Subchronic Study Research Articles

Effects of Multiwall Carbon Nanotubes on Premature Kidney Aging: Biochemical and Histological Analysis.

Carbon nanotubes (CNTs) have gained much attention due to their superb properties, which make them promising options for the reinforcing composite materials with desirable mechanical properties. However, little is known about the linkage between lung exposure to nanomaterials and kidney disease. In this study, we compared the effects on the kidneys and aging for two different types of multiwall carbon nanotubes (MWCNTs): pristine MWCNTs (PMWCNTs) and acid-treated MWCNTs (TMWCNTs), with TMWCNTs being the preferred form for use as a composite material due to its superior dispersion properties. We used tracheal instillation and maximum tolerated dose (MTD) for both types of CNTs. MTD was determined as a 10% weight loss dose in a 3-month subchronic study, and the appropriate dosage for 1-year exposure was 0.1 mg/mouse. Serum and kidney samples were analyzed using ELISA, Western blot, and immunohistochemistry after 6 months and 1 year of treatment. PMWCNT-administered mice showed the activation of pathways for inflammation, apoptosis, and insufficient autophagy, as well as decreased serum Klotho levels and increased serum levels of DKK-1, FGF-23, and sclerostin, while TMWCNTs did not. Our study suggests that lung exposure to PMWCNTs can induce premature kidney aging and highlights a possible toxic effect of using MWCNTs on the kidneys in the industrial field, further highlighting that dispersibility can affect the toxicity of the nanotubes.

Integrated Approach for Synthetic Cathinone Drug Prioritization and Risk Assessment: In Silico Approach and Sub-Chronic Studies in Daphnia magna and Tetrahymena thermophila.

Synthetic cathinones (SC) are drugs of abuse that have been reported in wastewaters and rivers raising concern about potential hazards to non-target organisms. In this work, 44 SC were selected for in silico studies, and a group of five emerging SC was prioritized for further in vivo ecotoxicity studies: buphedrone (BPD), 3,4-dimethylmethcathinone (3,4-DMMC), butylone (BTL), 3-methylmethcathinone (3-MMC), and 3,4-methylenedioxypyrovalerone (MDPV). In vivo short-term exposures were performed with the protozoan Tetrahymena thermophila (28 h growth inhibition assay) and the microcrustacean Daphnia magna by checking different indicators of toxicity across life stage (8 days sublethal assay at 10.00 µg L-1). The in silico approaches predicted a higher toxic potential of MDPV and lower toxicity of BTL to the model organisms (green algae, protozoan, daphnia, and fish), regarding the selected SC for the in vivo experiments. The in vivo assays showed protozoan growth inhibition with MDPV > BPD > 3,4-DMMC, whereas no effects were observed for BTL and stimulation of growth was observed for 3-MMC. For daphnia, the responses were dependent on the substance and life stage. Briefly, all five SC interfered with the morphophysiological parameters of juveniles and/or adults. Changes in swimming behavior were observed for BPD and 3,4-DMMC, and reproductive parameters were affected by MDPV. Oxidative stress and changes in enzymatic activities were noted except for 3-MMC. Overall, the in silico data agreed with the in vivo protozoan experiments except for 3-MMC, whereas daphnia in vivo experiments showed that at sublethal concentrations, all selected SC interfered with different endpoints. This study shows the importance to assess SC ecotoxicity as it can distress aquatic species and interfere with food web ecology and ecosystem balance.

Triethylenetetramine (TETA)

The WEEL for triethylenetetramine (TETA; CAS No. 112-24-3) was originally established in 1991 and updated in 1998 and 2009. Recent literature searches to identify new toxicity information were performed in 2016 and January 2021. No new studies or data relevant to the WEEL were identified. TETA is used in manufacturing; the hydrochloride salt of TETA is used as a copper-chelating drug in the treatment of Wilson's disease. TETA is severely irritating to the skin and eyes and produces skin sensitization; however, it is of low to moderate acute toxicity via the oral and dermal routes of exposure. In subchronic studies, signs of toxicity included multi-organ effects (lung, liver, and spleen) in mice, but not rats. TETA was genotoxic/mutagenic in short-term in vitro assays but not in in vivo assays. No data on reproductive toxicity were available. Embryo/fetal toxicity occurred at maternally toxic doses and was associated with copper deficiency. In humans, the use of TETA·2HCl for treatment of Wilson's disease during pregnancy resulted in no miscarriages or fetal abnormalities. No evidence of carcinogenicity was noted in a lifetime dermal study in mice. Based on a subchronic drinking water study in mice, 600 ppm (95mg/kg-day) was determined to be the no-observed-adverse-effect level (NOAEL) and the point of departure (POD). This NOAEL was converted to an equivalent inhalation concentration by adjusting for respiratory rate, interindividual variability, and uncertainty. The resulting 8-h time-weighted average WEEL value of 1 ppm is expected to provide a significant margin of safety against any potential adverse health effects in workers exposed to airborne TETA.

Safety Assessment of Schleichera oleosa Lour. Leaves Extract: Acute and Subchronic Studies.

<b>Background and Objective:</b> <i>Schleichera oleosa</i> (Sapindaceae) has been reported to be useful in traditional medicine and it has some potential pharmacological activities, such as anticancer, antioxidant and antimicrobial activities. This study aimed to assess its safety to provide complete data required for the development of <i>S. oleosa</i> as herbal medicine. <b>Materials and Methods:</b> The safety assessment of the extract was carried out by testing acute and subchronic toxicity in mice (male and female) and rats (male and female), respectively. The doses used in the acute toxicity test were 1000, 2000, 3000, 4000 and 5000 mg kg<sup>1</sup> of body weight and those in the subchronic treatment were 100, 200 and 400 mg kg<sup>1</sup> of body weight. <b>Results:</b> In the acute toxicity test, the <i>S. oleosa</i> leaf extract at all doses indicated that the LD<sub>50</sub> value of the extract was higher than 5000 mg kg<sup>1</sup> b.wt., which suggested that this extract is practically non-toxic according to the toxicity criteria. Furthermore, the subchronic toxicity test found that the administration of the extract to male and female rats at a daily dose of 100 and 200 mg kg<sup>1</sup> b.wt., for 90 days did not cause any significant change in blood haematology, blood biochemistry and histopathological picture of liver, kidney, heart, lymph and lung. Despite there being a significant increase in white blood counts, long-term use of the <i>S. oleosa</i> leaf extract is relatively safe. <b>Conclusion:</b> The results provided evidence regarding the potential of <i>S. oleosa</i> leaves to be used as herbal medicine. However, further research needs to be done to verify that activity and its safety in long-term use.

Evaluation of subchronic oral dose toxicity and allergen of freeze-dried powder of Locusta migratoria (Orthoptera: Acrididae) as a novel food source.

The migratory locust, Locusta migratoria (Orthoptera: Acrididae), is a well-known edible insect which may serve as new source of human food and animal feed. However, potential toxicity and food safety of L. migratoria had not been investigated extensively until now. Therefore, in this study, we aimed to investigate toxicity of freeze-dried powder of L. migratoria (fdLM) and identify allergic components in ELISA and PCR techniques. In this subchronic study, fdLM was administered once daily by oral gavage at the doses of 750, 1500, and 3000mg/kg/day. No toxicological changes were observed in both sexes of rats for 13weeks in accordance with the OECD guidelines and GLP conditions. In addition, fdLM did not induced increases of serum immunoglobulin E and 21 homologous proteins were not detected under our present conditions. In conclusion, the NOAEL (no-observed-adverse-effect level) was 3000mg/kg/day and no target organ was identified in both sexes. In conclusion, we found that fdLM is safe with no adverse effects and offers the potential of its use as an edible ingredient or other biological uses.

Acute and subchronic toxicity profile of methanol extract of leaves of Fimbristylis miliacea (L.) Vahl.

Fimbristylis miliacea (L.) Vahl (Cyperaceae) is a grass like herb habitually breeds as weed in paddy fields and mostly disseminated in tropical or sub-tropical countries of south and south-east Asia, northern Australia, and west Africa. The plant has been traditionally used to treat fever as a form of poultice. However, no scientific study regarding its toxicity profile has been testified. The study has been carried out to determine the potential toxicity of the methanol extract from leaves of the Fimbristylis miliacea, employing the technique of acute and subchronic oral administration in mice. In the acute toxicity study according to OECD guideline 425, oral administration of FM methanol extract at single doses of 2000 and 5000mg/kg in both sexes of Swiss albino mice was performed. Toxic symptoms, abnormal behavior, changes in body weight, and mortality were observed for 14 consecutive days. In subchronic toxicity study according to OECD guideline 407, plant extract was administered orally at doses of 100, 500, 1000, and 2000mg/kg daily for 28 days. The general toxic symptoms, abnormal behavior, changes in body weight were observed daily. Biochemical analysis of serum, and histopathological examination of liver were performed at the end of the study. No mortality, abnormal behavior and urination, changes in sleep, food intake, adverse effect, and non-linearity in body weight have been recorded during acute toxicity study at the doses of 2000 and 5000mg/kg. Also, in subchronic toxicity study, FM extract produced no mortality or any kind of adverse effects in regards of general behavior, body weight, urination, sleeping routine, and food intake. In case of analysis of thirteen different biochemical parameters, concentrations of aspartate transaminase (AST) and glucose were altered significantly in male and female mice in both acute and subchronic study. Total cholesterol and triglycerides at 5000mg/kg.bw were changed in male mice in acute toxicity study. On the other hand, female mice had altered triglycerides in subchronic test. All other critical parameters were found unaffected. In subchronic test, histopathological examination of liver demonstrated cellular necrosis at 2000mg/kg.bw in both male and female mice while minor necrosis was observed at 1000mg/kg.bw. Thus, the no observed adverse effect level (NOAEL) can be assumed around 1000mg/kg.bw. The present study suggests that treatment with FM extract does not reveal significant toxicity.

Safety evaluation of the genotoxicity and subchronic toxicity of standardized Bacopa extract (Bacognize®) from Bacopa monnieri

Bacopa monnieri is an important medicinal plant widely used in various food systems and gaining interest these days for its health benefits such as boosting brain function and improving quality of life. The objective of the present study was to examine the safety of Bacognize®, a standardized botanical extract obtained from the whole herb Bacopa monnieri (L.) Wettst., in subchronic toxicity and genotoxicity studies conducted in compliance with Good Laboratory Practice (GLP) and test guidelines established by the Organization for Economic Cooperation and Development (OECD). In the subchronic toxicity study, treatment with Bacognize® did not result in any toxicologically significant treatment-related changes in clinical observations, and in the clinical pathology as studied by hematology, serum chemistry, urinalysis, and terminal necropsy. Treatment-related adverse effects were not observed in ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. The results of genotoxicity studies as assessed by gene mutations in Salmonella typhimurium, in vitro chromosome aberrations and in vivo micronucleus test did not reveal any genotoxicity of Bacognize ®. The no-observed-adverse-effect level (NOAEL) for Bacognize® was established based on the subchronic study and was determined as at least 1000 mg/kg bw/day. These results indicate that Bacognize® does not cause significant adverse effects and suggest its tolerability up to 1000 mg/kg (highest dose tested) for the daily administration of 90 days in rats.

Spaceflight Maximum Allowable Concentrations for Ethyl Acetate.

INTRODUCTION: Ethyl acetate is a simple organic compound that occurs naturally and is used industrially as a solvent. It has been detected in the ISS atmosphere and is known to off-gas from building materials. As NASA astronauts have been and will be exposed to ethyl acetate during space missions, Spaceflight Maximum Allowable Concentrations (SMACs) were developed following an extensive review of the available literature.METHODS: Toxicological data relevant to SMAC development was collected from electronic databases using principles of systematic review, and from previous assessments and reviews of ethyl acetate.RESULTS: From an initial pool of over 35,000 studies, 10 were identified as studies appropriate to support SMAC development. The toxicological properties of ethyl acetate are relatively straightforward. Ethyl acetate is rapidly absorbed and converted by carboxyesterases to ethanol. At concentrations on the order of 400 ppm for 4-8 h, most volunteers experienced mild irritation but no lasting effects. In subchronic animal studies, mild sedative effects and changes in body weight and weight gain were observed at 750 ppm and above.DISCUSSION: Numerous studies were identified to support the development of both short- and long-duration SMACs. No chronic studies were available, but the high quality of the subchronic studies and the short half-life of ethyl acetate support extrapolation to longer durations.Williams ES, Ryder VE. Spaceflight maximum allowable concentrations for ethyl acetate. Aerosp Med Hum Perform. 2023; 94(1):25-33.

Olive juice dry extract containing hydroxytyrosol, as a nontoxic and safe substance: Results from pre-clinical studies and review of toxicological studies.

Products derived from olives, such as the raw fruit and oils, are widely consumed due to their taste, and purported nutritional/health benefits. Phenolic compounds, especially hydroxytyrosol (HT), have been proposed as one of the key substances involved in these effects. An olive juice extract, standardized to contain 20% HT ("OE20HT"), was produced to investigate its health benefits. The aim of this study was to demonstrate the genotoxic safety of this ingredient based on in vitro Ames assay and in vitro micronucleus assay. Results indicated that OE20HT was not mutagenic at concentrations of up to 5000µg/plate, with or without metabolic activation, and was neither aneugenic nor clastogenic after 3-hour exposure at concentrations of up to 60µg/mL with or without metabolic activation, or after 24-hour exposure at concentrations of up to 40µg/mL. To further substantiate the safety of OE20HT following ingestion without conducting additional animal studies, a comprehensive literature review was conducted. No safety concerns were identified based on acute or sub-chronic studies in animals, including reproductive and developmental studies. These results were supported by clinical studies demonstrating the absence of adverse effects after oral supplementation with olive extracts or HT. Based on in vitro data and the literature review, the OE20HT extract is therefore considered as safe for human consumption at doses up to 2.5mg/kg body weight/day.

Acute and Subchronic Toxicity Studies on the Aqueous Extract of the Plant Mixture (Bidens pilosa and Cymbopogon citratus Aerial Parts) in Rat Model.

Bidens pilosa (B. pilosa) and Cymbopogon citratus (C. citratus) are plants used individually or in combination in the traditional treatment of several ailments such as cardiovascular disorders. In order to valorise their traditional use, a toxicological study was conducted on the aqueous extract of the mixture of aerial parts of B. pilosa and C. citratus. The acute and subchronic toxicity studies were conducted according to the OECD 425 and 407 guidelines. Regarding the acute study, the aqueous extract of the mixture of B. pilosa and C. citratus 50 : 50 (2000 and 5000 mg/kg) was administered once to rats of both sexes. In the subchronic study, the aqueous extract of the mixture of B. pilosa and C. citratus (200, 400 and 800 mg/kg) was administered once daily to rats for 28 days. The aqueous extract of the mixture of B. pilosa and C. citratus (2000 and 5000 mg/kg) did not cause death and did not induce any apparent sign of toxicity during the 14 days of observation. The DL50 of the extract is therefore greater than 5000 mg/kg. Taken daily for 28 days, the extract had no significant effect on selected parameters (creatinine, AST, ALT, urea, and uric acid) of renal and hepatic function, as well as on the number of some blood cells. However, the aqueous extract of the mixture of B. pilosa and C. citratus (200 and 400 mg/kg) caused a significant (p < 0.05; p < 0.001, respectively) decrease in creatinine levels in male rats as compared to normal control animals. In females, the aqueous extract of the mixture of B. pilosa and C. citratus (200 and 400 mg/kg) resulted in a significant (p < 0.05) increase in total cholesterol levels as compared to normal control animals. The study showed that the aqueous extract of the mixture of B. pilosa and C. citratus has a low toxicity and does not cause any injury to the liver, kidney, lungs, or spleen.

Genotoxicity, acute, and subchronic toxicity evaluation of dried Neurospora crassa protein-rich biomass.

Filamentous fungus biomass is a protein-rich food, which can serve as an alternative to animal, plant, and legume protein sources. Neurospora crassa is a filamentous fungus that typically grows in tropical and sub-tropical regions. Traditionally, N. crassa has served as a model eukaryotic organism due to its ease of growth and propagation and suitability for genetic manipulation. However, filamentous fungi, such as Neurospora, have also been consumed or used to produce fermented foods for centuries and have been developed into protein-rich biomass ingredients to be used in conventional foods and meat substitutes. A panel of toxicological tests including genotoxic, acute, and subchronic studies were conducted on dried N. crassa biomass to support its safe use in food. The dried N. crassa biomass was found to be not genotoxic in a bacterial reverse mutation (Ames) assay, an in vitro chromosomal aberration test, and an in vivo micronucleus test. In the acute and subchronic toxicity studies, rats were orally gavaged with N. crassa biomass at concentrations of 0, 1,000, 2,500, and 5,000mg/kg body weight/day for 14 and 90days, respectively. At the conclusion of the studies, there were no test article-related toxicity results observed in clinical observations, body weight, food consumption, ophthalmology, hematology, clinical chemistry, coagulation, thyroid hormone, urinalysis, and macroscopic and microscopic findings. The no-observed-adverse-effect level for the dried N. crassa biomass ingredient was determined to be 5,000mg/kg body weight/day, the highest dose tested.

Safety of cellobiose as a novel food pursuant to regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panelon Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on cellobiose as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF consists of two glucose monomers linked by a β-(1-4) glucosidic bond. The applicant intends to add the NF to a variety of foods, and to food supplements aimed at the general population 3 years and older. The information provided on the manufacturing process, composition and specifications of the NF is sufficient and does not raise safety concerns. The applicant provided a subchronic toxicological study which did not raise safety concerns. The applicant provided a human dose-escalation study from which the Panelconcludes that the consumption of 20g per day of cellobiose (equivalent to 290mg/kg body weight (bw) per day in a 70-kg adult) does not raise concern regarding gastrointestinal tolerability. The maximum anticipated daily intake of cellobiose from the proposed uses is below 290mg/kg bw per day in the target population. Considering the nature, source, compositional characterisation, and production process of the NF, as well as the toxicological data provided, the Panelconsiders that the NF does not raise safety concerns under the proposed conditions of use.

Peroral Toxicological Assessment of Two-Dimensional Forms of Nickel Nanoparticles Sized between 20 and 120 nm.

Nickel (Ni) nanoparticles (NPs) are used as technological aids–catalysts in the oil and fat industry, in pharmaceuticals, and in the production of cosmetics and pesticides. The acute and subchronic oral toxicity of metallic Ni in the nanoform is not well understood. The study aimed to investigate the acute and subchronic oral toxicity of Ni NPs to rats. We used two NP preparations (Ni NP1 and Ni NP2) with spherical particles and an average diameter of 53.7 and 70.9 nm according to the electron microscopy data. In the study of acute toxicity, both kinds of Ni NPs were administered to male and female Wistar rats aged 8 weeks as a single dose of 2000 mg/kg b.w. through a gastric gavage. In the subchronic experiment, male Wistar rats initially aged 7 weeks received for 92 days Ni NP1 and Ni NP2 as well as the “traditional” soluble salt form of Ni (Ni basic carbonate) at doses of 0.1, 1, and 10 mg/kg body weight (mg/kg b.w.) in terms of Ni content as a part of the diet consumed. As a result, in an acute study, the oral LD50 for Ni NP2 in male and female rats was about 1600 mg/kg b.w. (IV hazard class). The oral dose of Ni NP1 equal to 2000 mg/kg b.w. exceeded LD100 for males and corresponded to LD90 for females. In the subchronic study, the bioaccumulation of both Ni NPs as well as Ni salt was observed in the kidney but not in the liver and spleen. Ni NP1 decreased body weight only at a dose of 1 mg/kg b.w.; affected the relative weight of the spleen at 0.1 mg/kg, the brain at 1.0 mg/kg, and the thymus at 10 mg/kg; and decreased locomotor activity at 0.1 and 10 mg/kg. Thus, for Ni NP1, in such cases where a monotonic dose–response relationship could be traced, LOEL could be stated at 10 mg/kg b.w./day for 92 days of oral intake. However, for some endpoints where such a monotonic relationship could be absent, significant toxic effects were observed even at a dose 0.1 mg/kg. In the case of Ni NP2, changes in the relative weight of the liver, thymus, and brain were recorded starting from 0.1 mg/kg b.w.; locomotor activity decreased starting from 0.1 mg/kg. Other effects, including basophiles count and platelet system indexes, were observed at a dose of 1 mg/kg or higher. Thus, the LOEL value for Ni NP2 can be fixed at 0.1 mg/kg. The critical organs affected by both Ni NPs were the brain and immune system. Most of the toxic effects exhibited by metallic Ni NPs were absent or had an opposite orientation upon administration of equivalent doses of Ni in the salt form which indicates the signs of “nanotoxicity” in metallic Ni NPs. In conclusion, the data obtained show that there may be some additional health risks caused by the intake of Ni in a nanoform compared to soluble ionized forms of this element at equivalent doses.

Acute and Sub-Acute Toxicity of Spray-Dried Extract of Tribulus Terrestris

The use of herbal medicines has tremendously grown over the past few years. Owing to their safety, they are more preferred over conventional allopathic medicine. Plant-based therapies have significantly improved and protected human health. Additionally, dry powdered herbal medications are more effective than liquid extracts. The numerous claims are not backed up by any data that can be verified. It is the first time that the activity of Tribulus Terrestris spray-dried extract has been linked to acute and suba-cute oral toxicity. The objective of the current work was to investigate the acute and sub-acute toxicity of spray-dried extract (SDE) of Tribulus terrestris. For acute toxicity, two different doses, i.e., 2000 and 5000 mg/kg, were given to the female Wistar rats. Only one dose was administered and each animal was observed for any signs of mortality along with behavioral changes and physical symptoms for 2 weeks. Multiple doses of the SDE were given to the Wistar (both genders) rats for 28 days in the sub-acute toxicity. Animals of both the genders received 500, 1000, and 1500 mg/kg/day SDE doses for 28 days consecutively. Blood samples were obtained for biochemical and hematological analysis on the 29th day of the experiment, following which subjects were sacrificed for the histopathological examination. The results of acute toxicity revealed no signs of morbidity and mortality in rats. Similar results were recorded in the sub-acute toxicity. Mild variations were observed at 1000 and 1500 mg/kg/day, however results were non-significant. The SDE of Tribulus terrestris did not show any significant harmful effects in the treated animals after 14 and 28 days of treatment. Therefore, SDE of Tribulus terrestris can be safely employed in pharmaceutical formulations for therapeutic use, addressing further safety in chronic and sub-chronic study.

NAM-based prediction of point-of-contact toxicity in the lung: A case example with 1,3-dichloropropene

Time, cost, ethical, and regulatory considerations surrounding in vivo testing methods render them insufficient to meet existing and future chemical safety testing demands. There is a need for the development of in vitro and in silico alternatives to replace traditional in vivo methods for inhalation toxicity assessment. Exposures of differentiated airway epithelial cultures to gases or aerosols at the air–liquid interface (ALI) can assess tissue responses and in vitro to in vivo extrapolation can align in vitro exposure levels with in-life exposures expected to give similar tissue exposures. Because the airway epithelium varies along its length, with various regions composed of different cell types, we have introduced a known toxic vapor to five human-derived, differentiated, in vitro airway epithelial cell culture models—MucilAir of nasal, tracheal, or bronchial origin, SmallAir, and EpiAlveolar—representing five regions of the airway epithelium—nasal, tracheal, bronchial, bronchiolar, and alveolar. We have monitored toxicity in these cultures 24 h after acute exposure using an assay for transepithelial conductance (for epithelial barrier integrity) and the lactate dehydrogenase (LDH) release assay (for cytotoxicity). Our vapor of choice in these experiments was 1,3-dichloropropene (1,3-DCP). Finally, we have developed an airway dosimetry model for 1,3-DCP vapor to predict in vivo external exposure scenarios that would produce toxic local tissue concentrations as determined by in vitro experiments. Measured in vitro points of departure (PoDs) for all tested cell culture models were similar. Calculated rat equivalent inhaled concentrations varied by model according to position of the modeled tissue within the airway, with nasal respiratory tissue being the most proximal and most sensitive tissue, and alveolar epithelium being the most distal and least sensitive tissue. These predictions are qualitatively in accordance with empirically determined in vivo PoDs. The predicted PoD concentrations were close to, but slightly higher than, PoDs determined by in vivo subchronic studies.

Inhibition of kidney potassium channels by fluoxetine: In vivo and in vitro studies.

In vitro studies have demonstrated that fluoxetine, a commonly used antidepressant drug, can modulate the activity of K+ channels. In the present study, we investigated the in vivo effect of acute and sub-chronic treatment of rats with fluoxetine on K+ renal transport. Furthermore, OK cells, a kidney epithelial cell line, were used in order to evaluate the in vitro effect of fluoxetine on K+ currents. In the sub-chronic study, fluoxetine was administrated daily (10mg/kg, p.o.) for 15 days to male adult Wistar rats. In the acute study, rats were given increasing doses of fluoxetine (1, 3, 10, 30 and 50 mg/kg, p.o.) for 24 h. Results from the sub-chronic study show that urinary K+ content (in mmol/L) was markedly reduced in the fluoxetine-treated animals (fluoxetine: 83 ± 9; control: 131 ± 10; P < 0.001). K+ fractional renal excretion (in %) was also significantly lower in the fluoxetine group (fluoxetine: 6 ± 1; control: 13 ± 2; P < 0.001). No significant changes was observed in creatinine clearance and on renal tubular Na+ ,K+ -ATPase activity. Results obtained from the acute study demonstrate that, after a 24-h administration, fluoxetine produced a dose-dependent decrease in urinary K+ , with an ED50 (in mg/kg) of 4.2 (2.8; 5.5) and a maximal effect of 62% reduction. In vitro, fluoxetine produced a concentration-dependent inhibition of K+ currents in OK cells, with an EC50 of 107 (84.8; 129.5) μM. In conclusion, fluoxetine produces a marked reduction on urinary K+ excretion; this effect constitutes an in vivo evidence for the inhibitory action of fluoxetine on kidney epithelial K+ channels.

Assessment of Lithium-Induced Cardiotoxicity in Rats and the Potential Effect of Selenium: Sub-Chronic Study

Assessment of Lithium-Induced Cardiotoxicity in Rats and the Potential Effect of Selenium: Sub-Chronic Study

Acute and Subchronic Oral Toxicity of Anthraquinone in Sprague Dawley Rats.

Objective: This study was conducted to evaluate the acute and subchronic toxicity of anthraquinone. An acute toxicity test was performed in female Sprague Dawley (SD) rats, and the oral median lethal dose (LD50) of anthraquinone was estimated to be >5000 mg/kg body weight (BW). In the subchronic study, groups of 10 male and 10 female rats were dosed with anthraquinone by gavage at 0, 1.36, 5.44, 21.76, and 174.08 mg/kg BW, 7 days/week for 90 days followed by a recovery period of 28 days. No appreciable toxic-related changes were observed in the 1.36 mg/kg BW group. When the animals received 5.44 mg/kg BW or more of anthraquinone, hyaline droplet accumulation in the renal tubules was observed in both the male and female rats, and anemia was observed in the females. When the anthraquinone dose reached 174.08 mg/kg BW, mild hepatocellular hypertrophy around the central vein of the hepatic lobule and hypothyroidism were observed in the female rats. During the recovery period, changes in clinical symptoms and parameters were considerably alleviated. Based on the results of this study, the no observed adverse effect level (NOAEL) for anthraquinone in rats was set at 1.36 mg/kg BW, and the lowest observed adverse effect level (LOAEL) was 5.44 mg/kg BW.

Risk Assessment of the Fungicide Aviator Xpro EC 225 with the Active Substances Bixafen and Prothioconazole

Aviator Xpro EC 225 is a new fungicide for use in cereals, containing the new active substance bixafen and the already approved active substance prothioconazole. Prothioconazole was assessed by the Norwegian Scientific Committee for Food Safety in 2006, and is therefore not included in this report.&#x0D; VKM was requested by the Norwegian Food Safety Authority to consider the possible health risk for operators related to the properties of bixafen used in Aviator Xpro EC 225; in particular to evaluate the relevance of the effects of bixafen on liver and coagulation parameters observed in rats and mice, thyroid tumours and reproductive effects observed in rats, and the establishment of NOAELs and reference values. VKM was also asked to evaluate the fate and behaviour of bixafen in the environment, and the ecotoxicological effects and risks related to its use. The risk assessment was finalized in a meeting on May 24. 2013 by VKM’s Scientific Panel on Plant Protection Products.&#x0D; VKM’s conclusions are as follows:&#x0D; Health:&#x0D; VKM concluded that the liver effects reported in sub-chronic and chronic studies in rats, dogs and mice exposed to bixafen, as well as the effects on coagulating parameters, should be considered adverse and of relevance to humans.&#x0D; It is the opinion of VKM that the thyroid follicular cell tumours reported in female rats exposed to bixafen is not sufficient to suggest that bixafen has a tumour inducing potential.&#x0D; It is further the opinion of VKM that it cannot be excluded that the reduced pup weight during lactation in the two-generation study is mediated by bixafen via the milk, and that bixafen has a direct effect on the number of stillborn pups in the F1 and F2 generation.&#x0D; Finally, the pup developmental variants and anomalies reported in the teratogenicity study are considered treatment related, and not as secondary effects related to maternal toxicity.&#x0D; VKM proposes a NOAEL of 2.0 mg/kg bw/day based on a 2 year feeding study in rats.&#x0D; VKM support/propose:&#x0D; &#x0D; ADI: 0.02 mg/kg bw/day&#x0D; AOEL: 0.13 mg/kg bw/day&#x0D; ARfD: 0.2 mg/kg bw/day&#x0D; &#x0D; Risk calculations show minimal risk if personal protective equipment is used.&#x0D; Environment:&#x0D; Bixafen is shown to be persistent in soil. VKM considers the results from a field study on a German site and the Finnish PEC calculator to be relevant and concludes that repeated annual applications can cause accumulation in soil under Norwegian conditions. There is also a potential for groundwater contamination from leaching of the metabolite M44.&#x0D; VKM has concluded that the use of bixafen as an ingredient in Aviator Xpro EC 225 with the proposed application regime in Norway will represent a minimal risk for toxic effects to terrestrial organisms.&#x0D; The toxicity of bixafen to aquatic organisms is high, and minimal risk of effects in surface waters can be achieved only if risk mitigation measures with bufferzones of 10 m are applied.

Risk Assessment of the Pesticide Coragen 20 SC with the Active Substance Chlorantraniliprole

Coragen 20 SC is a new product in Norway containing the active substance chlorantraniliprole. It is applied for use in apples against codling moth (Cydia pomonella), apple fruit moth (Argyresthia conjugella) and free leaf living larvae. The Norwegian Scientific Committee for Food Safety (VKM) was asked by the Norwegian Food Safety Authority to perform a risk assessment on human health, environmental fate and ecotoxicological of the active substance and the product. The risk assessment of the product was approved at a meeting 11th of May 2010 by VKMs Scientific Panel on Pesticides (Panel 2). VKMs Panel 2 concludes as following: The product and the active substance have low acute oral, dermal and inhalation toxicities. Both are non-irritating to the skin, and no allergenic potential by skin contact were shown. Coragen was non-irritating to the eyes, while chlorantraniliprole showed a weak irritating potential. Chlorantraniliprole is not shown to have any genotoxic or carcinogenic potential, or to be teratogenic or toxic to the reproduction of female animals. The potential for testicular toxicity of chlorantraniliprole is unclear because the study design and the limited number of young dogs (2/sex/group) do not provide basis for a firm conclusion. No particular target organ for toxicity in any species in the sub-chronic and chronic toxicity studies was seen. The observed dose- and time dependent increased degree of microvesiculation in the zona fasiculata of the adrenal cortex in male rats, is however of uncertain biological significance. All test species (rat, mice, dog) showed physiological adaption to chlorantraniliprole administration (increased liver metabolism with induction of cytochrome P450 enzymes) which was manifested as increased liver weight and hepatocellular hypertrophy. In the chronic toxicity study in mice, the increased liver weight and hepatocellular hypertophy was accompanied with eosinofilic foci, which was assessed as an adverse effect. The no observed effect level (NOAEL) derived from this study serves as basis for calculations of values for acceptable daily intake (ADI) and acceptable operator exposure level (AOEL). &#x0D; In Panel 2‘s opinion a sub-chronic study (90 days) with the technical material (E2Y45-282) including relevant concentration of the impurity IN-G2S78 should be performed. This would bring information on possible influence of the impurity on the toxicological profile of the technical material, and consequently on the assessment of the NOAELs in the various toxic studies. &#x0D; The estimated risk for operator and for bystanders or for workers re-entering treated crops is assessed as minimal. &#x0D; Chlorantraniliprole is persistent in soil with half live of about 1 year. The long half life indicates high potential for accumulation in soil after repeated use, which is confirmed by both model simulations and field studies. The Panel considers field data from the south of Europe not to be relevant for the Nordic conditions based on different climate conditions and soil properties contributing in different directions.&#x0D; The Panel considers that the existing documentation is not sufficient for a firm conclusion on the use of normalised field data for modelling purposes. However, the substance is persistent and expected to accumulate in soil. The Panel concludes that there is minimal risk for toxic effects on mammals, birds, bees, and microorganisms in soil due to chlorantraniliprole exposure with the proposed exposure regime. Panel concludes that there is “very high risk” for effects on in-field non target arthropods from chlorantraniliprole exposure. &#x0D; For soil living invertebrates, earthworms seem rather insensitive to chlorantraniliprole and the Panel considers the toxic effects to be minimal. Panel considers the risk for toxic effects on soil living arthropods to be high. Crustaceans and insects larvae are the aquatic organisms most sensitive to chlorantraniliprole. The Panel concludes that there is a minimal risk of toxic effects on aquatic organisms due to exposure to chlorantraniliprole with the proposed application regime provided that a buffer zone of 30 m to surface water is applied.