No-observed-adverse-effect Level Research Articles

Critical review of chronic toxicity testing approaches with the saltwater mysid (Americamysis bahia) used in pesticide registration.

The United States Environmental Protection Agency (USEPA) has a conditional requirement for a chronic toxicity test with mysids (Americamysis bahia) for registration of pesticide products. Achieving performance acceptability criteria in control treatments for this study can be challenging because the current draft test guideline, which was published in 1996 under USEPA Office of Prevention, Pesticides, and Toxic Substances (OPPTS) 850.1350, Mysid Chronic Toxicity Test, provides limited information on study design and conduct. This critical review was undertaken to 1) identify areas of inconsistency in acceptability criteria between the 1996 draft OPPTS test guideline and ASTM International test guidance, 2) highlight areas that require additional clarification, 3) discuss areas that are impractical or have uncertain scientific relevance regarding the objectives of the test, and 4) provide recommendations for revision of the draft OPPTS test guideline. To achieve this, 116 final study reports from chronic mysid toxicity tests conducted over approximately the past 30 years were collected. From these reports, survival, growth, and reproduction data from negative and solvent control groups were compiled. Through investigation of trends in the data, it became apparent that no-observed-effect-concentrations (NOECs) were most commonly based on reproductive endpoints, followed by adult growth endpoints and adult survival. Notably, less than 1% of studies had a NOEC based solely on a second-generation measurement endpoint. Analysis of this comprehensive data set provided clarity on the establishment of acceptability criteria for the study and elements of the testing procedure that can be streamlined without loss of critical information, which resulted in a set of recommendations to improve future versions of the chronic mysid toxicity test guideline.

Chronic cadmium exposure to minimal-risk doses causes dysfunction of epididymal adipose tissue and metabolic disorders.

Cadmium (Cd) is among the top seven most hazardous environmental contaminants. Minimal risk levels for daily exposure have been established, such as no observable adverse effect level (NOAEL) and lowest observable adverse effect level (LOAEL). Chronic exposure to Cd, at both NOAEL and LOAEL doses, causes toxicity in diverse tissues. However, Cd toxicity in adipose tissue, an endocrine and metabolic organ, remains relatively understudied. We aimed to investigate the potentially toxic effects of chronic Cd exposure (at NOAEL and LOAEL doses) on epidydimal adipose tissue of adult male Wistar rats. Ninety male Wistar rats were divided into three groups (n=30): Control Cd-free, NOAEL, and LOAEL that received CdCl2 in drinking water for 15days to 5months. We evaluated over time zoometry, serum and adipose Cd concentration, redox balance, GLUT4 and Nrf2 expression, histology, leptin, adiponectin, adipose insulin resistance index, free fatty acids, and glucose tolerance. The higher dose group showed a more pronounced and sustained increase in serum and adipose tissue of Cd concentration. Zoometry was similarly affected in both Cd-exposed groups with adipocyte hypertrophy. The redox balance was maintained due to the augmenting of Nrf2 expression. Leptin concentration augmented, while adiponectin diminished. Adipose insulin resistance increased simultaneously to lipolysis and glucose intolerance despite high GLUT4 expression. In conclusion, this study provides strong evidence that chronic Cd exposure, even at minimal risk levels (LOAEL and NOAEL doses), has toxic effects, disrupting the function of epididymal adipose tissue and contributing to metabolic disorders.

Intelligent consensus-based predictions of early life stage toxicity in fish tested in compliance with OECD Test Guideline 210.

Early life stage (ELS) toxicity testing in fish is a crucial test procedure used to evaluate the long-term effects of a wide range of chemicals, including pesticides, industrial chemicals, pharmaceuticals, and food additives. This test is particularly important for screening and prioritizing thousands of chemicals under the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation. In silico methods can be used to estimate the toxicity of a chemical when no experimental data is available and to reduce the cost, time, and resources involved in the experimentation process. In the present study, we developed predictive Quantitative Structure-Activity Relationship (QSAR) models to assess chronic effects of chemicals on ELS in fish. Toxicity data for ELS in fish was collected from two different sources, i.e. J-CHECK and eChemPortal, which contain robust study summaries of experimental studies performed according to OECD Test Guideline 210. The collected data included two types of endpoints - the No Observed Effect Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC), which were utilized to develop the QSAR models. Six different partial least squares (PLS) models with various descriptor combinations were created for both endpoints. These models were then employed for intelligent consensus-based prediction to enhance predictability for unknown chemicals. Among these models, the consensus model - 3 (Q2F1 = 0.71, Q2F2 = 0.71) and individual model - 3 (Q2F1 = 0.80, Q2F2 = 0.79) exhibited most promising results for both the NOEC and LOEC endpoints. Furthermore, these models were validated experimentally using experimental data from nine different industrial chemicals provided by Global Product Compliance (Europe) AB. Lastly, the models were used to screen and prioritize chemicals obtained from the Pesticide Properties (PPDB) and DrugBank databases.

Preclinical Safety Evaluation of SloIron CFTN-PS 5: a Pea-Derived Ferritin Product.

Ferritins are proteins present in plants and animals that are highly effective in storing iron and maintaining iron homeostasis. Iron deficiency anemia is a widespread nutritional disorder, and plant ferritins (phytoferritin) are potential sources of bioavailable iron with slow-release characteristics that prevent oxidative damage. These characteristics are related to receptor mediated endocytosis, the primary absorption mechanism in humans. However, the available toxicological data are insufficient to determine whether the use of phytoferritin as a nutritional supplement to enhance iron consumption in human populations is safe. Therefore, several GLP-compliant toxicology studies have been conducted with phytoferritin prepared from the seed of Psium sativum (trade name: SloIron CFTN-PS5). SloIron CFTN-PS5 was non-mutagenic and non-clastogenic in vitro and did not induce the formation of micronuclei in vivo. SloIron CFTN-PS5 was well-tolerated in a 90-day subchronic toxicity studies conducted in Sprague-Dawley rats at doses up to 1,950 mg/kg bw/day. These findings suggest that the oral consumption of SloIron CFTN-PS5 is of low toxicological concern, with a 90-day oral subchronic No Observed Adverse Effect Level (NOAEL) of 1,950 mg/kg-day, the highest dose tested.

Preclinical safety and efficacy of the recombinant CR1 drug product CSL040 in rats and cynomolgus monkeys.

CSL040 is a soluble, recombinant fragment of the complement receptor 1 (CR1) extracellular domain that acts as an inhibitor of all three pathways of the complement system. Systemic toxicity, toxicokinetics (TK), and pharmacodynamics (PD) of CSL040 were assessed in two-week intravenous (IV) bolus studies in Han Wistar rats and cynomolgus monkeys. Recovery from any effects was evaluated during a four-week recovery period. Daily repeat-dose administration for 2weeks at doses of up to 500mg/kg CSL040 IV was well tolerated in rats and cynomolgus monkeys, leading to a no observed adverse effect level (NOAEL) of 500mg/kg for both species. Safety pharmacology parameters such as electrophysiology of the heart, blood pressure, heart rate, and respiratory rate measurements, and general toxicological readouts were considered unaffected by CSL040 treatment. Anti-drug antibodies (ADAs) were observed in all cynomolgus monkeys and in some rats at the highest dose of CSL040, but with no effect on pharmacokinetics (PK), supportive of adequate exposure levels as required for a safety assessment. All three complement pathways were inhibited dose-dependently by CSL040. Additionally, no effect on cytokine levels by CSL040 was detected in vitro using a cytokine release assay. These non-clinical studies with CSL040 demonstrated PD activity consistent with its mode of action, adequate PK properties, and a safety profile supporting a phase 1 clinical strategy. A small follow-up study comparing the PK/PD effects of CSL040 following IV and subcutaneous (SC) administration also suggested that the latter route of administration might be a viable alternative to IV administration.

Teratogenic effect evaluation of Monascus red oral exposure to pregnant rats and their gut microbiota.

Monascus red (MR) is widely used as a natural food colorant and preservative in East Asia. However, the potential effects of MR during pregnancy remains unknown. In this study, MR was administrated to Sprague-Dawley (SD) rats at doses of 0, 0.50, 1.58, and 5.00g/kg bw on gestational days 6-15 by oral gavage. In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, serum endocrine indices, organ weights, thyroid histopathology, examinations of uterine contents and fetuses. In the gut microbiota analysis, the 5.00g/kg bw dose of MR decreased the α diversity and slightly changed their community structure at the genus level. Yet no marked toxicities in maternal animals or embryo-fetal development were observed. The no-observed-adverse-effect-level (NOAEL) of the maternal and developmental toxicity through oral exposure to MR was 5.00g/kg bw, the highest dose tested in rats.

Preclinical toxicity evaluation of the novel anti-hypertensive compound KSD179019.

The Secretin receptor (SCTR) presents a promising path for hypertension management, with KSD179019 as identified as a Positive Allosteric Modulator (PAM) of SCTR, demonstrating anti-hypertensive effects in animal models. Our objective was to comprehensively evaluate the potential toxicity of KSD179019 through in vitro and in vivo investigations. Initial in vitro studies showed minimal toxicity in liver and kidney cells and non-mutagenicity in bacterial assays. A 14-day acute toxicity test indicated an LD50 over 5000mg/kg body weight, suggesting a safe profile, yet necessitating further in vivo analysis before progressing to human trials. Following OECD protocols, we conducted sub-chronic (90 days) and chronic (180 days) toxicity studies in male and female C57 mice at various dosages. These included comprehensive hematological, biochemical, macroscopic, urinalysis, and histopathological examinations. The sub-chronic study reported minimal toxicity except at the highest doses (700 and 1000mg/kg), while the chronic study suggested a no-observed-adverse-effect-level (NOAEL) at 250mg/kg with limitations. QSAR analysis supported the non-mutagenic nature of KSD179019. KSD179019 demonstrated a favorable general toxicity profile at a dose of 250mg/kg in a 180-day chronic testing study. However, further preclinical investigations, including assessments of in vivo mutagenicity, reproductive and developmental toxicity, and carcinogenicity, are required to comprehensively establish its safety profile.

Cannabidiol in Foods and Food Supplements: Evaluation of Health Risks and Health Claims

Background: Cannabidiol (CBD) is a cannabinoid present in the hemp plant (Cannabis sativa L.). Non-medicinal CBD oils with typically 5–40% CBD are advertised for various alleged positive health effects. While such foodstuffs containing cannabinoids are covered by the Novel Food Regulation in the European Union (EU), none of these products have yet been authorized. Nevertheless, they continue to be available on the European market. Methods: The Permanent Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG) reviewed the currently available data on adverse and potential beneficial effects of CBD in the dose range relevant for foods. Results: Increased liver enzyme activities were observed in healthy volunteers following administration of 4.3 mg CBD/kg bw/day and higher for 3–4 weeks. As lower doses were not tested, a no observed adverse effect level (NOAEL) could not be derived, and the dose of 4.3 mg/kg bw/day was identified as the lowest observed adverse effect level (LOAEL). Based on the CBD content and dose recommendations of CBD products on the market, the SKLM considered several exposure scenarios and concluded that the LOAEL for liver toxicity may be easily reached, e.g., via consumption of 30 drops of an oil containing 20% CBD, or even exceeded. A critical evaluation of the available data on potential beneficial health effects of CBD in the dose range at or below the LOAEL of 4.3 mg/kg bw/day revealed no scientific evidence that would substantiate health claims, e.g., in relation to physical performance, the cardiovascular, immune, and nervous system, anxiety, relaxation, stress, sleep, pain, or menstrual health. Conclusions: The SKLM concluded that consumption of CBD-containing foods/food supplements may not provide substantiated health benefits and may even pose a health risk to consumers.

P-1088. Safety Study of Rifaquizinone in Dogs Following Intra-articular Administration

Abstract Background Rifaquizinone (RFQ, TNP-2092) is a novel multitargeting drug conjugate in development for the treatment of prosthetic joint infections (PJIs). RFQ exerts its antibacterial activity by inhibiting RNA polymerase, DNA gyrase, and topoisomerase IV. This study sought to investigate the safety/tolerability of RFQ following intra-articular (IA) administration in Beagle dogs. Methods Forty Beagle dogs (20/sex) were randomly assigned to 4 groups (5/sex/group) to receive 0, 1, 2.5, and 5 mg/kg/day RFQ in 5% (w/v) glucose once daily for 14 days by IA administration into the right knee joint. All the dogs had a 14-day recovery period to assess the reversibility, persistence, or delayed occurrence of adverse effects. Blood and synovial fluid samples were collected and concentrations of RFQ in each matrix were determined by liquid chromatography tandem mass spectrometry. Results No test article-related adverse effects in body weight, food consumption, temperature, clinical pathology, or organ weight were observed in any of the study groups. In 2.5 and 5 mg/kg/day groups, lameness, swelling and ulceration of right knee joint during treatment were observed. The 5 mg/kg group dosing was terminated prematurely due to marked arthritis on right knee joint. The no observed adverse effect level (NOAEL) was 1 mg/kg/day. At this dose level the steady state of RFQ concentrations in synovial fluid was achieved in 4 days and maintained until Day 14 (Figure 1). The mean RFQ concentrations on Day 14 in synovial fluids for male and female dogs were 35,900 and 19,200 ng/mL, respectively, as compared to the plasma Cmax 411 and 303 ng/mL for male and female dogs, respectively. Plasma toxicokinetics (TK) analysis indicated no apparent sex differences in systemic exposure at any dose level. Conclusion The NOAEL of RFQ in dogs was 1 mg/kg/day via IA administration. The synovial fluid concentration at this dose level exceeded minimum biofilm bactericidal concentration inhibit 90% bacterial growth (MBBC90) levels for both S. aures and S. epidermidis. IA administration of RFQ is a promising option for the treatment of PJIs. Disclosures Huan Wang, PhD, TenNor Therapeutics (Suzhou) Ltd: Employee Qin Cheng, Master, TenNor Therapeutics (Suzhou) Ltd: Employee Weijian Ke, Master, TenNor Therapeutics (Suzhou) Ltd: Investigator Zhenkun Ma, PhD, TenNor Therapeutics (Suzhou) Ltd: Employee

Safety of Mechanically Fibrillated Cellulose Nanofibers (CNFs) by Inhalation Exposure Based on TG412

An investigation into the acute toxicity of mechanically fibrillated cellulose nanofibers (fib-CNFs), with a fiber length ranging from 500 to 600 nm, was conducted in accordance with the OECD TG412 guidelines. In this study, rats were exposed to fib-CNFs via nasal inhalation for 6 h daily over a 28-day period. The highest exposure concentration was set at 35 mg/m3, with intermediate and low concentrations at 7.0 mg/m3 and 1.5 mg/m3, respectively. No significant differences were observed in body weight, hematological parameters, or biochemical profiles between the fib-CNF-exposed groups and the control group. However, the histopathological examination of lung tissue revealed elevated macrophage counts in both the alveolar spaces and lymph nodes, accompanied by a significant increase in lung weight. The most severe effects were observed in the high-concentration group, while the low-concentration group exhibited only mild inflammatory changes. Based on these findings, the no observable adverse effect level (NOAEL) for the acute toxicity of fib-CNFs is estimated to be below 1.5 mg/m3.

Alliumcepa exposed to Nativo® fungicide with and without swine liver enzyme biotransformation: A comparative genotoxicity study.

The biotransformation of compounds is a critical point in understanding their toxic effects in both toxicology and ecotoxicology. The objective of this study was to evaluate whether there is a difference in the phytogenotoxic potential of the commercial fungicide Nativo® between non-biotransformed samples and samples biotransformed by swine liver enzymes. The fungicide Nativo is a mixture of Tebuconazole (TEB; 200gL-1) and Trifloxystrobin (TRI; 100gL-1). The test organism used in this study was Allium cepa, and the mitotic index (MI), chromosomic aberrations, and micronucleus frequency in A. cepa cells were compared between samples of non-biotransformed Nativo and biotransformed Nativo. The results showed that the Nativo biotransformated products were less genotoxic than the non-biotransformed Nativo, with the no-observed effect concentration (NOEC) values for micronuclei formation being four times lower after swine enzymes biotransformation, while MI was not altered. The no observed effect concentration values for micronuclei formation by the fungicide mixture were 7.8 and 3.9mgL-1 for TEB and TRI, respectively, for the biotransformed samples, and 1.9 and 1.0mgL-1 for the non-biotransformed samples, demonstrating that swine liver enzyme activity decreased genotoxicity. The results obtained in this study demonstrate the importance of considering biotransformation in phytogenotoxicity studies, as this process can significantly alter phytogenotoxic effects.

P0637 Ebrasodebart (Ent001) First in Human trial in healthy volunteers: pharmacokinetic results and predicted therapeutic concentrations to preserve mucosal healing in patients with Ulcerative Colitis

Abstract Background Ebrasodebart (Ent001) is a human IgG4 monoclonal antibody that antagonizes the binding of IGFBP3 to the novel cell death receptor TMEM219, expressed on Intestinal Stem Cells (ISCs) and well conserved across human and animal species. Ebrasodebart is thus expected to inhibit TMEM219-mediated activation of Caspase-8 and the exaggerated apoptosis of ISCs observed in patients with Ulcerative Colitis (UC). Ebrasodebart is currently in clinical development as a novel first-in class investigational treatment in patients with UC. A FIH single ascending dose (SAD) study in healthy volunteers (HVs) was conducted to define the safety, tolerability and pharmacokinetics (PK) of ebrasodebart at the concentrations anticipated to be required to elicit pharmacological and therapeutic activity in patients. Methods Thirty (30) HVs were enrolled in the monocentric, randomized, double-blind, placebo-controlled SAD study, 29 subjects completed the study. In vitro and in vivo concentration-response preclinical experiments defined the pharmacologically active concentrations, measuring the inhibition of IGFBP3-induced Caspase-8 activation in human intestinal epithelial cell lines and organoids, and the exposure-response in DSS-induced chronic colitic mice, while modeling and simulation (M&S) predicted effective concentrations. Results After single intravenous (IV) doses of ebrasodebart in HVs, maximum exposure (Cmax) and systemic exposure (AUCinf) increased in an approximately dose proportional manner with a low intersubject variability at all dose levels (CV% < 20% for Cmax and AUCinf). Geometric mean t1/2 was between 17 to 19 days at the predicted therapeutic doses. Ebrasodebart achieved a Cmax of 296 µg/mL and AUC0-inf of 37646 µg/mL*h well below the No Observed Adverse Effect Level (NOAEL) from the 26-week chronic toxicity study in monkeys, but significantly higher than the minimal pharmacologically active concentration in vitro. The concentrations achieved in the FIH trial were also higher than those that significantly reduced the Disease Activity Index and both histological and endoscopic scores in mice, exceeding M&S predictions for pharmacological effectiveness in patients. Conclusion These data indicate that ebrasodebart concentrations with predictable PK and expected therapeutic efficacy can be safely reached in humans, and remained significantly below the NOAEL in monkeys, suggesting a potential for a wide therapeutic window in patients. A multicentric Phase 1b, randomized, double-blind, placebo-controlled trial is ongoing to evaluate safety, tolerability, PK, immunogenicity and preliminary efficacy of multiple ascending doses of ebrasodebart in patients with moderately to severely active UC.

26-Week Repeated-Dose Toxicity Study of a Novel Antiarrhythmic Drug Sulcardine Sulfate in Sprague-Dawley Rats.

Sulcardine sulfate (Sul) is a novel antiarrhythmic agent blocking multiple channels and exhibits unique pharmacological properties such as lower APD-dependent prolongation and reduced arrhythmia risk. Sul is currently in Phase III clinical trials, yet studies on its long-term toxicological profile and potential target organs remain unexplored. This study investigated the related toxicity of Sul in Sprague Dawley (SD) rats through repeated oral administration for 26 weeks, followed by a 4-week recovery period. Consistent with the clinical intended mode of administration, Sul was administered via oral gavage at daily doses of 0, 175, 350, and 700/525 mg/kg in rats. On account of clinically observed body weight loss of male and female rats in the high-dose group compared with the control group, with one female rat in the high-dose group dying after 8 weeks of administration, the high dose was adjusted to 525 mg/kg. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in male rats significantly increased in the medium- and high-dose groups, whereas female rats in these groups showed a significant rise in alkaline phosphatase (ALP) levels, accompanied by varying degrees of weight gain in the liver and lungs. Additionally, brownish-red pigment deposition was observed in hepatocytes and Kupffer cells across all dosing groups, along with foam cell deposition in the alveolar cavities. Concomitant toxicokinetics showed that the drug accumulated to some extent in the animals. Consequently, the liver and lungs were identified as potential target organs, and the no observed adverse effect level (NOAEL) was determined to be 175 mg/kg.

Risk of imidacloprid to soil invertebrates when applied as basal bark spray for the control of Hemlock Woolly Adelgid

The hemlock woolly adelgid (HWA Adelges tsugae) is an invasive insect on the east coast of North America where it has resulted in the widespread death and decline of hemlock trees. In Canada the most commonly used control strategy is the application of imidacloprid-based insecticides by basal bark spray, which could pose risk to non-target species. We monitored soil concentrations 50-400 cm away from trees for 24 months post application of Xytect 2f at a rate of 0.278 g imidacloprid/cm DBH and conducted a preliminary risk characterization by calculating Risk Quotients (RQ) for soil invertebrates derived from species sensitivity distributions build from No Observed Effect Concentrations (NOEC) and EC50 values. Imidacloprid was detected in 58.3–96.8% of samples at 50 and 100 cm and 8.3–45.8% at 200 and 400 cm from treated trees. The RQ values exceeded 1 at all times 50 cm from the tree for the median exposure, and at all distances and times for the upper 95% CI exposure. The frequency that RQ’s exceeded 1 declined with distance from tree at all time periods and declined over time at 50 and 100 cm from treated trees, but not at 200 and 400 cm. Overall, the highest risk to non-target soil invertebrates from basal bark application of imidacloprid occurs within 200 cm of treated trees.

Вплив бета-цифлутрину на репродуктивну функцію самиць щурів Wistar Hannover

Beta-cyfluthrin is the 2nd generation pirethroid, that is used as a broad-spectrum insecticide. The effect of the original beta-cyfluthrin molecule on reproductive function has not been studied. The assessment of possible reproductive toxicity of betacyfluthrin was based on the results of themulti-generational rat studyof cyfluthrin. Aim. To investigate the effect of beta-cyfluthrin on the reproductive function of femaleWistar Hannover rats during gametogenesis. Materials and Methods. Beta-cyfluthrin was administered per os 5 times a week by gavage in the form of an aqueous emulsion to two groups of females (20 animals each) in doses 3 and 30 mg/kg bw/day during 9 weeks. Control animals received distilled water with the addition of an emulsifier. In parallel with the control and experimental females, intact males were contained for mating. The estrous cycle was studied in female rats in the last 2 weeks of exposure to beta-cyfluthrin. After the period of exposure, the experimental females were mated with intact males for no longer than 3 weeks. On the 20th day of gestation, the experimental rats were euthanized to assess reproductive parameters. Results. The decrease in the body weight gain at a dose of 30 mg/kg establishes the general toxic effect of beta-cyfluthrin on female rats. It was also installed, that the test substance affects the estrous cycle of females, namely the duration of the proestrus stage, which received the maximum dose. The dose of 3 mg/kg bw/day had no effect on the reproductive function of females and no statistically significant changes were found between the experimental and control groups. Conclusion. Based on the results of the gonadotoxicity study, it can be concluded that beta-cyfluthrin has a general toxic effect and reproductive toxicity at a dose of 30 mg/kg bw/day. The no-observed-effect level (NOEL) was set at 3 mg/kg bw/day. Keywords: beta-cyfluthrin, pirethroid, reproductive function, estrous cycle, rats Wistar Han.

Inhalation exposure to cross-linked polyacrylic acid induces pulmonary disorders.

Organic polymers, widely used in food, daily necessities, and medicines, include cross-linked polyacrylic acid (CL-PAA), which has been reported to induce severe lung disease. While previous studies mainly used intratracheal instillation, our research focused on inhalation exposure to corroborate these findings. We conducted 5-day (short-term) and 13-week (subchronic) inhalation exposure studies with CL-PAA. In the short-term study, male F344 rats inhaled CL-PAA at 0.2, 2.0, or 20 mg/m³ for 6 hours/day over 5 days. Rats were dissected 3 days and 1 month post-exposure. In the subchronic study, rats inhaled CL-PAA at 0.2 or 2.0 mg/m³ for 6 hours/day, 5 days/week for 13 weeks, with dissections from 3 days to 6 months post-exposure. To investigate the mechanism of pulmonary disorders, an additional short-term study with 20 mg/m³ CL-PAA included intraperitoneal injections of the antioxidant N-acetylcysteine (NAC) (200 mg/kg) with dissection the day after exposure. Short-term exposure led to concentration-dependent increases in neutrophil influx, cytokine-induced neutrophil chemoattractant (CINC), total protein, lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF), and heme oxygenase-1 (HO-1) in lung tissue. Histopathology showed concentration-dependent neutrophil infiltration. Subchronic exposure caused persistent increases in BALF total protein and lung HO-1, with ongoing neutrophil infiltration and fibrosis. NAC administration reduced neutrophils, total protein, LDH, and CINC in BALF, and HO-1 in lung tissue, improving histopathological findings. Inhalation of CL-PAA caused concentration-dependent lung inflammation and persistent fibrosis. The no observed adverse effect level (NOAEL) for chronic pulmonary disorders was 0.2 mg/m³. Oxidative stress linked to CL-PAA-induced inflammation was mitigated by NAC administration.

Safety evaluation of an extension of use of the food enzyme glucose oxidase from the genetically modified Aspergillus niger strain ZGL.

The food enzyme glucose oxidase (β-d-glucose: oxygen 1-oxidoreductase, EC 1.1.3.4) is produced with the genetically modified Aspergillus niger strain ZGL by DSM Food Specialties B.V. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in one food manufacturing process. Subsequently, the applicant has requested to extend its use to include one additional process. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of two food manufacturing processes. Dietary exposure was calculated to be up to 0.025 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level (NOAEL) previously reported (1038 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 41,520. Based on the new data, the revised margin of exposure and the previous evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Single and repeated-dose toxicity studies by intravaginal administration of Lactobacillus plantarum ATG-K2 powder in female rats.

Bacterial vaginosis (BV) isa microbial dysbiosis that shifts the paradigms of vaginal flora from lactobacilli to opportunistic pathogens. Globally, BV is treated with antibiotic therapy and recurrence rates are > 70% occurring within 6months due to antibiotic resistance against pathogenic bacteria. An incorporation of lactobacilli orally or intravaginally for the recolonization of healthy microbes in vagina is the suggested course of treatment. Although Lactobacilli are suggested as a novel therapeutic for women's BV, evaluation of safety and toxicity have not been well understood previously. Therefore, in this study, we aimed to evaluate the safety profile of Lactobacillus plantarum ATG-K2 in subacute intravaginal animal toxicity in Sprague-Dawley rats under OECD guidelines and GLP regulations. Toxicological assessments were performed in a single-dose toxicity study by intravaginal administration with local tolerance study, 1-week repeated-dose intravaginal toxicity dose range finding (DRF) study, and a 2-week repeated-dose intravaginal toxicity study with a 2-week recovery period. Studies were performed at dose 3-18 × 109CFU/head/day. No toxicological changes in clinical signs, body weight, water and food consumption, urinalysis, hematology, clinical biochemistry, gross findings, or histopathological examination were observed in intravaginal repeated-dose toxicity. And Lactobacillus plantarum ATG-K2 did not show any local tolerance at the same doses as the intravaginal repeated-dose toxicity study. In conclusion, the no-observed-adverse-effect level (NOAEL) of Lactobacillus plantarum ATG-K2 was 12 × 109CFU/head/day and no target organ was identified in female rats. Our findings are the first to suggest that Lactobacillus plantarum is safe for use as an intravaginal treatment with no adverse effects observed in toxicological testing and has potential for application as a therapeutic agent or for other biological uses.

28-Day Repeated Dose Toxicity and Toxicokinetics Study on Dihydroartemisinin (DHA) in SD Rats.

Dihydroartemisinin (DHA) is an effective antimalarial drug with potential antitumor efficacy, yet toxicological information is limited. The present study was designed to evaluate the potential toxicity of oral DHA. DHA was administered orally by gavage to SD rats at doses of 0, 25, 50, and 75/60 mg/kg b.w./day for 28 days, followed by a 4-week recovery period. Concomitant toxicokinetics was also evaluated. Due to potential toxicity affecting survival, only the female top dose was adjusted from 75 to 60 mg/kg on study day 14 (D14). Female rats in the low-dose group and male rats in the low- and medium-dose groups did not show any signs of toxicity. In contrast, male rats in the high-dose group and female rats in the medium- and high-dose groups showed significant toxic effects, including weight loss, hair loss, and gastrointestinal reactions (soft stools, perianal dirt, and fecal abnormalities). At the end of administration, female rats in the 75/60 (dose-adjusted) mg/kg dose group had significantly higher reticulocytes (Ret% and RETIC) and alanine aminotransferase (ALT), increased liver weights, and significantly lower hemoglobin (HGB). In addition, histopathology showed mild vacuolation of hepatocytes. These findings suggest that female rats have a greater toxic response than males, and toxicokinetics further demonstrate this sex difference. However, the toxic effects of DHA were reversed at the end of the 4-week recovery period. Therefore, the liver was identified as the primary target organ. The no-observed-adverse-effect-level (NOAEL) was 25 and 50 mg/kg b.w./day in female and male rats, respectively.

Female rat liver after sub-acute dibutyl phthalate treatment: Histological, stereological, biochemical, and global gene expression study

Although it has been recognized that females are more susceptible to chemical-induced liver injury, the effects of dibutyl phthalate (DBP), a widely used synthetic chemical, on female liver structure and function are under-researched. Here, we sought to investigate the effects of DBP on histological, stereological, and biochemical parameters, as well as global gene expression in female rat liver. Female Wistar rats were exposed to 100, 500, and 5000 mg DBP/kg diet for 28 days, corresponding to 8.6, 41.43, and 447.33 mg DBP/kg body weight (B.W.)/day, respectively. The highest dose (447.33 mg DBP/kg B.W./day) was between the no-observed-adverse-effect level (NOAEL) and the lowest-observed-adverse-effect level for liver toxicity, whereas two lower doses (8.6 and 41.43 mg DBP/kg B.W./day) were below the NOAEL. Analysis of hematoxylin and eosin-stained sections revealed an increased volume of hepatocytes, their nuclei and cytoplasm, while the volume of sinusoids decreased in DBP-exposed groups compared to the control. Examination of Periodic acid-Schiff-stained sections showed reduced glycogen content, which was the most prominent in the highest dose group. Increased glutathione S-transferase and catalase activities, and decreased GSH content and superoxide dismutase activity were observed in DBP-exposed groups. The mRNA sequencing revealed DBP-induced dose-specific changes in various genes and biological functions in female rat liver. The highest number of deregulated genes was observed in the 500 mg DBP/kg diet group. In summary, exposure to DBP caused significant liver microstructural changes, decreased glycogen content, disturbed the redox status, and affected global gene expression in female rat liver.