Impact of a health alert and its implementation on flutamide prescriptions for women: an interrupted time series analysis

BACKGROUND

Off-label drug use among ambulatory patients is often based on little or no scientific support. This paper reports the impact of a health warning about the risks of off-label flutamide use by women and the actions subsequently implemented by the public health service targeting such use.

METHOD

The study was undertaken in a region in north-west Spain. We designed a segmented regression model of an interrupted time series, in which the dependent variable was the monthly value of defined daily doses of flutamide per 1000 inhabitants/day (DDD/TID), both total and stratified by sex. The following two data sources were used: flutamide prescriptions billed to the Spanish National Health Service; and flutamide deliveries made by wholesale drug distributors to pharmacies. The intervention assessed consisted of the issue of an official health warning and the actions subsequently taken to implement it.

RESULTS

There was an immediate reduction of 49.33% in DDD/TID billed to the Spanish National Health Service in respect of women; the mean value of the population percentage of DDD/TID of flutamide billed in respect of women fell from 34.4% pre-intervention to 23.72% post-intervention. There was an immediate reduction of 19.92% (95%CI: 6.68-33.15%) in total DDD/TID invoiced. There were no significant changes in DDD/TID billed in respect of men or in flutamide use in the private medical sector.

CONCLUSIONS

Off-label drug misuse is a reality among ambulatory patients, even after actions are implemented following a toxicity warning issued by the competent Health Authority.

Androgenic modulation of extraordinary muscle speed creates a performance trade-off with endurance

Performance trade-offs can dramatically alter an organism's evolutionary trajectory by making certain phenotypic outcomes unattainable. Understanding how these trade-offs arise from an animal's design is therefore an important goal of biology. To explore this topic, we studied how androgenic hormones, which regulate skeletal muscle function, influence performance trade-offs relevant to different components of complex reproductive behaviour. We conducted this work in golden-collared manakins (Manacus vitellinus), a neotropical bird in which males court females by rapidly snapping their wings together above their back. Androgens help mediate this behavior by radically increasing the twitch speed of a dorsal wing muscle (scapulohumeralis caudalis, SH), which actuates the bird's wing-snap. Through hormone manipulations and in situ muscle recordings, we tested how these positive effects on SH speed influence trade-offs with endurance. Indeed, this latter trait impacts the display by shaping signal length. We found that androgen-dependent increases in SH speed incur a cost to endurance, particularly when this muscle performs at its functional limits. Moreover, when behavioural data were overlaid on our muscle recordings, displaying animals appeared to balance display speed with fatigue-induced muscle fusion (physiological tetanus) to generate the fastest possible signal while maintaining an appropriate signal duration. Our results point to androgen action as a functional trigger of trade-offs in sexual performance - these hormones enhance one element of a courtship display, but in doing so, impede another.

Androgen/androgen receptor affects gentamicin-induced nephrotoxicity through regulation of megalin expression

AIM

Investigation whether androgen/androgen receptor (AR) might regulate megalin expression and/or functionality and thus affecting Gentamicin-induced nephrotoxicity (GIN).

MAIN METHODS

Male Wistar rats were treated with gentamicin with/out AR ligands (testosterone as agonist and flutamide as antagonist). Megalin expression in the kidney tissues was determined by real-time RT-PCR and western blot. Besides, megalin functionality was assessed using immunofluorescence imaging of fluorescein isothiocyanate (FITC) conjugated bovine serum albumin (BSA) (FITC-BSA). The effects of different treatments on the kidney were assessed at the structural level by histopathological evaluation and the biochemical level by colorimetric assay of blood urea nitrogen (BUN), serum creatinine (SCr) and urinary albumin/creatinine (A/C) ratio, besides, kidney expression of neutrophil gelatinase-associated lipocalin (NGAL) by immunoblotting.

KEY FINDINGS

Our results revealed that treatment with testosterone either alone or combined with gentamicin increased megalin expression at mRNA and protein levels as well as at the functional level. These effects were paralleled by increased GIN as manifested by increased SCr, BUN, A/C ratio, renal expression of NGAL or histopathological changes. On the other hand, treatment with flutamide ameliorated GIN and megalin expression and functionality. Computational analysis of megalin promotor revealed the presence of multiple response elements that mediate androgen response.

SIGNIFICANCE

Androgen/AR regulates megalin expression at the transcriptional level and consequently GIN. This may explain the sexual dimorphism in GIN and might represent a druggable target for treatment or prevention of GIN.

Degradation of the anticancer drug flutamide by solar photo-Fenton treatment at near-neutral pH: Identification of transformation products and in silico (Q)SAR risk assessment

Flutamide (FLUT) is a non-steroidal drug mainly used in the treatment of prostate cancer and has been detected in the aquatic environment at ng L^-1 levels. The environmental fate and effects of FLUT have not yet been studied. Conventional treatment technologies fail to completely remove pharmaceuticals, so the solar photo-Fenton process (SPF) has been proposed as an alternative. In this study, the degradation of FLUT, at two different initial concentrations in ultra-pure water, was carried out by SPF. The initial SPF conditions were pH₀ 5, [Fe²⁺]₀ = 5 mg L^-1, and [H₂O₂]₀ = 50 mg L^-1. Preliminary elimination rates of 53.4% and 73.4%. The kinetics of FLUT degradation could be fitted by a pseudo-first order model and the k_obs were 6.57 × 10^-3 and 9.13 × 10^-3 min^-1 t_30W and the half-life times were 95.62 and 73.10 min t_30W were achieved for [FLUT]₀ of 5 mg L^-1 and 500 μg L^-1, respectively. Analysis using LC-QTOF MS identified thirteen transformation products (TPs) during the FLUT degradation process. The main degradation pathways proposed were hydroxylation, hydrogen abstraction, demethylation, NO₂ elimination, cleavage, and aromatic ring opening. Different in silico (quantitative) structure-activity relationship ((Q)SAR) freeware models were used to predict the toxicities and environmental fates of FLUT and the TPs. The in silico predictions indicated that these substances were not biodegradable, while some TPs were classified near the threshold point to be considered as PBT compounds. The in silico (Q)SAR predictions gave positive alerts concerning the mutagenicity and carcinogenicity endpoints. Additionally, the (Q)SAR toolbox software provided structural alerts corresponding to the positive alerts obtained with the different mutagenicity and carcinogenicity models, supporting the positive alerts with more proactive information.

DMSO effects larval zebrafish (Danio rerio) behavior, with additive and interaction effects when combined with positive controls

Embryonic and larval zebrafish (Danio rerio) behavior is commonly used to identify neurotoxic compounds. Here, we investigated whether sub-lethal exposures to the common solvents dimethyl sulfoxide (DMSO, 0.01-1%) and methanol (MeOH, 0.01-1%), or the anti-fungal agent methylene blue (MB, 0.0001-0.0005%), can influence larval behavior in a simple light/dark paradigm conducted in 96-well plates. In addition, we tested whether the media volume within the behavioral arena or the zebrafish strain, AB wild type, AB Tübingen (AB/TU), or Tüpfel long-fin (TL), could also influence larval behavior. Following the single exposures, we co-exposed larvae to DMSO and either MB or two other compounds with known behavioral effects in larval zebrafish, flutamide and perfluorooctanesulfonic acid (PFOS). We found ≥0.55% DMSO and 0.0005% MB significantly affected larval behavior, but there was no effect of MeOH. Similarly, TL showed less movement compared to AB and AB/TU strains, whereas lower media volumes also significantly reduced larval movement. However, all strains responded similarly to DMSO and MB. In the co-exposure studies, we found either additive or interaction effects between DMSO and either MB, flutamide, or PFOS, depending on the behavioral endpoint measured. In addition, media volume had no effect on the DMSO concentration response curve, but again we observed additive effects on behavior. In conclusion, methodology can lead to alterations in baseline locomotor activity and compounds can have additive or interaction effects on behavioral endpoints. However, we found no evidence that strain effects should be a concern when deciding on solvents for a simple light/dark behavioral test in larval zebrafish.

Unraveling the electrochemical properties of lanthanum cobaltite decorated halloysite nanotube nanocomposite: An advanced electrocatalyst for determination of flutamide in environmental samples

Prostate cancer is one of the primary causes of death around the world. As an important drug, flutamide has been used in the clinical diagnosis of prostate cancer. However, the over dosage and improper discharge of flutamide could affect the living organism. Thus, it necessary to develop the sensor for detection of flutamide with highly sensitivity. In this paper, we report the synthesis of lanthanum cobaltite decorated halloysite nanotube (LCO/HNT) nanocomposite prepared by a facile method and evaluated for selective reduction of flutamide. The as-prepared LCO/HNT nanocomposite shows the best catalytic performance towards detection of flutamide, when compared to other bare and modified electrodes. The good electrochemical performance of the LCO/HNT nanocomposite modified electrode is ascribed to abundant active sites, large specific surface area and their synergetic effects. Furthermore, the LCO/HNT modified electrode exhibits low detection limit (0.002 μM), wide working range (0.009-145 μM) and excellent selectivity with remarkable stability. Meaningfully, the developed electrochemical sensor was applied in real environmental samples with an acceptable recovery range.

Development and evaluation of a harmonized whole body physiologically based pharmacokinetic (PBPK) model for flutamide in rats and its extrapolation to humans

By their definition, inadvertent exposure to endocrine disrupting compounds (EDCs) intervenes with the endocrine signalling system, even at low dose. On the one hand, some EDCs are used as important pharmaceutical drugs that one would not want to dismiss. On the other hand, these pharmaceutical drugs are having off-target effects and increasingly significant exposure to the general population with unwanted health implications. Flutamide, one of the top pharmaceutical products marketed all over the world for the treatment of prostate cancer, is also a pollutant. Its therapeutic action mainly depends on targeting the androgen receptors and inhibiting the androgen action that is essential for growth and survival of prostate tissue. Currently flutamide is of concern with respect to its categorization as an endocrine disruptor. In this work we have developed a physiologically based pharmacokinetic (PBPK) model of flutamide that could serve as a standard tool for its human risk assessment. First we built the model for rat (where many parameters have been measured). The rat PBPK model was extrapolated to human where the re-parameterization involved human-specific physiology, metabolic kinetics derived from in-vitro studies, and the partition coefficient same as the rat model. We have harmonized the model by integrating different sets of in-vitro, in-vivo and physiological data into a PBPK model. Then the model was used to simulate different exposure scenarios and the results were compared against the observed data. Both uncertainty and sensitivity analysis was done. Since this new whole-body PBPK model can predict flutamide concentrations not only in plasma but also in various organs, the model may have clinical applications in efficacy and safety assessment of flutamide. The model can also be used for reverse dosimetry in the context of interpreting the available biomonitoring data to estimate the degree to which the population is currently being exposed, and a tool for the pharmaceutical companies to validate the estimated Permitted Daily Exposure (PDE) for flutamide.

6β-Hydroxytestosterone, a metabolite of testosterone generated by CYP1B1, contributes to vascular changes in angiotensin II-induced hypertension in male mice

Background

Previously, we showed that 6β-hydroxytestosterone (6β-OHT), a cytochrome P450 1B1 (CYP1B1)-derived metabolite of testosterone, contributes to angiotensin II (Ang II)-induced hypertension in male mice. This study was conducted to test the hypothesis that 6β-OHT contributes to increased vascular reactivity, endothelial dysfunction, vascular hypertrophy, and reactive oxygen species production associated with Ang II-induced hypertension.

Methods

Eight- to 10-week-old intact or castrated C57BL/6 J (Cyp1b1^+/+ and Cyp1b1^−/−) mice were anesthetized for implantation of a micro-osmotic pump which delivered Ang II (700 ng/kg/day) or saline for 14 days. Mice were injected with 6β-OHT (15 μg/g b.w every third day), flutamide (8 mg/kg every day), or its vehicle. Blood pressure was measured via tail-cuff. Vascular reactivity, endothelial-dependent and endothelial-independent vasodilation, media to lumen ratio, fibrosis by collagen deposition, and reactive oxygen species production by dihydroethidium staining were determined in the isolated thoracic aorta.

Results

The response of thoracic aorta to phenylephrine and endothelin-1 was increased in Ang II-infused Cyp1b1^+/+ mice compared to intact Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice; these effects of Ang II were restored by treatment with 6β-OHT. Ang II infusion caused endothelial dysfunction, as indicated by decreased relaxation of the aorta to acetylcholine in Cyp1b1^+/+ but not Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice. 6β-OHT did not alter Ang II-induced endothelial dysfunction in Cyp1b1^+/+ mice but restored it in Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice. Ang II infusion increased media to lumen ratio and caused fibrosis and reactive oxygen species production in the aorta of Cyp1b1^+/+ mice. These effects were minimized in the aorta of Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice and restored by treatment with 6β-OHT. Treatment with the androgen receptor antagonist flutamide reduced blood pressure and vascular hypertrophy in castrated Ang II-infused mice injected with 6β-OHT.

Conclusions

6β-OHT is required for the action of Ang II to increase vascular reactivity and cause endothelial dysfunction, hypertrophy, and increase in oxygen radical production. The effect of 6β-OHT in mediating Ang II-induced hypertension and associated hypertrophy is dependent on the androgen receptor. Therefore, CYP1B1 could serve as a novel target for the development of therapeutics to treat vascular changes in hypertensive males.

Enzalutamide versus flutamide for castration-resistant prostate cancer after combined androgen blockade therapy with bicalutamide: the OCUU-CRPC study

BACKGROUND

Before the androgen target therapy era, flutamide was widely used for castration-resistant prostate cancer in Japan. Enzalutamide is currently the recommended treatment; however, the efficacy and safety of enzalutamide and flutamide after combined androgen blockade therapy with bicalutamide, has not been compared.

METHODS

Patients with castration-resistant prostate cancer who received combined androgen blockade therapy with bicalutamide were randomly assigned to receive either enzalutamide or flutamide. The primary endpoint for efficacy was the 3-month prostate-specific antigen response rate. This trial is registered with ClinicalTrials.gov (NCT02346578) and the University hospital Medical Information Network (UMIN000016301).

RESULTS

Overall, 103 patients were enrolled. The 3- (80.8% vs. 35.3%; p < 0.001) and 6-month (73.1% vs. 31.4%; p < 0.001) prostate-specific antigen response rates were higher in the enzalutamide than in the flutamide group. The 3-month disease progression rates (radiographic or prostate-specific antigen progression) were 6.4% and 38.8% in the enzalutamide and flutamide groups, respectively [hazard ratio (HR): 0.16; 95% confidence interval (CI): 0.05-0.47; p < 0.001]; the 6-month rates were 11.4% and 51.1%, respectively (HR 0.22; 95% CI 0.09-0.50; p < 0.001). Enzalutamide provided superior prostate-specific antigen progression-free survival compared with flutamide (HR 0.29; 95% CI 0.15-0.54; p < 0.001). Median time to prostate-specific antigen progression-free survival was not reached and was 6.6 months in the enzalutamide and flutamide groups, respectively.

CONCLUSIONS

As an alternative anti-androgen therapy in patients with castration-resistant prostate cancer who fail bicalutamide-combined androgen blockade therapy, enzalutamide provides superior clinical outcomes compared with flutamide. Enzalutamide should be preferred over flutamide in these patients.

Role for androgens in determination of ovarian fate in the common snapping turtle, Chelydra serpentina

Sex steroids are involved in sex determination in almost all vertebrates, including species with temperature-dependent sex determination (TSD). It is well established that aromatase and estrogens are involved in ovary determination in TSD species. In contrast, the role of non-aromatizable androgens in TSD is less clear. In this study, we used dihydrotestosterone (DHT) and an antagonist of the mammalian androgen receptor (flutamide) to examine the impact of androgens on sex determination in the snapping turtle. We incubated eggs at a male-producing temperature and treated embryos with drug delivery vehicle (5 L ethanol), DHT in vehicle, or flutamide in vehicle during the sex-determining period. We then measured expression of markers for ovarian and testicular development and genes involved in steroidogenesis. A subset of embryos and hatchlings were collected for histological analysis of gonad differentiation and sex determination. DHT and flutamide both induced ovarian development: 100% of vehicle-treated hatchlings had testes, while 60% of DHT-treated and 32% flutamide-treated hatchlings had ovaries. DHT and flutamide treatments also had feminizing effects on gene expression patterns and the structure of embryonic gonads. DHT treatment increased expression of FoxL2, androgen receptor, aromatase and several steroidogenic genes. Flutamide produced a similar, but weaker, pattern of gene expression. Genes involved in testis development (Sox9 and Amh) were influenced by flutamide treatment. Our findings support the hypothesis that androgens and the androgen receptor are involved in ovary determination in the common snapping turtle.

How does the high pressure affects the solubility of the drug within the polymer matrix in solid dispersion systems

In this paper, we employed Broadband Dielectric Spectroscopy (BDS) in order to determine the effect of the high pressure on the solubility limits of the amorphous flutamide within Kollidon VA64 matrix. In order to achieve this goal, drug-polymer systems have been examined: (i) at ambient pressure and both isothermal and nonisothermal conditions by means of BDS as well as Differential Scanning Calorimetry (DSC), to validate proposed method; (ii) at high pressure conditions (20 and 50 MPa) and elevated temperatures (343 K, 353 K and 363 K) by means of dielectric spectroscopy. Our studies revealed that regardless of applied pressure the solubility of the flutamide within the co-polymer matrix increases with increasing temperature at isobar conditions. Moreover, our results clearly indicate that with increasing pressure the solubility of the drug within the polymer matrix is decreasing at isothermal conditions. Therefore, during the solubility limit studies one should consider the situation in which by increasing the pressure (at constant temperature) would achieve an effect similar to the lowering of the temperature (at constant pressure).

How can we improve the physical stability of co-amorphous system containing flutamide and bicalutamide? The case of ternary amorphous solid dispersions

The article describes the preparation and characterization of binary mixtures of two antiandrogens used in prostate cancer treatment, i.e. flutamide (FL) and bicalutamide (BIC), as well as their ternary mixtures with either poly(methyl methacrylate-co-ethyl acrylate) (MMA/EA) or polyvinylpyrrolidone (PVP). The samples were converted into amorphous form to improve their water solubility and dissolution rate. Broadband dielectric spectroscopy and differential scanning calorimetry revealed that FL-BIC (65%) (w/w) does not tend to crystallize from the supercooled liquid state. We made the assumption that the drug-to-drug weight ratio should be maintained as in the case of monotherapy so we decided to investigate the system containing FL and BIC in 15:1 (w/w) ratio with 30% additive of polymers as stabilizers. Our research has shown that only in the case of the FL-BIC-PVP mixture the crystallization has been completely inhibited, both in glassy and supercooled liquid state, which was confirmed by X-ray diffraction studies. In addition, we performed solubility and dissolution rate tests, which showed a significant improvement in solubility of ternary system as compared to its crystalline counterpart. Enhanced physical stability and water solubility of the amorphous ternary system makes it promising for further studies.

Retinoic acid: A potential therapeutic agent for cryptorchidism infertility based on investigation of flutamide-induced cryptorchid rats in vivo and in vitro

Cryptorchidism is a common disorder in children and may cause infertility in adults. The BTB is essential for maintaining the microenvironment necessary for normal spermatogenesis. This study investigated whether retinoic acid (RA) may regulate the proteins that are essential for integrity of the BTB in cryptorchidism. Female Sprague-Dawley rats were administrated flutamide during late pregnancy to induce a model of cryptorchidism in male offspring. The concentrations of RA and BTB tight and gap junction protein levels were significantly lower in untreated cryptorchid pups compared with normal pups, but almost normal in cryptorchid pups given RA. Studies in vitro corroborated these findings. The sperm quality of RA-treated model pups was better compared with the untreated model. RA treatment may have therapeutic potential to restore retinoic acid and proteins associated with integrity of the BTB in cryptorchid testis.

Activation of androgen receptors protects intact male mice from memory impairments caused by aromatase inhibition

Although 17β-estradiol (E₂) is known to regulate hippocampal function, the specific contributions of hippocampally-synthesized E₂ remain unclear. Infusion of the aromatase inhibitor letrozole into the dorsal hippocampus (DH) of ovariectomized mice disrupts object recognition and object placement memory consolidation, suggesting that DH-synthesized E₂ is essential for memory. However, the role of DH-synthesized E₂ in memory among male rodents is unknown. Here, we examined effects of aromatase inhibition on memory consolidation in male mice. Intact and gonadectomized mice were infused with vehicle or letrozole into the DH immediately post-training in object placement and object recognition tasks. Letrozole blocked memory in both tasks among gonadectomized males only, suggesting that circulating androgens, or a rise in hippocampal androgens due to aromatase inhibition, may support memory consolidation in intact males. To test this hypothesis, intact males were infused with the androgen receptor antagonist flutamide into the DH after object training. A dose-dependent impairment was observed in both tasks, indicating that blocking androgen signaling can impair memory consolidation. To test if hippocampal androgen receptor activation protected intact males from the impairing effects of letrozole, a non-impairing dose of flutamide was co-infused with letrozole. Co-administration of both drugs blocked object placement and object recognition memory consolidation, demonstrating that letrozole impairs memory in intact males only if androgen receptors are blocked. Together, these data suggest that DH-synthesized E₂ and androgen receptor activation may work in concert to mediate memory consolidation in intact males, such that androgen receptor activation protects against memory impairments caused by aromatase inhibition.

Enzalutamide versus flutamide for castration-resistant prostate cancer after combined androgen blockade therapy with bicalutamide: study protocol for a multicenter randomized phase II trial (the OCUU-CRPC study)

Background

Enzalutamide is an oral androgen receptor targeted agent that has been shown to improve survival in PREVAIL trials and has been approved for patients with chemo-naïve metastatic castration-resistant prostate cancer (CRPC). Meanwhile, flutamide is a non-steroidal oral anti-androgen that was commonly used before the approval of bicalutamide. The objective of the OCUU-CRPC study is to compare the efficacy and safety between second-line hormonal therapy of enzalutamide and flutamide as alternative anti-androgen therapy (AAT) after combined androgen blockade (CAB) therapy that included bicalutamide in patients with CRPC.

Methods

A total of 100 patients with CRPC with or without distant metastases after disease progression who received CAB therapy with bicalutamide were randomly assigned at a 1:1 ratio according to distant metastases to the enzalutamide (160 mg/day, 4 × 40 mg capsules once daily) and flutamide (375 mg/day; 3 × 125 mg tablets thrice daily) groups. The primary endpoint for the drug efficacy is the response rate of prostate-specific antigen (PSA) (i.e., the ratio of patients whose PSA declined by ≥50% from baseline) at 3 months. Meanwhile, the secondary endpoints are PSA progression rate at 3 and 6 months, PSA response rate at 6 months, change in quality of life, PSA progression-free survival, and safety. The patient registration started in January 2015 and will end in March 2018, and the follow-up period is 6 months after the last patient registration. The main result will be reported in March 2019.

Discussion

In the OCUU-CRPC study, we compare the efficacy and safety of enzalutamide or alternative AAT with flutamide in participants with CRPC who were previously treated with a CAB therapy with bicalutamide. The expected results of this study will be that enzalutamide is superior to flutamide in terms of PSA response. A longer time to disease progression with enzalutamide over flutamide may translate to better overall survival. However, flutamide may be more accessible for patients owing to its lower cost than enzalutamide.

Trial registration

The OCUU-CRPC study was prospectively registered at clinicaltrials.gov (NCT02346578, January 2015) and University Hospital Medical Information Network (UMIN000016301, January 2015).

Flutamide-induced alterations in transcriptional profiling of neonatal porcine ovaries

Background

Androgens are involved in the regulation of ovarian development during fetal/neonatal life. Environmental chemicals displaying anti-androgenic activities may affect multiple signal transduction pathways by blocking endogenous androgen action. The aim of the current study was to examine effects of the anti-androgen flutamide on the expression of coding transcripts and long non-coding RNAs (lncRNAs) in neonatal porcine ovaries. By employing RNA-Seq technology we aimed to extend our understanding of the role of androgens in neonatal folliculogenesis and examine the impact of the anti-androgen flutamide on ovarian function.

Method

Piglets were subcutaneously injected with flutamide (50 mg/kg BW) or corn oil (controls) between postnatal days 1 and 10 (n = 3/group). Ovaries were excised from the 11-day-old piglets and total cellular RNAs were isolated and sequenced.

Results

Flutamide-treated piglet ovaries showed 280 differentially expressed genes (DEGs; P-adjusted < 0.05 and log₂ fold change ≥1.0) and 98 differentially expressed lncRNAs (DELs; P-adjusted < 0.05 and log₂FC ≥ 1.0). The DEGs were assigned to GO term, covering biological processes, molecular functions and cellular components, which linked the DEGs to functions associated with cellular transport, cell divisions and cytoskeleton. In addition, STRING software demonstrated strongest interactions between genes related to cell proliferation. Correlations between DEGs and DELs were also found, revealing that a majority of the genes targeted by the flutamide-affected lncRNAs were associated with intracellular transport and cell division.

Conclusions

Our results suggest that neonatal exposure of pigs to flutamide alters the expression of genes involved in ovarian cell proliferation, ovarian steroidogenesis and oocyte fertilization, which in turn may affect female reproduction in adult life.

Fertilization and male fertility in the rotifer Brachionus calyciflorus in the presence of three environmental endocrines

Many studies investigated the effects of environmental endocrine disruptors with the rotifer Brachionus calyciflorus. However, they focused on the reproductive behavior of rotifers, especially male-female fertilization, as a parameter in ecotoxicological and endocrine studies. In the present study, we used two environmental hormones (progesterone and testosterone) and one nonsteroidal antiandrogen (flutamide) at five different concentrations (0.5, 1, 2, 4, and 6 mg/L) to study the reproductive behavioral parameters of male rotifers. The average swimming speed of male rotifers in the blank group was 1.14 ± 0.43 mm/s. After exposure for 1 h, testosterone improved the swimming speed of males, with the greatest effect at a concentration of 2-4 mg/L, whereas flutamide and progesterone inhibited the swimming speed. Copulatory behavior experiments showed that, compared with the control group, the recognition ability of males was improved by testosterone at 1, 2, and 3 h (P < 0.05). After 4, 5, and 6 h, progesterone substantially suppressed the mating recognition ability of males, where the density of each group was extremely low at 6 h. Flutamide had a similar effect on the mating recognition ability of male rotifers as that of progesterone. The male fertilization rate in B. calyciflorus increased significantly under testosterone exposure at different concentrations (P < 0.05), with the highest level at 2 mg/L (male fertility rate = 48.61 ± 3.18%). The fertilization rate of male rotifers was suppressed by both progesterone and flutamide (P < 0.05), and higher drug concentrations had stronger suppressive effects.

Broadband dielectric spectroscopy as an experimental alternative to calorimetric determination of the solubility of drugs into polymer matrix: Case of flutamide and various polymeric matrixes

In this paper we determined the solubility limits of the amorphous flutamide within the two different polymeric matrixes - poly vinylpyrrolidone and poly vinylacetate. In order to achieve this goal, series of broadband dielectric spectroscopy measurements were performed. As a result we found that the maximal amount of the drug that can be successfully dissolved within the PVAc (maintaining the non-supersaturated conditions) is equal to 35 wt% of the amorphous solid dispersion system. Interestingly enough similar results, in terms of solubility limits, were achieved utilizing significantly higher amount of the pharmaceutical - 71 wt% - in the PVP matrix. Accordingly, we established the following relationship in the solubility limits of the amorphous flutamide dispersed within examined polymer matrixes: PVP > PVAc. It is worth highlighting that in order to preserve the thermodynamic stability - one of the two contributors to the physical stability - drug loading in the amorphous solid dispersion system should not exceed its solubility limits. Hence, choosing appropriate amount of the polymer addition will determine if obtained system remains physically stable. Subsequently, we presented the "stability maps" for all investigated FL-based ASD systems from which one might predict the stabilization effect exerted by certain amount of polymer.

Androgen receptor is a negative regulator of contextual fear memory in male mice

Although sex-hormones have a well-documented role in memory formation, most literature has focused on estrogens, whereas the role of androgens and their receptor (the androgen receptor; AR) in fear memory is relatively unexplored. To address this gap, we used a transgenic mouse model of AR overexpression (CMV-AR) to determine if AR regulates fear memory, and if this effect can be reversed either by the removal of circulating androgens via gonadectomy, or by antagonising AR activity with flutamide. We found that AR overexpression results in reduced freezing in response to foot shock, and that this difference is reversed with both gonadectomy and flutamide treatment. Differences between genotypes were reinstated by testosterone replacement in gonadectomized mice, suggesting that reduced fear memory in mutants results from AR activation by testosterone and is not secondary to group differences in circulating testosterone. Potential transcriptional mechanisms by which CMV-AR exerts its effects on fear memory were assessed by quantitating the expression of memory-related genes in area CA1 of the hippocampus. Several genes that are altered with AR inhibition and activation, including genes that encode for the histone variant H2A.Z, cholinergic receptors, glutamate receptors, and brain-derived neurotrophic factor. Overall, our findings suggest that AR is a negative regulator of fear memory and identify potential gene targets through which AR may mediate this effect.

Pigment epithelium derived factor (PEDF) expression in the male tract of Wistar rats

Pigment epithelium derived factor (PEDF) expression has been described in many organs as showing neurotrophic, anti-angiogenic, anti-apoptotic, anti-inflammatory, anti-oxidant and pro-cell survival properties. However, references to its activity in the male reproductive system are scarce. We aimed to characterize the expression of PEDF in the male reproductive tract of Wistar rats by using RT-PCR, western blot and immunostaining and also evaluate the effect of flutamide in PEDF expression. We found that PEDF is expressed in the epididymis, prostate and seminal vesicles in Wistar rats, but notably not in the testes. Under the effect of flutamide PEDF expression decreased, recovering by suppressing the antiandrogen. The epididymis is an essential organ in sperm maturation-storages. The role of PEDF in this physiological process has not been fully elucidated yet, but considering that in other systems PEDF has anti-apoptotic, anti-oxidants and pro-cell survival properties, its expression along the epididymis could play a role in the protection of spermatozoa while they are stored.

The effects of flutamide on cell-cell junctions in the testis, epididymis, and prostate

In this review, we summarize recent findings on the effect of the anti-androgen flutamide on cell-cell junctions in the male reproductive system. We outline developmental aspects of flutamide action on the testis, epididymis, and prostate, and describe changes in junction protein expression and organization of junctional complexes in the adult boar following prenatal and postnatal exposure. We also discuss findings on the mechanisms by which flutamide induces alterations in cell-cell junctions in reproductive tissues of adult males, with special emphasis on cytoplasmic effects. Based on the results from in vivo and in vitro studies in the rat, we propose that flutamide affects the expression of junction proteins and junction complex structure not only by inhibiting androgen receptor activity, but equally important by modulating protein kinase-dependent signaling in testicular cells. Additionally, results from studies on prostate cancer cell lines point to a role for the cellular molecular outfit in response to flutamide.

Determination of flutamide and two major metabolites using HPLC-DAD and HPTLC methods

Flutamide is a potential antineoplastic drug classified as an anti-androgen. It is a therapy for men with advanced prostate cancer, administered orally after which it undergoes extensively first pass metabolism in the liver with the production of several metabolites. These metabolites are predominantly excreted in urine. One of the important metabolites in plasma is 4-nitro-3-(trifluoromethyl)phenylamine (Flu-1), while the main metabolite in urine is 2-amino-5-nitro-4-(trifluoromethyl)phenol (Flu-3). In this work the two metabolites, Flu-1 and Flu-3, have been synthesized, and then structural confirmation has been carried out by HNMR analysis. Efforts were exerted to develop chromatographic methods for resolving Flutamide and its metabolites with the use of acceptable solvents without affecting the efficiency of the methods. The drug along with its metabolites were quantitatively analyzed in pure form, human urine, and plasma samples using two chromatographic methods, HPTLC and HPLC-DAD methods. FDA guidelines for bio-analytical method validation were followed and USP recommendations were used for analytical method validation. Interference from excipients has been tested by application of the methods to pharmaceutical tablets. No significant difference was found between the proposed methods and the official one when they were statistically compared at p value of 0.05%.

Aberrant Expression of Cx Isoforms in the Adult Caput Epididymis exposed to Estradiol Benzoate or Flutamide at the Weaning

Connexin (Cx) involves in the regulation of various physiological functions of tissue by forming a channel, a gap junction which allows direct cell-cell communication, between adjacent cells. The effect of a single subcutaneous treatment of estradiol benzoate (EB) or flutamide (Flu) at the weaning age on the expression of Cx isoforms in the adult caput epididymis was evaluated in this research. Using quantitative real-time PCR analysis, a low-dose of EB [0.015 μg/kg body weight (BW)] caused significant decreases of Cx30.3, Cx32, Cx40, Cx43, and Cx45 mRNA levels and no change of Cx26, Cx31, Cx31.1, Cx37 transcript levels. The treatment of a high-dose EB (1.5 μg/kg BW) resulted in reduced expression of Cx30.3, Cx31, Cx43, and Cx45 but increased expression of Cx37 and Cx40. Expression of all Cx isoforms examined, except Cx31, was significantly increased by the treatment of a low-dose Flu (500 μg/kg BW). However, the treatment of a high-dose Flu (5 mg/kg BW) led significant expressional suppression of Cx30.3, Cx31, Cx31.1, Cx32, Cx40, Cx43, and Cx45 but an increase of Cx37 transcript level. With the comparison of previous findings, the expression of Cx isoforms in the adult epididymis after the exposure to EB or Flu is likely differentially regulated in regional-specific and/or exposed postnatal age-specific manner.

Testosterone-induced modulation of peroxisomal morphology and peroxisome-related gene expression in brown trout (Salmo trutta f. fario) primary hepatocytes

Disruption of androgenic signaling has been linked to possible cross-modulation with other hormone-mediated pathways. Therefore, our objective was to explore effects caused by testosterone - T (1, 10 and 50μM) in peroxisomal signaling of brown trout hepatocytes. To study the underlying paths involved, several co-exposure conditions were tested, with flutamide - F (anti-androgen) and ICI 182,780 - ICI (anti-estrogen). Molecular and morphological approaches were both evaluated. Peroxisome proliferator-activated receptor alpha (PPARα), catalase and urate oxidase were the selected targets for gene expression analysis. The vitellogenin A gene was also included as a biomarker of estrogenicity. Peroxisome relative volumes were estimated by immunofluorescence, and transmission electron microscopy was used for qualitative morphological control. The single exposures of T caused a significant down-regulation of urate oxidase (10 and 50μM) and a general up-regulation of vitellogenin. A significant reduction of peroxisome relative volumes and smaller peroxisome profiles were observed at 50μM. Co-administration of T and ICI reversed the morphological modifications and vitellogenin levels. The simultaneous exposure of T and F caused a significant and concentration-dependent diminishing in vitellogenin expression. Together, the findings suggest that in the tested model, T acted via both androgen and estrogen receptors to shape the peroxisomal related targets.

Expressional Changes of Connexin Isoform Genes in the Rat Caput Epididymis Exposed to Flutamide or Estradiol Benzoate at the Early Postnatal Age

Direct communication between neighboring cells through connexin (Cx)-based gap junction is a crucial biolo–gical manner to regulate functions of a tissue consisting of multi-cell types. The present research evaluated expressional changes of Cx isoforms in the caput epididymis of adult rat exposed to estradiol benzoate (EB) or flutamide (Flu) at the early postnatal age. A single subcutaneous administration of EB at a low-dose [0.015 µg /kg body weight (BW)] or a high-dose (1.5 µg/kg BW) or Flu at a low-dose (500 µg/kg BW) or a high-dose (5 mg/kg BW) was performed to an animal at 1 week of age. Quantitative real-time PCR analysis was employed to determine expressional changes of Cx isoforms. The transcript levels of Cxs30.3 and 37 were decreased by a low-dose EB treatment, while decreases of Cxs31, 31.1, 32, 40, and 45 transcript levels were observed with a low-dose EB treatment. The treatment of a high-dose EB resulted in expressional reduction of Cxs30.3, 31, 31.1, 37, 40, 43, and 45. The Flu treatment at a low dose caused increases of Cxs26, 37, and 40 transcript levels but decreases of Cxs31.1, 43, and 45 transcript levels. Increases of Cxs30.3, 31, 37, and 40 mRNA amounts were induced by a high-dose Flu treatment. However, exposure to a high-dose Flu produced expressional decreases of Cxs31.1, 32, and 43 in the adult caput epididymis. These observations suggest that exposure to EB or Flu at the neonatal period could lead to aberrant expression of Cx isoforms in the adult caput epididymis.