Study on anti-androgenic effects of bisphenol a diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives using cells stably transfected with human androgen receptor, AR-EcoScreen.

We studied in vitro hormonal activity of bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE), which are used as a material of interior coating for food cans. We also examined related compounds such as 2,2-bis[4-(3-chloro-2-hydroxypropoxy)phenyl]propane (BADGE.2HCl), and bis[4-(3-chloro-2-hydroxypropoxy)phenyl]methane (BFDGE.2HCl) etc. For this purpose, we constructed two stably transfected CHO-K1 cell lines (AR-EcoScreen for androgenic activity and c-luc for cell toxicity evaluation). One stably expresses luciferase with induction of androgen. The other stably expresses luciferase without androgen induction. Also, we have determined the androgenic and anti-androgenic effects of the test chemicals by reporter gene assay with these cell lines. None of the chemicals tested by this assay exhibited androgen agonistic activity. However, BADGE.2HCl and BFDGE.2HCl had the conspicuous antagonistic activity for androgen. These compounds had a high binding affinity for androgen receptor. Furthermore, these two compounds did not show the estrogenic activity in vitro assays. On the contrary, bisphenol A and bisphenol F exhibited anti-androgenic activity in vitro in addition to the estrogenic activity. These results suggest that these chlorohydroxy compounds of BADGE and BFDGE act as androgen antagonist through the process of binding to androgen receptor.     

Determination of bisphenol diglycidyl ethers in topical dosage forms

A method involving extraction and LC-ESI-MS-MS detection of BADGE, BFDGE, BADGE*H2O, BADGE*2H2O, BADGE*HCl, BADGE*H2O*HCl, BADGE.2HCl and BFDGE*2HCl in aqueous cream was developed and validated. Initially, empty internally lacquered aluminum container closure systems were extracted with isopropanol as an attempt to estimate the upper limit of extractable bisphenol diglycidyl ethers present in lacquer. Six of the eight potential bisphenol diglycidyl ethers were quantified. In an accelerated experiment, on aqueous cream stored in lacquered aluminum tubes at 70 degrees C, all derivatives except BADGE*2HCl and BFDGE*2HCl were extracted from cream samples and quantified as an attempt to estimate the upper limit of compounds leaching to the cream. Detection limits were from 0.3+/-0.2 to 3.4+/-0.7 microgl(-1). Recoveries were determined for all compounds at three concentration levels (mean 63+/-6%). Mean inter-day and mean intra-day precision was 7+/-2 and 13+/-6%, respectively. Three commercially available creams were obtained from a local community pharmacy and analysed for bisphenol diglycidyl ethers. BADGE, BADGE*H2O, BADGE*2H2O and BADGE*H2O*HCl were detected and quantified. In conclusion, the developed method allows for the extraction and detection of bisphenol diglycidyl ethers originating from the epoxy phenol lacquer used in aluminum tubes. This study does not indicate that they leach into aqueous cream in significant amounts under normal storage conditions.     

Cytotoxic effects of BADGE (bisphenol A diglycidyl ether) and BFDGE (bisphenol F diglycidyl ether) on Caco-2 cells in vitro

Bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) are used as starting substances for the manufacturing of epoxy resins used in internal can coatings. They are obtained by a condensation reaction between epichlorohydrin with bisphenol A and bisphenol F, respectively. These potential endocrine disrupting chemicals are able to enter the food chain and to reach the intestinal epithelium, causing structural and functional damages. The human colorectal adenocarcinoma cell line Caco-2 is a widely used in vitro model of the intestinal cells. The aim of this study was to characterize BADGE and BFDGE toxicity in Caco-2 cells, in particular, at the cellular and molecular level. Using several approaches, we characterized BADGE- and BFDGE-induced cell toxicity in Caco-2 cells. The treatment was done using different concentrations up to cytotoxic doses and different times of exposure to the agents. We evaluated the effect of these compounds on cell morphology, cell detachment, cell proliferation, F-actin disruption and plasma membrane integrity. Both compounds are able to induce morphological changes, cell detachment from the substratum and to inhibit cell proliferation, being these effects time and dose-dependent. Moreover, BADGE and BFDGE induce F-actin depolymerization, this effect is very potent at 24 h of incubation with the agents and a complete F-actin disruption can be observed at 200 μM BADGE or BFDGE. In addition, cell integrity is not damaged, since neither propidium iodide uptake nor LDH release takes place in Caco-2 cells exposed to high doses of these agents for 24 h.     

Monitoring of bisphenols in canned tuna from Italian markets

Monitoring of food contamination from bisphenols is a necessary process for the consumers' risk assessment. A method for the quali-quantitative analysis of Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol A Diglycidyl Ether (BADGE), and Bisphenol F Diglycidyl Ether (BFDGE), by liquid chromatography with fluorescence detection (LC-FD), was performed and validated for their determination in 33 samples of tuna fish, canned in either oil or aqueous medium. Samples were collected in Italian markets. Tuna and the correspondent preservation medium were analyzed separately. Detected levels of bisphenols ranged from 19.1 to 187.0 ng/g in tuna matrix and from 6.3 to 66.9 ng/mL in oil medium. No bisphenols were found in aqueous medium. At least one of the analytes was found in 83% of the tuna samples in oil medium, whereas tuna samples in aqueous medium showed BPA alone in 67% of samples. 21% of the oil medium samples resulted positive for at least one bisphenol. On the basis of measured concentrations and general daily ingestion rate of canned tuna fish, the probable daily intake of BPA for Italian population was calculated.     

Contamination of semi-solid dosage forms by leachables from aluminium tubes

The objective of this study was to determine to what extent bisphenol A (BPA), bisphenol A diglycidyl ether (BADGE) and its derivatives are extractable from epoxy-based coatings of aluminium tubes for pharmaceutical use and to monitor their leaching into different kinds of semi-solid dosage forms. Migration increasing factors should be evaluated. Extraction tests using acetonitrile for 10 days at 40 degrees C turned out to be suitable to estimate the maximum amount of extractables. A plain variability in the nature and amount of extractables among tubes of different vendors (n=7) could be demonstrated. Leaching of the remnants into various semi-solid drug products (ointment, cream, gel) during storage (30 degrees C/40 degrees C) was verifiable. Leachable profiles were, apart from storage time and temperature, decisively influenced by the matrix. In particular, matrix polarity seemed to play a crucial role. Thus, the highest amount of leachables was found in isopropanol-based carbomer gel. Furthermore, in-use conditions (mechanical stress) enhanced migration significantly. In order to ensure quality and safety of semi-solid formulae, interactions between the coating material and the drug product should be thoroughly evaluated.     

Genotoxic and endocrine activities of bis(hydroxyphenyl)methane (bisphenol F) and its derivatives in the HepG2 cell line

Human can be exposed to bis(hydroxyphenyl)methane (bisphenol F or BPF) and its derivatives as environment and food's contaminants. This study was investigated to identify and to compare toxic potency of BPF, BFDGE, and two of BPF metabolites using in vitro methods. BPF did not induce any genic mutation in bacteria when the Ames test was performed according to the OECD guideline. In contrast, using Human cell lines and Comet assay, we demonstrated that BPF and Bisphenol F Diglycidyl Ether (BFDGE) were effective on HepG2 cell DNA fragmentation at non-cytotoxic concentrations. DHB was also positive but at higher concentrations, near its limit of solubility. Neither BPF, nor DHB induced a positive response in the micronucleus assay. The increase of micronuclei observed when cells were exposed to BFDGE was mostly due to a cytotoxic effect. Concerning endocrine activities, BPF increased the luciferase activity in HepG2 cells transiently transfected with a concentration dependant pattern, DHB also induced a positive response but at highest concentrations. Estrogenic responses in the HepG2 cells differed with the estrogen receptor (ER) involved. Using MDA-kb2 cell line stably transfected with pMMTV-neo-Luc, only BPF was anti-androgenic at the highest concentration (10(-5)M). Then, we demonstrated using human cell lines, especially HepG2, BPF was the most toxic compound in term of genotoxicity and endocrine activities compared to DHB and BPF-OH, the free metabolites identified in rat urine when BPF was administrated to rats.     

Melatonin ameliorates bisphenol A-induced biochemical toxicity in testicular mitochondria of mouse

Bisphenol A (BPA) is a monomer of polycarbonate plastic used to manufacture plastic baby bottles and lining of food cans. It has endocrine-disrupting potential and exerts both toxic and estrogenic effects on mammalian cells. We studied BPA-induced perturbation of mitochondrial marker enzymes in testes of Swiss albino mice and its amelioration by melatonin. Mice exposed to standardized dose of BPA (10 mg/kg body weight) orally for 14 days showed decrease in activities of marker mitochondrial enzymes such as succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, monoamine oxidase and NADH dehydrogenase. Besides, it also affected activities of antioxidant enzymes such as superoxide dismutase, glutathione reductase and glutathione peroxidase. BPA also caused lipid peroxidation (LPO) and decrease in reduced glutathione (GSH) content of mitochondria. Concomitant melatonin administration (10 mg/kg body weight; intraperitoneally for 14 days) lowered mitochondrial lipid peroxidation. It also restored the activity of mitochondrial marker enzymes and ameliorated decreased enzymatic and non-enzymatic antioxidants of mitochondria. These results demonstrate that melatonin has a potential role in ameliorating BPA-induced mitochondrial toxicity and the protection is due to its antioxidant property or by the direct free radical scavenging activity.     

Effect of smoke generation sources and smoke curing duration on the levels of polycyclic aromatic hydrocarbon (PAH) in different suites of fish

The research studied the impact of smoke generation sources on PAH contamination in four different smoke-cured fish (mackerel, sardine, tuna and Cigar minnows). The smoke sources used included acacia, sugarcane bagasse and mangrove. PAHs in the smoke-cured fish were analysed using Varian GC/MS (3800-GC) system. The mean total PAH concentrations in the smoked fish (n = 108) ranged from 250.59–1376.09 μg/kg in tuna, cigar minnows, sardine and mackerel smoke-cured with sugarcane bagasse, mangrove and acacia for between 2 and 8 h. The mean BaP levels for most fish cured with smoke from acacia and mangrove for between 2 and 8 h were all above the European Commission set limit of 5.0 μg/kg. Positive correlations (at P = 0.01, 2-tailed) were observed between PAH levels in smoked fish and lignin contents of wood type used for the smoke generation, the fat content and the smoke-curing duration. Risk assessment conducted using benzo[a]pyrene carcinogenic and mutagenic toxicity equivalency factors (TEF and MEF respectively) showed high risk associated with consuming fish smoke-cured with hard woods (acacia and mangroves). Sugarcane bagasse was found to be relatively the best and safest smoke-generating source for smoke-curing of fish among the three wood types when using the traditional kiln.     

Reactivity of bisphenol A-3,4-quinone with DNA. A quantum chemical study

Bisphenol A is a primary component of polycarbonate plastics found in many different products - from reusable drink bottles to cell phones. It is also an important component of epoxy resins, which serve as a protective layer inside food and drink cans. Chronic exposure to bisphenol A from food, drink and other sources is the reason that this chemical shows up at low levels in the urine of nearly everyone. Bisphenol A is a known endocrine disruptor with a variety of other effects, including genotoxicity. These facts have created a lot of concern about how toxic it is. To investigate the possible genotoxic mechanisms of bisphenol A we calculated the chemical reactivity of the bisphenol A metabolite bisphenol A-3,4-quinone with deoxyguanosine by using density functional theory in conjunction with Langevin dipoles solvation model. The calculated activation free energy of 23.1kcal/mol shows that bisphenol A-3,4-quinone could form an adduct with deoxyguanosine and could be a mutagen. The subsequent depurination reaction was also studied with the same methodology. The calculated activation energy was 22.5kcal/mol, providing evidence that the rate-limiting step essential to causing genotoxicity is nucleophilic addition of the N7-deoxyguanosine to bisphenol A-3,4-quinone rather than depurination.     

Estrogenic activity of octylphenol, nonylphenol, bisphenol A and methoxychlor in rats.

Considerable attention has recently been focused on environmental chemicals that disrupt the reproductive system by altering steroid receptor function. Although numerous in vitro and in vivo methods have been shown to be useful approaches for identifying chemicals that can disrupt reproduction through a direct interaction with the estrogen receptor, it is imperative that the protocols selected be capable of detecting chemicals with a broad range of estrogenic activity. Here we evaluate the reliability of the 3-day uterotrophic assay for detecting chemicals with strong or weak estrogenic activity in both prepubertal and ovariectomized adult Long Evans rats. These data were compared to additional measures of estrogenic activity, which included the age of vaginal opening, the induction of cornified vaginal epithelial cells in ovariectomized adult rats, and estrous cyclicity in intact adult rats. Test chemicals selected for these studies included 17-beta-estradiol, ethynyl estradiol, methoxychlor, 4-tert-octylphenol, 4-nonylphenol and bisphenol A. Data from in vitro receptor binding assays compared the ability of the test chemicals to compete with [3H]-estradiol or [3H]-promegestone for binding to estrogen or progesterone receptors. As expected, the binding affinities for the estrogen receptor ranged from high to low, as reflected by Ki concentrations of 0.4 nM for 17-beta-estradiol and ethynyl estradiol, and 0.05-65 microM for 4-tert-octyphenol, 4-nonylphenol, and methoxychlor. Although none of the test chemicals demonstrated a high affinity for binding to the progesterone receptor, 4-tert-octylphenol and 4-nonylphenol exhibited a weak affinity, with Ki concentrations ranging from 1.2 to 3.8 microM. In vivo studies indicated that the 3-day uterotrophic assay in prepubertal rats was the best method for detecting estrogenic activity when compared with all other end points, based upon the dose-response data for ethynyl estradiol (0.01-0.1 mg/kg), 4-tert-octylphenol (50-200 mg/kg, oral), and 4-nonylphenol (25-100 mg/kg, oral). Although oral doses of ethynyl estradiol (0.01 mg/kg) and 4-nonylphenol (50 mg/kg) induced a significant increase in uterine weight in the prepubertal rats, these doses were ineffective for stimulating a similar response in ovariectomized adult rats. The age of vaginal opening was advanced following oral exposure from postnatal days 21-35 to ethynyl estradiol (0.01 mg/kg), methoxychlor (50 mg/kg), 4-tert-octylphenol (200 mg/kg), and 4-nonylphenol (50 mg/kg). Although bisphenol A (200 mg/kg, oral) induced a significant uterotrophic response within 3 days in prepubertal rats, doses up to 400 mg/kg failed to advance the age of vaginal opening. Monitoring changes in the vaginal epithelium of ovariectomized adult rats was the least effective method for detecting estrogenic activity for 4-tert-octylphenol and bisphenol A. The number of 4-5 day estrous cycles was reduced during a 25-day exposure to ethynyl estradiol (0.01 mg/kg), methoxychlor (50 mg/ kg), 4-tert-octylphenol (200 mg/kg), 4-nonylphenol (100 mg/kg), and bisphenol A (100 mg/kg) by oral gavage. Although long periods of extended diestrus (7-14 days) were generally correlated with exposure to ethynyl estradiol and 4-tert-octylphenol, the cycling patterns following exposure to methoxychlor, 4-nonylphenol and bisphenol A were not as clearly defined, with shorter periods of extended diestrus (4-7 days) and/or estrus (3-5 days) intermittently observed throughout the exposure period. Together these data provide a comparison of the 3-day uterotrophic assay with alternative measures of estrogenic activity for a group of test chemicals with a broad range of affinities for the estrogen receptor. These data can be useful during the assessment and validation of methods for screening environmental chemicals for endocrine disrupting activity.     

Quercetin alleviates bisphenol A-induced changes in nucleic acid and protein contents in mice

The present study was an attempt to examine toxic effects of bisphenol A in liver and kidney of mice and its alleviation by quercetin. Oral administration of bisphenol A (60 and 120 mg/kg b. w./day) for 30 days caused, as compared to vehicle control significant, dose-dependent decrease in DNA, RNA and protein contents in liver and kidney of mice. Supplementation of quercetin (60 mg/kg b. w./day) along with bisphenol A for 30 days caused, as compared to bisphenol A alone treated groups, significant alleviation in DNA, RNA and protein contents. The amelioration was comparatively higher for high dose bisphenol A plus quercetin treated group than that of low dose plus quercetin treated group.     

Induction of apoptosis by UV-irradiated chlorinated bisphenol A in Jurkat cells

Chlorinated derivatives of bisphenol A (ClBPAs) have been detected in wastewater from waste paper recycling plants. We previously reported that bisphenol A (BPA) and ClBPAs [3-chlorobisphenol A, 3,3′-dichlorobisphenol A, and 3,3′,5-trichlorobisphenol A] irradiated with ultraviolet (UV) B or UVC (not with UVA) induced inhibition of cell growth, and that 3-hydroxybisphenol A (3-OHBPA) was detected in the photoproducts [Mutou, Y., Ibuki, Y., Terao, Y., Kojima, S., Goto, R., 2006b. Chemical change of chlorinated bisphenol A by ultraviolet irradiation and cytotoxicity of their products on Jurkat cells. Environmental Toxicology and Pharmacology, 21, 283–289]. The formation of hydroxylated BPAs by UV irradiation might contribute to the inhibition of cell growth, but the mechanism of the growth inhibition is not clarified. In this study, we investigated whether BPA and ClBPAs exposed to UVA, UVB, or UVC, and 3-OHBPA could induce the death of Jurkat cells and whether the pattern of cell death was apoptosis. ClBPAs exposed to UVB and UVC induced significant cell death, but those exposed to UVA and BPA did not. The cell death was apoptosis because chromatin condensation and DNA fragmentation were detected. Activation of caspase-3, -8, and -9 and cytochrome c release indicated that ClBPAs exposed to UVB or UVC induced apoptosis via typical apoptotic pathways. In addition, 3-OHBPA induced apoptosis similar to UVB- or UVC-irradiated ClBPA. These results suggested that the photoproducts of ClBPAs generated by UV irradiation, containing 3-OHBPA, contributed to the induction of apoptosis.     

Metabolism and pharmacokinetics of bisphenol A (BPA) and the embryo-fetal distribution of BPA and BPA-monoglucuronide in CD Sprague-Dawley rats at three gestational stages.

The pharmacokinetics of bisphenol A (BPA), including the quantification of the major BPA metabolite BPA-monoglucuronide conjugate (BPA-glucuronide) was studied in Sprague-Dawley rats at different stages of gestation. 14C-BPA was administered orally at 10 mg BPA/kg body weight (0.2 mCi/rat) to nongravid rats and to other groups on gestation days (GD) 6, 14, and 17. GD 0 was when the vaginal smear was sperm positive or a copulatory plug was observed. Radioactivity derived from 14C-BPA was quantified in the maternal blood, selected tissues, and the embryo or fetus. BPA and BPA-glucuronide were quantified in maternal plasma and excreta. Additional rats were dosed orally at 10 mg 14C-BPA/kg (0.2 mCi/rat or 0.5 mCi/rat) on GD 11, 13, and 16 to further study the distribution of BPA and BPA-glucuronide to the embryo/fetal tissue. The tissue distribution, metabolism, or the rates or routes of excretion of BPA, or the plasma concentration-time profiles of BPA-glucuronide did not appear to be altered at any stage of gestation as compared to nonpregnant rats. In the GD 11 group, neither BPA nor BPA-glucuronide was detected in the yolk sacs or embryos, except for trace concentrations of BPA-glucuronide in the yolk sacs at 15 min postdosing. In the GD 13 group, both BPA and BPA-glucuronide were detected in the yolk sacs of the conceptus but not in the embryos/fetuses, except for BPA at 15 min. For the animals dosed with 0.2 mCi/rat on GD 16, both analytes were detected in the placentae at 15 min and 12 h, but not at 96 h. Traces of both analytes were detected in fetal tissue in two of five specimens at 15 min only. In rats dosed on GD 16 with 0.5 mCi/rat, the BPA-glucuronide and BPA concentrations in maternal plasma at 15 min were 1.7 and 0.06 mug equivalents (eq)/g plasma, respectively. At the same time postdosing in these animals, the placental BPA-glucuronide concentrations were lower (0.34 mug eq BPA [as glucuronide]/g), and the BPA concentrations were about equivalent (0.095 mug/g). Fetal BPA-glucuronide and BPA concentrations were markedly lower, 0.013 and 0.018 mug eq/g, respectively. Therefore, no selective affinity of either yolk sac/placenta or embryo/fetus for BPA or BPA metabolites relative to maternal plasma or tissues was observed in this study.     

Preliminary study of responses in mussel (Mytilus edilus) exposed to bisphenol A, diallyl phthalate and tetrabromodiphenyl ether

Environmental pollutants with hormonal activity including bisphenol, diallyl phtalate and tetrabromodiphenyl ether, have the potential to alter gonadal development and reproduction in aquatic wildlife. Little is known about the biological impact of environmentally relevant concentrations in mussels. To investigate some aspects of their potential estrogenic action, mussels were continuously exposed during 3 weeks. Gonadal development and vitellogenin like protein levels were examined. Bisphenol (50 microg/l) induced the expression of phospho-proteins in females and spawning in both sexes. Diallyl phthalate and tetrabromodiphenyl ether decreased phospho-protein levels in both sexes and induced spawning in males. Moreover, severe damaging effects on ovarian follicles and ovocytes were observed in both bisphenol A- and tetrabromodiphenyl ether-exposed female mussels.     

Testicular toxicity of dietary 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) in F344 rats

Male F344/DuCrj (Fischer) rats were given bisphenol A (BPA) in the diet at levels of 0 (control), 0.25, 0.50 and 1.00%, equivalent to 0, 235, 466 and 950 mg/kg per day, respectively, for 44 days. Body weight gains were depressed dose-dependently in BPA-treated rats, and those of 0.50 and 1.00% groups were significant. Testis and epididymis weights were not significantly decreased. Both absolute and relative weights of dorsolateral prostate and preputial glands were reduced in a dose-related fashion. Absolute weights of seminal vesicles and hypophysis were also decreased. Histopathologically, seminiferous tubule degeneration and loss of elongated spermatids were observed, the severity being related to BPA dose. The disorganization, distortion and degeneration of late spermatids, and the atrophy of seminiferous tubules were found even in the 0.25% BPA group. Serum testosterone concentrations were not decreased in BPA-treated groups. These results indicate that BPA even at a level of 0.25% (235 mg/kg per day) is clearly toxic to male reproductive organs.     

The effect on sperm production in adult Sprague-Dawley rats exposed by gavage to bisphenol A between postnatal days 91-97.

M. Sakaue et al. (2001,J. Occup. Health vol. 43, pp. 185-190) have described how oral exposure of sexually mature male rats to bisphenol A (BPA) between postnatal days (PND) 91-97 led to a reduction in daily sperm production (DSP) 5 weeks later (18 weeks of age). Activity was observed over the dose range 20 microgram/kg-200 mg/kg BPA, with an absence of activity over the dose range 2 ng/kg-2 microgram/kg BPA. There was no evidence of a dose response relationship over the active dose range (five orders of magnitude range). The observation of endocrine disruption (ED) effects for BPA at such low doses, and in sexually mature animals, was unexpected. It was therefore decided to mount an independent repeat of their study. A total of four independent studies were conducted according to the protocol used by Sakaue et al. Doses of 20 microgram/kg, 2 mg/kg, or 200 mg/kg BPA were administered to adult Sprague-Dawley (SD) rats over PND 91-97, and the studies were terminated when the rats reached the age of 18 weeks. Three different rodent diets were employed (RM3, Purina 5002, and CE2), the last of which had been used by Sakaue et al. BPA failed to give any evidence of ED activities, including the changes in DSP reported by Sakaue et al. 2001. During the course of these studies, the test protocol was adapted to coincide more precisely with that used by Sakaue et al.; this included restricting the number of animals per cage, removing bedding from the cages, and changing to the use of glass water bottles in the cages. The only thing of interest to emerge from our studies was the observation of a significant difference in DSP between the control groups of our first and second study. As the change in diet from RM3 to Purina 5002 was the major difference between those two studies, we conducted a repeat of the second study, but we were unable to confirm the differences seen between the first and second study. The probability that those differences arose either by chance, or as the result of intrinsic study-to-study variability, was strengthened by the absence of significant differences in the sperm parameters in a final (fifth) study where the sperm parameters for control animals maintained on the three different diets were compared under the conditions of the main experiments. No explanation for our failure to replicate the effects reported by Sakaue et al. is evident. A review of DSP values reported in the recent literature is provided and discussed, and it is concluded that use of the term DSP/g testis rather than DSP/testis could increase the sensitivity of DSP assessments.     

Effects of bisphenol A-related diphenylalkanes on vitellogenin production in male carp (Cyprinus carpio) hepatocytes and aromatase (CYP19) activity in human H295R adrenocortical carcinoma cells

The present study investigated the effects of the known xenoestrogen bisphenol A (BPA) relative to eight BPA-related diphenylalkanes on estrogen receptor (ER)-mediated vitellogenin (vtg) production in hepatocytes from male carp (Cyprinus carpio), and on aromatase (CYP19) activity in the human adrenocortical H295R carcinoma cell line. Of the eight diphenylalkanes, only 4,4'-(hexafluoropropylidene)diphenol (BHF) and 2,2'-bis(4-hydroxy-3-methylphenyl)propane (BPRO) induced vtg, i.e., to a maximum of 3% to 4% (at 100 microM) compared with 8% for BPA relative to the maximum induction by 17beta-estradiol (E2, 1 microM). Bisphenol A diglycidyl ether (BADGE) was a potent antagonist of vtg production with an IC50 of 5.5 microM, virtually 100% inhibition of vtg at 20 microM, and an inhibitive (IC50) potency about one-tenth that of the known ER antagonist tamoxifen (IC50, 0.6 microM). 2,2'-Diallyl bisphenol A, 4,4'-(1,4-phenylene-diisopropylidene)bisphenol, BPRO, and BHF were much less inhibitory with IC50 concentrations of 20-70 microM, and relative potencies of 0.03 and 0.009 with tamoxifen. Bisphenol ethoxylate showed no anti-estrogenicity (up to 100 microM), and 4,4'-isopropylidene-diphenol diacetate was only antagonistic at 100 microM. When comparing the (anti)estrogenic potencies of these bisphenol A analogues/diphenylalkanes, anti-estrogenicity occurred at lower concentrations than estrogenicity. 4,4'-Isopropylidenebis(2,6-dimethylphenol) (IC50, 2.0 microM) reduced E2-induced (EC50, 100 nM) vtg production due to concentration-dependent cytotoxicity as indicated by a parallel decrease in MTT activity and vtg, whereas the remaining diphenylalkanes did not cause any cytotoxicity relative to controls. None of the diphenylalkanes (up to 100 microM) induced EROD activity indicating that concentration-dependent, CYP1A enzyme-mediated metabolism of E2, or any Ah-receptor-mediated interaction with the ER, was not a likely explanation for the observed anti-estrogenic effects. At concentrations as great as 100 microM, none of the diphenylalkanes directly inhibited aromatase (CYP19) activity in H295R cells. Environmental exposure of fish to BPA and related diphenylalkanes, depending on the structure, may pose anti-estrogenic, and to a lesser extent estrogenic, risks to development and reproduction.     

输液袋用聚碳酸酯组合盖中双酚A含量及双酚A向输液中迁移量的测定

目的建立输液袋用聚碳酸酯组合盖中双酚A含量及双酚A向输液中迁移量的高效液相色谱测定法。方法采用Diamosil-C18(4.6 mm×250 mm,5μm)色谱柱;流动相为甲醇-水(80∶20),检测波长为227 nm,流速1.0 mL.min 1。结果双酚A在1.354~27.08 ng内呈良好的线性关系(r=0.999 9);聚碳酸酯组合盖中双酚A含量和双酚A向输液中迁移量测定的平均回收率分别为91.7%(RSD=2.3%)和93.9%(RSD=1.8%)。结论该方法准确、灵敏、简便,适用于对输液袋用聚碳酸酯组合盖中双酚A含量及双酚A向输液中迁移量的测定。     

The protective activity of nanomicelle curcumin in bisphenol A‐induced cardiotoxicity following subacute exposure in rats

Bisphenol A (BPA), an estrogenic compound, is used in manufacture of polycarbonate plastics and epoxy resins. Curcumin, the active ingredient of turmeric, is a potent protective compound against cardiac diseases. In this study the protective effect of nanomicelle curcumin on BPA‐induced subchronic cardiotoxicity in rats was evaluated. Rats were divided into 6 groups including control, nanomicelle curcumin (50 mg/kg, gavage), BPA (50 mg/kg, gavage), nanomicelle curcumin (10, 25, and 50 mg/kg) plus BPA. The treatments were continued for 4 weeks. Results revealed that BPA significantly induced histophatological injuries including focal lymphatic inflammation, nuclear degenerative changes and cytoplasmic vacuolation, increased body weight, systolic and diastolic blood pressures, malondialdehyde and Creatine phosphokinase‐MB level and decreased glutathione content in comparison with control group. In addition, in electrocardiographic graph, RR, QT, and PQ intervals were increased by BPA. Western blot analysis showed that BPA up‐regulated phosphorylated p38 (p38‐mitogen‐activated protein kinase) and JNK (c‐jun NH₂ terminal kinases), while down‐regulated phosphorylated AKT (Protein Kinase B) and ERK1/2 (extracellular signal‐regulated protein kinases 1 and 2). However, nanomicelle curcumin (50 mg/kg) significantly improved these toxic effects of BPA in rat heart tissue. The results provide evidence that nanomicelle curcumin showed preventive effects on subchronic exposure to BPA induced toxicity in the heart tissue in rats.