2010-01-01

Human inter-alpha-inhibitor proteins (IaIp) are endogenous human plasma proteins that function as serine protease inhibitors. IaIp can block the systemic release of proteases in sepsis and block furin-mediated assembly of protective antigen, an essential stop in the intracellular delivery of the anthrax exotoxins, lethal toxin and edema toxin. IaIp administered on hour or up to 24 hours after spore challenge with Bacillus anthracis Sterne strain protected mice from lethality if administered with antimicrobial therapy (p<.001). These human plasma proteins possess combined actions against anthrax as general inhibitors of excess serine proteases in sepsis and specific inhibitors of anthrax toxin assembly. IaIp could represent a novel adjuvant therapy for the treatment of established anthrax infection. PMID:20523269

Trypanocidal Activity of Quinoxaline 1,4 Di-N-oxide Derivatives as Trypanothione Reductase Inhibitors.

PubMed

Chacón-Vargas, Karla Fabiola; Nogueda-Torres, Benjamin; Sánchez-Torres, Luvia E; Suarez-Contreras, Erick; Villalobos-Rocha, Juan Carlos; Torres-Martinez, Yuridia; Lara-Ramirez, Edgar E; Fiorani, Giulia; Krauth-Siegel, R Luise; Bolognesi, Maria Laura; Monge, Antonio; Rivera, Gildardo

2017-02-01

Chagas disease or American trypanosomiasis is a worldwide public health problem. In this work, we evaluated 26 new propyl and isopropyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives as potential trypanocidal agents. Additionally, molecular docking and enzymatic assays on trypanothione reductase (TR) were performed to provide a basis for their potential mechanism of action. Seven compounds showed better trypanocidal activity on epimastigotes than the reference drugs, and only four displayed activity on trypomastigotes; T-085 was the lead compound with an IC50 = 59.9 and 73.02 µM on NINOA and INC-5 strain, respectively. An in silico analysis proposed compound T-085 as a potential TR inhibitor with better affinity than the natural substrate. Enzymatic analysis revealed that T-085 inhibits parasite TR non-competitively. Compound T-085 carries a carbonyl, a CF3, and an isopropyl carboxylate group at 2-, 3- and 7-position, respectively. These results suggest the chemical structure of this compound as a good starting point for the design and synthesis of novel trypanocidal derivatives with higher TR inhibitory potency and lower toxicity.

Investigation of 7-dehydrocholesterol reductase pathway to elucidate off-target prenatal effects of pharmaceuticals: a systematic review

PubMed Central

Boland, M R; Tatonetti, N P

2016-01-01

Mendelian diseases contain important biological information regarding developmental effects of gene mutations that can guide drug discovery and toxicity efforts. In this review, we focus on Smith–Lemli–Opitz syndrome (SLOS), a rare Mendelian disease characterized by compound heterozygous mutations in 7-dehydrocholesterol reductase (DHCR7) resulting in severe fetal deformities. We present a compilation of SLOS-inducing DHCR7 mutations and the geographic distribution of those mutations in healthy and diseased populations. We observed that several mutations thought to be disease causing occur in healthy populations, indicating an incomplete understanding of the condition and highlighting new research opportunities. We describe the functional environment around DHCR7, including pharmacological DHCR7 inhibitors and cholesterol and vitamin D synthesis. Using PubMed, we investigated the fetal outcomes following prenatal exposure to DHCR7 modulators. First-trimester exposure to DHCR7 inhibitors resulted in outcomes similar to those of known teratogens (50 vs 48% born-healthy). DHCR7 activity should be considered during drug development and prenatal toxicity assessment. PMID:27401223

Identification and Development of Novel Inhibitors of Toxoplasma gondii Enoyl Reductase

PubMed Central

Tipparaju, Suresh K.; Muench, Stephen P.; Mui, Ernest J.; Ruzheinikov, Sergey N.; Lu, Jeffrey Z.; Hutson, Samuel L.; Kirisits, Michael J.; Prigge, Sean T.; Roberts, Craig W.; Henriquez, Fiona L.; Kozikowski, Alan P.; Rice, David W.; McLeod, Rima L.

2010-01-01

Toxoplasmosis causes significant morbidity and mortality and yet available medicines are limited by toxicities and hypersensitivity. Since improved medicines are needed urgently, rational approaches were used to identify novel lead compounds effective against Toxoplasma gondii enoyl reductase (TgENR), a type II fatty acid synthase enzyme essential in parasites but not present in animals. Fifty-three compounds, including three classes that inhibit ENRs, were tested. Six compounds have anti-parasite MIC90s ≤6μM without toxicity to host cells, three compounds have IC90s <45nM against recombinant TgENR and two protect mice. To further understand the mode of inhibition, the co-crystal structure of one of the most promising candidate compounds in complex with TgENR has been determined to 2.7Å. The crystal structure reveals that the aliphatic side chain of compound 19 occupies, as predicted, space made available by replacement of a bulky hydrophobic residue in homologous bacterial ENRs by Ala in TgENR. This provides a paradigm, conceptual foundation, reagents, and lead compounds for future rational development and discovery of improved inhibitors of T. gondii. PMID:20698542

Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation.

PubMed

Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

2015-07-10

Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Relationships between HMG-CoA reductase inhibitors (statin) use and strength, balance and falls in older people.

PubMed

Haerer, W; Delbaere, K; Bartlett, H; Lord, S R; Rowland, J

2012-12-01

To investigate associations between HMG-CoA reductase inhibitor (statin) use and muscle strength, balance, mobility and falls in older people. Five hundred community-dwelling people aged 70-90 years provided information about their medication use and undertook tests of lower limb strength, postural sway, leaning balance (maximal balance range and coordinated stability tests) and functional mobility. Participants were then followed up for 12 months with respect to falls. After adjusting for general health in analyses of covariance procedures, statin users had poorer maximal balance range than non-statin users (P = 0.017). Statin and non-statin users did not differ with respect to strength, postural sway, mobility or falls experienced in the follow-up year. In a sample of healthy older people, statin use was not associated with muscle weakness, postural sway, reduced mobility or falls. Statin users, however, had poorer leaning balance which may potentially increase fall risk in this group. © 2011 The Authors; Internal Medicine Journal © 2011 Royal Australasian College of Physicians.

Inhibitory activity and mechanism of inhibition of the N-[[(4-benzoylamino)phenyl]sulfonyl]amino acid aldose reductase inhibitors.

PubMed

DeRuiter, J; Mayfield, C A

1990-11-15

A series of substituted N-[[(4-benzoylamino)phenyl]sulfonyl]amino acids (BAPS-amino acids) were synthesized by established methods, and the stereochemistry of the products was confirmed by HPLC analysis after chiral derivatization. When tested against aldose reductase (alditol:NADP+ oxidoreductase; EC 1.1.1.21; ALR2) isolated from rat lens, all of the BAPS-amino acids were determined to be significantly more inhibitory than the corresponding N-(phenylsulfonyl)amino acids. Structure-inhibition and enzyme kinetic analyses suggest that the BAPS-amino acids inhibit ALR2 by a mechanism similar to the N-(phenylsulfonyl)amino acids. However, multiple inhibition analyses indicate that the increased inhibitory activity of the BAPS-amino acids is a result of interaction with multiple sites present on ALR2. Enzyme specificity studies with several of the BAPS-amino acids demonstrated that these compounds do not produce significant inhibition of other nucleotide-requiring enzymes including aldehyde reductase (alcohol: NADP+ oxidoreductase; EC 1.1.1.2; ALR1).

The 21st century form of vitamin E--tocotrienol.

PubMed

Bardhan, Jayeeta; Chakraborty, Runu; Raychaudhuri, Utpal

2011-01-01

Vitamin E family constitutes of tocopherol and tocotrienol. Each form has several isomers: alpha,beta, gamma, delta, desmo and didesmo. Although tocopherol is known much earlier, tocotrienol has been discovered more recently.Tocotrienol has higher antioxidant potential than tocopherol. Research shows that tocotrienol can inhibit the induced oxidative damage to lipids and proteins. Cholesterol biosynthesis pathway requires HMG Co A reductase. Tocotrienol degrades HMG Co A reductase protein and in turn lowers cholesterol synthesis. Tocotrienol can reverse ischemia-reperfusion which mediates cardiac dysfunction and induces c-Src protein expression. Tocotrienol prevents oxytosis and offers protection against Alzheimer's disease, Parkinson's disease, Hungtington's disease. Tocotrienol exerts anticancer property through cell cycle arrest, induction of apoptosis, inhibition of angiogenesis; antitumor activity. Tocotrienol also possesses anti-inflammatory, antidiabetic, antiadipogenic and antiatherogenic effect.

Cloning, expression, purification and crystallization of saccharopine reductase from Magnaporthe grisea.

PubMed

Johansson, E; Steffens, J J; Emptage, M; Lindqvist, Y; Schneider, G

2000-05-01

The gene coding for saccharopine reductase (E.C. 1.5.1.10), an enzyme of the alpha-aminoadipic pathway of lysine biosynthesis in the pathogenic fungus Magnaporthe grisea, was cloned and expressed in Escherichia coli. The purified enzyme was crystallized in space groups C2 and C222(1) using ammonium sulfate pH 4.8 or PEG 6000 pH 4. 1 as precipitants. The unit-cell parameters are a = 115.0, b = 56.6, c = 74.3 A, beta = 111.1 degrees for space group C2, and a = 89.3, b = 119.0, c = 195.9 A for space group C222(1). The crystals diffract to resolutions of 2.0 A (C2) and 2.4 A (C222(1)) at synchrotron sources.

Potential antiradical and alpha-glucosidase inhibitors from Ecklonia maxima (Osbeck) Papenfuss.

PubMed

Rengasamy, Kannan R R; Aderogba, Mutalib A; Amoo, Stephen O; Stirk, Wendy A; Van Staden, Johannes

2013-11-15

Alpha-glucosidase inhibitors play a potential role in the treatment of type 2 diabetes by delaying glucose absorption in the small intestine. Ecklonia maxima, a brown alga which grows abundantly on the west coast of South Africa, is used to produce alginate, animal feed, nutritional supplements and fertilizer. The crude aqueous methanol extract, four solvent fractions and three phlorotannins: 1,3,5-trihydroxybenezene (phloroglucinol) (1), dibenzo [1,4] dioxine-2,4,7,9-tetraol (2) and hexahydroxyphenoxydibenzo [1,4] dioxine (eckol) (3) isolated from E. maxima were evaluated for antiradical and alpha-glucosidase inhibitory activities. All the phlorotannins tested had strong antioxidant activities on DPPH free radicals with EC50 values ranging from 0.008 to 0.128μM. Compounds 2 and 3 demonstrated stronger antioxidant activity and an alpha-glucosidase inhibitory property than positive controls. These results suggest that E. maxima could be a natural source of potent antioxidants and alpha-glucosidase inhibitors. This study could facilitate effective utilization of E. maxima as an oral antidiabetic drug or functional food ingredient with a promising role in the formulation of medicines and nutrition supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vasodilating effect of norethisterone and its 5 alpha metabolites: a novel nongenomic action.

PubMed

Perusquía, Mercedes; Villalón, Carlos M; Navarrete, Erika; García, Gustavo A; Pérez-Palacios, Gregorio; Lemus, Ana E

2003-08-15

Estrogens are generally administered in hormone replacement therapy in combination with synthetic progestins. Studies of cardiovascular risk factors in postmenopausal women have shown a variety of responses according to the molecular structure of the progestin used in hormone replacement therapy schemes. The present study sets out to determine the vasoactive effects of norethisterone and its 5alpha-dihydro (5alpha-norethisterone) and -tetrahydro (3alpha,5alpha-norethisterone and 3beta,5alpha-norethisterone) metabolites in isolated precontracted rat thoracic aorta. The addition of norethisterone and 3alpha,5alpha-norethisterone in rat aorta exhibited a potent, concentration-response inhibition of noradrenaline-induced contraction, while 5alpha- and 3beta,5alpha-norethisterone had very little, if any, vasorelaxing effect. Relaxation to norethisterone and 3alpha,5alpha-norethisterone had very rapid time-courses and it was neither affected by the absence of endothelium nor by the inhibitor of nitric oxide synthase, Nomega-nitro-L-arginine methyl ester (L-NAME). The addition of specific anti-androgen, anti-progestin and anti-estrogen compounds and protein synthesis inhibitors did not preclude the vasorelaxing effect of norethisterone and its 3alpha,5alpha-reduced metabolite. The results strongly suggest that these effects are not mediated by nuclear sex steroid hormone receptors. The overall data document a novel nongenomic endothelium-independent vasorelaxing action of a 19-nor synthetic progestin and one of its A-ring-reduced derivatives.

Synthesis, kinetic characterization and metabolism of diastereomeric 2-(1-(4-phenoxyphenylsulfonyl)ethyl)thiiranes as potent gelatinase and MT1-MMP inhibitors.

PubMed

Gooyit, Major; Lee, Mijoon; Hesek, Dusan; Boggess, Bill; Oliver, Allen G; Fridman, Rafael; Mobashery, Shahriar; Chang, Mayland

2009-12-01

Gelatinases (MMP-2 and MMP-9) have been implicated in a number of pathological conditions, including cancer and cardiovascular disease. Hence, small molecule inhibitors of these enzymes are highly sought for use as potential therapeutic agents. 2-(4-Phenoxyphenylsulfonylmethyl)thiirane (SB-3CT) has previously been demonstrated to be a potent and selective inhibitor of gelatinases, however, it is rapidly metabolized because of oxidation at the para position of the phenoxy ring and at the alpha-position to the sulfonyl group. alpha-Methyl variants of SB-3CT were conceived to improve metabolic stability and as mechanistic probes. We describe herein the synthesis and evaluation of these structural variants as potent inhibitors of gelatinases. Two (compounds 5b and 5d) among the four synthetic stereoisomers were found to exhibit slow-binding inhibition of gelatinases and MMP-14 (MT1-MMP), which is a hallmark of the mechanism of this class of inhibitors. The ability of these compounds to inhibit MMP-2, MMP-9, and MMP-14 could target cancer tissues more effectively. Metabolism of the newly synthesized inhibitors showed that both oxidation at the alpha-position to the sulfonyl group and oxidation at the para position of the terminal phenyl ring were prevented. Instead oxidation on the thiirane sulfur is the only biotransformation pathway observed for these gelatinase inhibitors.

SRD5A1 genotype frequency differences in women with mild versus severe premenstrual symptoms.

PubMed

Adams, Marlene; McCrone, Susan

2012-02-01

The aims of this small pilot study were to explore the association between premenstrual symptom severity and two genes from the gamma-aminobutyric acid (GABA) pathway: steroid-5-alpha-reductase, alpha polypeptide 1 (SRD5A1) and gamma-aminobutyric acid receptor subunit alpha-4 (GABRA4). Saliva samples were obtained from a convenience sample of 19 Caucasian females ages 18-25 years, ten cases and nine controls. Deoxyribonucleic acid (DNA) was isolated, and genotyping performed on ten single nucleotide polymorphisms (SNPs). Ten percent of cases and 44% of controls had the cytosine/cytosine (C/C) genotype for the SRD5A1 SNP, rs501999 indicating that this genotype may protect women against severe premenstrual symptoms. Replication of this study using an adequately powered sample size is warranted.

Synthesis and activity of novel 16-dehydropregnenolone acetate derivatives as inhibitors of type 1 5α-reductase and on cancer cell line SK-LU-1.

PubMed

Silva-Ortiz, Aylin Viviana; Bratoeff, Eugene; Ramírez-Apan, Teresa; Heuze, Yvonne; Sánchez, Araceli; Soriano, Juan; Cabeza, Marisa

2015-12-15

Testosterone (T) plays a crucial role in prostate growth. In androgen-dependent tissues T is reduced to dihydrotestosterone (DHT) because of the presence of the 5α-reductase enzyme. This androgen is more active than T, since it has a higher affinity for the androgen receptor (AR). When this mechanism is altered, androgen-dependent diseases, including prostate cancer, could result. The aim of this study was to synthesize several 16-dehydropregnenolone acetate derivatives containing a triazole ring at C-21 and a linear or alicyclic ester moiety at C-3 of the steroidal skeleton. These steroids were designed as potential inhibitors of the activity of both types (1 and 2) of 5α-reductase. The cytotoxic activity of these compounds was also evaluated on a panel of PC-3, MCF7, and SK-LU-1 human cancer cell lines. The results from this study showed that with the exception of steroids 20-oxo-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-3β-yl-propionate and 20-oxo-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-3β-yl-pentanoate, the compounds exhibit a lower inhibitory activity for both isoenzymes of 5α-reductase than finasteride. Furthermore the 3β-hydroxy-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-20-one and 20-oxo-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-3β-yl-acetate derivatives display 80% cytotoxic activity on the SK-LU-1 cell line. These results also indicated that the triazole derivatives, which have a hydroxyl or acetoxy group at C-3, could have an anticancer effect, whereas the derivatives with a alicyclic ester group at C-3 do not show biological activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of the Pharmacological Effects of a Novel Selective Androgen Receptor Modulator, the 5α-Reductase Inhibitor Finasteride, and the Antiandrogen Hydroxyflutamide in Intact Rats: New Approach for Benign Prostate Hyperplasia

PubMed Central

Gao, Wenqing; Kearbey, Jeffrey D.; Nair, Vipin A.; Chung, Kiwon; Parlow, A. F.; Miller, Duane D.; Dalton, James T.

2007-01-01

Tissue-selective androgen receptor modulators (SARMs) demonstrate tissue selectivity in both castrated and intact male rats, behaving as partial agonists in androgenic tissues (i.e. prostate and seminal vesicle), but full agonists in anabolic tissues (i.e. levator ani muscle). The partial agonist activity of SARMs (compounds S-1 and S-4) in the prostate of intact rats suggested that SARM could be used for androgen suppression in the treatment of benign prostate hyperplasia (BPH). This study was designed to explore the mechanisms of action of SARM and to characterize the tissue selectivity of S-1 in intact male rats compared with that of hydroxyflutamide (antiandrogen) and finasteride (5α-reductase inhibitor), two major drugs used for androgen suppression treatment of BPH. In intact male rats, S-1 (5, 10, and 25 mg/kg) selectively decreased the prostate weight with similar efficacy to finasteride (5 mg/kg), without affecting the levator ani muscle or increasing the plasma levels of testosterone, LH, and FSH. Hydroxyflutamide (0.5, 1, 5, 10, and 25 mg/kg), however, decreased both the prostate and levator ani muscle weights without any selectivity and increased plasma hormone levels in a dose-dependent manner. Furthermore, S-1 and S-4 showed very weak inhibitory effects toward transiently expressed type I and II human 5α-reductase (Ki, >20 µM) during in vitro assays. Therefore, although S-1 and finasteride showed very similar suppressive effects in the prostate of intact male rats, they decreased prostate size via different mechanisms of action. S-1 simply worked as androgen receptor partial agonist, whereas finasteride inhibited prostatic 5α-reductase. These studies indicate that SARMs may demonstrate clinical utility as single agent or combination therapy for BPH. PMID:15308613

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laouar, A.; Glesne, D.; Huberman, E.

The role of protein kinase C-{beta} (PKC-{beta}) in apoptosis induced by tumor necrosis factor (TNF)-{alpha} and anti-Fas monoclonal antibody (mAb) in the human myeloid HL-60 leukemia cell line was studied by using its variant HL-525, which is deficient in PKC-{beta}. In contrast to the parental HL-60 cells, HL-525 is resistant to TNF-{alpha}-induced apoptosis but sensitive to anti-Fas mAb-induced apoptosis. Both cell types expressed similar levels of the TNF-receptor I, whereas the Fas receptor was detected only in HL-525 cells. Transfecting the HL-525 cells with an expression vector containing PKC-{beta} reestablished their susceptibility to TNF-{alpha}-induced apoptosis. The apoptotic effect of TNF-{alpha}more » in HL-60 and the transfectants was abrogated by fumonisin, an inhibitor of ceramide generation, and by the peptide Ac-YVAD-BoMK, an inhibitor of caspase-1 and -4. Supplementing HL-525 cells with exogenous ceramides bypassed the PKC-{beta} deficiency and induced apoptosis, which was also restrained by the caspase-1 and -4 inhibitor. The apoptotic effect of anti-Fas mAb in HL-525 cells was abrogated by the antioxidants N-acetylcysteine and glutathione and by the peptide z-DEVD-FMK, an inhibitor of caspase-3 and -7. We suggest that TNF-{alpha}-induced apoptosis involves PKC-{beta} and then ceramide and, in turn, caspase-1 and/or -4, whereas anti-Fas mAb-induced apoptosis utilizes reactive oxygen intermediates and, in turn, caspase-3 and/or -7.« less

Noradrenaline and alpha-adrenergic signaling induce the hsp70 gene promoter in mollusc immune cells.

PubMed

Lacoste, A; De Cian, M C; Cueff, A; Poulet, S A

2001-10-01

Expression of heat shock proteins (hsp) is a homeostatic mechanism induced in both prokaryotic and eukaryotic cells in response to metabolic and environmental insults. A growing body of evidence suggests that in mammals, the hsp response is integrated with physiological responses through neuroendocrine signaling. In the present study, we have examined the effect of noradrenaline (NA) on the hsp70 response in mollusc immune cells. Oyster and abalone hemocytes transfected with a gene construct containing a gastropod hsp70 gene promoter linked to the luciferase reporter-gene were exposed to physiological concentrations of NA, or to various alpha- and beta-adrenoceptor agonists and antagonists. Results show that NA and alpha-adrenergic stimulations induced the expression of luciferase in transfected mollusc immunocytes. Furthermore, exposure of hemocytes to NA or to the alpha-adrenoceptor agonist phenylephrine (PE) resulted in the expression of the inducible isoform of the hsp70 protein. Pertussis toxin (PTX), the phospholipase C (PLC) inhibitor U73122, the protein kinase C (PKC) inhibitor calphostin C, the Ca(2+)-dependent PKC inhibitor Gö 6976 and the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor LY294002 blocked the PE-mediated induction of the hsp70 gene promoter. These results suggest that alpha-adrenergic signaling induces the transcriptionnal upregulation of hsp70 in mollusc hemocytes through a PTX-sensitive G-protein, PLC, Ca(2+)-dependent PKC and PI 3-kinase. Thus, a functional link exists between neuroendocrine signaling and the hsp70 response in mollusc immune cells.

Trimethyltin-activated cyclooxygenase stimulates tumor necrosis factor-alpha release from glial cells through reactive oxygen species.

PubMed

Viviani, B; Corsini, E; Pesenti, M; Galli, C L; Marinovich, M

2001-04-15

Exposure of a primary culture of glial cells to the classical neurotoxicant trimethyltin (TMT) results in the release of prostaglandin (PG)E(2) and tumor necrosis factor (TNF)-alpha. Prior treatment of glial cells with either the nonspecific inhibitor of cyclooxygenase and lypoxygenase eicosatetraynoic acid (ETYA) or the cyclooxygenase inhibitor indomethacin completely prevented TMT-induced PGE(2) production and TNF-alpha release, suggesting a role for cyclooxygenase metabolites in TMT-induced TNF-alpha release. Exposure of glial cells to increasing concentrations of PGE(2) or other prostanoids did not increase TNF-alpha synthesis, while the presence of exogenous PGE(2) during treatment of glial cells with TMT actually suppressed TNF-alpha release. The activation of arachidonic acid metabolism produces reactive oxygen species (ROS). Scavenging of ROS by means of the antioxidant trolox prevented the TMT-induced release of TNF-alpha from glial cells, while indomethacin was found to suppress ROS formation induced by 1 microM TMT in glial cells. These results suggest that activation of arachidonic acid metabolism causes TNF-alpha release through the production of ROS rather than PGE(2). Indeed, PGE(2) may exert negative feedback on the release of TNF-alpha. Copyright 2001 Academic Press.

Apolipoprotein CIII-induced THP-1 cell adhesion to endothelial cells involves pertussis toxin-sensitive G protein- and protein kinase C alpha-mediated nuclear factor-kappaB activation.

PubMed

Kawakami, Akio; Aikawa, Masanori; Nitta, Noriko; Yoshida, Masayuki; Libby, Peter; Sacks, Frank M

2007-01-01

Plasma apolipoprotein CIII (apoCIII) independently predicts risk for coronary heart disease (CHD). We recently reported that apoCIII directly enhances adhesion of human monocytes to endothelial cells (ECs), and identified the activation of PKC alpha as a necessary upstream event of enhanced monocyte adhesion. This study tested the hypothesis that apoCIII activates PKC alpha in human monocytic THP-1 cells, leading to NF-kappaB activation. Among inhibitors specific to PKC activators, phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor D609 limited apoCIII-induced PKC alpha activation and THP-1 cell adhesion. ApoCIII increased PC-PLC activity in THP-1 cells, resulting in PKC alpha activation. Pertussis toxin (PTX) inhibited apoCIII-induced PC-PLC activation and subsequent PKC alpha activation, implicating PTX-sensitive G protein pathway. ApoCIII further activated nuclear factor-kappaB (NF-kappaB) through PKC alpha in THP-1 cells and augmented beta1-integrin expression. The NF-kappaB inhibitor peptide SN50 partially inhibited apoCIII-induced beta1-integrin expression and THP-1 cell adhesion. ApoCIII-rich VLDL had similar effects to apoCIII alone. PTX-sensitive G protein pathway participates critically in PKC alpha stimulation in THP-1 cells exposed to apoCIII, activating NF-kappaB, and increasing beta1-integrin. This action causes monocytic cells to adhere to endothelial cells. Furthermore, because leukocyte NF-kappaB activation contributes to inflammatory aspects of atherogenesis, apoCIII may stimulate diverse inflammatory responses through monocyte activation.

Discovery and quantitative structure-activity relationship study of lepidopteran HMG-CoA reductase inhibitors as selective insecticides.

PubMed

Zang, Yang-Yang; Li, Yuan-Mei; Yin, Yue; Chen, Shan-Shan; Kai, Zhen-Peng

2017-09-01

In a previous study we have demonstrated that insect 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) can be a potential selective insecticide target. Three series of inhibitors were designed on the basis of the difference in HMGR structures from Homo sapiens and Manduca sexta, with the aim of discovering potent selective insecticide candidates. An in vitro bioassay showed that gem-difluoromethylenated statin analogues have potent effects on JH biosynthesis of M. sexta and high selectivity between H. sapiens and M. sexta. All series II compounds {1,3,5-trisubstituted [4-tert-butyl 2-(5,5-difluoro-2,2-dimethyl-6-vinyl-4-yl) acetate] pyrazoles} have some effect on JH biosynthesis, whereas most of them are inactive on human HMGR. In particular, the IC 50 value of compound II-12 (37.8 nm) is lower than that of lovastatin (99.5 nm) and similar to that of rosuvastatin (24.2 nm). An in vivo bioassay showed that I-1, I-2, I-3 and II-12 are potential selective insecticides, especially for lepidopteran pest control. A predictable and statistically meaningful CoMFA model of 23 inhibitors (20 as training sets and three as test sets) was obtained with a value of q 2 and r 2 of 0.66 and 0.996 respectively. The final model suggested that a potent insect HMGR inhibitor should contain suitable small and non-electronegative groups in the ring part, and electronegative groups in the side chain. Four analogues were discovered as potent selective lepidopteran HMGR inhibitors, which can specifically be used for lepidopteran pest control. The CoMFA model will be useful for the design of new selective insect HMGR inhibitors that are structurally related to the training set compounds. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

PubMed

Rashid, Davood; Panda, B P; Vohora, Divya

2015-11-01

Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids. Copyright © 2015 Elsevier Ltd. All rights reserved.

New pharmacologic approaches to treating diabetic retinopathy.

PubMed

Ryan, Gina J

2007-09-01

The goal of treatment of diabetic retinopathy, limitations of laser photocoagulation, endpoints used in clinical studies of diabetic retinopathy treatments, and the mechanism of action, efficacy, and safety of several new and emerging therapies targeting the biochemical pathways that link chronic hyperglycemia with microvascular damage in patients with diabetic retinopathy are discussed. Improving or preserving vision is the primary goal of treatment for diabetic retinopathy. Limitations of laser photocoagulation include a lack of efficacy in some cases, discomfort from the procedure, the need for repeated treatment, and a risk of retinal damage and scarring. Visual acuity, quality of life, and macular thickness are used as endpoints in clinical studies of diabetic retinopathy treatments. Microvascular damage in patients with chronic hyperglycemia is mediated by interrelated pathways involving aldose reductase, advanced glycation end products, protein kinase C (PKC), and vascular endothelial growth factor (VEGF). Oral aldose reductase inhibitors have been studied with some success only in patients with diabetic peripheral neuropathy. The oral PKC inhibitor midostaurin and oral selective PKC beta inhibitor ruboxistaurin appear promising for improving or maintaining visual acuity, with gastrointestinal complaints the most commonly reported adverse effects. Intra-vitreal injection of corticosteroids or VEGF inhibitors is associated with short-lived improvement in or maintenance of visual acuity, a need for repeated injection, and a risk of local adverse effects. A variety of promising new therapies for diabetic retinopathy targeting the biochemical pathways that cause microvascular damage are under investigation. Additional clinical research is needed to determine the role of these new therapies in treating diabetic retinopathy.

Effect of conformational mobility and hydrogen-bonding interactions on the selectivity of some guanidinoaryl-substituted mechanism-based inhibitors of trypsin-like serine proteases.

PubMed

Rai, R; Katzenellenbogen, J A

1992-11-13

Previously, we have reported that some guanidino-substituted alpha- and beta-aryl enol lactones I and II behaved as selective, mechanism-based inhibitors of some trypsin-like proteases (Rai, R.; Katzenellenbogen, J.A. J. Med. Chem., submitted). In this study, we describe the synthesis and kinetic evaluation of some related, guanidino-substituted enol lactones having greater conformational mobility and affording additional hydrogen-bonding sites at the active site. The alpha-aryl-substituted lactones 1 and 2, which have greater conformational mobility in the guanidinoaryl linkage than I, selectively inhibited the trypsin-like enzymes, and they were relatively poor inactivators of alpha-chymotrypsin and human neutrophil elastase (HNE). The iodo enol lactone 2 permanently inactivated trypsin, urokinase, tissue plasminogen activator, and plasmin, showing exceptionally high specificity in its interaction with trypsin and urokinase. The selectivity pattern exhibited by the closely related, conformationally less mobile alpha-aryl-substituted iodo lactone Ib, which was previously shown to be a selective suicide substrate of urokinase and plasmin, provides an interesting comparison. The alpha-benzamido-substituted lactones 3 and 4, which afford an additional site for active-site hydrogen bonding, were found to be very potent alternate substrate inhibitors of trypsin and urokinase. In addition, the iodo lactone 4 permanently inactivated alpha-chymotrypsin. The importance of secondary interactions in increasing the specificities in the case of alpha-chymotrypsin is discussed.

EGF receptor tyrosine kinase inhibitors diminish transforming growth factor-alpha-induced pulmonary fibrosis.

PubMed

Hardie, William D; Davidson, Cynthia; Ikegami, Machiko; Leikauf, George D; Le Cras, Timothy D; Prestridge, Adrienne; Whitsett, Jeffrey A; Korfhagen, Thomas R

2008-06-01

Transforming growth factor-alpha (TGF-alpha) is a ligand for the EGF receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. We determined the effects of EGFR tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) on the development and progression of TGF-alpha-induced pulmonary fibrosis. Using a doxycycline-regulatable transgenic mouse model of lung-specific TGF-alpha expression, we determined effects of treatment with gefitinib and erlotinib on changes in lung histology, total lung collagen, pulmonary mechanics, pulmonary hypertension, and expression of genes associated with synthesis of ECM and vascular remodeling. Induction in the lung of TGF-alpha caused progressive pulmonary fibrosis over an 8-wk period. Daily administration of gefitinib or erlotinib prevented development of fibrosis, reduced accumulation of total lung collagen, prevented weight loss, and prevented changes in pulmonary mechanics. Treatment of mice with gefitinib 4 wk after the induction of TGF-alpha prevented further increases in and partially reversed total collagen levels and changes in pulmonary mechanics and pulmonary hypertension. Increases in expression of genes associated with synthesis of ECM as well as decreases of genes associated with vascular remodeling were also prevented or partially reversed. Administration of gefitinib or erlotinib did not cause interstitial fibrosis or increases in lavage cell counts. Administration of small molecule EGFR tyrosine kinase inhibitors prevented further increases in and partially reversed pulmonary fibrosis induced directly by EGFR activation without inducing inflammatory cell influx or additional lung injury.

Aqueous Molecular Dynamics Simulations of the M. tuberculosis Enoyl-ACP Reductase-NADH System and Its Complex with a Substrate Mimic or Diphenyl Ethers Inhibitors

PubMed Central

da Silva Lima, Camilo Henrique; de Alencastro, Ricardo Bicca; Kaiser, Carlos Roland; de Souza, Marcus Vinícius Nora; Rodrigues, Carlos Rangel; Albuquerque, Magaly Girão

2015-01-01

Molecular dynamics (MD) simulations of 12 aqueous systems of the NADH-dependent enoyl-ACP reductase from Mycobacterium tuberculosis (InhA) were carried out for up to 20–40 ns using the GROMACS 4.5 package. Simulations of the holoenzyme, holoenzyme-substrate, and 10 holoenzyme-inhibitor complexes were conducted in order to gain more insight about the secondary structure motifs of the InhA substrate-binding pocket. We monitored the lifetime of the main intermolecular interactions: hydrogen bonds and hydrophobic contacts. Our MD simulations demonstrate the importance of evaluating the conformational changes that occur close to the active site of the enzyme-cofactor complex before and after binding of the ligand and the influence of the water molecules. Moreover, the protein-inhibitor total steric (ELJ) and electrostatic (EC) interaction energies, related to Gly96 and Tyr158, are able to explain 80% of the biological response variance according to the best linear equation, pKi = 7.772 − 0.1885 × Gly96 + 0.0517 × Tyr158 (R2 = 0.80; n = 10), where interactions with Gly96, mainly electrostatic, increase the biological response, while those with Tyr158 decrease. These results will help to understand the structure-activity relationships and to design new and more potent anti-TB drugs. PMID:26457706

Efficacy of non-surgical treatments for androgenetic alopecia: a systematic review and network meta-analysis.

PubMed

Gupta, Aditya K; Mays, Rachel R; Dotzert, Michelle S; Versteeg, Sarah G; Shear, Neil H; Piguet, Vincent

2018-05-24

Androgenetic alopecia, or male/female pattern baldness, is the most common type of progressive hair loss disorder. The aim of this paper is to review recent advances in non-surgical treatments for androgenetic alopecia and identify the most effective treatments. A network meta-analysis (NMA) was conducted of the available literature of the six most common non-surgical treatment options for treating androgenetic alopecia in both men and women; dutasteride 0.5mg, finasteride 1mg, low level laser therapy (LLLT), minoxidil 2%, minoxidil 5% and platelet rich plasma (PRP). Seventy-eight studies met the inclusion criteria and twenty-two studies had the data necessary for a network meta-analysis. Relative effects show LLLT as the superior treatment. Relative effects show PRP, finasteride 1 mg (male), finasteride 1 mg (female), minoxidil 5%, minoxidil 2% and dutasteride (male) are approximately equivalent in mean change hair count following treatment. Minoxidil 5% and minoxidil 2% reported the most drug-related adverse events (n=45 and n=23, respectively). The quality of evidence of minoxidil 2% vs. minoxidil 5% was high; minoxidil 5% vs. placebo was moderate; dutasteride (male) vs. placebo, finasteride (female) vs placebo, minoxidil 2% vs. placebo, minoxidil 5% vs. LLLT was low and finasteride (male) vs. placebo, LLLT vs. sham, PRP vs. placebo, finasteride vs. minoxidil 2% was very low. Results of this NMA indicate the emergence of novel, non-hormonal therapies as effective treatments for hair loss; however, the quality of evidence is generally low. High quality randomized controlled trials and head to head trials are required to support these findings and aid in the development of more standardized protocols, particularly for PRP. Regardless, this analysis may aid physicians in clinical decision making and highlight the variety of non-surgical hair restoration options for patients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Inhibition of HIF-2.alpha. heterodimerization with HIF1.beta. (ARNT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruick, Richard K.; Caldwell, Charles G.; Frantz, Doug E.

2017-09-12

Provided is a method of inhibiting heterodimerization of HIF-2.alpha. to HIF1.beta. (ARNT) comprising binding certain small molecules to the HIF-2.alpha. PAS-B domain cavity but not to HIF1.alpha. and inhibiting HIF-2.alpha. heterodimerization to HIF1.beta. (ARNT) but not inhibiting HIF1.alpha. heterodimerization to HIF1.beta. (ARNT). Those certain small molecules are also referenced synonymously as HIF2-HDI and HIF2.alpha. heterodimerization inhibitors and also simply as certain small molecules.

Effects of a caffeine-free Cola nitida nuts extract on elastase/alpha-1-proteinase inhibitor balance.

PubMed

Daels-Rakotoarison, Dominique A; Kouakou, Gisèle; Gressier, Bernard; Dine, Thierry; Brunet, Claude; Luyckx, Michel; Bailleul, François; Trotin, Francis

2003-11-01

In an infection, polymorphonuclear neutrophils (PMN) become activated and they produce oxidizing compounds and elastase in the extracellular medium. Alpha-1-proteinase inhibitor (alpha1PI), a protease inhibitor which is inactivated by oxidants, is the main endogenous inhibitor of elastase helping to limit excessive elastase activity. This study evaluates the ability of a plant extract, Cola nitida nuts, to protect alpha1PI from inactivation by oxidizing compounds as reactive oxygen species. On the one hand, we have evaluated the direct effect of cola nut extract on neutrophil elastase, and on the H(2)O(2) and myeloperoxidase (MPO)-H(2)O(2) system via cell-free systems. Results showed that cola nut extract scavenges H(2)O(2) and therefore protects alpha1PI from HOCl which is produced from the MPO-H(2)O(2) system. Experiments also showed that cola extract has the capacity to limit elastase activity. On the other hand, we have worked on cellular systems including isolated PMN with the aim to study the effect of cola extract on PMN metabolism. PMN were stimulated with PMA, calcium ionophore or fMLP. Each stimulant possesses its own stimulation pathway. According to the inhibitory concentration obtained at 50%, the results on cellular systems led to the conclusion that cola extract can reduce elastase liberation from PMN. It can then be concluded that cola nut extract can protect alpha1PI from inactivation, and has an effect both on elastase liberation and elastase activity. The cola nut extract effect is rather biased towards a reduction in elastase release, thus limiting the injurious effects caused by this enzyme.

Natural products as alpha-amylase and alpha-glucosidase inhibitors and their hypoglycaemic potential in the treatment of diabetes: an update.

PubMed

Tundis, R; Loizzo, M R; Menichini, F

2010-04-01

The inhibition of alpha-glucosidase and alpha-amylase, enzymes involved in the digestion of carbohydrates, can significantly reduce the post-prandial increase of blood glucose and therefore can be an important strategy in the management of blood glucose level in type 2 diabetic and borderline patients. Currently, there is renewed interest in plant-based medicines and functional foods modulating physiological effects in the prevention and cure of diabetes and obesity. The plant kingdom is a wide field to search for natural effective oral hypoglycaemic agents that have slight or no side effects. More than ca. 1200 plant species have been recorded to be used empirically worldwide for their alleged hypoglycaemic activity. Therefore, natural alpha-glucosidase and alpha-amylase inhibitors from plant sources offer an attractive strategy for the control of hyperglycaemia. This article reviews recent data on plant extracts and isolated natural compounds that are being tested for their hypglycaemic activity, highlights ongoing research and considers the future persepctives.

Insights into Enzyme Catalysis and Thyroid Hormone Regulation of Cerebral Ketimine Reductase/μ-Crystallin Under Physiological Conditions.

PubMed

Hallen, André; Cooper, Arthur J L; Jamie, Joanne F; Karuso, Peter

2015-06-01

Mammalian ketimine reductase is identical to μ-crystallin (CRYM)-a protein that is also an important thyroid hormone binding protein. This dual functionality implies a role for thyroid hormones in ketimine reductase regulation and also a reciprocal role for enzyme catalysis in thyroid hormone bioavailability. In this research we demonstrate potent sub-nanomolar inhibition of enzyme catalysis at neutral pH by the thyroid hormones L-thyroxine and 3,5,3'-triiodothyronine, whereas other thyroid hormone analogues were shown to be far weaker inhibitors. We also investigated (a) enzyme inhibition by the substrate analogues pyrrole-2-carboxylate, 4,5-dibromopyrrole-2-carboxylate and picolinate, and (b) enzyme catalysis at neutral pH of the cyclic ketimines S-(2-aminoethyl)-L-cysteine ketimine (owing to the complex nomenclature trivial names are used for the sulfur-containing cyclic ketimines as per the original authors' descriptions) (AECK), Δ(1)-piperideine-2-carboxylate (P2C), Δ(1)-pyrroline-2-carboxylate (Pyr2C) and Δ(2)-thiazoline-2-carboxylate. Kinetic data obtained at neutral pH suggests that ketimine reductase/CRYM plays a major role as a P2C/Pyr2C reductase and that AECK is not a major substrate at this pH. Thus, ketimine reductase is a key enzyme in the pipecolate pathway, which is the main lysine degradation pathway in the brain. In silico docking of various ligands into the active site of the X-ray structure of the enzyme suggests an unusual catalytic mechanism involving an arginine residue as a proton donor. Given the critical importance of thyroid hormones in brain function this research further expands on our knowledge of the connection between amino acid metabolism and regulation of thyroid hormone levels.

Tumor necrosis factor-alpha antagonists: differential clinical effects by different biotechnological molecules.

PubMed

Licastro, F; Chiappelli, M; Ianni, M; Porcellini, E

2009-01-01

Inhibitors of tumor necrosis factor-alpha have deeply changed the therapy of several inflammatory human diseases. For instance, clinical management of rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis have profoundly benefited after the introduction of new therapeutic tools, such as antagonist of TNF-alpha molecule. These drugs include etanercept, a soluble TNF-alpha receptor antagonist, three anti-TNF-alpha antibodies, adalimumab, infliximab, golimumab and certolizumab a humanized Fab fragment combined with polyethylene glycol. These compounds efficiently inhibit several TNF-alpha biological-mediated effects, however, they have also shown differential clinical efficacy in several trials from different autoimmune diseases. It is of clinical relevance that non-responders to one of these drugs often positively responded to another. Different mechanisms of action and diversity in pharmacokinetics of these three compounds may partially explain different clinical effects. However, partially diverse pathogenetic mechanisms in different diseases also contribute to differential therapeutic responses. Therefore, these apparently homogeneous agents can not be considered equivalent in their clinically efficacy. Differential therapeutic actions of these drugs may be advantageously used in clinical practice and further improve the great potential of individual TNF-alpha inhibitors.

Binding Energy Calculation of Patchouli Alcohol Isomer Cyclooxygenase Complexes Suggested as COX-1/COX-2 Selective Inhibitor

PubMed Central

Mahdi, Chanif; Nurdiana, Nurdiana; Kikuchi, Takheshi; Fatchiyah, Fatchiyah

2014-01-01

To understand the structural features that dictate the selectivity of the two isoforms of the prostaglandin H2 synthase (PGHS/COX), the three-dimensional (3D) structure of COX-1/COX-2 was assessed by means of binding energy calculation of virtual molecular dynamic with using ligand alpha-Patchouli alcohol isomers. Molecular interaction studies with COX-1 and COX-2 were done using the molecular docking tools by Hex 8.0. Interactions were further visualized by using Discovery Studio Client 3.5 software tool. The binding energy of molecular interaction was calculated by AMBER12 and Virtual Molecular Dynamic 1.9.1 software. The analysis of the alpha-Patchouli alcohol isomer compounds showed that all alpha-Patchouli alcohol isomers were suggested as inhibitor of COX-1 and COX-2. Collectively, the scoring binding energy calculation (with PBSA Model Solvent) of alpha-Patchouli alcohol isomer compounds (CID442384, CID6432585, CID3080622, CID10955174, and CID56928117) was suggested as candidate for a selective COX-1 inhibitor and CID521903 as nonselective COX-1/COX-2. PMID:25484897

Characterization of nicotine binding in mouse brain and comparison with the binding of alpha-bungarotoxin and quinuclidinyl benzilate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, M.J.; Collins, A.C.

1982-11-01

The binding of (/sup 3/H)nicotine to mouse brain has been measured and subsequently compared with the binding of (/sup 125/I)alpha-bungarotoxin (alpha-BTX) and L-(/sup 3/H)quinuclidinyl benzilate (QNB). The binding of nicotine was saturable, reversible, and stereospecific. Although the rates of association and dissociation of nicotine were temperature-dependent, the incubation temperature had no effect on either KD or Bmax. Nicotine binding was unaffected by the addition of NaCl, KCl, CaCl/sub 2/, or MgSO/sub 4/ to the incubation medium. Nicotinic cholinergic agonists were potent inhibitors of nicotine binding; however, nicotinic antagonists were poor inhibitors. The regional distribution of binding was not uniform: midbrainmore » and striatum contained the highest number of receptors, whereas cerebellum had the fewest. Differences in site densities, regional distribution, inhibitor potencies, and thermal denaturation indicated that nicotine binding was not the same as either QNB or alpha-BTX binding, and therefore that receptors for nicotine may represent a unique population of cholinergic receptors.« less

Biological activity of aldose reductase and lipophilicity of pyrrolyl-acetic acid derivatives

NASA Astrophysics Data System (ADS)

Kumari, A.; Kumari, R.; Kumar, R.; Gupta, M.

2011-12-01

Quantitative Structure-Activity Relationship modeling is a powerful approach for correlating an organic compound to its lipophilicity. In this paper QSAR models are established for estimation of correlation of the lipophilicity of a series of pyrrolyl-acetic acid derivatives, inhibitors of the aldose reductase enzyme, in the n-octanol-water system with biological activity of aldose reductase. Lipophilicity, expressed by the logarithm of n-octnol-water partition coefficient log P and biological activity of aldose reductase inhibitory activity by log it. Result obtained by QSAR modeling of compound series reveal a definite trend in biological activity and a further improvement in quantitative relationships are established if, beside log P, Hammett electronic constant σ and connectivity index chi-3 (3 χ) term included in the regression equation. The tri-parametric model with log P, 3 χ and σ as correlating parameters have been found to be the best which gives a variance of 87% ( R 2 = 0.8743). A compound has been found to be serious outlier and when the same has been excluded the model explains about 94% variance of the data set ( R 2 = 0.9447). The topological index (3 χ) has been found to be a good parameter for modeling the biological activity.

Nitrate reductase gene involvement in hexachlorobiphenyl dechlorination by Phanerochaete chrysosporium.

PubMed

De, Supriyo; Perkins, Michael; Dutta, Sisir K

2006-07-31

Polychlorobiphenyl (PCB) degradation usually occurs through reductive dechlorination under anaerobic conditions and phenolic ring cleavage under aerobic conditions. In this paper, we provide evidence of nitrate reductase (NaR) mediated dechlorination of hexachlorobiphenyl (PCB-153) in Phanerochaete chrysosporium under non-ligninolytic condition and the gene involved. The NaR enzyme and its cofactor, molybdenum (Mo), were found to mediate reductive dechlorination of PCBs even in aerobic condition. Tungsten (W), a competitive inhibitor of this enzyme, was found to suppress this dechlorination. Chlorine release assay provided further evidence of this nitrate reductase mediated dechlorination. Commercially available pure NaR enzyme from Aspergillus was used to confirm these results. Through homology search using TBLASTN program, NaR gene was identified, primers were designed and the RT-PCR product was sequenced. The NaR gene was then annotated in the P. chrysosporium genome (GenBank accession no. AY700576). This is the first report regarding the presence of nitrate reductase gene in this fungus with the explanation why this fungus can dechlorinate PCBs even in aerobic condition. These fungal inoculums are used commercially as pellets in sawdust for enhanced bioremediation of PCBs at the risk of depleting soil nitrates. Hence, the addition of nitrates to the pellets will reduce this risk as well as enhance its activity.

Trypanothione Reductase: A Target for the Development of Anti- Trypanosoma cruzi Drugs.

PubMed

Vázquez, Karina; Paulino, Margot; Salas, Cristian O; Zarate-Ramos, Juan J; Vera, Brenda; Rivera, Gildardo

2017-01-01

Chagas disease or American trypanosomiasis is a major parasitic disease in Latin America with restricted available treatment: nifurtimox and benznidazole. These two drugs are ineffective in the chronic phase of the disease; therefore, there is a need for the development of new, efficient and safe drugs for the treatment of this pathology. With this goal, one of the promising targets is trypanothione reductase (TR), a key enzyme in the metabolism of Trypanosoma cruzi. In this review, we analyse the importance of TR as a drug target, as well as the well-known and new inhibitors reported in the last decade as potential therapeutic agents for Chagas disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Recent Advances in Drug Design and Drug Discovery for Androgen-Dependent Diseases

PubMed Central

Cabeza, Marisa; Sánchez-Márquez, Araceli; Garrido, Mariana; Silva, Aylín; Bratoeff, Eugene

2016-01-01

This article summarizes the importance of different targets such as 5α-reductase, 17β-HSD, CYP17A, androgen receptor and protein kinase A for the treatment of prostate cancer and benign prostatic hyperplasia. It is a well known fact that dihydrotestosterone (DHT) is associated with the development of androgen-dependent afflictions. At the present time, several research groups are attempting to develop new steroidal and non-steroidal molecules with the purpose of inhibiting the synthesis and biological response of DHT. This review also discusses the most recent studies reported in the literature that describe the therapeutic potential of novel compounds, as well as the new drugs, principally inhibitors of 5α-reductase. PMID:26861003

Direct Measurement of S-Nitrosothiols with an Orbitrap Fusion Mass Spectrometer: S-Nitrosoglutathione Reductase as a Model Protein.

PubMed

Guerra, Damian; Truebridge, Ian; Eyles, Stephen J; Treffon, Patrick; Vierling, Elizabeth

2018-01-01

Recent studies suggest cysteine S-nitrosation of S-nitrosoglutathione reductase (GSNOR) could regulate protein redox homeostasis. "Switch" assays enable discovery of putatively S-nitrosated proteins. However, with few exceptions, researchers have not examined the kinetics and biophysical consequences of S-nitrosation. Methods to quantify protein S-nitrosothiol (SNO) abundance and formation kinetics would bridge this mechanistic gap and allow interpretation of the consequences of specific modifications, as well as facilitate development of specific S-nitrosation inhibitors. Here, we describe a rapid assay to estimate protein SNO abundance with intact protein electrospray ionization mass spectrometry. Originally designed using recombinant GSNOR, these methods are applicable to any purified protein to test for or further study nitrosatable cysteines.

Potential Chemopreventive Agents Based on the Structure of the Lead Compound 2-Bromo-1-hydroxyphenazine, Isolated from Streptomyces sp., Strain CNS284

PubMed Central

Conda-Sheridan, Martin; Marler, Laura; Park, Eun-Jung; Kondratyuk, Tamara P.; Jermihov, Katherine; Mesecar, Andrew D.; Pezzuto, John M.; Asolkar, Ratnakar N.; Fenical, William; Cushman, Mark

2010-01-01

The isolation of 2-bromo-1-hydroxyphenazine from a marine Streptomyces sp., strain CNS284, and its activity against NFκB, suggested that a short and flexible route for the synthesis of this metabolite and a variety of phenazine analogues be developed. Numerous phenazines were subsequently prepared and evaluated as inducers of quinone reductase 1 (QR1) and inhibitors of quinone reductase 2 (QR2), NF-κB, and inducible nitric oxide synthase (iNOS). Several of the active phenazine derivatives displayed IC50 values vs. QR1 induction and QR2 inhibition in the nanomolar range, suggesting they may find utility as cancer chemopreventive agents. PMID:21105712