Toxicity Assessment of 4-Amino-2-Nitrotoluene

2013 ◽  
Vol 32 (2) ◽  
pp. 113-122 ◽  
Author(s):  
John T. Houpt ◽  
Glenn J. Leach ◽  
Larry R. Williams ◽  
Mark S. Johnson ◽  
Gunda Reddy

4-Amino-2-nitrotoluene (4A2NT; CAS 119-32-4) is a degradation product of 2,4-dinitrotoluene. The toxicity data on 4A2NT are limited. Therefore, we collected toxicity data from rats to assess environmental and human health effects from exposures. The approximate lethal dose for both sexes was 5000 mg/kg. A 14-day toxicity study in rats was conducted with 4A2NT in the feed at concentrations of 0, 125, 250, 500, 1000, and 2000 ppm. Based on a 14-day oral dose range toxicity study with 4A2NT in the feed, 2000 ppm was selected as highest concentration for a subsequent 90-day study. An oral 90-day subchronic toxicity study in rats was conducted with concentrations of 0, 500, 1000, or 2000 ppm of 4A2NT in the feed. The calculated consumed doses of 4A2NT in the feed were 0, 27, 52, or 115 mg/kg/d for males and 0, 32, 65, or 138 mg/kg/d for females. A no-observed adverse effect level could not be determined. The lowest observed adverse effect level was 27 mg/kg/d for males and 32 mg/kg/d for female rats based upon decreased body weight gain. The decreased body weight gain in male rats was the most sensitive adverse event observed in this study and was used to derive a benchmark dose (BMD). A BMD of 23.1 mg/kg/d and BMD with 10% effect level of 15.5 mg/kg/d were calculated for male rats, which were used to derive an oral reference dose (RfD). The human RfD of 1.26 μg/kg/d was derived using current United States Environmental Protection Agency guidelines.

2021 ◽  
Vol 12 ◽  
Author(s):  
John Turner ◽  
Albert Licollari ◽  
Emil Mihalcea ◽  
Aimin Tan

NAD+ is an abundant molecule in the body and vital to all living cells. NAD+ levels decline with age, and this decline correlates with age-related diseases. Therefore, sustaining NAD+ levels offers potential benefits to healthspan and longevity. Here we conducted toxicity studies to evaluate the safety of Restorin® NMN, a high purity form of the direct NAD+ precursor, β-nicotinamide mononucleotide (NMN). Based on the preliminary toxicity study and a 14-days repeated dose toxicity study at a higher dose level exposure, Restorin® NMN was administered orally to Sprague-Dawley rats for 91 days followed by a 14-days recovery period. The oral doses of 500, 1,000, and 2000 mg/kg/day were compared. There were no test item-related findings that could be considered adverse events in animals dosed at 500 mg/kg/day. The findings in the Restorin® NMN high dose group (2000 mg/kg/day) were similar to the reference item (Nicotinamide Riboside Chloride) dosed at 1740 mg/kg/day: reduced body weight, reductions in body weight gains, and diminished food consumption. In conclusion, the No-Observed-Adverse-Effect-Level (NOAEL) for Restorin® NMN is 1,000 mg/kg/day in female rats and 500 mg/kg/day in male rats, and the Low-Observed-Adverse-Effect-Level (LOAEL) for Resotrin® NMN is 2000 mg/kg/day.


2020 ◽  
Vol 70 (2) ◽  
pp. 144-151
Author(s):  
María del Rocío Padilla Galindo ◽  
Alma Gabriela Martínez Moreno ◽  
Fatima Ezzahra Housni ◽  
Zyanya Reyes Castillo ◽  
Erika Saenz-Pardo Reyes

El consumo de stevia ha sido promovido por su bajo aporte calórico, su efecto antidiabético y antihipercolesterolémico. Sin embargo, los efectos de la ingesta de stevia parecen no ser los mismos para las ratas hembras respecto de los machos. El propósito de este estudio fue evaluar el efecto de la ingesta de stevia sobre el consumo de alimento, peso corporal y niveles de glucosa, insulina, colesterol y triglicéridos en ratas hembras Wistar durante 13 semanas y realizar un análisis predictivo del peso corporal y la ingesta de alimento a 20 semanas. Se utilizaron 20 ratas hembras adultas, que se dividieron en 2 grupos: control (CG) y stevia (SG), ambos grupos recibieron agua y comida a libre acceso, así como una solución de stevia al 0,2 % para el grupo SG. Se registró diariamente el consumo de alimento, agua y solución de stevia; la medición del peso corporal se realizó semanalmente. Al final de las 13 semanas de experimentación, los animales se sacrificaron para evaluar los parámetros metabolicos. El grupo SG mostró un mayor consumo de alimento, mayor proporción de ganancia de peso corporal, niveles de glucosa y colesterol que el grupo CG. No se encontraron diferencias significativas en los niveles de triglicéridos e insulina. Respecto al análisis predictivo (semanas 14-20), se mantiene un incremento significativo en el consumo de alimento y se observa una tendencia de aumento en la proporción de ganancia de peso corporal. Esto indica que el consumo de stevia en ratas hembras parece no tener los mismos efectos benéficos reportados en machos. Consumption of stevia has been promoted due to its low caloric intake, it’s effects as anti-diabetic and anti-hypercholesterolemic. However, the effects of stevia consumption is apparently not the same in females than males. The purpose of this study was to evaluate the effect of stevia intake on meal consumption, body weight and levels of glucose, insulin, cholesterol and triglycerides in female Wistar rats during 13 weeks and develop a predictive analysis of the body weight and meal intake over 20 weeks. 20 adult female rats were utilized, these were divided into two groups: control (CG) and stevia (SG), both groups received free access to water and food, the SG also received a stevia solution at 0.2%. Consumption of food, water and stevia solution was recorded daily, while weight was recorded weekly. At the end of the 13 weeks of experiment, the subjects were sacrificed to evaluate the metabolic parameters. The SG group showed a higher consumption of food, higher proportion of body weight gain, glucose levels and cholesterol than the CG. No significant differences were found in levels of triglyceride or insulin. Respect to the predictive analysis (weeks 14-20), a significant increase in food consumption is maintained and an increasing trend is observed in the proportion of body weight gain. This indicates that stevia consumption appears not to have the same benefit effects in female rats than male rats.


2021 ◽  
pp. 109158182098607
Author(s):  
Narendra S. Deshmukh ◽  
Shailesh Gumaste ◽  
Silma Subah ◽  
Nathasha Omal Bogoda

Palmitoylethanolamide (PEA) is an endogenous ethanolamine playing a protective and homeodynamic role in animals and plants. Prenatal developmental toxicity of PEA was tested following oral administration to pregnant female Wistar rats, from days 0 to 19 of gestation, at dosage of 250, 500, or 1,000 mg/kg body weight, according to Organisation for Economic Co-operation and Development Test Guideline No. 414. On gestation day 20, cesarean sections were performed on the dams, followed by examination of their ovaries and uterine contents. The fetuses were further examined for external, visceral, and skeletal abnormalities. Palmitoylethanolamide did not cause any alterations at any of the given dosages in the measured maternal parameters of systemic toxicity (body weight, food consumption, survival, thyroid functions, organ weight, histopathology), reproductive toxicity (preimplantation and postimplantation losses, uterus weight, number of live/dead implants and early/late resorptions, litter size and weights, number of fetuses, their sex ratio), and fetal external, visceral, or skeletal observations. Any alterations that were recorded were “normal variations” or “minor anomalies,” which were unrelated to treatment with PEA. Under the condition of this prenatal study, the no-observed-adverse-effect level of PEA for maternal toxicity, embryotoxicity, fetotoxicity, and teratogenicity in rats was found to be >1,000 mg/kg body weight/d. It indicates that PEA is well tolerated by and is safe to pregnant rats even at a high dose of 1,000 mg/kg body weight/d, equivalent to a human dose of greater than 9.7 g/d. This prenatal developmental toxicity study contributes greatly in building a robust safety profile for PEA.


2003 ◽  
Vol 285 (2) ◽  
pp. H499-H506 ◽  
Author(s):  
Stéphanie Héon ◽  
Martin Bernier ◽  
Nicolas Servant ◽  
Stevan Dostanic ◽  
Chunlei Wang ◽  
...  

Doxorubicin (DOX), an anticancer drug, causes a dose-dependent cardiotoxicity. Some evidence suggests that female children have an increased risk for DOX-mediated cardiac damage. To determine whether the iron chelator dexrazoxane (DXR) could reduce DOX-induced cardiotoxicity in the young, we injected day 10 neonate female and male rat pups with a single dose of saline or DOX, DXR, or DXR + DOX (20:1). We followed body weight gain with growth, measured cardiac hypertrophy after a 2-wk swim exercise program, markers of apoptosis (Bcl-2, BAX, BNIP1, caspase 3 activation), oxidative stress (heme oxygenase 1, protein carbonyl levels), the chaperone protein clusterin, and the transcriptional activator early growth response gene-1 (Egr-1) in hearts of nonexercised and exercised rats on neonate day 38. All DOX-alone and DXR + DOX-treated rats showed decreased weight gain, with female rats affected earlier than male rats. DXR-alone, DOX-alone, and DXR + DOX-treated rats had an increased heart weight-to-body weight (heart wt/body wt) ratio after the exercise program with female rats showing the largest increase in heart wt/body wt. Drug-treated females also showed increased cardiac apoptosis, as measured by the increased expression of the proapoptotic proteins BAX and BNIP1 and the appearance of caspase 3 activation products, and oxidative stress, as measured by increased heme oxygenase 1 expression, and reduced Egr-1 and clusterin expression when compared with the similarly treated male rats. We conclude that DXR preinjection did not reduce DOX-induced noncardiac and cardiac damage and that young female rats were more susceptible to DXR and DOX toxicities than age-matched male rats.


2018 ◽  
Vol 315 (1) ◽  
pp. E29-E37 ◽  
Author(s):  
Mariana Peduti Halah ◽  
Paula Beatriz Marangon ◽  
Jose Antunes-Rodrigues ◽  
Lucila L. K. Elias

Neonatal nutritional changes induce long-lasting effects on energy homeostasis. Adiponectin influences food intake and body weight. The aim of this study was to investigate the effects of neonatal nutritional programming on the central stimulation of adiponectin. Male Wistar rats were divided on postnatal (PN) day 3 in litters of 3 (small litter, SL), 10 (normal litter, NL), or 16 pups/dam (large litter, LL). We assessed body weight gain for 60 days, adiponectin concentration, and white adipose tissue weight. We examined the response of SL, NL, and LL rats on body weight gain, food intake, oxygen consumption (V̇o2), respiratory exchange ratio (RER), calorimetry, locomotor activity, phosphorylated-AMP-activated protein kinase (AMPK) expression in the hypothalamus, and uncoupling protein (UCP)-1 in the brown adipose tissue after central stimulus with adiponectin. After weaning, SL rats maintained higher body weight gain despite similar food intake compared with NL rats. LL rats showed lower body weight at weaning, with a catch up afterward and higher food intake. Both LL and SL groups had decreased plasma concentrations of adiponectin at PN60. SL rats had increased white adipose tissue. Central injection of adiponectin decreased body weight and food intake and increased V̇o2, RER, calorimetry, p-AMPK and UCP- 1 expression in NL rats, but it had no effect on SL and LL rats, compared with the respective vehicle groups. In conclusion, neonatal under- and overfeeding induced an increase in body weight gain in juvenile and early adult life. Unresponsiveness to central effects of adiponectin contributes to the imbalance of the energy homeostasis in adult life induced by neonatal nutritional programming.


2021 ◽  
Vol 54 (1) ◽  
pp. 52-61
Author(s):  
NR Shepelskaya ◽  
YaV Kolyanchuk

Aim. Studying the effect of generic pesticides cyproconazole (98 %) and two samples of epoxiconazole (epoxiconazole 1 — 95,75 % and epoxiconazole 2 — 98,7 %) on the reproductive system of male and female Wistar Han rats at the level of the organism when exposed during gametogenesis, identification and characterization of their hazard, as well as assessment of the risk of reproductive toxicity of these compounds. Materials and Methods. The test samples were administered daily (5 days a week) by oral gavage at doses of 0.2 and 2.0 mg/kg for cyproconazole and 0.5 and 2.0 mg/kg for epoxiconazoles during 11 weeks for males, and 10 weeks for females. Also, there were kept intact males and females, intended for crossover mating with experimental animals. After the end of the exposure, functional indicators of the state of the gonads and the ability of animals to reproduce offspring were studied. The duration and the frequency of each stage of the estrous cycle in female rats and the number of motile sperm, the total amount of sperm and the number of abnormal forms of germ cells of the male rats were studied. The reproductive function state in females was evaluated on day 20th of pregnancy. Thereby the number of corpora lutea in the ovaries, number of alive, dead and resorbed foetuses and embryos, the foetus weight, total weight of litters were registered. The studies were carried out in accordance with the recommendations of the Bioethics Commission and the Centre’s standard operating procedures, developed in accordance with the recommendations and requirements of Good Laboratory Practice (GLP). Conclusions. Test substances at a maximum dose of 2.0 mg/kg of body weight have reproductive toxicity and endocrine-disruptive effect, exerting a significant antiandrogenic effect on males and antiestrogenic effect on female rats. No-observed-adverse-effect-level (NOАEL) for gonadal and reproductive toxicity for male and female Wistar Han rats were established. They are 0.2 mg/kg body weight for cyproconazole and 0.5 mg/kg body weight for epoxiconazole. Key Words: azole fungicides, cyproconazole, epoxiconazole, reproductive toxicity, antiandrogenic and antiestrogenic effects, Wistar Han rats.


2019 ◽  
Vol 35 (3) ◽  
pp. 196-203

1,1,2,2-Tetrafluoroethane (HFC-134) is a colorless gas used as a foam expansion agent and heat transfer fluid. HFC-134 has a low acute inhalation toxicity with an LC50 of >244,000 ppm. The no-observed adverse effect level (NOAEL) and lowest-observed adverse effect level for cardiac sensitization (in epinephrine-challenged beagle dogs) were 75,000 and 100,000 ppm, respectively. A subacute 4-week GLP inhalation toxicity study exposed male and female Crl: CD®BR rats (10/sex) to 0, 2000, 10,000, or 50,000 ppm via whole-body inhalation. Transient and non-dose-response–related body weight changes were observed throughout the exposure period, but no statistically significant, test substance-related adverse effects were observed in any clinical observations, chemistry, hematology, or pathology. This study identified a NOAEL for HFC-134 of 50,000 ppm, the highest exposure level tested. HFC-134 is not genotoxic in in vitro studies; however, no in vivo studies are available. No developmental or maternal toxicity was found in female rats exposed to HFC-134 up to 50,000 ppm via whole-body inhalation in two different studies. Based on data for a similar material (HFC-134a), HFC-134 is not expected to be extensively metabolized or to cause genetic toxicity or carcinogenicity. The HFC-134 workplace environmental exposure level (WEEL) is based primarily on the subacute 4-week inhalation toxicity study in rats with the NOAEL of 50,000 ppm selected as the point of departure for the derivation of the 8-h TWA, health-based WEEL value. The developmental toxicity study also had a NOAEL of 50,000 ppm and was the highest exposure level tested. The subacute inhalation NOAEL was adjusted to account for interindividual variability, subacute to chronic duration, animal to human extrapolation, daily duration of exposure, and residual uncertainty. In addition, the lack of adverse effects noted in the toxicology studies for HFC-134a was considered. The resulting 8-h TWA WEEL value of 1000 ppm is expected to provide a significant margin of safety against the production of any potential adverse health effects in workers following long-term inhalation exposure to HFC-134.


Life Sciences ◽  
2007 ◽  
Vol 81 (12) ◽  
pp. 1024-1030 ◽  
Author(s):  
SuJean Choi ◽  
Briana DiSilvio ◽  
JayLynn Unangst ◽  
John D. Fernstrom

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