A non-clinical and clinical IUCLID database for 530 pharmaceuticals (part I): Methodological aspects of its development.

A new IUCLID database is provided containing results from non-clinical animal studies and human information for 530 approved drugs. The database was developed by extracting data from pharmacological reviews of repeat-dose, carcinogenicity, developmental, and reproductive toxicity studies. In the database, observed and no-observed effects are linked to the respective effect levels, including information on severity/incidence and transiency/reversibility. It also includes some information on effects in humans, that were extracted from relevant sections of standard product labels of the approved drugs. The database is complemented with a specific ontology for reporting effects that was developed as an improved version of the Ontology Lookup Service's mammalian and human phenotype ontologies and includes different hierarchical levels. The developed ontology contains novel and unique standardized terms, including ontological terms for reproductive and endocrine effects. The database aims to facilitate correlation and concordance analyses based on the link between observed and no-observed effects and their respective effect levels. In addition, it offers a robust dataset on drug information for the pharmaceutical industry and research. The reported ontology supports the analyses of toxicological information, especially for reproductive and endocrine endpoints and can be used to encode legacy data or develop additional ontologies. The new database and ontology can be used to support the development of alternative non-animal approaches, to elucidate mechanisms of toxicity, and to analyse human relevance. The new IUCLID database is provided free of charge at https://iuclid6.echa.europa.eu/us-fda-toxicity-data.

Predicting in vivo effect levels for repeat-dose systemic toxicity using chemical, biological, kinetic and study covariates.

In an effort to address a major challenge in chemical safety assessment, alternative approaches for characterizing systemic effect levels, a predictive model was developed. Systemic effect levels were curated from ToxRefDB, HESS-DB and COSMOS-DB from numerous study types totaling 4379 in vivo studies for 1247 chemicals. Observed systemic effects in mammalian models are a complex function of chemical dynamics, kinetics, and inter- and intra-individual variability. To address this complex problem, systemic effect levels were modeled at the study-level by leveraging study covariates (e.g., study type, strain, administration route) in addition to multiple descriptor sets, including chemical (ToxPrint, PaDEL, and Physchem), biological (ToxCast), and kinetic descriptors. Using random forest modeling with cross-validation and external validation procedures, study-level covariates alone accounted for approximately 15% of the variance reducing the root mean squared error (RMSE) from 0.96 log10 to 0.85 log10 mg/kg/day, providing a baseline performance metric (lower expectation of model performance). A consensus model developed using a combination of study-level covariates, chemical, biological, and kinetic descriptors explained a total of 43% of the variance with an RMSE of 0.69 log10 mg/kg/day. A benchmark model (upper expectation of model performance) was also developed with an RMSE of 0.5 log10 mg/kg/day by incorporating study-level covariates and the mean effect level per chemical. To achieve a representative chemical-level prediction, the minimum study-level predicted and observed effect level per chemical were compared reducing the RMSE from 1.0 to 0.73 log10 mg/kg/day, equivalent to 87% of predictions falling within an order-of-magnitude of the observed value. Although biological descriptors did not improve model performance, the final model was enriched for biological descriptors that indicated xenobiotic metabolism gene expression, oxidative stress, and cytotoxicity, demonstrating the importance of accounting for kinetics and non-specific bioactivity in predicting systemic effect levels. Herein, we generated an externally predictive model of systemic effect levels for use as a safety assessment tool and have generated forward predictions for over 30,000 chemicals.

The chronic hepatotoxicity assessment of the herbal formula Zishen Yutai pill.

Zishen Yutai pill (ZYP) is an oriental herbal formula, while hepatotoxicity assessment of ZYP was rarely evaluated. Therefore, our aim is to re-evaluate its hepatotoxicity in both normal and carbon tetrachloride (CCl4) induced chronic liver injury rats. In the normal model, two doses of ZYP (1.575 and 9.450 g kg-1 d-1; i.e. 1 × , 6 × clinical doses) were given orally to rats for 24 weeks. In the chronic liver injury model, 10% CCl4 was administered to rats abdominally twice a week at a dose of 5 mL kg-1 for 12 consecutive weeks. Administration time started from 4 weeks after the beginning of CCl4 treatment. Toxicological parameters included mortality, body weight, food consumption, clinical signs, biochemical parameters, gross observation, organ weight, necropsy findings and histopathology were monitored. In the normal model, we found no any mortality or abnormality in clinical signs, relative liver weight, biochemical parameters and histopathology in ZYP treatment groups. In the chronic liver injury model, liver damage related parameter such as ALT was elevated at the high dose of ZYP treatment in contrast to the CCl4-treated group (P < 0.01). In histopathological assessment, there were no significant difference between ZYP treatment groups and CCl4-treated group. No observed adverse effect on livers were established for 9.450 g kg-1 d-1 ZYP in the normal rats and 9.450 g kg-1 d-1 ZYP in the injury rats.

Acute and repeated doses (28 days) oral toxicity study of Vicenin-1, a flavonoid glycoside isolated from fenugreek seeds in laboratory mice.

Vicenin-1 (fenugreek glycoside) has been proven to possess potent anti-inflammatory and anti-oxidant activity. The objective of the present investigation was to determine in-vivo acute and subacute (28-days repeated dose) oral toxicity of Vicenin-1 isolated from fenugreek seed. Vicenin-1 (93%) was isolated from a hydroalcoholic extract of fenugreek seed and characterized using HPLC, TLC, 1H NMR and 13C NMR. Acute oral toxicity (AOT) and subacute toxicity studies of Vicenin-1 were carried out according to OECD 425 (up-and-down procedure) and OCED 407 guidelines in Swiss albino mice. In AOT, Vicenin-1 showed 10% mortality when administered at a dose of 5000 mg/kg. However, when vicenin-1 was administered for at doses of 37.5, 75, or 150 mg/kg 28-days it did not show any mortality at the administered doses. Vicenin-1 (75 mg/kg) did not show observational, behavioral, biochemical or histopathological toxic effects. There were minor alterations in body weight, hematology, and histopathology of mice administered with Vicenin-1 (150 mg/kg), but these changes were within normal laboratory ranges. The highest concentration of Venicin-1 was found in liver (3.46%) followed by lung (0.65%). In conclusion, Vicenin-1 showed median lethal dose (LD50) of 4837.5 mg/kg with no-observed-adverse-effect levels (NOAEL) at 75 mg/kg and lowest adverse effect levels (LOAEL) at 150 mg/kg for both sexes of mice during AOT and sub-acute toxicity study, respectively.

Risk assessment of human health from exposure to the discharged ballast water after full-scale electrolysis treatment.

The presence of disinfection by-products (DBPs) releasing from ballast water management systems (BWMS) can cause a possible adverse effects on humans. The objectives of this study were to compute the Derived No Effect Levels (DNELs) for different exposure scenarios and to compare these levels with the exposure levels from the measured DBPs in treated ballast water. The risk assessment showed that when using animal toxicity data, all the DNELs values were approximately 10(3)-10(12) times higher than the exposure levels of occupational and general public exposure scenarios, indicating the level of risk was low (risk characterization ratios (RCRs) < 1). However, when using human data, the RCRs were higher than 1 for dichlorobromomethane and trichloromethane, indicating that the risk of adverse effects on human were significant. This implies that there are apparent discrepancies between risk characterization from animal and human data, which may affect the overall results. We therefore recommend that when appropriate, human data should be used in risk assessment as much as possible, although human data are very limited. Moreover, more appropriate assessment factors can be considered to be employed in estimating the DNELs for human when the animal data is selected as the dose descriptors.

Acute and repeated doses (28 days) oral toxicity study of glycosides based standardized fenugreek seed extract in laboratory mice.

The objective of the present work was to study acute and subacute (28-days repeated dose) oral toxicity effect of glycosides based standardized fenugreek seed extract (SFSE-G) in vivo. SFSE-G was prepared by resin-based chromatography and standardized to glycosides namely trigoneoside Ib (76%) and vicenin 1 (15%). The acute oral toxicity (AOT) and subacute toxicity studies were performed in Swiss albino mice (5 mice/sex/group) as per OECD 425 (up-and-down procedure) and OCED 407 guidelines respectively. Acute oral administration of 5000mg/kg of SFSE-G showed 40% mortality with no mortality in lower dosages. The subacute oral administration of SFSE-G did not show observational or toxicological effects on the body or organ weights, food consumption, ophthalmic effects, locomotor activity, hematology, blood biochemistry, urinalysis, or histopathology at dose 250mg/kg. However, SFSE-G (1000mg/kg) showed mortality and minor alterations to body weight, relative liver weights, hematology and blood chemistry parameters related to treatment but it was within normal laboratory ranges. In conclusion, SFSE-G showed median lethal dose (LD50) more than 4350mg/kg and no-observed adverse effect levels (NOAEL) of 250mg/kg for both sexes during AOT and sub-acute toxicity study, respectively.

Comparative analysis of toxicological evaluations for dermal exposure performed under two different EU regulatory frameworks.

Dermal exposure to chemicals is highly relevant in relation to the use of cosmetic products, both in consumers and in individuals exposed occupationally. Regulatory frameworks exist within the EU to limit the dermal exposure of the general population and workers to chemicals in general, as well as to limit the use of certain substances in cosmetic products. The objective of the study was to investigate and compare toxicological evaluations of dermal exposure performed under current regulatory frameworks. The publicly disseminated hazard information under the respective regulatory frameworks was compiled and compared for the five substances resorcinol, p-phenylenediamine, p-aminophenol, N-phenyl-p-phenylenediamine, and diethylene glycol monoethyl ether. A low consistency between evaluations was observed in respect to data coverage and cited dose descriptors. No systematic differences over all five substances were identified from the viewpoint of dermal hazard assessment. The critical effect and corresponding systemic effect dose descriptor was identical for two substances, differed somewhat for two other (a factor of 2-2.5). For N-phenyl-p-phenylenediamine a critical effect was only identified under REACH.

Assessment of no-observed-effect-levels for DNA adducts formation by genotoxic carcinogens in fetal turkey livers.

For genotoxic carcinogens, covalent binding to DNA is a critical initiating event in tumorigenesis. The present research investigated dose-effect relationships of three genotoxic carcinogens representing different structural classes, 2-acetylaminofluorene (2-AAF), benzo[a]pyrene (B[a]P) and quinoline (QUI), to assess the existence of no-observed-effect-levels (NOELs) for the formation of DNA adducts. Carcinogens were administered into the air sac of fertilized turkey eggs over wide dose ranges in three daily injections on days 22 to 24 of incubation. DNA adducts were measured in the fetal turkey livers by the 32P-nucleotide postlabeling (NPL) assay. B[a]P and QUI produced DNA adducts in a dosage-related manner and exhibited NOELs at 0.65 and 0.35 mg/kg bw/day, respectively. In contrast, 2-AAF formed DNA adducts at all tested dosages down to 0.005 mg/kg bw/day. Benchmark dose (BMD) analysis identified the potencies of 2-AAF and QUI to be similar, while B[a]P was the least potent compound. Overall, findings in fetal turkey livers demonstrated that exposure levels to genotoxic compounds that do not result in DNA adducts can exist but are not evident with all carcinogens of this type. The use of mechanistic dose-effect studies for genotoxic endpoints can provide critical information for prioritization of concerns for risk assessment.

Toxicity of diclofenac sodium salt in Yucatan minipigs (Sus scrofa) following 4 weeks of daily intramuscular administration.

Diclofenac sodium salt (DSS) is a widely used nonsteroidal anti-inflammatory drug. The present study was performed under good laboratory practice (GLP) regulations to investigate the toxicity of DSS after 4 weeks of repeated intramuscular administration at doses of 0, 2, 10, or 20 mg/kg/day in 32 minipigs and to evaluate the DSS effect following a 2-week recovery period. Dose-related clinical signs and alterations of hematological or clinical chemistry parameters, organ weight, and macroscopic as well as histopathological findings in hepatic, renal, gastrointestinal, skin and injection sites were observed in both sexes' animals of the 10 or 20 mg/kg/day group. With the exception of the skin-related findings, most symptoms showed a tendency to resolve after the 2-week recovery period. The systemic exposure (AUClast) of DSS in plasma showed similar pattern to the increase rate of the dose and similar values between males and females except for the female 20 mg/kg dose group (56 %) on Day1. The systemic exposure showed a decreasing trend in the 10 or 20 mg/kg group after 4-week of repeated administration compared to Day1. The no-observed-adverse-effect level of DSS in this study was considered to be 2 mg/kg/day in both male and female minipigs.