Concentrations Of Flutamide Research Articles

Self assembled three dimensional β-Cu2V2O7 hierarchical flower decorated porous carbon: An efficient electrocatalyst for flutamide detection in biological and environmental samples

The serious situation mandates the use of anticancer drugs, which protect people all over the world from the growth of prostate cancer. In particular, excessive dosage and erroneous discharge of flutamide concentration cause make environmental pollution on the surface of the wastewater. In this study, the highly sensitive and selective electrochemical approach based on copper vanadium oxide decorated porous carbon (denoted as β-Cu2V2O7/PC) composite modified glassy carbon electrode (GCE) has been developed and it was applied for sensitive detection of anticancer drug flutamide (FTM). Moreover, using the co-precipitation method, the flower-like β-Cu2V2O7 hierarchical microstructure was synthesized, and through the wet chemical process, the β-Cu2V2O7/PC composite was obtained. The resultant product was characterized by XRD, FTIR, RAMAN, XPS and structural morphology established by FESEM analysis. Besides that, the electrochemical characterization and properties were analyzed by cyclic voltammetry (CV) and amperometric (i-t) techniques. The β-Cu2V2O7/PC/RDGCE had two linear ranges at 0.01–2.11 μM and 2.31–30.81 μM. The lower limits of detection and sensitivity were found at 0.62 nM (S/N = 3), and 24.33 μA μM−1 cm−2 respectively. The practicability test was applied for the determination of FTM in urine, blood serum and environmental aquatic fluid with satisfactory recovery obtained.

Electrochemical detection of Flutamide as an anticancer drug with gold nanoparticles modified glassy carbon electrode in the presence of prostate cancer cells

In the current study, a novel electrochemical sensor was constructed based on gold nanoparticles modified glassy carbon electrode (AuNPs/GCE) to detect Flutamide. Field emission scanning electron microscope was used to identify the morphology of the modified electrode. Cyclic voltammetry and differential pulse voltammetry (DPV) were used to investigate the electrochemical activity of the modified electrode. Flutamide concentration, pH, and scan rate were optimized as electrochemical parameters. Flutamide peak currents obtained by DPV were linear within the concentration range of 1–600 µM, and the detection limit was calculated as 1.5 nM. In addition, the fabricated electrochemical sensor was successfully employed to detect Flutamide in a cell culture media containing prostate cancer cells as the biological sample. The stability of the modified electrode within a day showed an appropriate precision.

Evaluation of Human Liver Microtissues for Drug Screening on Schistosoma mansoni Schistosomula.

Schistosomiasis is a major neglected tropical disease with more than 200 million infections annually. Despite only one drug, praziquantel, being available, the drug pipeline against schistosomiasis is empty, and drug screening tools have limitations. We evaluated the potential of human liver microtissues (hLiMTs) in antischistosomal drug discovery. Because hLiMTs express all human P450 enzymes, they are an excellent tool to evaluate compounds' bioinactivation, bioactivation, and toxicity. To validate the metabolic conversion capacity of hLiMTs, we first quantified (R)- and (S)-praziquantel and the main metabolite trans-OH-praziquantel following incubation with 0.032-50 μM (0.01-15.62 μg/mL) praziquantel for up to 72 h by a validated LC-MS/MS method. We cocultured hLiMTs with newly transformed schistosomula (NTS) and evaluated the antischistosomal activity and cytotoxicity of three prodrugs terfenadine, tamoxifen citrate, and flutamide. HLiMTs converted 300-350 ng (R)-praziquantel within 24 h into trans-OH-praziquantel. We observed changes in the IC50 values for terfenadine, flutamide, and tamoxifen citrate in comparison to the standard NTS assay in vitro. Cytotoxicity was observed at high concentrations of flutamide and tamoxifen citrate. An in vitro platform containing hLiMTs could serve as an advanced drug screening tool for Schistosoma mansoni, providing information on reduced or increased activity and toxicity.

Electrochemical detection of flutamide with gold electrode as an anticancer drug

In this research, the Gold electrode was used to investigate the electrochemical behavior of the Flutamide by cyclic voltammetry and differential pulse voltammetry method. In addition, the morphology of the gold electrode surface was demonstrated with field emission scanning electron microscope (FESEM). Some of the effective parameters such as pH, scan rates, and Flutamide concentration were optimized. The pH 7 was selected as optimal pH. The currents of peak according to Flutamide concentration from 6 to 60 μM and 100–600 μM were linear, and the limit of detection was calculated 1.8 μM. This electrochemical sensor could detect Flutamide selectable in the presence of some interferents. • FESEM, CV, and DPV methods were used to study the electrochemical behavior of Flutamide. • The electrode was successfully detected Flutamide in presence of some interferents, with high selectivity.

Square wave voltammetric determination of anticancer drug flutamide using carbon paste electrode modified by CuO/GO/PANI nanocomposite

The electrochemical behavior of flutamide was investigated using a carbon paste electrode (CPE) modified by CuO nanoparticles/graphene oxide/polyaniline (CuO/GO/PANI) nanocomposite. Square wave and differential pulse voltammetry were studied in different concentrations of flutamide. Square wave voltammetry which is a rapid and sensitive method for reversible systems was used to determine flutamide. Based on the studies carried out by the present method, the electrode has an excellent electrochemical activity to the flutamide oxidation. Under the optimized experimental conditions, the sensor showed excellent linearity from 0.050 to 200.0 nM with a detection limit of 14.0 pM; the best values obtained already for flutamide. The modified electrode was applied for the determination of flutamide in human urine and pharmaceutical samples with satisfy results.

Effect of anti-androgen and progesterone on development of regrowth antlers in 6 year old sika deer

To investigate the effects of anti-androgen drugs and melengestrol acetate (MGA) on development of regrowth antlers in 6 year old sika deer, twenty healthysika deerwith similar body weight and antler weightwere randomly divided into five groups by using single factor test design: flutamide (n=4), bicalutamide (n=4), progesterone acetate (CPA, n=4), melengestrol acetate (MGA, n=4), control(n=4). All deer were fed with same diets and were housed outside together in an opened fence of 15 m×30 m with free access to water and feed. Treatment groups were injected subcutaneously sustained-release agents of the four drugs respectively when two-branched antlers were harvested. The control group had no special treatment. In the experiment period of 60 d, blood sampleswere collected for 4 times for each deer. The concentration of testosterone in plasma was tested and analyzed to compare the changes between different groups. Development of regrowth antlers was observed. At the end of the experiment, regrowth antlers were weighted and analyzed. The resultsshowed that the weights of regrowth antlers in treatment groups were significantly greater than those from control group and the weight gain (as compared with the control group) was 100.50%, 64.46%, 87.16% and 117.46% respectively in flutamide group, bicalutamide group, progesterone acetate group and melengestrol acetate group. For plasma testosterone concentration, it was not significantly different in the early stage (in the first 35 d), but at the end of the experimen, it was significantly higher than that of earlier stage (P<0.01) in various groups. Testosterone concentration of flutamide treated group was significantly lower than that of the other groups (P<0.01), while the level inbicalutamide and MGA treated groups was significantly higher than that in other groups (P<0.01). The results showed that both anti-androgen drugs and MGA treatment promoted the development of regrowth antlers and increased the weight of regrowth antlers, where the effect was most significant by MGA treatment. From the morphological observation of the antlers, it was found that anti-androgen and MGA treatments prolonged the growth period of regrowth antlers through delaying the ossification of antlers. However, plasma testosterone concentration was not affected by the treatments.

Electrochemical determination of anticancer drug, flutamide in human plasma sample using a microfabricated sensor based on hyperbranchedpolyglycerol modified graphene oxide reinforced hollow fiber-pencil graphite electrode

Flutamide (FLT) is a non-steroidal anti-androgen drug that has a specific anti-androgenic activity so that it is used in the treatment of prostate cancer. FLT may also be used to treat excess androgen levels in women. A sensitive electrochemical sensor based on hyperbranchedpolyglycerol functionalized- graphene oxide developed, using ionic liquid mediated hollow fiber-pencil graphite electrode (HF/HBP-GO/PGE) as a working electrode for determination of an anticancer drug, flutamide (FLT. In this design, a two centimeter piece of porous polypropylene hollow fiber membrane was impregnated with ionic liquid (1-Pentyl-3-methylimidazoliumbromide), and a graphite rod modified with hyperbranchedpolyglycerol/graphene oxide (HBP-GO), was located inside the fiber lumen. The modified electrode exhibits sorption activity, high sensitivity, stability and applicability over a wide range of concentration of FLT. The morphology and the electrochemical properties of the modified electrode were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). The effect of the amount of graphene oxide (GO), scan rate, pH, concentration of ionic liquid, extraction time and agitation rate on electrochemical behavior of flutamide molecules was investigated. The square wave voltammetric method showed a linear behavior over the drug concentration range 0.1–110 μM. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 0.029 μM and 0.099 μM, respectively. The proposed sensor was applied for determination of FLT in human plasma sample with satisfactory results.

Flutamide Induces Hepatic Cell Death and Mitochondrial Dysfunction via Inhibition of Nrf2-Mediated Heme Oxygenase-1.

Flutamide is a widely used nonsteroidal antiandrogen for prostate cancer therapy, but its clinical application is restricted by the concurrent liver injury. Increasing evidence suggests that flutamide-induced liver injury is associated with oxidative stress, though the precise mechanism is poorly understood. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master transcription factor regulating endogenous antioxidants including heme oxygenase-1 (HO-1). This study was designed to delineate the role of Nrf2/HO-1 in flutamide-induced hepatic cell injury. Our results showed that flutamide concentration dependently induced cytotoxicity, hydrogen peroxide accumulation, and mitochondrial dysfunction as indicated by mitochondrial membrane potential loss and ATP depletion. The protein expression of Nrf2 and HO-1 was induced by flutamide at 12.5 μM but was downregulated by higher concentrations of flutamide. Silencing either Nrf2 or HO-1 was found to aggravate flutamide-induced hydrogen peroxide accumulation and mitochondrial dysfunction as well as inhibition of the Nrf2 pathway. Moreover, preinduction of HO-1 by Copp significantly attenuated flutamide-induced oxidative stress and mitochondrial dysfunction, while inhibition of HO-1 by Snpp aggravated these deleterious effects. These findings suggest that flutamide-induced hepatic cell death and mitochondrial dysfunction is assoicated with inhibition of Nrf2-mediated HO-1. Pharmacologic intervention of Nrf2/HO-1 may provide a promising therapeutic approach in flutamide-induced liver injury.

Optimized treatment of wastewater containing cytotoxic drugs by living and dead biomass of the freshwater microalga, Chlorella vulgaris

The presence of recalcitrant cytotoxic drugs in aquatic environments pose significant harmful effects to the ecosystems and human health. Due to the problems associated with physicochemical methods in treatment of effluents containing cytotoxic agents, the present study aimed to evaluate the efficiency of microalgae in bioremediation of these compounds. Biosorption of the anticancer drug, Flutamide (FLU), was performed by living and dead biomass of Chlorella vulgaris. The living microalga showed a better performance in the drug removal considering the amount of biomass, pH and time of adsorption. A nonlinear regression approach revealed that the Freundlich and Langmuir isotherms could fit well to the adsorption data. Maximum sorption capacity of the living microalga (26.8mgg−1) was higher than the dead biomass (12.5mgg−1). Kinetic studies showed that adsorption process by living and dead microalga followed the modified Freundlich model. Optimization of the process by response surface methodology (RSM) indicated that at FLU concentration of 50μM, pH 7.4 and 10min, 98.5% drug removal could be obtained by the living biomass. The results indicate that the use of microalga can be a promising technology for the treatment of wastewaters containing cytotoxic compounds.

A New Method To Identify Physically Stable Concentration of Amorphous Solid Dispersions (I): Case of Flutamide + Kollidon VA64.

In this paper, a novel approach to determine stable concentration in API-polymer systems is presented. As a model, binary amorphous mixtures flutamide (FL) drug with a copolymer Kollidon VA64 (PVP/VA) have been used. It is worthwhile to note that finding an effective method to achieve this goal is a matter of great importance because physical stability of the amorphous pharmaceuticals is the key issue that is investigated worldwide. Due to the fact that molecular dynamics was found to be the crucial factor affecting physical stability of disordered pharmaceuticals, we examined it for both neat FL and its PVP/VA mixtures by means of broadband dielectric spectroscopy (BDS). Thorough investigation of the impact of polymeric additive on the molecular mobility of disordered FL reveals unusual, previously unreported behavior. Namely, simultaneously with the beginning of the recrystallization process, we observe some transformation from unstable supersaturated concentration of investigated mixture to the different, unknown concentration of FL-PVP/VA. Observed, during BDS experiment, transformation enables us to determine the limiting, highly physically stable concentration of FL in PVP/VA polymer (saturated solution), which is equivalent to FL + 41% wt. of PVP/VA. The described high physical stability of this unveiled system has been confirmed by means of long-term XRD measurements. According to our knowledge, this is the first time when such a behavior has been observed by means of BDS.

Effects of testosterone and flutamide on reproduction in Brachionus calyciflorus

The effects of testosterone and flutamide on reproduction in Brachionus calyciflorus were studied. Asexual reproduction in B. calyciflorus was not affected by testosterone at different concentrations of flutamide. Flutamide in combination with 0, 25, 50, or 75 µg L−1 testosterone had a significant effect on mixis rate. The combination of 5 µg L−1 flutamide with 25 µg L−1 or 50 µg L−1 testosterone resulted in a mixis rate that was 2.2× lower than that with flutamide alone. Fertilization rate was significantly decreased by 7.5 µg L−1 flutamide in combination with 25, 50, or 75 µg L−1 testosterone. The number of resting eggs produced per mictic female was significantly lower at all concentrations of testosterone. A low concentration of flutamide in combination with testosterone resulted in antagonism, increasing the number of resting eggs produced. However, when testosterone was combined with a higher concentration of flutamide, resting egg production declined. Therefore, long-term exposure to either testosterone, flutamide, or a combination of these two compounds may significantly reduce resting egg production in rotifers. This implies that resting egg production is affected differently by hormone pathways.

Developing a sensitive DNA biosensor for the detection of flutamide using electrochemical method

An uncomplicated method was applied to fabricate a novel electrochemical DNA biosensor for the determination of flutamide. This biosensor was composed of pretreated screen-printed electrode (SPE) that was modified with reduced graphene oxide (rGO) and decorated with ds-DNA. This biosensor was applied via the interaction of small molecules such as flutamide with the DNA. The interaction of salmon sperm ds-DNA with flutamide on the surface of ds-DNA-modified rGO–SPE (ds-DNA/rGO/SPE) was examined. The oxidation currents of guanine and adenine were used as probes in order to peruse the resulting interaction. Through the interaction of flutamide with the DNA, the oxidation currents of guanine and adenine declined at the ds-DNA/rGO/SPE, using differential pulse voltammetry (DPV). There was a linear dependence of the adenine oxidation currents and the flutamide concentration in the range of 0.0025–0.075 and 0.075–7.50 nmol L−1, with a limit of detection 1.5 pmol L−1. The relative standard deviations (RSD) for five replicate measurements of 0.05 and 5.0 nmol L−1 flutamide were obtained as 4.5 and 3.5%, using the adenine signal. This method was successfully applied to determine the trace amount of flutamide in real samples.

Development of a cleanup and electrochemical determination of flutamide using silica thin film pencil graphite electrode functionalized with thiol groups

This work mainly deals with the application of cleanup, preconcentration and electrochemical determination of flutamide. A new system is developed to cleanup and detect of flutamide at the surface of a working electrode. Differential pulse voltammetry (DPV) was used as a detection system. A modified pencil graphite electrode (PGE) was used as a working electrode. The surface of the PGE was coated with sodium dodecyl sulfate (SDS)-modified silica thin film. Flutamide is extracted from sample to the modified silica thin film and reduced electrochemically, and then, it was oxidized at the electrode surface. The effect of sample pH, SDS concentration, percentage of ingredients fiber structure, applied potential on the formation of fiber, and applied potential time on the electrode surface to form the fiber were evaluated. Other essential factors for flutamide extraction such as extraction time, stirring rate, pretreatment potential and electrochemical parameters were optimized. Using the extraction system, the DPV responses of different concentrations of flutamide were linear in the range of 0.10–100.0 nmol L−1 and 0.10–100.0 μmol L−1 with a detection limit of 34 pmol L−1. The technique was successfully applied for the determination of flutamide in human urine and plasma samples. The technique was successfully applied for the determination of flutamide in human urine and plasma samples.

Does anti-androgen, flutamide cancel out the in vivo effects of the androgen, dihydrotestosterone on sexual development in juvenile Murray rainbowfish (Melanotaenia fluviatilis)?

The aim of the present study was to investigate if the effects of the androgen, dihydrotestosterone (DHT) on the sexual development in juvenile Murray rainbowfish (Melanotaenia fluviatilis) are canceled out by the anti-androgen, flutamide. Fish (60 days post hatch) were exposed to 250ng/L of DHT, 25μg/L of flutamide (Flu-low), 250μg/L of flutamide (Flu-high), DHT+Flu low and DHT+Flu high. After 35 days of exposure, lengths and weights of the fish were measured and the condition factor (CF) calculated; vitellogenin (VTG) concentrations were measured in tail tissue; sex steroid hormones (17β-estradiol [E2] and 11-keto testosterone [11-KT]) were measured in the head tissue and abdominal regions were used in histological investigation of the gonads. Treatment with DHT reduced the body-length of both male and female fish, an effect which was canceled out by low and high concentrations of flutamide. However, flutamide (low or high) could not nullify the DHT-induced reduction in the CF in either sex. The E2 levels were reduced only in female fish after exposure to DHT but returned to normal after treatment with Flu-high. DHT increased the levels of 11-KT and decreased the E2/11-KT ratio in both sexes. Flu-high, but not Flu-low, could nullify these effects. Both DHT and flutamide (low or high) induced VTG production and this effect persisted when both chemicals were co-administered. Treatment with DHT did not affect gonadal cell development in the testes. However, the female fish treated with DHT contained ovaries in early-vitellogenic stage in comparison to the pre-vitellogenic ovaries in control fish. Co-treatment with flutamide (low or high) resulted in oocyte atresia. The results from the present study suggest that treatment with Flu-high could cancel out DHT-induced effects only on the hormonal profile and body-length in both male and female fish. Juvenile fish co-treated with DHT and flutamide (low or high) had high VTG levels and low CF. In addition, the ovaries in female fish were atretic. These data represent potential adverse effects on the ability of the fish to reproduce successfully.

Effects of short-term exposure to the model anti-androgen, flutamide on reproductive function based endpoints in female Murray rainbowfish (Melanotaenia fluviatilis)

The aim of the present study was to evaluate the responses of female Murray rainbowfish (Melanotaenia fluviatilis) to the model anti-androgen, flutamide in a short-term exposure. Adult female Murray rainbowfish were exposed to nominal (measured) concentrations of 125 (104), 250 (163), 500 (378) and 1000 (769)µg/L of flutamide for seven days in a semi-static set-up. Plasma vitellogenin (VTG), 11-keto testosterone (11-KT) and 17β-estradiol (E2) concentrations, brain aromatase activity and ovarian histology were assessed following the exposure. No treatment-related mortality was found in rainbowfish and there was no effect of flutamide on the developmental stage of the ovaries. Histological investigation revealed absence of mature oocytes in flutamide-treated fish. In addition, a significant reduction in the sizes of the vitellogenic oocytes was found after treatment with 500 and 1000µg/L flutamide. The circulating levels of VTG and the activity of aromatase in the brain were also significantly reduced in fish treated with 500 and 1000µg/L flutamide. Treatment with higher concentrations of flutamide reduced the levels of 11-KT and E2 in plasma. The results from this study demonstrate that a short-term exposure to the model anti-androgen, flutamide can adversely affect the reproductive function based on end-points such as plasma VTG, 11-KT and E2; brain aromatase activity and sizes of the oocytes in female Murray rainbowfish. Further, a positive correlation between these experimental variables suggests hormonal imbalance.

Investigation of the hepatotoxicity of flutamide: Pro-survival/apoptotic and necrotic switch in primary rat hepatocytes characterized by metabolic and transcriptomic profiles in microfluidic liver biochips

We investigated the effects of the liver damage induced by flutamide in primary rat hepatocytes using liver microfluidic biochips. Flutamide is a non-steroidal anti-androgenic drug. Two flutamide concentrations, 10μM and 100μM, were used to expose the hepatocytes for 24h under perfusion. Thanks to the maintenance of hepatocyte differentiation phenotype and to the biotransformation performance in the microfluidic cultures, the metabolic ratio analysis of hydroxyflutamide, flutamide-gluthatione and hydroxyflutamide-gluthatione productions demonstrated saturation of the drug’s biotransformation process and the maintenance of a high level of flutamide at 100μM when compared to 10μM. A microarray analysis comparing flutamide (10 or 100μM) with controls revealed a common response for both concentrations illustrated by modulating the expression of the mRNA of genes associated with mitochondrial perturbation, of the proliferator-activated receptors (Ppar) signaling, lipid and fatty acid metabolism, antioxidant defense, and cell death pathways, consistently with in vitro and in vivo reports. Additionally to literature reports, our integration of the transcriptomic profiles demonstrated a specific dose dependent response. We found at 10μM a typical pro-survival/apoptosis network activation (through IGF/PDGFD upstream route and via a downstream up regulation in CREB5, BCL2, IKBKG routes in the PI3K/signaling). We also found a down regulation of mRNA levels in sugar and amino acid metabolism pathways. At 100μM a typical necrosis switch was observed associated with a down regulation of the tight junctions’ pathway, a cellular aggregation and a reduction of the cell viability. Altogether our data demonstrated the potential and the sensitivity of our liver microfluidic cultures to evaluate xenobiotic toxicity by improving in vitro analysis and reproducing both in vitro and in vivo results. Finally, we proposed two integrated synthetic networks to describe the response of rat hepatocytes to both exposure concentrations of flutamide.

Contributions of Arylacetamide Deacetylase and Carboxylesterase 2 to Flutamide Hydrolysis in Human Liver

Flutamide, an antiandrogen drug, is widely used for the treatment of prostate cancer. The major metabolic pathways of flutamide are hydroxylation and hydrolysis. The hydrolyzed metabolite, 5-amino-2-nitrobenzotrifluoride (FLU-1), is further metabolized to N-hydroxy FLU-1, an assumed hepatotoxicant. Our previous study demonstrated that arylacetamide deacetylase (AADAC), one of the major serine esterases expressed in the human liver and gastrointestinal tract, catalyzes the flutamide hydrolysis. However, the enzyme kinetics in human tissue microsomes were not consistent with the kinetics by recombinant human AADAC. Thus, it seemed that AADAC is not the sole enzyme responsible for flutamide hydrolysis in human. In the present study, we found that recombinant carboxylesterase (CES) 2 could hydrolyze flutamide at low concentrations of flutamide. In the inhibition assay, the flutamide hydrolase activities at a flutamide concentration of 5 μM in human liver and jejunum microsomes were strongly inhibited by a selective CES2 inhibitor, 10 μM loperamide, with the residual activities of 22.9 ± 3.5 and 18.6 ± 0.7%, respectively. These results suggest that CES2 is also involved in the flutamide hydrolysis in human tissues. Using six individual human livers, the contributions of AADAC and CES2 to flutamide hydrolysis were estimated by using the relative activity factor. The relative contribution of CES2 was approximately 75 to 99% at the concentration of 5 μM flutamide. In contrast, the relative contribution of AADAC increased in parallel with the concentration of flutamide. Thus, CES2, rather than AADAC, largely contributed to the flutamide hydrolysis in clinical therapeutics.

Mate calling behavior of male South African clawed frogs ( Xenopus laevis) is suppressed by the antiandrogenic endocrine disrupting compound flutamide

Several environmental pollutants have been identified as antiandrogenic endocrine disrupting chemicals (EDC), with flutamide (FLU) being a model compound for this type of action. Despite impacts of EDC interfering with sexual differentiation and reproduction in amphibians, established information about suggested effects on sexual behavior is still lacking. In this study adult male Xenopus laevis were injected with human chorionic gonadotropin (hCG) to initiate mate calling behavior. After one day hCG-stimulated frogs were treated via aqueous exposure over three days without and with FLU at concentrations of 10 −8 and 10 −6 M in comparison to untreated frogs. Androgen controlled mate calling behavior was recorded during the 12 h dark period. At the end of exposure circulating levels of testosterone (T) and 17β-estradiol (E2) were determined and furthermore gene expression was measured concerning reproductive biomarkers such as hypophysial luteinizing hormone (LH), follicle-stimulating hormone (FSH), testicular aromatase (ARO), 5α reductase type 1 (SRD5α1) and 5α reductase type 2 (SRD5α2). Both concentrations of FLU caused a significant decrease in calling activity starting at the second day of exposure. HCG injected positive controls had elevated levels of T compared to negative control frogs while in parallel treatment with FLU did not affect significantly the hCG elevated sex steroid levels. Furthermore, hCG treatment led to significantly decreased levels of gene expression for ARO and SRD5α2 but no impacts were detected on LH, FSH or SRD5α1 mRNA levels compared to negative controls. In summary, the behavioral parameter mate calling is the most sensitive biomarker detecting antiandrogenic modes of action in this challenge-experiment indicating that this non-invasive method could markedly contribute for sensitive assessment of antiandrogenic EDC.

Endocrine-disrupting equivalents in industrial effluents discharged into Yangtze River

The endocrine-disrupting equivalents in effluents from three chemical industry wastewater treatment systems in the vicinity of Yangtze River were determined by several transactivation reporter gene assays. Transient transfections of African green monkey kidney cell line (CV-1) were used to determine the estrogenic, anti-androgenic and anti-thyroid equivalents in the effluents. Organic extracts of the effluents contained compounds that were potent anti-androgens and the activities measured as an equivalent concentration of flutamide were 45.53, 34.65 and 91.61 nM, respectively. The extracts also contained detectable concentrations of thyroid antagonists. Estrogenic activities, measured with the reporter gene assay, were near or below the method detection limit (0.58 pM as E2). Concentrations of some of the major constituents such as di(2-ethylhexyl)phthalate, dibutyl phthalate, 2,6-dinitrotoluene and nitrobenzene were quantified. The data suggest that the reporter gene assay is useful to predication of endocrine disrupting effects in polluted aquatic body.

Androgen disruption of early development in Qurt strain medaka ( Oryzias latipes)

Androgen disrupting chemicals (ADCs) are widespread in the aquatic environment, where they may pose a risk to aquatic organisms during critical periods of development. In this study, static renewal 96-h toxicity tests were followed over a 3-month growth period to investigate the endocrine disrupting effects of the androgen 11-ketotestosterone (11-KT), and the antiandrogen flutamide (FLU) on 1-week-old Qurt strain medaka larvae. The measured endpoints included: survival, growth performance (i.e., body weight, body length, condition index), and histopathology. There was no significant acute mortality, except for males treated with the highest FLU concentration (96 h-LC 50 = 1.92 mg/l). Gender-specific effects in growth were identified after 11-KT and FLU treatments. Histopathological alterations including thyroid follicular hypertrophy (TFH), germ cell necrosis (GCN), ovarian atresia (OA), and testis-ova (TO) were observed in medaka at 90-day post-exposure. We observed TFH in all 11-KT treatment levels. The incidence of TFH in males was double that in females 11-KT or FLU treatment. Females showed GCN at lower 11-KT concentrations (0.01, 0.1 mg/l) than males (1.0 mg/l). Severe OA was observed at low (0.01 mg/l) and high (1.0 mg/l) 11-KT concentrations in females. Flutamide induced TO (0.32, 1.0 mg/l), ovarian cell necrosis (0.32 mg/l), and disrupted spermatogenesis (3.2 mg/l) in males. The lowest observed effective concentration (LOEC) for TO induction in Qurt medaka males was 0.32 mg/l. The present study underscores the importance of fish early life stage tests for detecting the interaction of ADCs with the reproductive and thyroid glands in both genders.