Search Our Scientific Publications & Authors

J Toxicol Sci 2019 ;44(2):93-105

Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology.

Maternal exposure to 3,3'-iminodipropionitrile (IDPN) affects hippocampal neurogenesis in mouse offspring, with biphasic disruption, which facilitates neurogenesis during exposure and reduces the broad range of the granule cell lineage population at the adult stage. The present study investigated the epigenetically hypermethylated and downregulated genes related to the IDPN-induced disrupted neurogenesis. Mated female mice were treated with IDPN at 0 or 1200 ppm in drinking water from gestational day 6 to postnatal day (PND) 21 on weaning. Read More

J Toxicol Sci 2019 ;44(2):83-92

Laboratory of Molecular Nutrition and Toxicology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University.

Immunological functions are disturbed in humans who have been chronically exposed to arsenic via contaminated groundwater. Little is known about the specific mechanisms underlying the impairment of immunological defense system caused by arsenic. The activation of macrophage cells upon infection with bacteria and viruses plays important roles in the defense against these pathogens. Read More

J Toxicol Sci 2019 ;44(2):73-81

Division of Pathology, National Institute of Health Sciences.

To investigate the chemopreventive mechanisms of 4-Methylthio-3-butenyl isothiocyanate (MTBITC), we analyzed cell viability, cell cycle distribution, and expression levels for cell cycle and apoptosis-related proteins in MTBITC-treated malignant esophageal KYSE510 cells, with and without the reactive oxygen species (ROS) scavenger N-acethyl-L-Cysteine (NAC). MTBITC dose-dependently reduced cell viability and Bcl2 protein expression, while it induced cleavages of caspase-3, caspase-9, and PARP-1, suggesting that reduced cell viability occurred through the mitochondrial apoptotic pathway in KYSE510 cells. In cell cycle distribution analysis, MTBITC (20-40 µM) induced cell cycle arrest at G2/M phase. Read More

J Toxicol Sci 2019 ;44(2):121-131

College of Food Engineering and Nutritional Science, Shaanxi Normal University, China.

Benzo(α)pyrene (BaP) possesses a forceful hepatotoxicity, and is ubiquitous in foods and ambient air. Our previous study found that BaP induced pyroptotic and autophagic death in HL-7702 human liver cells; the relevant mechanisms, however, remain unknown. This work was therefore to unravel the effects of the PI3K/Akt signaling pathway on pyroptotic and autophagic death triggered by BaP. Read More

J Toxicol Sci 2019 ;44(2):113-120

Department of Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science.

Although cytotoxicity of inorganic metals has been well investigated, little is known about the cytotoxicity of organic-inorganic hybrid molecules. The cytotoxicity of zinc complexes was evaluated using a culture system of vascular endothelial cells. We found that bis(1,4-dihydro-2-methyl-1-phenyl-4-thioxo-3-pyridiolato)zinc(II), termed Zn-06, exhibited strong cytotoxicity in vascular smooth muscle cells, epithelial cells, fibroblastic cells, and vascular endothelial cells. Read More

J Toxicol Sci 2019 ;44(2):107-112

Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.

Inhalation of toxic gases is dangerous to humans; experiments using toxic gases themselves are also hazardous to researchers. Gas-releasing molecules are widely used as alternatives to toxic gases, but their impacts on the whole body remain to be examined. To investigate responses during hydrogen sulfide (HS) poisoning, rats (Sprague-Dawley, male, 8-week-old) were intraperitoneally (i. Read More

J Toxicol Sci 2019 ;44(1):57-71

College of Pharmacy, Dankook University, Korea.

Cisplatin (CP) is an anti-cancer drug used for treatment of solid tumors, but the major adverse effect is drug-induced nephrotoxicity. The current study aimed to determine biomarkers that might predict nephrotoxicity induced by CP using serum or urinary proton nuclear magnetic resonance (H NMR) spectral data in male Sprague-Dawley (S-D) rats. CP (0, 0. Read More

J Toxicol Sci 2019 ;44(1):47-56

Department of Obstetrics, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, China.

Galectin-3 (Gal-3) is a multifunctional carbohydrate-binding protein associated with cell migration, cell proliferation, cell adhesion, and cell-cell interaction in tumor cells. It has been implied to be involved in the tumor progression and chemoresistance of epithelial ovarian cancer (EOC). However, it is unclear whether the Gal-3-mediated regulation on the EOC chemosensitivity is associated with hypoxia or mitochondrial dysfunction. Read More

J Toxicol Sci 2019 ;44(1):35-45

Laboratory of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, China.

Due to its excellent properties such as ultraviolet obscuration, chemical stability and small particle size, nano-titanium dioxide (nano-TiO) is widely used, particularly in sunblock products. The skin is therefore a chief route for exposure. Studies have found that oral or respiratory exposure to nano-TiO has an adverse impact on the cardiovascular system. Read More

J Toxicol Sci 2019 ;44(1):23-34

Safety Science Research Laboratories, Kao Corporation.

Cosmetic ingredients often comprise complex mixtures, such as botanical extracts, which may contain skin sensitizing constituents. In our previous study for the sensitivity of the evaluations of skin sensitizing constituents in mixtures using the binary in vitro test battery with KeratinoSens and h-CLAT, some sensitizers showed higher detection limits in in vitro test methods than in murine local lymph node assays (LLNA). Thus, to minimize the uncertainty associated with decreased sensitivity for these sensitizers, a risk assessment strategy was developed for mixtures with negative results from the binary test battery. Read More

J Toxicol Sci 2019 ;44(1):13-21

Safety Science Research Laboratories, Kao Corporation.

Cosmetic ingredients are often complex mixtures from natural sources such as botanical extracts that might contain minute amounts of constituents with sensitizing potential. The sensitivity of in vitro skin sensitization test methods such as KeratinoSens and h-CLAT for the detection of minute amounts of sensitizer in mixtures remains unclear. In this study, we assessed the detection sensitivity of the binary test battery comprising KeratinoSens and h-CLAT for minute amounts of sensitizers by comparing the LLNA EC3 (estimated concentration of a substance expected to produce a stimulation index of 3) values to the minimum detection concentrations (MDCs) exceeding the positive criteria for each of the two in vitro test methods. Read More

J Toxicol Sci 2019 ;44(1):1-11

Graduate School of Pharmaceutical Sciences, Josai University.

Cosmetics containing rhododendrol (RD) were voluntarily recalled after incidents of leukoderma related to their use. Users reported using up to five different RD-containing products by layered application. In this study, we investigated the effects of layered application, formulations, and their components on the skin permeation of cosmetics containing RD. Read More

J Toxicol Sci 2018 ;43(12):751-768

Working Group on Alternatives to Primary Skin Irritation Test, Japanese Society of Alternatives to Animal Experiments (JSAAE).

The Organisation for Economic Co-operation and Development (OECD) Test Guideline (TG) 439 is an in vitro test method of reconstructed human epidermis (RhE), which was developed for hazard identification of irritating chemicals in accordance with a primary skin irritation test using rabbits with 4-hr exposure. A regulation for quasi-drugs in Japan requires data from primary skin irritation tests using rabbits to undergo 24-hr exposure, and this is used as an evidence for 24-hr closed patch tests in humans. In this study with the same chemicals, primary skin irritation test data using rabbits undergoing 24-hr exposure and a 24-hr occlusive human patch test data were analyzed by comparing the results obtained with four test methods adopted in OECD TG 439. Read More

J Toxicol Sci 2018 ;43(12):741-749

Department of Dermatology, Tohoku University Graduate School of Medicine.

In all current in vitro skin sensitisation assays, DMSO is used to dissolve water-insoluble chemicals. However, our previous study suggested the superiority of the modified IL-8 Luc assay (mIL-8 Luc), in which X-VIVO 15 is used to dissolve chemicals, over the original assay using DMSO (oIL-8 Luc). In this study, to confirm the superiority of the mIL-8 Luc, we first increased the number of chemicals examined and demonstrated the superiority of the mIL-8 Luc, in which the mIL-8 Luc provided 87. Read More

J Toxicol Sci 2018 ;43(12):735-740

Faculty of Pharmaceutical Sciences, Toho University.

It has been well established that organic-inorganic hybrid molecules can exhibit biological activities that are different from those of either their intramolecular metals in inorganic forms or their organic structures. We have previously reported that organoantimony compound Sb-phenyl-N-methyl-5,
6,7,12-tetrahydrodibenz[c,f][1,5]azastibocine (PMTAS) is nontoxic, but that the compound exhibits cytotoxicity in vascular endothelial cells when the antimony atom is replaced with a bismuth atom. In the present study, we investigated the cytotoxicity and intracellular accumulation of PMTAS and its analogs and found that the cytotoxicity of PMTAS analogs also decrease depending on the electron-withdrawing property of the substituent bound to the intramolecular antimony atom. Read More

J Toxicol Sci 2018 ;43(12):727-734

Division of Pharmacology, National Institute of Health Sciences, Japan.

5-fluorouracil (5-FU) has been widely used for the treatment of tumors. Regardless of its widespread use as an anti-cancer drug, 5-FU therapy can cause several side effects, including developmental toxicity and neurotoxicity. However, the potential action of 5-FU at the early fetal stage has not yet been completely elucidated. Read More

J Toxicol Sci 2018 ;43(12):717-725

Department of Biology, Faculty of Science, University of Ottawa, Ottawa, Canada K1N 9B4.

Monomethylmercury (MMHg) is a potent neurotoxicant that can be bioaccumulated and biomagnified through trophic levels. Human populations whose diets contain MMHg are at risk of MMHg toxicity. The gut microbiota was identified as a potential factor causing variation in MMHg absorption and body burden. Read More

J Toxicol Sci 2018 ;43(12):711-715

Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Japan.

SIRT1, an NAD-dependent deacetylase, causes deacetylation and down-regulation of its target p53. Given that p53 is an upstream regulator of the transcription of the cyclin-dependent kinase inhibitor p21/Cip1, SIRT1 is hypothesized to play a stimulatory role in carcinoma cell proliferation. We previously reported that down-regulation of SIRT1 caused the increase in p21/Cip1 in a post-transcriptional manner, suggesting that p53 is not involved in the p21/Cip1 increase and raising the question whether SIRT1 exhibits the activity other than deacetylase. Read More

J Toxicol Sci 2018 ;43(12):697-709

School of Food and Biological Engineering, Jiangsu University, China.

Silver nanoparticles (Ag-NPs) are known as a noble metal, and owing to their exclusive properties, their use is widespread in consumer products and they are mostly incorporated into food packaging and food contact products. The aim of this work was to evaluate the effects of direct ingestion of Ag-NPs through food to assess their toxicity effects on the growth and development of silkworms at different concentrations (1 mg·L to 100 mg·L), in addition to the examination of the distribution of Ag-NPs in the silkworm body and midgut histopathological analysis. RNA sequencing was performed to investigate the transcriptomic responses to Ag-NPs exposure. Read More

J Toxicol Sci 2018 ;43(11):685-695

Central Institute for Experimental Animals.

We investigated the viability of a combined repeated dose toxicity study, including toxicokinetics (TK), in common marmosets according to the ICH-S4, ICH-S3A and ICH-S7A Guidelines using valsartan as test article whose non-clinical repeated dose toxicity studies had been conducted using this species for regulatory purpose. Valsartan was administered orally to 3 animals/sex at 200 mg/kg/day for 2 weeks. In addition to the routine parameters in repeated dose toxicity studies, safety pharmacology parameters (examinations of the central nervous, respiratory and cardiovascular systems) were also evaluated. Read More

J Toxicol Sci 2018 ;43(11):671-684

Physiology Department, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos, Mexico.

Thalidomide was originally developed to treat primary neurological and psychiatric diseases. There are reports of anticonvulsant effects of thalidomide in rats and antiepileptic effects in patients. Hence, thalidomide (100, 200 and 400 mg/kg) was herein administered to mice to evaluate possible protection against seizures induced by the systemic administration of neurotoxins: 10 mg/kg of 4-aminopyridine (4-AP), 90 mg/kg of pentylenetetrazol (PTZ), or 380 mg/kg of pilocarpine. Read More

J Toxicol Sci 2018 ;43(11):659-669

Depertment of Ophthalmology, Linyi People's Hospital, China.

High energy-consumption in retinal pigmented epithelium (RPE) cells poses oxidative stress (OS) and contributes to mitochondrial dysfunction (MD) for retinal degeneration-associated diseases. In the present study, we evaluated the protective role of Melatonin, a natural antioxidant, against the hydrogen peroxide (HO)-induced damage to RPE cells. The cellular viability, apoptosis, the expression of apoptosis-associated proteins and mitochondrial function were examined in the retinal ARPE-19 cells, post the treatment with HO or (and) with Melatonin. Read More

J Toxicol Sci 2018 ;43(11):645-657

School of Public Health, Southwest Medical University, China.

Previous studies have reported the potential developmental neurobehavioral effects of decabrominated diphenyl ethers (BDE 209) on developing animals, but the effects on adult animals are rare or controversial and the mechanism is not fully understood. In the present study, male adult Sprague-Dawley rats performed poor spatial learning and memory in Morris water maze after exposure to BDE 209 by gavage for 30 days. The expression of hippocampal glutamate receptor subunits NR1, NR2B and GluR1, the phosphorylation of NR2B subunit at Ser1301 (p-NR2B Ser1303) and GluR1 subunit at Ser831 (p-GluR1 Ser831) were all decreased, and the phosphorylation ratio of NR2B revealed an increasing trend after BDE 209 exposure. Read More

J Toxicol Sci 2018 ;43(11):631-643

National Institute for Environmental Studies.

Autism is a complex neurodevelopmental disorder characterized by impaired social communication and social interactions, and repetitive behaviors. The etiology of autism remains unknown and its molecular basis is not yet well understood. Pregnant Sprague-Dawley (SD) rats were administered 600 mg/kg of valproic acid (VPA) by intraperitoneal injection on day 12. Read More

J Toxicol Sci 2018 ;43(11):623-630

Department of Anatomy, Medical College of Nanchang University, China.

Lead exposure contributing to cardiovascular diseases is known and recognized widely. As the deleterious effects of low lead exposure attained increasing attention over the last decades, there have been numerous studies exploring the association of low levels of lead exposure and cardiovascular diseases. Moreover, it has been observed that lead exposure could cause telomere shortening and lipid disturbance, and that telomere shortening and lipid disturbance are closely related with cardiovascular diseases. Read More

J Toxicol Sci 2018 ;43(10):611-621

Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology.

Mineralocorticoid receptor (MR)/NADPH oxidase (NOX) signaling is involved in the development of obesity, insulin resistance, and renal diseases; however, the role of this signaling on steatotic preneoplastic liver lesions is not fully elucidated. We determined the effects of the MR antagonist potassium canrenoate (PC) on MR/NOX signaling in hepatic steatosis and preneoplastic glutathione S-transferase placental form (GST-P)-positive liver foci. Rats were subjected to a two-stage hepatocarcinogenesis model and fed with basal diet or high fat diet (HFD) that was co-administered with PC alone or in combination with the antioxidant alpha-glycosyl isoquercitrin (AGIQ). Read More

J Toxicol Sci 2018 ;43(10):601-610

Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Azabu University.

Previously, we have demonstrated the potential of plasma 2-hydroxyglutarate (2HG) as an easily detectable biomarker for skeletal muscle injury in rats. Here, we examined whether plasma 2HG was superior to conventional skeletal muscle damage biomarkers, including aspartate aminotransferase (AST), creatine kinase (CK), and skeletal muscle-type CK isoenzyme (CK-MM) levels, in rats. Skeletal muscle injury was induced in 4- or 9-week-old male Fischer 344 rats by cerivastatin (CER) or tetramethyl-p-phenylenediamine (TMPD) administration. Read More

J Toxicol Sci 2018 ;43(10):587-600

Department of Nutritional Science and Food Safety, Faculty of Applied Biosciences, Tokyo University of Agriculture.

The present study comparatively examined carcinogenicity of 7 different multi-wall carbon nanotubes (MWCNTs) with different physicochemical characteristics. Physicochemical characteristics of MWCNTs (referred to as M-, N-, WL-, SD1-, WS-, SD2- and T-CNTs in the present study) were determined using scanning electron and light microscopes and a collision type inductively coupled plasma mass spectrometer. Male Fischer 344 rats (10 weeks old, 15 animals per group) were administered MWCNTs at a single intraperitoneal dose of 1 mg/kg body weight, and sacrificed up to 52 weeks after the commencement. Read More

J Toxicol Sci 2018 ;43(10):579-586

CICS-UBI - Centro de Investigação em Ciências da Saúde, University of Beira Interior, Portugal.

Bisphenol A (BPA) is an endocrine disrupting chemical used on a wide range in industry. This compound has been used in the production of polycarbonate plastics and epoxy resins. For this reason and their global use, BPA is one of the most common environmental chemicals to which humans are exposed. Read More

J Toxicol Sci 2018 ;43(10):565-577

Pfizer Worldwide Research and Development, Groton, CT 06340.

Precision medicine is an approach to developing drugs that focuses on employing biomarkers to stratify patients in clinical trials with the goal of improving efficacy and/or safety outcomes, ultimately increasing the odds of clinical success and drug approval. Precision medicine is an important tool for toxicologists to utilize, because its principles can be used to decide whether to pursue a drug target, to understand interindividual differences in response to drugs in both nonclinical and clinical settings, to aid in selecting doses that optimize efficacy or reduce adverse events, and to facilitate understanding of a drug's mode-of-action. Nonclinical models such as the mouse and non-human primate can be used to understand genetic variation and its potential translation to humans, and are available for toxicologists to employ in advance of drugs moving into clinical development. Read More

J Toxicol Sci 2018 ;43(9):557-563

Department Molecular Pathology, Osaka City University.

There is sometimes controversy over whether or not statistically significant responses produced in carcinogenicity studies have biologically significance. Ambiguous results from our previous two-year oral carcinogenicity study on acotiamide hydrochloride hydrate (acotiamide-HH), a prokinetic drug for functional dyspepsia, in rats made it unclear whether the drug may exhibit uterine carcinogenicity. To check this finding, we performed a second long-term carcinogenicity study using two identical control groups to more accurately evaluate uterine carcinogenesis by considering the incidence of spontaneous neoplasms. Read More

J Toxicol Sci 2018 ;43(9):545-555

Department of Emergency, the First Hospital, China Medical University, China.

Objective: To investigate the protective effect and underlying mechanism of the superoxide dismutase mimic, manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride (MnTMPyP), on paraquat (PQ)-induced lung alveolar epithelial-like cell injury.

Methods: Lung alveolar epithelial-like cells (A549) were pretreated with 10 μM MnTMPyP for 1.5 hr and then cultured with or without PQ (750 uM) for 24 hr. Read More

J Toxicol Sci 2018 ;43(9):537-543

Laboratory of Xenobiotic Metabolism and Environmental Toxicology, Faculty of Pharmaceutical Sciences, Hiroshima International University (HIU).

There is adequate evidence for the carcinogenicity of cadmium (Cd). However, a significant unaddressed question remains as to how this metal actually causes malignant transformation (tumor initiation). Since it has been shown that Cd only has the weak direct interaction potential with DNA, the metal is recognized as an indirect genotoxicant and mutagen. Read More

J Toxicol Sci 2018 ;43(9):531-536

Department of Human Intelligence Systems, Kyushu Institute of Technology.

Perinatal exposure to bisphenol A (BPA) causes several alterations in brain function and behavior. In previous studies, we showed that prenatal treatment with low-level BPA impaired gender-specific behavior, enhanced depression-like behavior, and augmented behavioral responses to predator odor in rats. On this premise, we hypothesized that BPA-treated rats were more susceptible to predator odor stress. Read More

J Toxicol Sci 2018 ;43(8):521-529

Drug Metabolism and Pharmacokinetics Tsukuba, Global Drug Metabolism and Pharmacokinetics, Biopharmaceutical Assessments Core Function Unit, Medicine Development Center, Eisai Co., Ltd.

During drug discovery, in vitro models are used to predict the in vivo pharmacokinetic and toxicological properties of drug candidates in humans. However, the conventional method of culturing human hepatocytes as monolayers does not necessarily replicate biologic reactions and does not support liver-specific functions, such as cytochrome P450 (CYP) activities, for prolonged periods. To remedy these problems and thus increase and prolong hepatic functions, we developed a culture system comprising a collagen vitrigel membrane (CVM) chamber and PXB-cells®, fresh hepatocytes isolated from liver-humanized chimeric mice (PXB-mice®). Read More

J Toxicol Sci 2018 ;43(8):513-520

Faculty of Engineering, Dept. of Materials Science and Engineering, Yokohama National University.

We evaluated the skin sensitizing potential of 10 natural organic chemicals, or their derivatives, which are included in foods and/or skin products, using a modified local lymph node assay (LLNA), with an elicitation phase (LLNA:DAE). The following compounds were tested: carminic acid, esculetin, 4-methyl esculetin, coumarin, quercetin, curcumin, naringenin, chlorogenic acid, isoscopoletin, and shikonin. Esculetin, 4-methyl esculetin, isoscopoletin, and shikonin yielded positive results. Read More

J Toxicol Sci 2018 ;43(8):507-512

Department of Pharmacology, Toho University Graduate School of Medicine.

We analyzed electropharmacological characteristics of microminipigs under halothane-anesthesia using anti-influenza virus drug oseltamivir, which has been known to possess multi-channel blocking properties, including Na, Ca and K channels (n = 4). Oseltamivir in doses of 0.3, 3 and 30 mg/kg was intravenously infused over 10 min with an interval of 20 min, which provided peak plasma concentrations 1. Read More

J Toxicol Sci 2018 ;43(8):493-506

Research Division, Chugai Pharmaceutical Co., Ltd.

We used motion field imaging to characterize the conduction and contraction of a sheet of cardiomyocytes derived from human induced pluripotent stem cells (hiPS-CMs). A hiPS-CMs sheet of 2.8 mm × 2. Read More

J Toxicol Sci 2018 ;43(8):485-492

National Center for Efficacy Evaluation of Respiratory Disease Product, Korea Institute of Toxicology, Korea.

Polyhexamethylene guanidine phosphate (PHMG) is an antimicrobial biocide that causes severe lung injury accompanied with inflammation and subsequent fibrosis. Cytokines mediate the inflammatory response, leading to fibrosis in injured tissues. PHMG is known to induce the expression of various cytokines in vitro and in vivo. Read More

J Toxicol Sci 2018 ;43(7):473-484

Research Laboratories for Health Science and Food Technologies, Kirin Co., Ltd.

It has been demonstrated that successive ingestion of matured hop extract (MHE), produced by extraction from heat-treated hops, results in body fat reduction in animals and humans; however, preclinical safety studies have not been reported. In this study, we conducted in vitro and in vivo safety studies for MHE. Genotoxicity was evaluated using the Ames test, in vitro chromosomal aberration test, and in vivo micronucleus test. Read More

J Toxicol Sci 2018 ;43(7):459-471

Faculty of Environmental & Symbiotic Sciences, Prefectural University of Kumamoto.

Total mercury (THg) and methylmercury (MeHg) bioaccumulation was explored in the Bimastus parvus species of earthworm (B. parvus) native to the leachate-contaminated forest soils around a Hg-polluted traditional landfill in Japan. General soil properties and concentrations of THg and MeHg in forest soils and in B. Read More

J Toxicol Sci 2018 ;43(7):451-458

Ina Research Inc.

The purpose of this study was to investigate the discriminative stimulus properties of morphine and codeine using different administration routes to that used at drug discrimination training. Rats were trained to discriminate morphine at 3 mg/kg from saline by the intraperitoneal route in a standard two-lever drug discrimination paradigm. Generalization of morphine by the subcutaneous and the oral routes, and codeine by the intraperitoneal and the oral routes to the discriminative stimulus properties of the morphine training dose were investigated. Read More

J Toxicol Sci 2018 ;43(7):443-450

Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka.

The nuclear receptor pregnane X receptor (PXR) plays a major role in the xenobiotic-induced expression of drug-metabolizing enzymes. PXR activation is also associated with several adverse events in the liver. Especially, the receptor enhances hepatocyte proliferation mediated by chemical liver tumor promoters, suggesting that exposure to PXR activators increases the risk of liver cancer. Read More

J Toxicol Sci 2018 ;43(7):435-442

Tokyo University of Agriculture.

Teriparatide, a drug used in the treatment of osteoporosis, was administered to rats subcutaneously for the duration of 3 months, at a frequency of either once weekly or once daily to demonstrate the varying levels of anabolic action the drug can have on bone depending on the dosing frequency. The levels of biomarkers in the blood were compared and found to vary in osteocalcin (OC), a biomarker of bone formation, and cross-linked N-telopeptide of type 1 collagen (NTx), a biomarker of bone resorption, according to the dosing frequency. In the once-weekly regimen, teriparatide did not affect NTx levels at any of the doses studied, while OC levels increased with dose, peaking at 72 hr, then returning to normal before the next injection (after 1 week). Read More

J Toxicol Sci 2018 ;43(7):423-433

Division of Pathology, National Institute of Health Sciences.

Although obesity is increasing worldwide, experimental studies examining the possible association between obesity and susceptibility to chemical toxicity are limited. In the present study, we performed a 13-week toxicity study for acetaminophen (APAP), a well-known drug that exhibits hepatotoxicity as an adverse effect, using an obese rat model to investigate the differences in susceptibility between obese and normal individuals. Male F344 and obese Zucker (lean and fatty) rats were administered 0, 80, 253, 800, 2,530, or 8,000 ppm APAP in the diet for 13 weeks. Read More

J Toxicol Sci 2018 ;43(7):407-422

Faculty of Engineering, Department of Materials Science and Engineering, Yokohama National University.

The Short Time Exposure (STE) test method is an in vitro method for assessing the eye irritation potential of chemicals and is used to classify the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Category 1 and No Category (NC). The method has been adopted by the Organisation for Economic Co-operation and Development (OECD) as test guideline (TG) 491 since 2015. While this method can be used to classify GHS NC, it is not suitable for testing highly volatile substances and solids other than surfactants. Read More

J Toxicol Sci 2018 ;43(6):395-405

Toxicology Research Lab., Central Pharmaceutical Research Institute, JAPAN TOBACCO Inc.

Valproic acid (VPA) is known to induce hepatic steatosis due to mitochondrial toxicity in rodents and humans. In the present study, we administered VPA to SD rats for 3 or 14 days at 250 and 500 mg/kg and then performed lipidomics analysis to reveal VPA-induced alteration of the hepatic lipid profile and its association with the plasma lipid profile. VPA induced hepatic steatosis at the high dose level without any degenerative changes in the liver on day 4 (after 3 days dosing) and at the low dose level on day 15 (after 14 days dosing). Read More

J Toxicol Sci 2018 ;43(6):387-393

Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University.

Medicinal carnitine-derived and dietary-derived malodorous trimethylamine and its non-malodorous metabolite trimethylamine N-oxide were historically regarded as nontoxic. Clinical and toxicological interest has recently arisen because of their potential association with atherosclerosis. We previously reported a human physiologically based pharmacokinetic (PBPK) model for trimethylamine and its primary metabolite, trimethylamine N-oxide, based on reported rat trimethylamine pharmacokinetics. Read More

J Toxicol Sci 2018 ;43(6):377-385

Henan Guangan Biotechnology Co., Ltd., China.

Aflatoxin B (AFB) and zearalenone (ZEA) are the secondary toxic metabolites of fungi which contaminate a wide range of food and feedstuffs. Limiting exposure of humans and livestock to them is very essential. Among numerous methods of mycotoxin-degradation, biodegradation by microorganisms and enzymes is an effective and promising approach to eliminate their hazards. Read More

J Toxicol Sci 2018 ;43(6):369-375

Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University.

Lenalidomide has been shown to be potentially teratogenic in thalidomide-sensitive animal species. Screening for thalidomide analogs devoid of teratogenicity/toxicity-attributable to drug metabolism and disposition, but having immunomodulatory properties-is a strategic pathway towards development of new anticancer drugs. Plasma concentrations of lenalidomide were investigated in immunodeficient control and humanized-liver mice following oral administration of lenalidomide (50 mg/kg). Read More