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In our daily life, we are exposed to numerous industrial chemicals that may be harmful to the retina, which is a delicate and sensitive part of our eyes. This could lead to irreversible changes and cause retinal diseases or blindness. Current retinal environmental health studies primarily utilize animal models, isolated mammalian retinas, animal- or human-derived retinal cells, and retinal organoids, to address both pre- and postnatal exposure. However, as there is limited toxicological information available for specific populations, human induced pluripotent stem cell (hiPSC)-induced models could be effective tools to supplement such data. In order to obtain more comprehensive and reliable toxicological information, we need more appropriate models, novel evaluation methods, and computational technologies to develop portable equipment. This review mainly focused on current toxicology models with particular emphasis on retinal organoids, and it looks forward to future models, analytical methods, and equipment that can efficiently and accurately evaluate retinal toxicity.

Performing risk assessments (RA) on household use of flexible polyurethane (PU) foams requires access to reliable data about emission and migration of potential diamine impurities. A toluene diisocyanate (TDI) and a methylene diphenyl diisocyanate (MDI) based foam were thermally treated to enable measurements on samples with defined concentrations of the corresponding diamines, toluene diamine (TDA), and methylene dianiline (MDA). The thermally treated foams used for emission testing contained up to 15 mg.kg−1 of TDA and 27 mg.kg−1 of MDA. Those used for migration testing contained 5.1 mg.kg−1 of TDA and 14.1 mg.kg−1 of MDA. Stability of the thermally generated diamines was sufficient for testing over a 37-day period. Analytical techniques that did not decompose the polymer matrix were applied. Emission rates for TDA and MDA isomers were less than the limit of quantitation (LOQ) of 0.008–0.07 μg.m−2.h−1. Migration was studied using samples of the same thermally treated foams over a 35-day period. Quantifiable migration of MDA from the MDI-based foam was only observed on Days 1 and 2. From Day 3 onward, migration rates were less than the LOQ. Quantifiable migration of TDA from the TDI-based foam rapidly decreased with time and was only observed on Days 1 thru 3. From Day 4 onward, migration rates were less than the LOQ. Theoretically, the migration rate should be inversely proportional to the square root of time (t) as t−0.5. This relationship was confirmed by the experimental data and enables extrapolating migration values to more extended time periods to conduct RAs.

A sampling chamber was developed for emission testing of diisocyanates, methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and corresponding diamines, methylene diphenyl diamine (MDA), and toluene diamine (TDA) from polyurethane (PU) product surfaces. In addition, a methodology for validation of the sampling chamber was presented, based on the introduction of generated standard atmospheres of the different diisocyanates and diamines to the sampling chamber system. Sampling of diisocyanates and diamines was performed on a circular glass fiber filter (150 mm diameter) impregnated with dihexyl amine (DHA) and acetic acid (AA) positioned inside a cylindrical stainless steel sampling chamber. The diisocyanates were immediately derivatized to DHA derivatives, and the amines were derivatized in a subsequent work-up procedure with ethyl chloroformate (ECF). The design of the sampling chamber and the presented methodology allowed for simultaneous sampling and analysis of diisocyanates and diamines of emission from a large surface area with minimal interior wall interaction in the sampling chamber. Performance characteristics of the sampling chamber for different sampling times and air humidity were obtained by determining collected amounts of the diisocyanates and diamines in the different parts of the sampling chamber. The repeatability of the collected amount on the impregnated filters in the sampling chamber was 15% with an overall recovery for 8 h of sampling in the range of 61% to 96%. The performance of the sampling chamber was not affected by air humidity (5%–75% RH), and no breakthrough during sampling was observed. LC-MS/MS determinations allowed for emission testing of diisocyanates and diamines on product surfaces as low as 10–30 ng m−2 h−1.

Vibration exposure from handheld tools can affect the hands with neurological symptoms and vibration-induced Raynaud’s phenomenon (VRP). The underlying pathophysiological mechanisms are not fully known, however, changes in the composition of blood parameters may contribute to VRP with an increase in blood viscosity and inflammatory response. The aim of this study was to examine the effect on blood parameters in capillary blood from fingers that had been exposed to a vibrating hand-held tool. This study involved nine healthy participants who had been exposed to vibration and an unexposed control group of six participants. Capillary blood samples were collected before and after vibration exposure for the exposed group, and repeated samples also from the control group. The exposed groups were exposed to vibration for a 15-min period or until they reached a 5.0 m/s2 vibration dose. Analysis of blood status and differential counting of leucocytes was performed on the capillary blood samples. The results of the blood samples showed an increase in mean value for erythrocyte volume fraction (EVF), hemoglobin, red blood cell count, white blood cell count and neutrophils, as well as a decrease of mean cell volume, mean cell hemoglobin, and mean cell hemoglobin concentration. The increase of EVF and neutrophils was statistically significant for samples taken from the index finger but not the little finger. Even though the study was small it showed that an acute vibration exposure to the hands might increase EVF and neutrophilic granulocytes levels in the capillary blood taken from index fingers.

Bisphenol A (BPA) has been reported to injure the developing and adult brain. However, the underlying mechanism still remains elusive. This study used neuro-2a cells as a cellular model to investigate the neurotoxic effects of BPA. Microtubule-associated protein 2 (MAP2) and tau protein maintain microtubule normal function and promote the normal development of the nervous system. Synaptophysin (SYP) and drebrin (Dbn) proteins are involved in regulating synaptic plasticity. Cells were exposed to the minimum essential medium (MEM), 0.01% (v/v) DMSO, and 150 μM BPA for 12, 24, or 36 h. Morphological analysis revealed that the cells in the BPA-treated groups shrank and collapsed compared with those in the control groups. CCK-8 and lactate dehydrogenase assay (LDH) assays showed that the mortality of neuro-2a cells increased as the BPA treatment time was prolonged. Ultrastructural analysis further revealed that cells demonstrated nucleolar swelling, dissolution of nuclear and mitochondrial membranes, and partial mitochondrial condensation following exposure to BPA. BPA also decreased the relative protein expression levels of MAP2, tau, and Dbn. Interestingly, the relative protein expression levels of SYP increased. These results indicated that BPA inhibited the proliferation and disrupted cytoskeleton and synaptic integrity of neuro-2a cells.

Toxic pneumonitis and related respiratory symptoms are common among waste management workers (WMWs). Products of different cellular responses following exposure to toxic components of wastes can lead to the production of a variety of biomolecules. There is a growing recognition of the importance of biomarkers in risk assessment and a strong advocacy for their determination and use as indicators of health and safety. This study assessed the prevalence of respiratory symptoms and the relevance of pulmonary surfactant protein A (SP-A) and Clara cell 16 protein (CC16) as indicators of occupational inhalation exposure to toxic substances and irritants in WMW. A total of 172 subjects consisting of 112 WMWs and 60 Non-WMWs were recruited by purposive sampling. Data on socio-economic and work-related symptoms were collected using structured questionnaire. CC16 and SP-A were determined by ELISA in serum samples. Clinical history reveals a slightly higher prevalence of respiratory symptoms in WMWs relative to control subjects. Increased permeability of the lung–blood barrier, characterized by significant elevation of serum SP-A and serum CC16, was associated with respiratory symptoms in WMWs. Steady increases in SP-A and CC16, respectively, in relation to occupational duration were observed in WMWs relative to control. Receiver operating characteristic curve and multivariate analyses revealed SP-A and CC16 as important lung biomarkers for assessing sub-clinical effects of occupational exposure. Our data suggest SP-A and CC16 may be relevant indicators for assessing occupational inhalation exposure to toxic substances and irritants among WMWs.

Lead shielding is used as a guard against scatter radiation. Lead aprons can emit particulate lead into the occupational environment, resulting in the accumulation of lead dust on the skin and garments of workers. This study aimed to assess the risk of lead exposure among radiologists working in the radiology departments by estimating hair and blood lead levels. A total of 40 radiology personnel (18 wearing aprons and 22 not wearing aprons) with a comparable control group (20 personnel not working in a radiology department) underwent a pre-designed questionnaire with estimation of blood and hair levels. The hair and blood lead levels in radiologists wearing aprons were significantly higher than those of the control group and that of the radiologist not wearing aprons. The lead levels in hair and blood were correlated significantly with the duration of wearing aprons in years and weekly working hours. Health care workers in radiology departments demonstrated high hair and blood levels that were higher among workers wearing aprons than those not wearing protective equipment. Hair lead levels can be detected quickly, cheaply, and non-invasively, and could be a helpful screening test for occupational exposure.

Benzo(a)pyrene is a ubiquitous environmental contaminant, which could induce renal injury. It is reported that melatonin has a protective effect against multiple organ injuries by regulating oxidative stress, apoptosis, and autophagy. The aim of this study was to estimate the melatonin effects on benzo(a)pyrene renal toxicity in mice and the possible molecular mechanisms involved in this model. Thirty male mice were allocated to five groups and treated with benzo(a)pyrene (75 mg/kg, oral gavage) and/or melatonin (10 and 20 mg/kg, intraperitoneally). The oxidative stress factors were evaluated in renal tissue. The levels of apoptotic (the Bax/Bcl-2 ratio and caspase-3) and autophagic (the LC3 II/I, Beclin-1, and Sirt1) proteins were examined using Western blot. Following the administration of benzo(a)pyrene, malondialdehyde, caspase-3 and the Bax/Bcl-2 ratio increased in renal tissue, while Sirt1, Beclin-1, and the LC3 II/I ratio diminished. Interestingly, the co-administration of 20 mg/kg melatonin along with benzo(a)pyrene reduced the oxidative stress markers, apoptotic and autophagic proteins. Collectively, melatonin exhibited a protective effect against benzo(a)pyrene-induced renal injury through the suppression of oxidative stress and apoptosis and the inhibition of Sirt1/autophagy pathway.

Pesticides are routinely applied by cocoa farmers to enhance cocoa production, which is threatened by pest infestations and diseases. However, the undesired health implications of pesticide applications on the farmers are yet to be fully elucidated especially among cocoa farmers in Idanre despite being the hub of cocoa production in Southwestern Nigeria. This study assessed the extent of pesticide use by cocoa farmers in the study area and determined the effects of exposure on their health using haematological and biochemical parameters as indices. A cross-sectional survey comprising 150 cocoa farmers and 50 controls (artisans) was carried out using structured questionnaire. Blood samples were obtained from participants for the determination of copper and sulphate levels, haematological (haematocrit, red blood cell counts, white blood cell counts and platelet counts) and biochemical (creatinine, cholesterol, direct bilirubin and total bilirubin) parameters. The blood levels of copper and sulphate were significantly higher in the cocoa farmers than in the controls. However, there was no significant difference between the subjects and controls for most of the haematological and biochemical parameters except for the platelet counts and total bilirubin levels. The data from the study did not suggest any serious health effects due to pesticide exposure on the cocoa farmers despite the high blood levels of copper and sulphate, probably due to exposure to copper-based fungicides. However, the high serum bilirubin level among the subjects was an indication of possible liver damage. As such, cocoa farmers should be guided against indiscriminate use of pesticides on their farms.

This is a safety assessment of 6 Eucalyptus globulus (eucalyptus)-derived ingredients as used in cosmetics. The reported functions of the Eucalyptus globulus (eucalyptus)-derived ingredients include abrasive, fragrance ingredient, and skin-conditioning agent (miscellaneous and occlusive). The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the relevant data on these ingredients. Because final product formulations may contain multiple botanicals, each containing the same constituents of concern, formulators are advised to be aware of these constituents and to avoid reaching levels that may be hazardous to consumers. Industry should use good manufacturing practices to limit impurities. The Panel concluded that Eucalyptus globulus (eucalyptus)-derived ingredients are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-sensitizing.

This is a review of the scientific literature and unpublished data that are relevant for assessing the safety of 12 Helianthus annuus (sunflower)-derived ingredients as used in cosmetics. Because final product formulations may contain multiple botanicals, each containing similar constituents of concern, formulators are advised to be aware of these constituents and to avoid levels that may be hazardous to consumers. Helianthus annuus (sunflower)-derived ingredients may contain allergens, including 2S albumins and sesquiterpene lactones. Industry should use current good manufacturing practices (cGMP) to limit impurities and constituents of concern. The Expert Panel for Cosmetic Ingredient Safety (Panel) concluded that 9 Helianthus annuus (sunflower) seed- and flower-derived ingredients are safe as used in cosmetics in the present practices of use and concentration described in this safety assessment. The data are insufficient to evaluate the safety of 3 ingredients that are derived from other plant parts.

There is considerable evidence that Bisphenol S (BPS) induces various toxicological effects and is an industrial health issue. However, little data are available on the in vivo effects of BPS on the liver, a major target of drug toxicity. In this study, we evaluated the potential harmfulness of low levels of BPS in the liver of male mice. Also, we investigated the interaction between BPS and peroxisome proliferator-activated receptor-gamma (PPARγ) by computational docking approach. PPARγ is a member of the superfamily of nuclear hormone receptors. It acts as a transcription factor and regulates the genes involved in lipid and glucose metabolism and in inflammation and necrosis. Mice were exposed to BPS, in drinking water at 25, 50, and 100 μg/kg for 10 weeks. The protocol was started after weaning. At the time of sacrifice, blood samples were collected for a biochemical analysis, followed by liver tissue collection for histopathological study. Results showed that BPS-induced hypertriglyceridemia, increased liver injury markers, and initiated histopathological changes, including inflammatory cell infiltration, hepatocellular necrosis, and steatosis. BPS did not affect glycated hemoglobin (HbA1C). Interestingly, data showed that BPS could interact with the PPARγ ligand-binding pocket by hydrogen bonds with Asn 219, Cys 276, Ser 280, and Thr 283. We suggest that PPARγ is among the targets of BPS and could play a key role in the cascade reaction of BPS-induced liver disruption. These findings support the hypothesis that the post-weaning period is sensitive to low-dose BPS exposure that can lead to dyslipidemia signature later in life.

The nitramine explosive, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is associated with acute and chronic toxicity in mammals and targets both the central nervous system and liver. After a single oral dose of RDX in male rats, the systemic distribution of RDX and the toxicodynamic response was measured using clinical chemistry and Affymetrix Rat Genome® 230 2.0 gene expression arrays, respectively. Nominal doses of 0, 9 and 36 mg/kg pure RDX were administered to animals followed by liver, cerebral cortex, and hippocampus gene expression analysis at 0, 3.5, 24, and 48 hours. RDX quickly entered the liver and brain, increasing up to 24 hours. For the 36 mg/kg dose, RDX was still measurable in liver and brain at 48 hours, but was non-detectible for the 9 mg/kg dose. At 3.5 hours, the time within which most convulsions reportedly occur after RDX ingestion, the hippocampus displayed the highest response for both gene expression and pathways, while the cortex was relatively non-responsive. The top 2 impacted pathways, primarily involved in neurotransmission, were the GABAergic and glutamatergic pathways. High numbers of genes also responded to RDX in the liver with P450 metabolism pathways significantly involved. Compared to the liver, the hippocampus displayed more consistent biological effects across dose and time with neurotransmission pathways predominating. Overall, based on gene expression data, RDX responses were high in both the hippocampus and liver, but were minimal in the cerebral cortex. These results identify the hippocampus as an important target for RDX based on gene expression.

Occupational exposure to dimethylacetamide (DMAc) has been reported to cause toxic hepatitis. Sixty spandex workers were included in this study to research the clinical manifestations and expression of cytokines and lymphocytes in DMAc-induced toxic hepatitis. Chinese drugs (reduced glutathione and Hugan tablets) were used to treat them. The manifestations including jaundice, asthenia, appetite, nausea, emesis, abdominal distension, yellow urine, and dizziness were scored. The percentages of patients rated as 0–3, 4–6, 7–9, and 10–12 points were 33.3%, 43.3%, 21.7%, and 1.7%, respectively, before treatment, and all patients showed 0–3 points after the treatment. The ultrasonic and CT imaging revealed diffuse intrahepatic hypodensity, intrahepatic calcification, signs of liver injury, and splenomegaly, which improved after therapy. Blood analysis showed that ALT, AST, TBIL, IL-6, IL-10, TNF-α, IFN-γ, CD3+%, and CD4+/CD8+ statistically decreased after drug treatment. Correlation analysis demonstrated positive linear correlations between ALT and TBIL, AST and TBIL, IL-10 and ATL, IL-10 and AST, IL-10 and TBIL, IFN-γ and IL-6, IFN-γ and TNF-α, and CD3+% and ALT. Pro-inflammatory cytokines and lymphocytes in DMAc-induced toxic hepatitis reflected an active immune state that decreased after treatment. IL-10 may inhibit the immune response in this disease, as a protective mechanism.

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 11 Cocos nucifera (coconut)-derived ingredients, most of which are reported to function as skin-conditioning agents in cosmetic products. The Panel reviewed the available data to determine the safety of these ingredients. The Panel concluded that 10 ingredients, derived from coconut flower, fruit, and liquid endosperm, are safe in cosmetics in the present practices of use and concentration described in this safety assessment, and that the available data are insufficient to make a determination of safety for Cocos Nucifera (Coconut) Shell Powder under the intended conditions of use in cosmetic formulations.

The decisions we make on chemical safety, for consumers, workers and the environment, must be based on the best scientific data and knowledge available. Rapid advances in biology, in cell-based technologies and assays, and in analytical and computational approaches, have led to new types of highly relevant scientific data being generated. Such data enable us to improve the safety decisions we make, whilst also enabling us to avoid animal testing. Stimulated by the UK and EU bans on animal testing for cosmetics, Next Generation Risk Assessment (NGRA) approaches, which integrate various types of non-animal scientific data, have been established for assessing the safety of chemical ingredients used in cosmetics and other consumer products. In stark contrast, the chemicals regulations in Europe and other parts of the world have not kept pace with modern safety science and regulators are now mandating even more animal testing. Urgently closing this science–regulation gap is essential to upholding the EU’s legislative requirement that any animal testing is a last resort. The ongoing revisions of UK and EU chemicals strategy and regulations provide an opportunity to fundamentally change the design and assessment paradigm needed to underpin safe and more sustainable innovation, through applying the best science and tools available rather than continuing to be anchored in animal tests dating back many decades. A range of initiatives have recently been launched in response to this urgent need, in the UK as well as in the EU.

The failure rate for the translation of drugs from animal testing to human treatments remains at over 92%, where it has been for the past few decades. The majority of these failures are due to unexpected toxicity — that is, safety issues revealed in human trials that were not apparent in animal tests — or lack of efficacy. However, the use of more innovative tools, such as organs-on-chips, in the preclinical pipeline for drug testing, has revealed that these tools are more able to predict unexpected safety events prior to clinical trials and so can be used for this, as well as for efficacy testing. Here, we review several disease areas, and consider how the use of animal models has failed to offer effective new treatments. We also make some suggestions as to how the more human-relevant new approach methodologies might be applied to address this.

The purpose of this study was to characterize the microRNA (miRNA) profile of the lung tissues from coal workers’ pneumoconiosis (CWP) and silicosis and to analyze the changes in downstream genes, biological processes, and signaling pathways based on the differently expressed miRNAs. Lung tissues from three CWP patients, eight silicosis patients, and four healthy controls were collected and analyzed for their miRNA profiles using Affymetrix® GeneChip® miRNA Arrays. Differentially expressed miRNAs (DEMs) were identified between the different groups. The miRanda and TargetScan databases were used to predict the putative target genes, and volcano and heat maps were drawn. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses were then performed to screen the DEMs-associated biological process and signaling pathways, respectively. Further identification with a comprehensive literature research involving particle exposure, fibrosis, inflammation and lung cancer were used to further screen DEMs of CWP and silicosis. Microarray data showed that 375 and 88 miRNAs were differentially expressed in CWP and silicosis lung tissues compared with healthy lung tissues, while 34 miRNAs were differentially expressed in CWP compared with silicosis lung tissues. The GO and KEGG pathway analyses showed that, the target genes were mainly enriched in the TGF-β, MAPK, p53 and other signal pathways. These results provided insight into the miRNA-related underlying mechanisms of CWP and silicosis, and they provided new clues for miRNAs as biomarkers for the diagnosis and differential diagnosis of these two diseases.

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 9 Centella asiatica-derived ingredients, which reportedly function primarily as skin conditioning agents in cosmetic products. The Panel reviewed relevant data relating to the safety of these ingredients. The Panel concluded that Centella Asiatica Extract, Centella Asiatica Callus Culture, Centella Asiatica Flower/Leaf/Stem Extract, Centella Asiatica Leaf Cell Culture Extract, Centella Asiatica Leaf Extract, Centella Asiatica Leaf Water, Centella Asiatica Meristem Cell Culture, Centella Asiatica Meristem Cell Culture Extract, and Centella Asiatica Root Extract are safe in the present practices of use and concentration in cosmetics, as described in this safety assessment, when formulated to be non-sensitizing.

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of 26 apple-derived ingredients, which reportedly function mostly as skin conditioning agents in cosmetic products. Because apple-derived ingredients may be obtained from different apple cultivars, the composition of ingredients derived from different cultivars should be similar to that of ingredients reviewed in this safety assessment. Additionally, industry should continue to use good manufacturing practices to limit impurities that could be present in botanical ingredients. The Panel reviewed the available data to determine the safety of these ingredients and concluded that 21 of these ingredients are safe in cosmetics in the present practices of use and concentrations described in this safety assessment. However, the Panel also determined that the available data are insufficient to determine the safety of Pyrus Malus (Apple) Root Extract, Pyrus Malus (or Malus Domestica) (Apple) Stem Extract, Malus Domestica (Apple) Callus Extract, and Malus Domestica (Apple) Oil.

In many industrial processes, worker exposure to cadmium causes kidney damage; thus, protection against cadmium toxicity is important in workplace health. Cadmium toxicity involves oxidative stress by increasing the levels of reactive oxygen species. Statins have shown antioxidant effects that might prevent this increase in oxidative stress. We investigated the potential effects of atorvastatin pretreatment in protecting experimental rats against kidney toxicity caused by cadmium. Experiments were performed on 56 adult male Wistar rats (200 ± 20 g), randomly assigned to eight groups. Atorvastatin was administered by oral gavage for 15 days at 20 mg/kg/day, starting 7 days before cadmium chloride intra-peritoneal administration (at 1, 2, and 3 mg/kg) for 8 days. On day 16, blood samples were collected, and kidneys were excised to evaluate the biochemical and histopathological changes. Cadmium chloride significantly increased malondialdehyde, serum creatinine, blood urea nitrogen, and decreased superoxide dismutase, glutathione, and glutathione peroxidase levels. Pre-administration of rats with atorvastatin at a dose of 20 mg/kg decreased blood urea nitrogen, creatinine, and lipid peroxidation, increased the activities of antioxidant enzymes, and prevented changes in physiological variables compared with animals that were not pretreated. Atorvastatin pretreatment prevented kidney damage following exposure to toxic doses of cadmium. In conclusion, atorvastatin pretreatment in rats with cadmium chloride-induced kidney toxicity could reduce oxidative stress by changing biochemical functions and thereby decreasing damage to kidney tissue.

Species selection plays a pivotal part during non-clinical safety assessment in drug development. If possible, use of non-human primates (NHPs) should be avoided due to ethical considerations. However, limiting factors as lack of pharmacologic activity in other species could necessitate use of NHPs. LAI-PCSK9i is a bi-functional molecule combining a long-acting insulin analogue with a PCSK9 inhibitor peptide aiming to provide glycaemic control and to reduce plasma LDL concentrations. The NHP was chosen for the safety assessment of LAI-PCSK9i being the most relevant species with basal levels and plasma lipid composition closest to humans, while the dog and initially also the minipig were deemed irrelevant due to lack of pharmacologic activity on LDL-lowering and biological differences in lipid profiles. An in vivo tolerability and toxicokinetic study of LAI-PCSK9i in NHPs showed recurrent and severe hypoglycaemia at very low doses. Therefore, the minipig was re-evaluated and a follow-up study thoroughly assessing blood glucose and cholesterol levels and clinical signs illustrated that minipigs dosed with LAI-PCSK9i, tolerated the compound and LAI-PCSK9i decreased glucose and LDL over time. This work underlines that careful consideration is required when selecting species during safety assessment in drug development. The tolerability issue in NHPs led to the subsequent selection of the minipig for safety evaluation of LAI-PCSK9i although as a suboptimal alternative, which unexpectedly had a measurable pharmacologic response on LDL lowering. In conclusion, the NHPs may be unsuitable as test species for safety assessment of long-acting insulin analogues due to high sensitivity to recurring hypoglycaemic episodes.

Physis is a complex cartilaginous structure that is critical for longitudinal bone growth. As one of the endocrine-disrupting chemicals, bisphenol A (BPA) can interfere with the physis by deranging the complex networks of nutritional, cellular, paracrine, and endocrine factors, and this affects longitudinal bone growth, leading to different growth outcomes. However, the exact mechanisms underlying these phenomena remain unclear. Therefore, understanding the molecular pathways involved in the physis after neonatal exposure to low-dose BPA may permit the identification of research targets for therapeutics, which may aid in modulating the process of growth plate closure. In the present study, female Sprague–Dawley rats were exposed to 0.05 mg·kg−1·day−1 of BPA and corn oil vehicle from postnatal day 1 (PND1) to 15 via subcutaneous injection. Next-generation RNA sequencing was performed for the mRNA isolated from the physis. The levels of osteocalcin (OC), growth hormone (GH), and insulin-like growth factor 1 (IGF-1) were measured on PND30 (BPA0.05mg vs. Vehicle; n = 5 for each group). We observed statistically significant enrichment of gene sets in the BPA0.05mg tissues compared with the Vehicle tissues. Further analysis of the differentially expressed genes (DEGs) identified BPA0.05mg-specific networks of secreted proteins (LEP, NPY, AGT, ACE2, C4B, and C4BPA) as well as those of local matrix and protease proteins (FBN2, LAMC2, ADAMTS16, and ADAMTS19). Furthermore, the levels of OC and GH were affected by BPA exposure. Our results revealed the specific molecular characteristics of physis contaminated with BPA and may provide new clues for physis maturation and supervision of industrial products and occupational exposure.

The occurrence of thyroid dysfunction is affected by environmental factors, and BPA is a ubiquitous environmental pollutant with the potential to cause thyroid dysfunction. However, the limited epidemiological evidence shows an inconsistent association between BPA exposure and thyroid dysfunction. Therefore, the literature on the impact of BPA on thyroid was sorted and analyzed to study the relationship between BPA and adult thyroid function. The studies published on or before 23rd May 2022 from PubMed, Web of Science, and Scopus were collected analyzing the association between BPA exposure and the levels of thyroid hormones. The methodological quality of each study was assessed, the sensitivity analysis and subgroup analysis based on study population and gender were also performed, and publication bias was evaluated. A total of 2969 literature studies were retrieved. Based on inclusion and exclusion criteria, eleven studies were included. Our results showed that BPA concentration was negatively correlated with FT4 and TSH in males. Pooled correlation coefficients between BPA and FT4/TSH were −0.027 (95%CI = −0.030∼−0.024) and −0.058 (95%CI = −0.111∼−0.004). BPA concentration was positively correlated with FT4 in females, and the pooled correlation coefficient was 0.006 (95%CI = 0.003–0.008). The effects of BPA on thyroid hormone levels were significantly different between males and females. BPA may significantly decrease the levels of FT4 and TSH in males but increase the levels of FT4 in females. Considering the high heterogeneity among studies and the limited investigations into subgroups, the relationship between BPA exposure and thyroid dysfunction needs to be further investigated.

Gene therapy has become an important modality for a wide range of therapeutic indications with a rapid increase in the number of therapeutic candidates being developed in this field. Understanding the molecular biology underlying the gene therapy is often critical to develop appropriate safety assessment strategies. We aimed to discuss some of the commonly used gene therapy modalities and common preclinical toxicology testing considerations when developing gene therapies. Non-viral gene delivery methods such as electroporation, microinjection, peptide nanoparticles and lipid nanoparticles are deployed as innovative molecular molecular construct which are included in the design of novel gene therapies and the associated molecular biology mechanisms have become relevant knowledge to non-clinical toxicology. Viral gene delivery methodologies including Adenovirus vectors, Adeno-Associated virus vectors and Lentivirus gene therapy vectors have also advanced considerably across numerous therapeutic areas, raising unique non-clinical toxicology and immunological considerations. General toxicology, biodistribution and tumorigenicity are the pillars of non-clinical safety testing in gene therapies. Evaluating the tumorigenicity potential of a gene editing therapy often leverages molecular pathology while some translational challenges remain. Toxicology study design is entering a new era where science-driven customized approaches and program specific considerations have become the norm.

Lithium, which has a high industrial value, is an environmental pollutant of concern to those who work with lithium in industry as well as to the general public. Biological parameters such as MDA, 8-OHdG, apoptosis (caspase-3), and acetylcholinesterase (AChE) were studied to determine the toxic effects on the brain tissue of the model organism ( Carassius auratus) exposed to high dose lithium. According to the results obtained, it was found that lithium exposure caused oxidative stress with an increase in MDA level over time and, accordingly, DNA damage and apoptosis occured in brain tissue. It was also found that a decrease in AChE activity was observed, and the high levels of MDA, 8-OHdG, and caspase-3 activity obtained in brain tissue supported this result. The solid phase extraction (SPE) method was used to effectively remove lithium, which has unfavorable effects on living organisms, from aqueous solutions. In this method, a sawdust loaded with magnetite nanoparticles (MNLS) was prepared as an adsorbent for solid phase extraction by a simple method, and it was characterized. Optimal conditions for the SPE process were defined and it was found that lithium could be removed from solution onto the MNLS surface with a high yield of about 96%. The results of the study are crucial for proposing a simple and applicable high performance method.

In recent decades, it has become clear that in many fields — such as drug development, particularly with regard to drug dosage and specific disease treatment — the sex of a patient must be taken into consideration, in view of the fact that male and female physiology and pathophysiology show many differences of practical concern. While, in the last decade or so, considerable efforts have been undertaken to consider the sex of the animals during the planning of experiments, this topic has just started to be acknowledged in in vitro studies. Cells in such studies seem mainly to be used according to their availability, without considering the sex of the original donor. Even when such information is available, experimental data are reported without overtly detailing this information. In recent years, the increasing complexity of in vitro models (e.g. stem cell-based, 3-D cultures, organoids, or organ-on-a-chip technologies) has contributed to systems that better resemble the human in vivo situation. However, the issue of the sex of the experimental organisms being used has not yet been properly taken up by the cell culture community. Thus, alongside the increasing complexity of multicell-type models, we now see in vitro models that incorporate cells from both male and female origin — this representing, in fact, a genetic chimaera. Here, we aim to discuss where we are currently, with respect to considering the sex of any animals or humans used in experiments, and we try to identify what is lacking in the cell culture field, in order to help facilitate change.

Silicosis is an important industrial health problem for those workers exposed to silica. The present study aimed to investigate the sensitivity and specificity of combined detection of biomarkers in early auxiliary diagnosis of silicosis, the risk factors of silicosis were also studied. The study sample comprised 65 workers who had clinical silicosis and 70 matched control subjects who were exposed to silica but did not have clinical silicosis. The levels of superoxide dismutase, malondialdehyde, interleukin 6 (IL-6), tumor necrosis factor-alpha, and cholinesterases in the serum of 135 subjects were measured. After completing the biochemical assays, a logistic regression model based on the above biochemical determination results was established, and the receiver operating characteristic curve was used for judging the discrimination ability of different statistical indexes. The expression levels of MDA, IL-6, and TNF-alpha in serum samples of patients with stage I silicosis and MDA and IL-6 in serum samples of patients with stage II silicosis were all significantly higher. Results from logistic regression analysis showed that ChEs were protective factors for silicosis, while age, chronic respiratory symptoms, IL-6, and MDA were risk factors. The areas under the ROC curve (AUC) were 0.86 (IL-6), 0.81 (MDA), and 0.65 (TNF-alpha or ChEs). AUC-ROC = 0.90 (95%CI:0.84–0.95). The diagnostic efficiency of IL-6 combined with MDA and TNF-alpha was better than that of any single biomarker.

Zinc oxide nanoparticles (ZnO NP) are commonly used engineered NPs with extensive usage in consumer products, thus leading to direct exposure to humans. The direct route of exposure is through inhalation. Once inhaled, these particles accumulate in the lungs, increasing the chances of respiratory tract illness through cellular organelle damage. Zinc oxide nanoparticle-treated lung cells are reported to display cytotoxicity, increase DNA damage, and induce oxidative stress. The current study focused on the effects of ZnO NPs on mitochondrial dynamics (fission and fusion) in human lung epithelial cells (A549). The lung cells were exposed to ZnO NPs at 50 and 100 μg/ml concentrations, and their mitochondrial dynamics were assessed to understand the effects of the NPs. Treatment with ZnO NPs reduced the activity of mitochondrial complex I and complex III and altered mitochondrial structural and functional characteristics in a concentration-dependent manner. Zinc oxide nanoparticles exposure showed an increase in small and round-shaped mitochondria. The expression of various fission proteins (Drp1 and Fis1) and fusion proteins (Mfn1, Mfn2, and OPA1) was altered upon exposure to ZnO NPs. Our studies showed dysfunction of the mitochondria induced by ZnO NPs. In fibroblast mitochondrial dynamics, fission symbolizes threshold damage. In this paper, we have shown that the mitochondrial fission phenotype increased upon exposure to ZnO NPs. The paper emphasizes that these particles enter mitochondria, triggering a stress response that results in the removal of mitochondria via fission. It provides relevant data for safety guidelines to ensure the safer use of these particles.

The fungicide mancozeb increases oxygen-free radicals in the central nervous system. As an antioxidant, L-carnitine protects DNA and cell membranes from damage caused by oxygen-free radicals. The present study investigated how L-carnitine affected the acoustic startle response (ASR) in rats exposed to mancozeb. In this experimental study, male Wistar rats were gavaged orally with mancozeb (500, 1000, and 2000 mg/kg), L-carnitine (100, 200, and 400 mg/kg), or L-carnitine (200 mg/kg) + mancozeb (500 mg/kg) three times in 1 week. In the sham group, saline (0.9%, 10 mL/kg) was gavaged at a volume equivalent to that of the drugs. The control group did not receive any treatment. The results showed that locomotor activity and the percentage of prepulse inhibition in the mancozeb groups decreased compared to the sham group while these parameters increased in the L-carnitine group (200 mg/kg) compared to sham rats. In conclusion, mancozeb may increase the risk factor for cognitive diseases such as schizophrenia in people exposed to it while pretreatment with L-carnitine can attenuate the toxic effect.

Cisplatin is a chemotherapeutic drug used to treat a great variety of solid tumors. Its dose is commonly limited by its nephrotoxicity, manifested as acute kidney injury (AKI). Erythropoietin (Epo) is a glycoprotein hormone that regulates the production of red blood cells. This study was performed to evaluate the presence of endogenous Epo in male Wistar rat urine and to analyse changes in urinary Epo levels in response to cisplatin- induced AKI. Dose-dependent studies and time-dependent experiments were performed to evaluate changes in urea nitrogen and creatinine in plasma as well as Epo, neutrophil gelatinase-associated lipocalin (NGAL), alkaline phosphatase (AP) activity, creatinine and total proteins in urine at 2 days post-dosing. Rats received 2, 5 or 10 mg/kg b.w., i.p. of cisplatin. At 5 mg/kg b.w., i.p. cisplatin, significant increases in urinary Epo were detected. Significant increases in urea nitrogen and creatinine in plasma, NGAL, AP, proteins, and Epo were observed in urine from rats that received 10 mg/kg b.w., i.p. of cisplatin. In the time-dependent experiments, rats were injected with a dose of 5 mg/kg b.w., i.p. of cisplatin, and sampling occurred 2, 4, and 14 days post-dosing. In these animals, there were significant increases in urea nitrogen and creatinine in plasma and total proteins, AP activity, Epo, and NGAL in urine on day 4. Urinary Epo was also detected on day 2. Taken together, these findings provide weight of evidence for urinary Epo as a promising early biomarker of cisplatin-induced AKI in male rats.

The NCG triple immunodeficient mice on a NOD/Nju background lack functional/mature T, B, and NK cells, and have reduced macrophage and dendritic cell function. This study characterized the NCG mouse model for toxicity, engraftment and tumorigenicity assessments of cell therapies, using CD34+ hHSPC adult mobilized cells with two myeloablation regimens. Mice received sub-lethal irradiation or busulfan and were then injected intravenously with CD34+ hHSPCs (1.0 x 106 cells/mouse) or PBS (control), while positive control animals received 2 x 106 HL-60 cells/mouse. hCD34+ cell donors were treated with the mobilizing agent G-CSF prior to leukapheresis. Following injections, mouse blood samples were collected to assess engraftment rates by flow cytometry with body weights recorded periodically up to 20 weeks post-cell injection. No significant clinical signs or body weight changes were observed. At week 10 post-cell injection, the peripheral blood chimerism of hCD45+ cells was above 20%. While mCD45+ concentration was constant between week 10 and 17 in whole blood samples, hCD45+ concentration and chimerism slightly decreased at week 17. However, chimerism remained above 10%, with busulfan-treated mice presenting higher values. Chimerism was further assessed by quantifying human Alu sequences in blood and multiple organs using qPCR. Alu sequences were most abundant in the spleen and bone marrow, while lowest in the testes. In the positive control group, expected mortalities due to tumorigenesis were observed between days 27 and 40 post-cell injection. Overall, study results may be used to inform study design and potential toxicological endpoints relevant to non-clinical cell therapy development.

Nickel has long been known to have a toxic effect in humans and has been defined as a human carcinogen. However, recent studies have suggested that nickel chloride (NiCl2) may also possess anticancer properties. The liver is one of the target organs for nickel, and thus, the present study aims to evaluate the effect of NiCl2 on anticancer biological responses in hepatocellular carcinoma (HCC) cell lines. Both HuH-7, a well-differentiated HCC cell line, and Mahlavu cell line, a poorly differentiated HCC cell line, were exposed to NiCl2. It was determined that NiCl2 decreased cell viability in both cell lines in a dose- and time-dependent manner. Nickel chloride exposure at IC50 doses were observed to suppress the ability of HCC cells to produce colonies and also induce apoptosis of HCC cells by increasing Cleaved Caspase-3 protein levels. It was found that NiCl2 exposure affected cellular morphology, increased the LC3-II protein levels, and induced autophagy in parallel to increased apoptosis in HCC cells. It was also observed that NiCl2 suppressed cell migration, decreased the size and viability of HCC tumor spheroids generated in 3D cell cultures, and disrupted the spheroid structure of the tumor cells depending on E-cadherin expression levels. Furthermore, it was observed that all anticancer biological responses induced by NiCl2 occurred independently of the AKT signaling pathway. In conclusion, our results suggested that NiCl2 induced anticancer biological responses in HCC cell lines. Moreover, this study provided important new molecular and cellular biological basic data about the action mechanisms of NiCl2 in HCC.

Although both can cause DNA damage, the combined impact of volatile anesthetics halothane/sevoflurane/isoflurane and radiotherapeutic exposure on sensitive brain cells in vivo has not been previously analyzed. Healthy Swiss albino male mice (240 in total, 48 groups) were exposed to either halothane/sevoflurane/isoflurane therapeutic doses alone (2 h); 1 or 2 gray of gamma radiation alone; or combined exposure. Frontal lobe brain samples from five animals were taken immediately and 2, 6, and 24 h after exposure. DNA damage and cellular repair index were analyzed using the alkaline comet assay and the tail intensity parameter. Elevated tail intensity levels for sevoflurane/halothane were the highest at 6 h and returned to baseline within 24 h for sevoflurane, but not for halothane, while isoflurane treatment caused lower tail intensity than control values. Combined exposure demonstrated a slightly halothane/sevoflurane protective and isoflurane protective effect, which was stronger for 2 than for 1 gray. Cellular repair indices and tail intensity histograms indicated different modes of action in DNA damage creation. Isoflurane/sevoflurane/halothane preconditioning demonstrated protective effects in sensitive brain cells in vivo. Owing to the constant increases in the combined use of radiotherapy and volatile anesthetics, further studies should explore the mechanisms behind these effects, including longer and multiple exposure treatments and in vivo brain tumor models.

The Institute for In Vitro Sciences (IIVS) is sponsoring a series of workshops to identify, discuss and develop recommendations for optimal scientific and technical approaches for conducting in vitro assays, to assess potential toxicity within and across tobacco and various next generation nicotine and tobacco products (NGPs), including heated tobacco products (HTPs) and electronic nicotine delivery systems (ENDS). The third workshop (24–26 February 2020) summarised the key challenges and made recommendations concerning appropriate methods of test article generation and cell exposure from combustible cigarettes, HTPs and ENDS. Expert speakers provided their research, perspectives and recommendations for the three basic types of tobacco-related test articles: i) pad-collected material (PCM); ii) gas vapour phase (GVP); and iii) whole smoke/aerosol. These three types of samples can be tested individually, or the PCM and GVP can be combined. Whole smoke/aerosol can be bubbled through media or applied directly to cells at the air–liquid interface. Summaries of the speaker presentations and the recommendations developed by the workgroup are presented. Following discussion, the workshop concluded the following: that there needs to be greater standardisation in aerosol generation and collection processes; that methods for testing the NGPs need to be developed and/or optimised, since simply mirroring cigarette smoke testing approaches may be insufficient; that understanding and quantitating the applied dose is fundamental to the interpretation of data and conclusions from each study; and that whole smoke/aerosol approaches must be contextualised with regard to key information, including appropriate experimental controls, environmental conditioning, analytical monitoring, verification and performance criteria.