Behavioral changes and hyperglycemia in NODEF mice following bisphenol S exposure are affected by diets.

Bisphenol S (BPS), an analogue of the controversial bisphenol A (BPA) that is found in epoxy resins and plastics, is a potential endocrine-disrupting chemical that can mimic endogenous hormone signaling. However, little is known about the behavioral or immunologic effects of BPS. The purpose of this study was to examine the impact of diets in BPS-treated mice in relation to hyperglycemia, development of type 1 diabetes, immunomodulation, and behavioral changes. Adult male and female nonobese diabetic excluded flora (NODEF) mice were exposed to environmentally relevant doses of BPS (VH, 30, or 300 µg/kg BW) and fed either a soy-based diet, a phytoestrogen-free diet, or a Western diet. NODEF male mice fed a soy-based diet exhibited a decreased curiosity/desire to explore, and possibly increased anxiety-like behavior and decreased short-term memory when exposed to BPS (300 µg/kg BW). In addition, these mice had significant increases in non-fasting blood glucose levels along with increased insulin sensitivity, impaired glucose tolerance, resistance to fasting and proinflammation. Although BPS had little effect on the glucose parameters in NODEF male mice fed a Western diet, there were decreases in %CD24+CD5+ and %B220+CD40L-cell populations and increases in distance traveled during the novel object test, suggesting hyperactivity. NODEF females fed a phytoestrogen-free diet exhibited slight decreases in time spent immobile during the tail suspension test in both the 30 and 300 µg/kg BW dose groups along with increases in %CD4+CD8+ and %Mac3+CD45R+ cell populations, signifying increased hyperactivity and anxiety-like behavior. In conclusion, BPS-exposed NODEF mice exhibited sex and diet-related changes in hyperglycemia, behaviors and immune endpoints.

Urinary crystal formation and urothelial effects of pyroxasulfone administered to male rats.

Pyroxasulfone induced a low incidence of urinary bladder tumors in male rats in a 2-year bioassay at 1000 and 2000 ppm, with occasional urinary calculi. No increased incidence of tumors of any tissue occurred in female rats or in mice of either gender. We performed three short-term studies to evaluate early development of pyroxasulfone-induced urinary crystals and urothelial cytotoxicity with consequent regenerative proliferation. First, male rats were treated with dietary 50, 1000 or 2000 ppm pyroxasulfone for 1, 3 or 7 days. The urothelium was examined by light and scanning electron microscopy (LM, SEM) and bromodeoxyuridine labeling index (BrdU LI). In two other studies, male rats were treated with dietary 20 000 ppm pyroxasulfone for 1 week. Urine collected at various times of day was examined by SEM and energy dispersive spectroscopy (EDS) or by LM, SEM, EDS, and infrared spectroscopy (IFS). Urinary crystals were present at various time points. EDS and IFS showed some contained calcium; others contained organic matter. Cytotoxicity was detected by SEM as cellular swelling, craters, and necrosis and by LM as cellular hypertrophy. Increased cell proliferation was detected by LM (hyperplasia), SEM (piling up of round cells), and by increased BrdU LI. There was no evidence of increased apoptosis. These findings support a mode of action for pyroxasulfone-associated bladder tumors in male rats involving formation of urinary crystals leading to urothelial cytotoxicity and regenerative proliferation. This is a high dose phenomenon, therefore, pyroxasulfone is not likely to be carcinogenic to humans at exposure levels that do not cause crystals with subsequent calculi formation in the urinary tract.

Toxicity and tissue distribution of methylsulfonylmethane following oral gavage in broilers.

An experiment was conducted to investigate the toxicity and tissue distribution of methylsulfonylmethane (MSM) following oral gavage in broilers. A total of four hundred and thirty-two 15-day-old Ross 308 male broilers were allotted to 6 treatments with 6 replicates of 12 birds per replicate and administered a single oral dose of MSM at 0, 50, 100, 300, 1,000, or 2,000 mg/kg BW (Study 1). Another one hundred and sixty-eight 3-day-old chicks were allotted to either control or test group (Study 2) and administered a daily oral gavage of either 0 or 1, 500 mg/kg BW of MSM for 21 D consecutively. Blood and tissue samples were collected over a 48 h (Study 1) or 21 D (Study 2) period and analyzed for MSM concentrations. Toxicity was assessed through changes in hematology and clinical blood chemistry. In Study 1, plasma MSM concentrations were below 167 µg/mL at all time-points in birds receiving up to 300 mg/kg BW, and were significantly higher (P < 0.05) in birds receiving 1,000 or 2,000 mg/kg BW. Similarly, only the highest 2 MSM dosages elicited increased lymphocyte and decreased heterophil counts at 8 h (P < 0.003) and decreased hematocrit at 48 h (P = 0.015). Growth performance variables were unaffected by MSM in Study 2, and plasma and tissue MSM concentrations were highest on study day 21, with MSM-dosed birds always exhibiting higher (P < 0.03) concentrations compared with the control. Birds in Study 2 that were dosed with MSM had decreased liver enzyme concentrations at day 7 and 21 and decreased glucose and phosphorus at day 7. Importantly, MSM was detected in plasma and all tissues of control groups, confirming that MSM is synthesized de novo in chickens. In conclusion, oral MSM at either acute (single dose at 1,000 to 2,000 mg/kg BW) or sub-chronic (1,500 mg/kg BW daily for 21 D) concentrations did not cause any adverse effects on growth or clinical outcomes and appeared to be absorbed and distributed throughout the body.

Effects of Bisphenol S on hypothalamic neuropeptides regulating feeding behavior and apelin/APJ system in mice.

Since 2010, Bisphenol A (BPA), an endocrine disruptor has been restricted and replaced by analogues like Bisphenol S (BPS). However, little is known about BPS effects and growing concern have suspected the "BPA-free" Label. Several recent studies suggest that BPS is associated with increased risk of diabetes and obesity. However, the underlying mechanisms remain unidentified. The current study investigates investigate BPS effects on hypothalamic neuropeptides regulating feeding behavior, either orexigenic or anorexigenic in Swiss Albino mice. We also studied the effect of BPS on the apelinergic system (apelin/apelin receptor (APJ)) as an original physiological system with pleiotropic actions. Bisphenol S at 25, 50, 100 µg/kg was administered to mice in water drink for 10 weeks started after weaning. Our results showed that BPS exposure alters orexigenic hypothalamic neuropeptide (AgRP) regulating feeding behavior but not anorexigenic neuropeptides (POMC, CART). Such orexigenic alterations may underlay appetite disorders leading to a concomitant food intake and body weight gain increase. In addition, data show that BPS affects the hypothalamic apelinergic system. We found a significant decrease in APJ mRNA but not in apelin expression. Based on hypothalamic APJ distribution, we suggested a potent specific physiological alteration of this receptor in mediating neuroendocrine responses in hypothalamus. Thus, our findings provide that BPS exposure could contribute to the development of obesity and metabolic disorders.

Suspect and untargeted screening of bisphenol S metabolites produced by in vitro human liver metabolism.

Bisphenol S (BPS) is increasingly used as substitute for bisphenol A, resulting in higher potential of human exposure to this compound. Yet, information on the human metabolism of BPS is limited. Hence, current biomonitoring studies rely only on the measurement of BPS itself, leading to a potential underestimation of assessing human exposure to this emerging contaminant. The aims of this study were to investigate the in vitro metabolic pathways of BPS using human liver microsomes and cytosol fractions and propose in vitro metabolites for evaluation in pharmacokinetics studies. Liquid chromatography coupled to quadrupole time-of-flight high-resolution mass spectrometry was used for the screening, identification, and structural elucidation of Phase I and II metabolites of BPS for the first time. Metabolite identification was performed using two complementary workflows: suspect and untargeted screening. Two Phase I metabolites were formed through hydroxylation of the phenolic rings. Four Phase II metabolites were formed through conjugation with glucuronic acid or sulfate. Three of these metabolites, namely dihydroxy-BPS, hydroxy-BPS-glucuronide and hydroxy-BPS-sulfate were identified and structurally elucidated for the first time. As such, we provide an expanded set of in vitro biotransformation products of BPS, which can potentially support a reliable assessment of BPS exposure in future biomonitoring studies.

Low-dose exposure to bisphenol A and replacement bisphenol S induces precocious hypothalamic neurogenesis in embryonic zebrafish.

Bisphenol A (BPA), a ubiquitous endocrine disruptor that is present in many household products, has been linked to obesity, cancer, and, most relevant here, childhood neurological disorders such as anxiety and hyperactivity. However, how BPA exposure translates into these neurodevelopmental disorders remains poorly understood. Here, we used zebrafish to link BPA mechanistically to disease etiology. Strikingly, treatment of embryonic zebrafish with very low-dose BPA (0.0068 µM, 1,000-fold lower than the accepted human daily exposure) and bisphenol S (BPS), a common analog used in BPA-free products, resulted in 180% and 240% increases, respectively, in neuronal birth (neurogenesis) within the hypothalamus, a highly conserved brain region involved in hyperactivity. Furthermore, restricted BPA/BPS exposure specifically during the neurogenic window caused later hyperactive behaviors in zebrafish larvae. Unexpectedly, we show that BPA-mediated precocious neurogenesis and the concomitant behavioral phenotype were not dependent on predicted estrogen receptors but relied on androgen receptor-mediated up-regulation of aromatase. Although human epidemiological results are still emerging, an association between high maternal urinary BPA during gestation and hyperactivity and other behavioral disturbances in the child has been suggested. Our studies here provide mechanistic support that the neurogenic period indeed may be a window of vulnerability and uncovers previously unexplored avenues of research into how endocrine disruptors might perturb early brain development. Furthermore, our results show that BPA-free products are not necessarily safer and support the removal of all bisphenols from consumer merchandise.

Subchronic toxicity and genotoxicity of diiodomethyl-p-tolylsulfone (DIMPTS) in laboratory animals.

These studies were conducted to determine subchronic toxicity and genotoxicity of the biocide diiodomethyl-p-tolysulfone (DIMPTS) in rats and dogs. Male and female Sprague-Dawley rats and Beagle dogs were administered DIMPTS for 90-days via the diet at 0, 5, 20, and 80 mg/kg/day to rats and via capsules at 0, 2, 10, and 60 mg/kg/day to dogs. In rats, the only treatment-related finding was squamous metaplasia of the salivary gland duct in the 80 mg/kg/day group. In dogs, female body weights in the high-dose group were significantly lower than controls. Altered clinical pathology parameters were considered secondary to inflammatory changes observed in some of the dogs. Treatment-related alterations were found in the thyroid glands, salivary glands, GI-tract in the mid- and/or high-dose groups. DIMPTS was negative in the four in vitro and one in vivo genotoxicity assays. The toxicological effects noted in the two mammalian species are consistent with the principal toxic effects of iodine, and are proposed to arise from release of iodide from the DIMPTS molecule with toxic sequelae.

Severe hypoglycemia associated with an illegal sexual enhancement product adulterated with glibenclamide: MR imaging findings.

PURPOSE: To describe the magnetic resonance (MR) imaging findings associated with severe hypoglycemia after consumption of an illegal sexual enhancement product (Power 1 Walnut) adulterated with glibenclamide, an oral hypoglycemic agent used to treat diabetes mellitus. MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective study. Records in eight male patients with severe hypoglycemia of unknown cause, without prior treatment for diabetes, and with positive blood toxicology results for glibenclamide were reviewed. MR imaging included diffusion-weighted imaging and, in some patients, MR angiography, dynamic contrast material-enhanced perfusion MR imaging, and MR spectroscopy. RESULTS: In seven patients, there were hyperintense abnormalities on diffusion-weighted and T2-weighted images in the hippocampus and cerebral cortex, sparing the subcortical white matter and cerebellum. Three patients had abnormalities of the splenium of the corpus callosum, and one had widespread involvement, including the caudate nucleus, basal ganglia, and internal capsule bilaterally. In three patients, unilateral cortical involvement, which did not conform to the typical cerebral arterial territories, was noted. In one patient, perfusion MR imaging showed slightly increased relative cerebral blood volume, and MR spectroscopy revealed no evidence of abnormal lactate in the affected cerebral cortex. CONCLUSION: Diffusion-weighted MR imaging findings in patients with severe hypoglycemia showed typical lesions in the hippocampus and cerebral cortex, but the caudate nucleus and basal ganglia were involved in only the most severely affected patient. The splenium of the corpus callosum and internal capsule were also abnormal in three patients, and unilateral cortical lesions could be distinguished from acute ischemic stroke by the pattern of involvement and MR angiographic, perfusion, and spectroscopic findings.

Oral developmental toxicity study of methylsulfonylmethane in rats.

Methylsulfonylmethane (MSM) is a metabolite of dimethyl sulfoxide, and occurs naturally at low levels in many foods. MSM has received wide attention as a dietary supplement to promote joint health. The objective of these studies was to determine the developmental toxicity potential of MSM when administered orally to pregnant rats during the period of major organogenesis and histogenesis. In a preliminary dose-finding study, distilled MSM microprill (i.e., microspherical pellets of MSM) was administered by oral gavage at dose levels of 0 (vehicle control), 50, 250, 500, and 1000 mg/kg/day to 8-9 sperm-positive female Sprague-Dawley rats/group/day on gestation days 6-20. No evidence of maternal or fetal toxicity was observed. For the definitive developmental study, four groups of 24-25 timed-bred primiparous female rats were administered 0, 50, 500, or 1000 mg MSM/kg/day via gavage on gestation days 6-20. Maternal feed consumption, body weight, body weight gain, uterus weight and corrected body weight/body weight gain were unaffected by treatment. No evidence of maternal toxicity, and no significant differences in litter viability, litter size, or litter body weight were detected. Fetal evaluations failed to show any biologically significant increase in the incidence of anomalies in the MSM treated groups, and no malformations were seen in any of the fetuses. No evidence of fetal mortality, alterations to growth, or structural alterations were observed in the fetuses of dams administered 50-1000 mg/kg/day. Therefore, under the conditions of this study, the no-observed-adverse-effect level (NOAEL) for maternal and developmental toxicity was 1000 mg/kg/day.

Etoricoxib (MK-0663): preclinical profile and comparison with other agents that selectively inhibit cyclooxygenase-2.

We report here the preclinical profile of etoricoxib (MK-0663) [5-chloro-2-(6-methylpyridin-3-yl)-3-(4-methylsulfonylphenyl) pyridine], a novel orally active agent that selectively inhibits cyclooxygenase-2 (COX-2), that has been developed for high selectivity in vitro using whole blood assays and sensitive COX-1 enzyme assays at low substrate concentration. Etoricoxib selectively inhibited COX-2 in human whole blood assays in vitro, with an IC(50) value of 1.1 +/- 0.1 microM for COX-2 (LPS-induced prostaglandin E2 synthesis), compared with an IC(50) value of 116 +/- 8 microM for COX-1 (serum thromboxane B2 generation after clotting of the blood). Using the ratio of IC(50) values (COX-1/COX-2), the selectivity ratio for the inhibition of COX-2 by etoricoxib in the human whole blood assay was 106, compared with values of 35, 30, 7.6, 7.3, 2.4, and 2.0 for rofecoxib, valdecoxib, celecoxib, nimesulide, etodolac, and meloxicam, respectively. Etoricoxib did not inhibit platelet or human recombinant COX-1 under most assay conditions (IC(50) > 100 microM). In a highly sensitive assay for COX-1 with U937 microsomes where the arachidonic acid concentration was lowered to 0.1 microM, IC(50) values of 12, 2, 0.25, and 0.05 microM were obtained for etoricoxib, rofecoxib, valdecoxib, and celecoxib, respectively. These differences in potency were in agreement with the dissociation constants (K(i)) for binding to COX-1 as estimated from an assay based on the ability of the compounds to delay the time-dependent inhibition by indomethacin. Etoricoxib was a potent inhibitor in models of carrageenan-induced paw edema (ID(50) = 0.64 mg/kg), carrageenan-induced paw hyperalgesia (ID(50) = 0.34 mg/kg), LPS-induced pyresis (ID(50) = 0.88 mg/kg), and adjuvant-induced arthritis (ID(50) = 0.6 mg/kg/day) in rats, without effects on gastrointestinal permeability up to a dose of 200 mg/kg/day for 10 days. In squirrel monkeys, etoricoxib reversed LPS-induced pyresis by 81% within 2 h of administration at a dose of 3 mg/kg and showed no effect in a fecal 51Cr excretion model of gastropathy at 100 mg/kg/day for 5 days, in contrast to lower doses of diclofenac or naproxen. In summary, etoricoxib represents a novel agent that selectively inhibits COX-2 with 106-fold selectivity in human whole blood assays in vitro and with the lowest potency of inhibition of COX-1 compared with other reported selective agents.

Effects of bis(4-chlorophenyl) sulfone on rats following 28-day dietary exposure.

The short-term oral toxicity of a recently identified environmental pollutant, bis(4-chlorophenyl) sulfone (BCPS), was studied. Groups of male Sprague-Dawley rats (n = 6) were administered BCPS via the diet at 0 (control), 10, 100, or 1000 ppm for 4 wk. Additional control and 1000 ppm groups were also treated for 1, 2, and 3 wk. At termination, high-dose animals showed depressed growth rate and food consumption, and 1 high dose animal in each of the wk-1, -3, and -4 groups had marked hematuria. Increased liver to body weight ratio was present at 100 ppm and increased kidney to body weight ratio at 1000 ppm. Marked increases in hepatic benzoylresorufin O-dealkylase (BROD) and pentoxyresorufin O-dealkylase (PROD) activities were detected starting at 10 ppm. There was a significant decrease in methoxyresorufin O-dealkylase (MROD) activity at 1000 ppm. Hepatic UDP-glucuronosyltransferase (UDPGT) and glutathione S-transferase (GST) activities also increased starting at 100 ppm. A marked increase in urinary excretion of ascorbic acid was apparent starting at 10 ppm, while there were no changes in urinary N-acetylglucosaminidase (NAG) activity and protein levels. A threefold increase in serum cholesterol and a 30% increase in platelet counts were observed in the 1000 ppm group. Levels of thiobarbituric acid-reactive substances (TBARS) were increased by threefold in the liver of the high-dose animals but were not significantly altered in the serum. Tissue BCPS concentrations were dose dependent and followed the order: adipose tissue >>> liver > kidneys > brain, spleen, lungs. In the time-course study involving the control and high-dose groups, most of the treatment effects were clearly present in wk 1, and the severity of the effects remained at more or less the same levels thereafter. The exceptions were hepatic BROD and PROD activities, which showed a trend toward further increases with time of treatment. Liver and adipose tissue concentrations of BCPS remained unchanged from wk 1 to wk 4, while kidney concentrations increased with time. The results indicated that BCPS produced hepatic effects at the lowest dose level tested (10 ppm in the diet or 0.8 mg/kg/d).

2,3-Diarylcyclopentenones as orally active, highly selective cyclooxygenase-2 inhibitors.

Cyclopentenones containing a 4-(methylsulfonyl)phenyl group in the 3-position and a phenyl ring in the 2-position are selective inhibitors of cyclooxygenase-2 (COX-2). The selectivity for COX-2 over COX-1 is dramatically improved by substituting the 2-phenyl group with halogens in the meta position or by replacing the phenyl ring with a 2- or 3-pyridyl ring. Thus the 3,5-difluorophenyl derivative 7 (L-776,967) and the 3-pyridyl derivative 13 (L-784,506) are particularly interesting as potential antiinflammatory agents with reduced side-effect profiles. Both exhibit good oral bioavailability and are potent in standard models of pain, fever, and inflammation yet have a much reduced effect on the GI integrity of rats compared to standard nonsteroidal antiflammatory drugs.

Prolactin lowering activity of the retinoid Ro 14-9706 affecting lactation and pup survival.

The arotinoid Ro 14-9706, though devoid of any teratogenic potential, was found to reduce dose dependently the survival of pups when their mothers were treated with toxic doses during days 6-15 of gestation. The increased mortality was primarily seen during early lactation. When pups derived from treated mothers were nursed by control foster mothers unexposed to the drug, their survival was significantly improved indicating that the increased mortality was not solely due to fetal drug exposure. When pups derived from untreated mothers were fostered by dams that were exposed to the arotinoid during pregnancy, a significant pup mortality (p < 0.01) was observed, suggesting that the nursing behaviour of lactating dams was seriously affected. This impairment could be linked to a prolactin-suppressive activity of the arotinoid during lactation which was also seen during pregnancy. Other pituitary hormones, however, were not affected by the compound. Although the drug induced pronounced structural alterations in mitochondria of adrenocortical cells, visualized by light microscopy as extended vacuolization in the zona fasciculata and reticularis, this pathological finding did not translate into functional impairment of steroidogenesis. Thus, the arotinoid Ro 14-9706 exhibits in rats a prolactin-suppressive activity which affects lactation and subsequently pup survival. This particular endocrinological interference is a new phenomenon and uncommon for retinoids.

[Effect of diucifon and its structural precursors on inflammatory and pain reactions]. / Vliianie diutsifona i ego strukturnykh predshestvennikov na vospalitel'nuiu i bolevuiu reaktsii.

The anti-inflammatory and analgesic action of diucifon, methyluracil and 4,4'-diaminodiphenylsulfone (DDS) was studied in comparison with some nonsteroid preparations. In three traditional models of agar, kaolin and carrageenan paw edema and in the models of analgesia (convulsions, induced by intraabdominal administration of acetic acid to mice and hyperalgesia according to Randall-Selitto's test in rats), diucifon proved more active than its precursors. In Randall-Selitto's test the efficiency of diucifon was 1.5 times less than that of butadione but 24 times higher than that of methyluracil; DDS had no analgetic activity. Diucifon, methyluracil and DDS did not exert any ulcerogenic action.

[Study of the mechanism of action of fasciolocides using bimolecular phospholipid membranes]. / Issledovanie mekhanizma deistviia fastsiolotsidov s pomoshch'ie bimolekuliarnykh fosfolipidnykh membran

The effects of compounds (see article), where M = -S-, -SO-, -SO2- and of some of their derivatives (18 substances) on electroconductivity of bimolecular lipid membranes (BLM) of different composition in 30 mM tris-HCl (pH 7.5) is studied. The results obtained are compared with literature data concerning fasciolocide and toxic effect of these substances. Certain correlations are found between the action on BLM and biological effects of substances. The analysis of the results allowed a conclusion that the latter are concerned with a discoupling effect of substances on oxidative phosphorylation in mitochondria of helmets and their host. BLM may be applied for evaluating the value of fasciolocide and toxic effects of the substances protonophores.