Dual Color Imaging from a Single BF2-Azadipyrromethene Fluorophore Demonstrated in vivo for Lymph Node Identification.

Dual emissions at ~700 and 800 nm have been achieved from a single NIR-AZA fluorophore 1 by establishing parameters in which it can exist in either its isolated molecular or aggregated states. Dual near infrared (NIR) fluorescence color lymph node (LN) mapping with 1 was achieved in a large-animal porcine model, with injection site, channels and nodes all detectable at both 700 and 800 nm using a preclinical open camera system. The fluorophore was also compatible with imaging using two clinical instruments for fluorescence guided surgery. Methods: An NIR-AZA fluorophore with hydrophilic and phobic features was synthesised in a straightforward manner and its aggregation properties characterised spectroscopically and by TEM imaging. Toxicity was assessed in a rodent model and dual color fluorescence imaging evaluated by lymph node mapping in a large animal porcine models and in ex-vivo human tissue specimen. Results: Dual color fluorescence imaging has been achieved in the highly complex biomedical scenario of lymph node mapping. Emissions at 700 and 800 nm can be achieved from a single fluorophore by establishing molecular and aggregate forms. Fluorophore was compatible with clinical systems for fluorescence guided surgery and no toxicity was observed in high dosage testing. Conclusion: A new, biomedical compatible form of NIR-dual emission wavelength imaging has been established using a readily accessible fluorophore with significant scope for clinical translation.

Afidopyropen: Challenges and impact of a toxicokinetic study designed to identify a point of inflection from dose-proportionality.

Afidopyropen is an insecticide that acts as a transient receptor potential vanilloid subtype (TRPV) channel modulator in chordotonal organs of target insects and has been assessed for a wide range of toxicity endpoints including chronic toxicity and carcinogenicity in rats and mice. The current study evaluates the toxicokinetic properties of afidopyropen and its plasma metabolites in rats at dose levels where the pharmacokinetics (PK) are linear and nonlinear in an attempt to identify a point of inflection. Based on the results of this study and depending on the analysis method used, the kinetically derived maximum dose (KMD) is estimated to be between 2.5 and 12.5 mg/kg bw/d with linearity observed at doses below 2.5 mg/kg bw/d. A defined point of inflection could not be determined. These data demonstrate that consideration of PK is critical for improving the dose-selection in toxicity studies as well as to enhance human relevance of the interpretation of animal toxicity studies. The study also demonstrates the technical difficulty in obtaining a defined point of inflection from in vivo PK data.

Classes of organic pigments meet tentative PSLT criteria and lack toxicity in short-term inhalation studies.

Here, we present a non-animal testing battery to identify PSLT (poorly soluble, low toxicity) substances based on their solubility in phagolysosomal lung fluid simulant, surface reactivity and effects on alveolar macrophages in vitro. This is exemplified by eleven organic pigments belonging to five chemical classes that cover a significant share of the European market. Three of the pigments were tested as both, nanoform and non-nanoform. The results obtained in this integrated non-animal testing battery qualified two pigments as non PSLT, one pigment as poorly soluble and eight pigments as poorly soluble and low toxicity in vitro. The low toxic potency of the eight PSLT and the one poorly soluble pigment was corroborated by short-term inhalation studies with rats. These pigments did not elicit apparent toxic effects at 10 mg/m3 (systemic and in the respiratory tract). One of the pigments, Diarylide Pigment Yellow 83 transparent, however, caused minimal infiltration of neutrophils; hence its low toxicity is ambiguous and needs further verification or falsification. The present test battery provides an opportunity to identify PSLT-properties of test substances to prioritise particles for further development. Thus, it can help to reduce animal testing and steer product development towards safe applications.

Dermal toxicity, dermal irritation, and delayed contact sensitization evaluation of oil body linked oleosin-hEGF microgel emulsion via transdermal drug delivery for wound healing.

Objective: The expression of therapeutic proteins in plant oil body bioreactors has attracted much attention. But its safety is not yet clear. This article determines the risk of safety after using the drug. Methods: The oil body-linked oleosin-hEGF microgel emulsion (OBEME) was prepared by mixing the xanthan gum with suitable concentrations in an appropriate proportion. Skin irritation and sensitization reaction were investigated in rats and guinea pigs using OBEME as test article.Results: The OBEME did not produce dermal erythema/eschar or oedema responses. The dermal subacute and subchronic toxicity of OBEME were evaluated in accordance with OECD guidelines. Compared with the control group, the basic physical signs, such as weight, feed, drinking, excretion, and behaviour of experimental animals, were not abnormal. In addition, no abnormality was found in haematological parameters, biochemical indexes, relative organ weight, and histopathological observation of organs, and there was no significant difference compared with normal saline treatment group. Therefore, we conclude that OBEME has no toxic effects and is safe and reliable to be used for topical application.

Subacute dermal toxicity of perfluoroalkyl carboxylic acids: comparison with different carbon-chain lengths in human skin equivalents and systemic effects of perfluoroheptanoic acid in Sprague Dawley rats.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are used in various fields but raise concerns regarding human health and environmental consequences. Among PFASs, perfluorooctanoic acid (PFOA) and short-chain perfluoroalkyl carboxylic acids (SC PFCAs) are detectable in skin-contact consumer products and have dermal absorption potential. Here, we investigated the effects of dermal exposure to PFOA and SC PFCAs using in vitro and in vivo models. Human skin equivalents were topically treated with 0.25 mM and 2.5 mM PFOA and SC PFCAs (perfluoropentanoic acid, PFPeA; perfluorohexanoic acid, PFHxA; and perfluoroheptanoic acid, PFHpA) for 6 days, and cell viability, interleukin (IL)-1α, oxidative stress markers (malondialdehyde, MDA; and 8-hydroxydeoxyguanosine, 8-OHdG), and histopathology were examined. MDA levels were significantly higher in the PFASs groups than in controls. Compared with SC PFCAs, 2.5 mM PFOA caused more IL-1α (p < 0.001) release, decreased skin thickness and microscopic abnormalities. To evaluate systemic effects, Sprague Dawley (SD) rats were dermally treated with 250 and 1000 mg/kg PFHpA for 2 weeks and clinical and anatomic pathology were assessed. At 1000 mg/kg, 83% of the rats died, with severe ulcerative dermatitis at the application site. Adverse PFHpA-treated systemic changes were observed in the kidney, liver and testes, and histopathologic lesions such as renal tubular necrosis, hepatocellular necrosis, and germ cell degeneration were seen at 250 and 1000 mg/kg. Our study suggests that SC PFCAs have fewer effects on the skin than PFOA, but SC PFCAs can have adverse effects on major organs with systemic exposure at high concentrations.

Evaluation of the avian acute oral and sub-acute dietary toxicity test for pesticide registration.

The United States Environmental Protection Agency (USEPA), as well as other international regulatory agencies, require pesticide registrants to submit toxicity data that are used to conduct ecological risk assessments. While the USEPA has required both an acute oral and sub-acute dietary test in birds, trends in the use of data from these tests over the past 20 years have suggested that the avian sub-acute dietary test generally does not contribute to risk assessment conclusions. To address this question, a retrospective analysis was conducted to evaluate 119 pesticides with publicly available ecological risk assessments that were registered into commerce between 1998 and 2017. New pesticides (i.e., registered in the United States within the past 20 years) were chosen for the retrospective analysis to show utility of these tests for modern pesticide chemistries. Risk quotient (RQ) values (a point estimate of exposure divided by a deterministic toxicity endpoint) from the avian acute oral and dietary tests, as well as risk assessment conclusions, were compared to determine which test(s) drove the risk assessment findings. The RQ values were chosen as the data point for comparison in order to assess total risk (i.e., exposure and toxicity). After comparing RQ values from avian acute oral versus sub-acute dietary tests, there was only one case in which an avian sub-acute dietary RQ was greater than the acute oral RQ. Thus, the sub-acute dietary test did not identify risk in greater than 99% (118 out of 119) of chemicals based on results that either the acute oral RQ was higher than the sub-acute dietary RQ, or both the acute oral and the subacute dietary tests did not generate an RQ value of concern. For the one exception, both the oral and sub-acute RQ values were greater than the USEPA's level of concern for endangered species. Based on the results of the retrospective analysis, it is concluded that in most cases avian risk can confidently be assessed without conducting the sub-acute dietary test.

Safety and tolerability of sustained exogenous ketosis using ketone monoester drinks for 28 days in healthy adults.

Throughout history, the only way humans could raise their blood ketone levels was by several days of fasting or by following a strict low-carb, high-fat diet. A recently developed, dietary source of ketones, a ketone monoester, elevates d-ß-hydroxybutyrate (ßHB) to similar concentrations within minutes, with ßHB remaining raised for several hours. To date, the longest human safety study of the exogenous ketone ester was for 5 days, but longer consumption times may be desired. Here we report results for 24 healthy adults, aged 18-70 years, who drank 25 ml (26.8 g) of the ketone monoester, (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, three times a day for 28 days (a total of 2.1 L). Anthropomorphic measurements, plus fasting blood and urine analyses were made weekly. It was found that elevating blood ßHB concentrations from 0.1 to 4.1 (±1.1) mM three times a day for 28 days had no effect on body weights or composition, fasting blood glucose, cholesterol, triglyceride or electrolyte concentrations, nor blood gases or kidney function, which were invariably normal. Mild nausea was reported following 6 of the 2,016 drinks consumed. We conclude that sustained exogenous ketosis using a ketone monoester is safe and well-tolerated by healthy adults.

Rac1-mediated cardiac damage causes diastolic dysfunction in a mouse model of subacute doxorubicin-induced cardiotoxicity.

The anticancer efficacy of anthracyclines is limited by congestive heart failure. Clinically established markers of early onset of cardiotoxicity following anthracycline treatment and preventive measures are missing. Although statins are reported to alleviate anthracycline-induced cardiotoxicity in vivo, the molecular mechanisms involved remain elusive. In vitro data point to Rac1 as major target of the cytoprotective statin effects. Here we investigated whether specific inhibition of Rac1 by NSC23766 is as effective as lovastatin in preventing subacute cardiotoxicity following doxorubicin treatment. C57BL/6 mice were treated over 3 weeks with multiple low doses of doxorubicin (6 × 3 mg/kg BW, i.p.) and the level of DNA damage, apoptosis and regenerative proliferation as well as pro-inflammatory, pro-fibrotic and oxidative stress responses were investigated. Moreover, heart function was monitored by echocardiography. Doxorubicin induced subacute cardiotoxicity which was reflected on the level of residual DNA damage, frequency of apoptotic and mitotic cells as well as elevated mRNA expression of markers of heart failure, remodeling and mitochondrial biogenesis. These molecular markers of cardiotoxicity were mitigated to a similar extent by co-treatment with either lovastatin (10 mg/kg BW, p.o.) or NSC23766 (5 mg/kg BW, i.p.) three times a week. Moreover, doxorubicin caused diastolic dysfunction as reflected by increased E-wave acceleration time (EAT), which again was prevented by pharmacological inhibition of Rac1. Inhibition of Rac1 signaling is of major relevance for the cardioprotective effects of lovastatin in the context of anthracycline-induced cardiotoxicity. Moreover, EAT is a useful marker of subacute cardiotoxicity caused by persisting harmful effects of doxorubicin.

Chronic dietary toxicity and carcinogenicity studies of dammar resin in F344 rats.

Dammar resin is a natural food additive and flavoring substance present in many foods and drinks. The present study evaluates the chronic toxicity and carcinogenicity of dietary dammar resin in F344 rats. Dietary concentrations in the 52-week chronic toxicity study were 0, 0.03, 0.125, 0.5, or 2%. The major treatment-related deleterious effects were body weight suppression, increased relative liver weight, and low hemoglobin levels in males and females. Foci of cellular alteration in the liver were observed in the male 2% group, but not in any other group. The no-observed-adverse-effect level for chronic toxicity was 0.125% for males (200.4 mg/kg b.w./day) and females (241.9 mg/kg b.w./day). Dietary concentrations in the 104-week carcinogenicity study were 0, 0.03, 0.5, or 2%. Dammar resin induced hemorrhagic diathesis in males and females, possibly via the inhibition of extrinsic and intrinsic coagulation pathways. Incidences of hepatocellular adenomas and carcinomas were significantly increased in the male 2% group, but not in any other group. In the 4-week subacute toxicity study, the livers of male rat-fed diet-containing 2% dammar resin had increased levels of protein oxidation and increased the expression of two anti-apoptotic and seven cytochrome P450 (CYP) genes. There was also an increased tendency of oxidative DNA damage. These findings demonstrate that dammar resin is hepatocarcinogenic in male F344 rats and underlines the roles of inhibition of apoptosis, induction of CYP enzymes, and oxidative stress in dammar resin-induced hepatocarcinogenesis.

Toxicological evaluation of 5-methoxy-2-aminoindane (MEAI): Binge mitigating agent in development.

5-Methoxy-2-aminoindane (MEAI) is a psychoactive compound of the aminoindane class, which in recent years has been recreationally used by many people, who reported of a mild euphoric, alcohol-like tipsy experience and reduced desire to consume alcoholic beverages. In the light of these observations it was decided to progress MEAI through a preliminary drug development route and evaluate the acute and subacute toxicity of MEAI administrated orally to Sprague Dawley rats, as well as to determine potential in-vitro cytotoxic and mutagenic effects using state-of-the-art protocols. Furthermore, the interaction of MEAI at the highest non-toxic concentration (100mg/L) with ethanol at cytotoxic levels of 6% and 7.5% was explored, in order to identify possible additive or synergistic effects. MEAI showed a good safety profile in rats at 10 and 30mg/kg body weight, corresponding to the human doses of 1.6mg/kg and 4.8mg/kg body weight, respectively. Cytotoxic effect was demonstrated using concentrations of 500 and 1000mg/L with calculated IC50 value of 368.2mg/L for rat brain striatum primary neurons and 403.1mg/L for human primary healthy hepatocytes. The combination of 6% or 7.5% ethanol with 100mg/L MEAI revealed no statistically significant increase of cytotoxic effect. Further studies, especially long term chronic and addictive behavior studies, are required in-order to assess MEAI safety profile.

In vivo cardiomyocyte response to YTX- and AZA-1-induced damage: autophagy versus apoptosis.

Yessotoxins (YTX) and azaspiracids (AZAs) are marine toxins produced by phytoplanktonic dinoflagellates that get accumulated in filter feeding shellfish and finally reach human consumers through the food web. Both toxin classes are worldwide distributed, and food safety authorities have regulated their content in shellfish in many countries. Recently, YTXs and AZAs have been described as compounds with subacute cardiotoxic potential in rats owed to alterations of the cardiovascular function and ultrastructural heart damage. These molecules are also well known in vitro inducers of cell death. The aim of this study was to explore the presence of cardiomyocyte death after repeated subacute exposure of rats to AZA-1 and YTX for 15 days. Because autophagy and apoptosis are often found in dying cardiomyocytes, several autophagic and apoptotic markers were determined by western blot in heart tissues of these rats. The results showed that hearts from YTX-treated rats presented increased levels of the autophagic markers microtubule-associated protein light chain 3-II (LC3-II) and beclin-1, nevertheless AZA-1-treated hearts evidenced increased levels of the apoptosis markers cleaved caspase-3 and -8, cleaved PARP and Fas ligand. Therefore, while YTX-induced damage to the heart triggers autophagic processes, apoptosis activation occurs in the case of AZA-1. For the first time, activation of cell death signals in cardiomyocytes is demonstrated for these toxins with in vivo experiments, which may be related to alterations of the cardiovascular function.

Safety evaluation of auraptene in rats in acute and subacute toxicity studies.

Auraptene (AUR) is a natural, bioactive, monoterpene coumarin ether. It has anti-inflammatory, anti-carcinogenic, anti-bacterial, neuroprotective, and hepatoprotective properties. The aim of the present study was to assess the acute and subacute toxicity of oral administration of AUR in rats by evaluating clinical signs, haematology, biochemical factors, pathological changes and immune-toxicity. Acute administration of AUR in doses of 125, 250, 500, 1000 and 2000 mg/kg body weight had no mortality or clinical signs in a period of two days. To evaluate subacute toxicity, AUR was administrated for 28 days by oral gavage in doses of 125 and 250 mg/kg. There were significant differences in the haematological and biochemical data of the treated and untreated groups. However, almost all haematological differences were within normal reference ranges. Subacute administration of AUR showed no toxic histopathological effects on organ tissue. Evaluation of immune-toxicity also revealed no significant differences between treatment and untreated groups.

Immunotoxicological and neurotoxicological profile of health effects following subacute exposure to geogenic dust from sand dunes at the Nellis Dunes Recreation Area, Las Vegas, NV.

Exposure to geogenic particulate matter (PM) comprised of mineral particles has been linked to human health effects. However, very little data exist on health effects associated with geogenic dust exposure in natural settings. Therefore, we characterized particulate matter size, metal chemistry, and health effects of dust collected from the Nellis Dunes Recreation Area (NDRA), a popular off-road vehicle area located near Las Vegas, NV. Adult female B6C3F1 mice were exposed to several concentrations of mineral dust collected from active and vegetated sand dunes in NDRA. Dust samples (median diameter: 4.4 µm) were suspended in phosphate-buffered saline and delivered at concentrations ranging from 0.01 to 100 mg dust/kg body weight by oropharyngeal aspiration. ICP-MS analyses of total dissolution of the dust resulted in aluminum (55,090 µg/g), vanadium (70 µg/g), chromium (33 µg/g), manganese (511 µg/g), iron (21,600 µg/g), cobalt (9.4 µg/g), copper (69 µg/g), zinc (79 µg/g), arsenic (62 µg/g), strontium (620 µg/g), cesium (13 µg/g), lead 25 µg/g) and uranium (4.7 µg/g). Arsenic was present only as As(V). Mice received four exposures, once/week over 28-days to mimic a month of weekend exposures. Descriptive and functional assays to assess immunotoxicity and neurotoxicity were performed 24 h after the final exposure. The primary observation was that 0.1 to 100 mg/kg of this sand dune derived dust dose-responsively reduced antigen-specific IgM antibody responses, suggesting that dust from this area of NDRA may present a potential health risk.

Toxicity Studies.

Toxicity studies in the animal models are done to determine the dose level recommended for the treatment of disease as drug. This guideline enables the characterization of adverse effects following repeated daily inhalation exposure to a test. This chapter includes oral and dermal toxicity studies which are discussed as per OECD guidelines. Both acute and subacute toxicity studies are given special emphasis.

Acute and subacute toxicity studies of CMICE-013, a novel iodinated rotenone-based myocardial perfusion tracer, in Sprague Dawley rats and Gottingen minipigs.

PURPOSE: Extensive acute and subacute toxicities studies are required to evaluate the toxicological profile of the novel cardiac perfusion imaging tracer (123)I-CMICE-013 to support applications for clinical trials. METHODS: Sprague-Dawley rats and Gottingen minipigs received injections of non-radioactive 127I-CMICE-013 at two dosage levels of 1 and 5 µg/kg, and vehicle buffer as control. In the acute toxicity studies, each animal was injected on two occasions 24 h apart and then underwent a 14-day recovery period; in the subacute study, animals received daily injections for 14 days continuously. The health status and mortality of test animals were monitored daily and body weight, food consumption, physiological and biochemical parameters were measured at various time points during the study. Animals were euthanized at the end of the studies and dissected for pathologic examination of organs and tissues. RESULTS: The acute and subacute administrations of injections of the non-radioactive CMICE-013 in rats and minipigs were well tolerated. Little to no dosing-related adverse effects were observed in animal body and organ weights, hematology, coagulation, clinical chemistry, urinalysis, ophthalmoscopy, electrocardiograms, heart rates, blood pressure, macroscopic and microscopic examination of the preserved animal tissues including the brain. CONCLUSION: The lack of adverse effects from acute and subacute dosing suggest that the CMICE-013 injection solution has a reasonable safety margin within the designed concentration range to be utilized in imaging applications. The dosage level of 5 µg/kg was considered the no adverse effect level for both rats and minipigs based on our acute and subacute studies.

A 90-day subchronic toxicity study with sodium formononetin-3'-sulphonate (Sul-F) delivered to dogs via intravenous administration.

Sodium formononetin-3'-sulphonate (Sul-F) is a water-soluble derivate of formononetin, and an increasing number of studies have shown that Sul-F not only possesses favorable water solubility but also exhibits good lipid-lowering and bioactivities. In the current study, the toxicity of Sul-F was evaluated in dogs after 90-day intravenous infusion. Dogs were treated with Sul-F at dose of 0, 33.3, 100, and 300 mg/kg, and observed for 90-day followed by 28-day recovery period. Weekly measurement of body weight, temperature and food consumption were conducted. Ophthalmoscopy, ECG examination, urinalysis, serum biochemistry and hematology examination were performed at pre-test, on days 45 and 90, and following by 28-day recovery period. Histological examination was performed on day 90 and 28-day recovery period. No mortality, ophthalmic abnormalities or treatment-related findings in body weight, clinical chemistry, hematology, and histopathological examination were detected. However, a white crystal (non-metabolic Sul-F), transient vomiting and recoverable vascular stimulation were observed in 300 mg/kg/day Sul-F treated dogs. Under the conditions, the no-observed-adverse-effect-level (NOAEL) for Sul-F was 100 mg/kg in dogs.

Toxicological evaluation of advanced glycation end product Nε-(carboxymethyl)lysine: Acute and subacute oral toxicity studies.

Nε-(carboxymethyl)lysine (CML) as a novel potential noxious compound in various food products has aroused extensive concern in recent years. This study aimed to investigate the oral acute and subacute toxicity of CML in mice as per OECD 420 and 407 guidelines. Acute administration of 2000 and 5000 mg/kg CML did not induce any mortality within 14 days, nevertheless some toxicological symptoms and histopathological changes were observed. The estimated LD50 of CML was >5000 mg/kg. In subacute toxicity test, CML was dosed at 200, 500 and 1000 mg/kg in both genders for 28 days. The body weights reduced which was accompanied with the decrease of food consumptions. Hematology parameters viz. RBC, HGB and MCH showed minor alteration but these were still within normal range. Biochemical analysis of hepatic and renal function markers showed significant elevating in AST, ALT, Cr and BUN etc. Histopathological alterations were observed in lung, liver, kidney and spleen. Subacute toxicity of CML involved oxidative stress caused by reducing antioxidant enzyme (SOD and GSH-Px) activities, and significantly increasing lipid peroxide (MDA) level. In conclusion, CML was unlikely to present an acute hazard, but repeated administration could produce deleterious effects on mice especially inducing liver and kidney damage through oxidative stress.

Multi-level biological responses in Ucides cordatus (Linnaeus, 1763) (Brachyura, Ucididae) as indicators of conservation status in mangrove areas from the western atlantic.

There is a global lack of knowledge on tropical ecotoxicology, particularly in terms of mangrove areas. These areas often serve as nurseries or homes for several animal species, including Ucides cordatus (the uçá crab). This species is widely distributed, is part of the diet of human coastal communities, and is considered to be a sentinel species due to its sensitivity to toxic xenobiotics in natural environments. Sublethal damages to benthic populations reveal pre-pathological conditions, but discussions of the implications are scarce in the literature. In Brazil, the state of São Paulo offers an interesting scenario for ecotoxicology and population studies: it is easy to distinguish between mangroves that are well preserved and those which are significantly impacted by human activity. The objectives of this study were to provide the normal baseline values for the frequency of Micronucleated cells (MN‰) and for neutral red retention time (NRRT) in U. cordatus at pristine locations, as well to indicate the conservation status of different mangrove areas using a multi-level biological response approach in which these biomarkers and population indicators (condition factor and crab density) are applied in relation to environmental quality indicators (determined via information in the literature and solid waste volume). A mangrove area with no effects of impact (areas of reference or pristine areas) presented a mean value of MN‰<3 and NRRT>120min, values which were assumed as baseline values representing genetic and physiological normality. A significant correlation was found between NRRT and MN, with both showing similar and effective results for distinguishing between different mangrove areas according to conservation status. Furthermore, crab density was lower in more impacted mangrove areas, a finding which also reflects the effects of sublethal damage; this finding was not determined by condition factor measurements. Multi-level biological responses were able to reflect the conservation status of the mangrove areas studied using information on guideline values of MN‰, NRRT, and density of the uçá crab in order to categorize three levels of human impacts in mangrove areas: PNI (probable null impact); PLI (probable low impact); and PHI (probable high impact). Results confirm the success of U. cordatus species' multi-level biological responses in diagnosing threats to mangrove areas. Therefore, this species represents an effective tool in studies on mangrove conservation statuses in the Western Atlantic.

Evaluation of submarine atmospheres: effects of carbon monoxide, carbon dioxide and oxygen on general toxicology, neurobehavioral performance, reproduction and development in rats. I. Subacute exposures.

The inhalation toxicity of submarine contaminants is of concern to ensure the health of men and women aboard submarines during operational deployments. Due to a lack of adequate prior studies, potential general, neurobehavioral, reproductive and developmental toxicity was evaluated in male and female rats exposed to mixtures of three critical submarine atmospheric components: carbon monoxide (CO) and carbon dioxide (CO2; levels elevated above ambient), and oxygen (O2; levels decreased below ambient). In a 14-day, 23 h/day, whole-body inhalation study of exposure to clean air (0.4 ppm CO, 0.1% CO2 and 20.6% O2), low-dose, mid-dose and high-dose gas mixtures (high dose of 88.4 ppm CO, 2.5% CO2 and 15.0% O2), no adverse effects on survival, body weight or histopathology were observed. Reproductive, developmental and neurobehavioral performance were evaluated after a 28-day exposure in similar atmospheres. No adverse effects on estrus phase, mating, gestation or parturition were observed. No developmental or functional deficits were observed in either exposed parents or offspring related to motor activity, exploratory behavior or higher-level cognitive functions (learning and memory). Only minimal effects were discovered in parent-offspring emotionality tests. While statistically significant increases in hematological parameters were observed in the offspring of exposed parents compared to controls, these parameters remained within normal clinical ranges for blood cells and components and were not considered adverse. In summary, subacute exposures to elevated concentrations of the submarine atmosphere gases did not affect the ability of rats to reproduce and did not appear to have any significant adverse health effects.

Toxicological evaluation of ferrous N-carbamylglycinate chelate: Acute, Sub-acute toxicity and mutagenicity.

Iron is an essential trace element that is vital important in various biological process. A deficiency in iron could induce public health problem e.g. anaemia, while an overload could induce ROS production, lipid peroxidation and DNA bases modifications. In the present study, a new iron fortifier was synthesized, and its acute/sub-acute toxicity was investigated. According to the improved Karber's method, the median lethal dose (LD50) of the ferrous N-carbamylglycinate in SD rat was 3.02 g/kg and the 95% confidence intervals were between 2.78 and 3.31 g/kg. No biologically significant or test substance-related differences were observed in body weights, feed consumption, clinical signs, organ weights, histopathology, ophthalmology, hematology, and clinical chemistry parameters in any of the treatment groups of ferrous N-carbamylglycinate at target concentrations corresponding to 150, 300, and 600 mg/kg/day for 28 days. The no observed adverse effect level (NOAEL) for ferrous N-carbamylglycinate was at least 600 mg/kg b.w. day in rats. In addition, no evidence of mutagenicity was found, either in vitro in bacterial reverse mutation assay or in vivo in mice bone marrow micronucleus assay and sperm shape abnormality assay. On the basis of our findings, we conclude that ferrous N-carbamylglycinate is a low-toxic substance with no genotoxicity.