J Toxicol Sci [JOURNAL]
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200 papers
Propofol improves ischemia reperfusion-induced liver fibrosis by regulating lncRNA HOXA11-AS.
Luo J, Liu J, Mou Y … +3 more , Luo F, Liao Q, Liao Y
J Toxicol Sci · 2023 · PMID 37258239 · Publisher ↗
Liver ischemia reperfusion (IR) injury induces hepatic stellate cell (HSC) activation and liver fibrosis. Propofol (PRO) possesses a positive protective effect on liver ischemia reperfusion injury. We aimed to investigat...
Liver ischemia reperfusion (IR) injury induces hepatic stellate cell (HSC) activation and liver fibrosis. Propofol (PRO) possesses a positive protective effect on liver ischemia reperfusion injury. We aimed to investigate PRO function and mechanism in IR-induced liver fibrosis. A mice model of liver IR was established. Hematoxylin-eosin (HE) staining was utilized to evaluate liver tissue's pathological changes. Masson staining was applied to evaluate liver fibrosis. The expression level of α-SMA was measured by immunohistochemical (IHC). The expressions of lncRNA HOXA11-AS (HOXA11-AS), PTBP1, HDAC4, α-SMA, COL1A1 and Fibronectin were tested by qRT-PCR or Western blot. The commercial kits detected alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations in serum. Enzyme-linked immunosorbent assay (ELISA) measured TNF-α and IL-6 levels. The binding relationship between HOXA11-AS, PTBP1 and HDAC4 was verified by RNA immunoprecipitation (RIP). Our results showed that PRO alleviated liver fibrosis and the inflammation in IR-induced mice. PRO decreased the expression levels of HOXA11-AS, PTBP1 and HDAC4. Furthermore, HOXA11-AS overexpression abolished the protective effect of PRO against liver fibrosis in mice with IR-disposed. HOXA11-AS interacted with PTBP1 to regulate HDAC4 level and prevented its degradation in JS-1 cells. HDAC4 silencing eliminated the regulatory of HOXA11-AS overexpression on fibrosis and inflammation in IR-induced mice PRO inhibited HOXA11-AS expression to regulate HDAC4, thereby influencing liver fibrosis and inflammation induced by IR. It suggesting that PRO plays a protective role in liver fibrosis induced by ischemia-reperfusion in mice by regulating HOXA11-AS/PTBP1/HDAC4 axis.
Human gut microbiota influences drug-metabolizing enzyme hepatic Cyp3a: A human flora-associated mice study.
Togao M, Kurakawa T, Tajima S … +5 more , Wagai G, Ohta-Takada Y, Otsuka J, Kurita A, Kawakami K
J Toxicol Sci · 2023 · PMID 37258238 · Publisher ↗
Several studies revealed that gut microbiota affects the hepatic drug-metabolizing enzyme cytochrome P450 (Cyp). We hypothesized that individual gut microbiota variations could contribute to CYP activity. Human flora-ass...
Several studies revealed that gut microbiota affects the hepatic drug-metabolizing enzyme cytochrome P450 (Cyp). We hypothesized that individual gut microbiota variations could contribute to CYP activity. Human flora-associated (HFA) mice are established from germ-free mice using human feces and are often used to determine the effect of the human gut microbiota on the host. This study generated two groups of HFA mice using feces from two healthy individuals. Then, the composition of gut microbiota and hepatic Cyp activity was compared to analyze the effects of gut microbiota in healthy individuals on hepatic Cyp activity. A principal coordinate analysis based on the UniFrac distance for the composition of the cecal and fecal microbiota revealed apparent differences between the recipient groups. Hepatic Cyp, which is a marked difference in Cyp3a activity and Cyp3a11 gene expression, was observed between the recipient groups. Cyp2c and Cyp1a activities did not differ between recipient groups, with significantly lower enzymatic activities in recipients than in germ-free mice. These results indicate that the human gut microbiota affects hepatic Cyp activity. Especially, human gut microbiota composition differences have a pronounced effect on Cyp3a activity via Cyp3a11 gene expression regulation. Therefore, human gut microbiota variations among individuals may affect numerous drug metabolism, leading to drug efficacy and toxicity.
Early detection of hepatocarcinogens in rats by immunohistochemistry of γ-H2AX.
Toyoda T, Sone M, Matsushita K … +6 more , Akane H, Akagi JI, Morikawa T, Mizuta Y, Cho YM, Ogawa K
J Toxicol Sci · 2023 · PMID 37258237 · Publisher ↗
We have developed an early detection method for bladder carcinogens with high sensitivity and specificity using immunohistochemistry of γ-H2AX, a well-known marker of DNA damage. To investigate the potential application...
We have developed an early detection method for bladder carcinogens with high sensitivity and specificity using immunohistochemistry of γ-H2AX, a well-known marker of DNA damage. To investigate the potential application of γ-H2AX as a biomarker for early detection of hepatocarcinogens, we examined γ-H2AX formation in the liver of rats treated with several different chemicals for 28 days. Six-week-old male F344 rats were orally treated for 28 days with five hepatocarcinogens: N-nitrosodiethylamine (DEN), di(2-ethylhexyl) phthalate, 1,4-dioxane (DO), 3,3'-dimethylbenzidine dihydrochloride, or thioacetamide (TAA), or with two non-hepatocarcinogens: 4-chloro-o-phenylenediamine and N-ethyl-N-nitrosourea. At the end of the treatment period, immunohistochemistry for γ-H2AX and Ki67 and expression analysis of DNA repair-related genes were performed. Significant increases in γ-H2AX-positive hepatocytes with upregulation of Rad51 mRNA expression were induced by three of five hepatocarcinogens (DEN, DO, and TAA), whereas no changes were seen for the other two hepatocarcinogens and the two non-hepatocarcinogens. Significant increases in Ki67 expression with upregulation of Brip1, Xrcc5, and Lig4 were observed in rats treated with TAA, a nongenotoxic hepatocarcinogen, suggesting that both direct DNA damage and secondary DNA damage due to cell replication stress may be associated with γ-H2AX formation. These results suggest that γ-H2AX immunostaining has potential value for early detection of hepatocarcinogens, but examination of the effects of more chemicals is needed, as is whether γ-H2AX immunostaining should be combined with other markers to increase sensitivity. γ-H2AX immunostaining using formalin-fixed paraffin-embedded specimens can be easily incorporated into existing 28-day repeated-dose toxicity studies, and further improvements in this method are expected.
Evaluation of neurotoxicity of anticancer drugs using nematode Caenorhabditis elegans as a model organism.
Sakaguchi Y, Mizukami M, Hiroka Y … +4 more , Miyasaka K, Niwa K, Arizono K, Ichikawa N
J Toxicol Sci · 2023 · PMID 37258236 · Publisher ↗
It is well established that platinum-based drugs, including oxaliplatin (L-OHP) and cisplatin (CDDP), as well as microtubule inhibitors paclitaxel (PTX) and vincristine (VCR), are associated with chemotherapy-induced per...
It is well established that platinum-based drugs, including oxaliplatin (L-OHP) and cisplatin (CDDP), as well as microtubule inhibitors paclitaxel (PTX) and vincristine (VCR), are associated with chemotherapy-induced peripheral neuropathy (CIPN). In this study, we examined and compared the characteristics of neuropathies induced by L-OHP, CDDP, PTX, and VCR to evaluate whether Caenorhabditis elegans (C. elegans) could serve as a model organism for human CIPN. Worms were cultured on nematode growth medium plates, and L1 larvae synchronized by gel filtration were employed. We then performed bioassays and examined motility. In the motility test, exposure was performed for 2, 24, and 48 hr, and time-dependent effects were measured for each exposure time and 24 hr after terminating exposure. Herein, we observed that L-OHP and CDDP exerted concentration-dependent effects above a certain concentration, and PTX and VCR exerted concentration-dependent negative effects in the bioassay. Motility recovered in L-OHP-, PTX-, and VCR-treated worms on terminating exposure. However, CDDP exposure tended to reduce motility even 24 hr after terminating exposure. L-OHP exposure could decrease motility 2 hr after exposure, with a trend toward recovery 24 hr after terminating drug exposure. The findings of the present study revealed that C. elegans could exhibit neuropathy characteristics suggested to be similar to those observed in humans, indicating that this organism could be a suitable model to explore human CIPN.
The mechanism of monobutyl phthalate -induced ferroptosis via TNF/IL6/STAT3 signal pathway in TM-3 cells.
Guo X, Hao Y, Ma H … +5 more , Li H, Li L, Yan F, Huang J, Li L
J Toxicol Sci · 2023 · PMID 37121744 · Publisher ↗
As a common environmental endocrine disruptor, monobutyl phthalate (MBP) has been connected to reports of ROS accumulation, sperm destruction and reproductive damage. However, the specific mechanism of reproductive injur...
As a common environmental endocrine disruptor, monobutyl phthalate (MBP) has been connected to reports of ROS accumulation, sperm destruction and reproductive damage. However, the specific mechanism of reproductive injury caused by MBP remains uncertain. Ferroptosis is a non-apoptotic, controlled oxidative damage-related cell death that is usually connected with reactive oxygen species and lipid peroxidation. In this work, to evaluate the mechanism of MBP-induced ferroptosis in reproductive damage, bioinformation analysis and experimental validation were used. Based on bioinformatics analysis, the interleukin-6 (IL-6) and signal transducer and activator of transcription 3 (STAT3) genes may be involved in the tumor necrosis factor (TNF) signaling pathway, which controls inflammation. Experimental study validated the significance of IL6 and STAT3 in MBP-induced ferroptosis. Western blotting and quantitative real-time PCR revealed that Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4), Tumor necrosis factor-α (TNF-α), IL6, and STAT3 were all elevated with treatment of MBP, but Glutathione peroxidase 4 was significantly decreased. To determine the participation of IL6/STAT3, we added the ferroptosis inhibitor Ferrastain-1 (Fer-1) and the IL6/STAT3 pathway inhibitor Angoline. In conclusion, we found that MBP induced ferroptosis in TM3 cells to damage male reproductive system through the TNF/IL6/STAT signal pathway, resulting in lipid peroxidation and iron metabolite degradation.
Simulation-based risk assessment for the leakage of toxic substances in a chemical plant and the effects on the human body: ethanol as a working model.
Horiguchi A, Numazawa S
J Toxicol Sci · 2023 · PMID 37121743 · Publisher ↗
Chemical plants must handle a wide variety of hazardous substances. To ensure safety in such plants, it is necessary to conduct extensive and highly accurate risk assessments. In this study, we aimed at developing a meth...
Chemical plants must handle a wide variety of hazardous substances. To ensure safety in such plants, it is necessary to conduct extensive and highly accurate risk assessments. In this study, we aimed at developing a method that enables flexible and accurate risk assessment. We combined two different simulation tools to reproduce the phenomena of toxic gas leakage and diffusion as well as its impact on human health. The atmospheric diffusion after the leakage of toxic gas was simulated by computational fluid dynamics (CFD). Assuming the movement line of the person, toxic gas absorption and subsequent metabolism were calculated by a physiologically based pharmacokinetic (PBPK) model. From this, changes in blood concentration of toxic substances with time were simulated and we evaluated the effects of toxic gases on human body. Ethanol was selected as a toxic gas in this study. Based on the assumed scenario, the diffusion of leaked ethanol gas was calculated by CFD leading to the confirmation that the concentration of ethanol gas varies significantly with wind speed, human position, and elapsed time. The PBPK model showed that the maximum blood concentration of ethanol was 161 µmol/L, which is sufficiently low compared to that of ethanol poisoning (i.e., 10,900 µmol/L). These results suggest that the effects on the human body are relatively low and the evacuation can be performed safely. Compared to conventional methods of risk assessment, our new method allows the risk assessment of multiple scenarios, namely interindividual differences, activity status and the used of protective equipment.
Oxidative stress-induced TET1 upregulation mediates active DNA demethylation in human gastric epithelial cells.
Zuo M, He J, Yin Q … +6 more , He X, Liu Y, Liu Y, Liu J, Liu S, Ma L
J Toxicol Sci · 2023 · PMID 37121742 · Publisher ↗
The gastrointestinal (GI) tract is more vulnerable to effects by the outside environment, and experiences oxidative stress. A wide diversity of GI disorders can be partially attributed to oxidative stress. However, the m...
The gastrointestinal (GI) tract is more vulnerable to effects by the outside environment, and experiences oxidative stress. A wide diversity of GI disorders can be partially attributed to oxidative stress. However, the mechanism of oxidative stress-caused GI pathological changes is not clear. In the present study, human gastric epithelial cells (hGECs) were treated with hydrogen peroxide (HO), and oxidative stress was determined. The effect of oxidative stress on the levels of some antioxidative enzymes, proliferation, nuclear DNA damage, apoptosis, expression of ten-eleven translocation (TET), and level of DNA methylation was determined in these cells. The results showed that HO treatment caused oxidative stress, increased the levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA), decreased the level of glutathione (GSH), inhibited proliferation, caused nuclear DNA damage and apoptosis, upregulated the expression of TET1 gene, and ultimately led to active DNA demethylation in hGECs. The present study presents a mechanism by which oxidative stress induces active DNA demethylation in hGECs. We propose that TET inhibitors can be used to restore the oxidative stress-induced DNA demethylation, and thus inhibit possible malignant transformation of GI cells.
Oxidative stress and cellular toxicity induced by dihydropyrazine: a comparative study with other Maillard reaction products.
Miyauchi Y, Koba H, Sawai M … +2 more , Kansui H, Takechi S
J Toxicol Sci · 2023 · PMID 37121741 · Publisher ↗
Glycation products are generated during the Maillard reaction, a non-enzymatic reaction between reducing sugars and the amino groups of proteins, which accumulate in the body with aging and cause many diseases. Herein, w...
Glycation products are generated during the Maillard reaction, a non-enzymatic reaction between reducing sugars and the amino groups of proteins, which accumulate in the body with aging and cause many diseases. Herein, we have focused on dihydropyrazines (DHPs), which are glycation products formed by the dimerization of D-glucosamine or 5-aminolevulinic acid, and have reported that DHPs can produce several kinds of radicals and induce cytotoxicity via oxidative stress. To advance our understanding of DHP-mediated cytotoxicity, we selected a DHP, 3-hydro-2,2,5,6-tetramethylpyrazine (DHP-3), and two major Maillard reaction products, N-(carboxymethyl)-L-lysine (CML) and acrylamide, and performed comparative experiments focusing on their cytotoxicity and their ability to induce oxidative stress. The order of increasing cytotoxicity was DHP-3, acrylamide, and CML, and the LC value could be calculated only for DHP-3 (0.53 mM), indicating that DHP-3 is more toxic than the other Maillard reaction products. However, their toxicities were significantly lower than those of common toxic chemicals. Further, the results of their cytotoxicity assay were consistent with the results of intracellular reactive oxygen species production and activation of oxidative stress response signaling. These results indicate that the acute toxicity of Maillard reaction products is closely related to their ability to induce oxidative stress, and that DHP-3 is a particularly strong inducer of oxidative stress and thus exhibits high cytotoxicity among Maillard reaction products. In addition, we have shown that a comprehensive analysis comparing multiple Maillard reaction products is effective for elucidating their complex and diverse toxicities.
Construction of extended and functional bile canaliculi using long-term sandwich-cultured cryopreserved human hepatocytes and the application of hepatocytes for predicting the biliary excretion of pharmaceutical and food-related compounds.
Kitaguchi T, Horiuchi S, Kuroda Y … +4 more , Ohno K, Kobayashi K, Tanaka M, Ishida S
J Toxicol Sci · 2023 · PMID 37121740 · Publisher ↗
The biliary excretion of pharmaceutical and food-related compounds is an important factor for assessing pharmacokinetics and toxicities in humans, and a highly predictive in vitro method for human biliary excretion is re...
The biliary excretion of pharmaceutical and food-related compounds is an important factor for assessing pharmacokinetics and toxicities in humans, and a highly predictive in vitro method for human biliary excretion is required. We have developed a simple in vitro culture method for generating extended and functional bile canaliculi using cryopreserved human hepatocytes. We evaluated the uptake of compounds by hepatocytes and bile canaliculi, and the biliary excretion index (BEI) was calculated. After 21 days of culture, the presence of extended and functional bile canaliculi was confirmed by the uptake of two fluorescent substrates. Positive BEIs were observed for taurocholic acid-d, rosuvastatin, pitavastatin, pravastatin, valsartan, olmesartan, and topotecan (reported biliary-excreted compounds in humans), but no difference in BEI was observed for salicylic acid (a nonbiliary-excreted compound). Furthermore, 8 of 21 food-related compounds with specific structures and reported biliary transporter involvement exhibited positive BEIs. The developed in vitro system was characterized by functional bile canaliculus-like structures, and it could be applied to the prediction of the biliary excretion of pharmaceutical and food-related compounds.
Development of a GCN-based model to predict in vitro phototoxicity from the chemical structure and HOMO-LUMO gap.
Igarashi Y, Re S, Kojima R … +2 more , Okuno Y, Yamada H
J Toxicol Sci · 2023 · PMID 37121739 · Publisher ↗
The interaction between sunlight and drugs can lead to phototoxicity in patients who have received such drugs. Phototoxicity assessment is a regulatory requirement globally and one of the main toxicity screening steps in...
The interaction between sunlight and drugs can lead to phototoxicity in patients who have received such drugs. Phototoxicity assessment is a regulatory requirement globally and one of the main toxicity screening steps in the early stages of drug discovery. An in silico-in vitro approach has been utilized mainly for toxicology assessments at these stages. Although several quantitative structure-activity relationship (QSAR) models for phototoxicity have been developed, in silico technology to evaluate phototoxicity has not been well established. In this study, we attempted to develop an artificial intelligence (AI) model to predict the in vitro Neutral Red Uptake Phototoxicity Test results from a chemical structure and its derived information. To accomplish this, we utilized an open-source software library, kMoL. kMoL employs a graph convolutional neural networks (GCN) approach, which allows it to learn the data for the specified chemical structure. kMoL also utilizes the integrated gradient (IG) method, enabling it to visually display the substructures contributing to any positive results. To construct this AI model, we used only the chemical structure as a basis, then added the descriptors and the HOMO-LUMO gap, which was obtained from quantum chemical calculations. As a result, the assortment of chemical structures and the HOMO-LUMO gap produced an AI model with high discrimination performance, and an F1 score of 0.857. Additionally, our AI model could visualize the substructures involved in phototoxicity using the IG method. Our AI model can be applied as a toxicity screening method and could enhance productivity in drug development.
Carcinogenicity and chronic toxicity of butyl methacrylate in rats and mice by a two-year inhalation study.
Furukawa Y, Hirai S, Kasai T … +6 more , Senoh H, Takanobu K, Sasaki T, Kano H, Matsumoto M, Aiso S
J Toxicol Sci · 2023 · PMID 37121738 · Publisher ↗
We conducted a two-year inhalation study of butyl methacrylate using F344/DuCrlCrlj rats and B6D2F/Crl mice. Rats were exposed to 0, 30, 125 and 500 ppm (v/v) and mice were exposed to 0, 8, 30 and 125 ppm (v/v) using who...
We conducted a two-year inhalation study of butyl methacrylate using F344/DuCrlCrlj rats and B6D2F/Crl mice. Rats were exposed to 0, 30, 125 and 500 ppm (v/v) and mice were exposed to 0, 8, 30 and 125 ppm (v/v) using whole-body inhalation chambers. Non-neoplastic lesions developed in the nasal cavities of both rats and mice, but neoplastic lesions were not found. There was also a positive trend in the incidence of large granular lymphocytic (LGL) leukemia in the spleen of male rats. No changes were observed in female rats. Overall, there is some evidence of carcinogenicity in male rats, but there is no evidence of carcinogenicity in female rats. In male mice, there was a positive trend by Peto's test in the incidence of hepatocellular adenomas, and the incidence of hepatocellular adenomas and hepatocellular carcinomas combined was significantly increased compared to the controls by Fisher's exact test in the 30 ppm exposed male group. In female mice, the incidence of hemangiosarcoma in all organs combined showed a positive trend by Peto's test. Therefore, there is some evidence of carcinogenicity in male mice, and there is equivocal evidence of carcinogenicity in female mice.
Experience in the treatment of chlorfenapyr poisoning.
Wu B, Xue F, Lu M … +2 more , Ma A, Fan L
J Toxicol Sci · 2023 · PMID 37005280 · Publisher ↗
In China, the extensive use of the pesticide chlorfenapyr has led to an increase in chlorfenapyr poisoning. However, there are limited reports on chlorfenapyr poisoning, and most of them are fatal cases. This study retro...
In China, the extensive use of the pesticide chlorfenapyr has led to an increase in chlorfenapyr poisoning. However, there are limited reports on chlorfenapyr poisoning, and most of them are fatal cases. This study retrospectively analyzed four patients admitted to the emergency room after chlorfenapyr intake and detected different concentrations of chlorfenapyr in their plasma. Among them, one patient died and three patients survived. Case 1 suffered respiratory and circulatory failure with a deep coma shortly after oral administration of 100 mL of a the chlorfenapyr-containing mixture and died 30 min after admission. Case 2 experienced transient nausea and vomiting after oral administration of chlorfenapyr (50 mL). The patient had normal laboratory results and was discharged with no further treatment. Case 3 developed nausea and vomiting and a light coma after taking 30 mL of chlorfenapyr orally. He underwent blood perfusion and plasma exchange in the intensive care unit (ICU) and was discharged with recovery. A two-week follow-up visit, however, revealed hyperhidrosis. Case 4 (advanced age with severe underlying disease) developed a light coma after oral intake of 30 mL of chlorfenapyr. Subsequently, pulmonary infection and gastrointestinal bleeding were developed. The patient experienced blood perfusion and mechanical ventilation in the ICU and finally survived after treatment. The present study provides the basic information, plasma concentration of toxins, onset of poisoning and treatment process of the four patients mentioned above, providing novel insights into the clinical diagnosis and treatment of chlorfenapyr poisoning.
Exposure to bisphenol A or its phenolic analogs during early life induces different types of anxiety-like behaviors after maturity in male mice.
Sasaki T, Saito H, Furukawa Y … +4 more , Tominaga T, Kitajima S, Kanno J, Tanemura K
J Toxicol Sci · 2023 · PMID 37005279 · Publisher ↗
Products used in daily life contain multiple chemicals capable of inducing endocrine disruption in animals, including humans. One such typical substance is bisphenol A (BPA). BPA has been widely used in epoxy resins and...
Products used in daily life contain multiple chemicals capable of inducing endocrine disruption in animals, including humans. One such typical substance is bisphenol A (BPA). BPA has been widely used in epoxy resins and polycarbonate plastics and can exert several adverse effects. Furthermore, given their structural similarity to BPA, phenolic analogs of BPA, i.e., synthetic phenolic antioxidants (SPAs), are considered to exhibit similar toxicity; however, the effects of early SPA exposure on the adult central nervous system remain poorly clarified. In the present study, we aimed to evaluate and compare the neurobehavioral effects of early life exposure to BPA and two selected SPAs, 4,4'-butylidenebis (6-tert-butyl-m-cresol) (BB) and 2,2'-methylenebis (6-tert-butyl-p-cresol) (MB). We exposed mice to low levels of these chemicals through drinking water during prenatal and postnatal periods. Subsequently, we examined the adverse effects of these chemicals on the central nervous system using a mouse behavioral test battery, comprising the open field test, light/dark transition test, elevated plus-maze test, contextual/cued fear conditioning test, and prepulse inhibition test, at 12-13 weeks old. Based on the behavioral analysis, SPAs, like BPA, may cause affective disorders even at low doses, although qualitative differences were noted in anxiety-related behaviors. In conclusion, our findings could be valuable for clarifying the potential adverse developmental risks of SPA exposure in early life.
Behavioral effects induced by the oral administration of acetamiprid in male mice during the postnatal lactation period or adulthood.
Saito H, Tanemura K, Furukawa Y … +3 more , Sasaki T, Kanno J, Kitajima S
J Toxicol Sci · 2023 · PMID 37005278 · Publisher ↗
Acetamiprid (ACE), a neonicotinoid chemical, is widely used as a pesticide due to its rapid insecticidal activity. Although neonicotinoids exert very low toxicity in mammals, the effects of early exposure to neonicotinoi...
Acetamiprid (ACE), a neonicotinoid chemical, is widely used as a pesticide due to its rapid insecticidal activity. Although neonicotinoids exert very low toxicity in mammals, the effects of early exposure to neonicotinoids on the adult central nervous system are poorly understood. This study investigated the effects of ACE exposure in early life on brain function in adult mice. We exposed male C57BL/6N mice to ACE (10 mg/kg) orally when they were two (postnatal lactation) or 11 weeks old (adult). We examined the effects of ACE on the central nervous system using the mouse behavioral test battery, consisting of the open field test, light/dark transition test, elevated plus-maze test, contextual/cued fear conditioning test, and pre-pulse inhibition test at 12-13 weeks old. In the mouse behavioral test battery, learning memory abnormalities were detected in the mature treatment group. In addition, learning memory and emotional abnormalities were detected in the postnatal lactation treatment group. These results suggest that the behavioral effects of postnatal lactation treatment with ACE were qualitatively different from the behavioral abnormalities in the mature treatment group.
Toxicity manifestations and sex differences due to MARTA olanzapine.
Hattori-Usami N, Kaizaki-Mitsumoto A, Ashino T … +2 more , Yamamoto M, Numazawa S
J Toxicol Sci · 2023 · PMID 37005277 · Publisher ↗
Olanzapine is widely used as a treatment for schizophrenia and other psychiatric disorders. Its metabolic side effects, including weight gain and hyperglycemia, are a clinical problem; however, their full mechanism is no...
Olanzapine is widely used as a treatment for schizophrenia and other psychiatric disorders. Its metabolic side effects, including weight gain and hyperglycemia, are a clinical problem; however, their full mechanism is not yet clearly understood. Recently, it was reported that the accumulation of oxidative stress in the hypothalamus may cause obesity and diabetes mellitus. Epidemiologically, metabolic side effects are known to be more likely to occur in women. In the present study, we investigated and tested the hypothesis that olanzapine induces oxidative stress in the hypothalamus and induces metabolic side effects. We also examined its association with sex differences. Olanzapine was administered intraperitoneally to male and female C57BL/6 mice, and the expression levels of oxidative stress-responsible genes in the hypothalamus and cerebral cortex were measured by qRT-PCR. In addition, olanzapine was administered intraperitoneally to C57BL/6 and Nrf2 KO mice, and the expression level of total glutathione was measured. Gene expressions induced by the Keap1-Nrf2-regulated system showed different responses to olanzapine for each gene. Under the conditions of this experiment, cystine-glutamate transporter was decreased although heme oxygenase-1 and γ-glutamylcysteine synthetase were increased. It was also clear that these responses were not hypothalamus-specific. Long-term feeding with olanzapine suppressed weight gain in males but not females. No glucose intolerance was observed at 13 weeks of administration. Furthermore, deaths occurred only in females. In conclusion, this study failed to provide evidence that olanzapine induces oxidative stress in a hypothalamic-specific manner. Instead, sex differences were observed in response to long-term and high-dose olanzapine administration, suggesting that individual susceptibility to olanzapine toxicity occurred in female mice.
The toxicity assessment of neorudin in cynomolgus monkeys.
Liu YB, Ren BY, Zhou XC … +6 more , Zhang L, Liu Y, Zheng C, Wei JF, Wu CT, Jin JD
J Toxicol Sci · 2023 · PMID 37005276 · Publisher ↗
In this study, the toxicity effects on circulatory system and respiratory system, and the acute toxicity test of recombinant neorudin (EPR-hirudin, EH) in cynomolgus monkeys were evaluated to provide reference informatio...
In this study, the toxicity effects on circulatory system and respiratory system, and the acute toxicity test of recombinant neorudin (EPR-hirudin, EH) in cynomolgus monkeys were evaluated to provide reference information for clinical studies. Eighteen cynomolgus monkeys were randomly divided into three groups for single intravenous administration of 3, 30 mg/kg EH and normal saline, respectively. The changes of respiratory frequency, respiratory intensity, blood pressure and electrocardiogram before and after administration were recorded. In acute toxicity test, six cynomolgus monkeys were intravenously received EH at a single dose of 171, 257, 385, 578, 867 and 1300 mg/kg respectively. The vital signs, hematology, serum biochemistry, coagulation indexes and electrocardiogram indexes of the animals were determined before administration and on the 7th and 14th day after administration. As the results showed that there were no significant abnormal changes in respiratory frequency, respiratory intensity, blood pressure or electrocardiogram in cynomolgus monkeys after receiving EH at 3 mg/kg and 30 mg/kg, and there was no statistical difference between the treated groups and normal saline group. In the acute toxicity test, no significant abnormalities were observed in vital signs, hematology, serum biochemistry, coagulation indexes and electrocardiogram indexes of six cynomolgus monkeys at day 7 and 14 after EH administration. Furthermore, autopsies of all cynomolgus monkeys showed no abnormalities. The results of toxicokinetics showed that AUClast of the drug increased in proportion to the EH dose in the range of 171-578 mg/kg, and increased in over proportion to the EH dose in the range of 578-1300 mg/kg. The variation of Cmax was basically consistent with AUClast. In a sum, A single intravenous injection of 3 and 30 mg/kg of EH did not affect the circulatory system and respiratory system in cynomolgus monkeys and the maximum tolerated dose of EH in cynomolgus monkey is over 1300 mg/kg (equivalent to 619-1300 times of the proposed clinical equivalent dose).
Both osmolality-dependent and independent mechanisms are associated with acute hyperglycemia-induced cardiovascular adverse reactions: Analysis of the mutual interactions leading to cardiovascular phenotypes in dogs.
Kambayashi R, Izumi-Nakaseko H, Goto A … +5 more , Takei Y, Matsumoto A, Lorch U, Täubel J, Sugiyama A
J Toxicol Sci · 2023 · PMID 36858642 · Publisher ↗
Acute hyperglycemia causes various cardiovascular responses; however, the underlying pathophysiology in vivo is myriad and complex, of which mutual interactions remain poorly understood. We analyzed the cardiovascular ef...
Acute hyperglycemia causes various cardiovascular responses; however, the underlying pathophysiology in vivo is myriad and complex, of which mutual interactions remain poorly understood. We analyzed the cardiovascular effects of acute hyperglycemia in comparison with those of hyperosmolality alone. Three g/kg of D-glucose (n = 4) or D-mannitol (n = 4) was intravenously infused to isoflurane-anesthetized intact dogs. Glucose infusion increased plasma glucose level and osmolality, whereas mannitol infusion similarly changed osmolality to glucose infusion but decreased glucose level. Glucose infusion decreased total peripheral vascular resistance, but increased heart rate, left ventricular contraction, left ventricular preload and cardiac output without altering mean blood pressure. Mannitol infusion likewise changed them, but its positive chronotropic and inotropic effects were less potent than those of glucose infusion. Glucose infusion prolonged PR interval, QRS width and QTcV. Mannitol infusion similarly changed them, but its QTcV prolongation was smaller than that of glucose infusion. Glucose infusion-induced cardiovascular responses would be basically attributed to osmolality-dependent mechanisms, whereas its positive chronotropic and inotropic effects along with repolarization delay may be enhanced by osmolality-independent mechanisms, including hyperglycemia by itself and insulin release.
Tributyltin activates the Keap1-Nrf2 pathway via a macroautophagy-independent reduction in Keap1.
Hatano M, Hatamiya S, Miyara M … +1 more , Kotake Y
J Toxicol Sci · 2023 · PMID 36858641 · Publisher ↗
Tributyltin (TBT) is an environmental chemical, which was used as an antifouling agent for ships. Although its use has been banned, it is still persistently present in ocean sediments. Although TBT reportedly causes vari...
Tributyltin (TBT) is an environmental chemical, which was used as an antifouling agent for ships. Although its use has been banned, it is still persistently present in ocean sediments. Although TBT reportedly causes various toxicity in mammals, few studies on the mechanisms of biological response against TBT toxicity exist. The well-established Keap1-Nrf2 pathway is activated as a cytoprotective mechanism under stressful conditions. The relationship between TBT and the Keap1-Nrf2 pathway remains unclear. In the present study, we evaluated the effect of TBT on the Keap1-Nrf2 pathway. TBT reduced Keap1 protein expression in Neuro2a cells, a mouse neuroblastoma cell line, after 6 hr without altering mRNA expression levels. TBT also promoted the nuclear translocation of Nrf2, a transcription factor for antioxidant proteins, after 12 hr and augmented the expression of heme oxygenase 1, a downstream protein of Nrf2. Furthermore, TBT decreased Keap1 levels in mouse embryonic fibroblast (MEF) cells, with the knockout of Atg5, which is essential for macroautophagy, as well as in wild-type MEF cells. These results suggest that TBT activates the Keap1-Nrf2 pathway via the reduction in the Keap1 protein level in a macroautophagy-independent manner. The Keap1-Nrf2 pathway is activated by conformational changes in Keap1 induced by reactive oxygen species or electrophiles. Furthermore, any unutilized Keap1 protein is degraded by macroautophagy. Understanding the novel mechanism governing the macroautophagy-independent reduction in Keap1 by TBT may provide insights into the unresolved biological response mechanism against TBT toxicity and the activation mechanism of the Keap1-Nrf2 pathway.
Effects of early-life tosufloxacin tosilate hydrate administration on growth rate, neurobehavior, and gut microbiota at adulthood in male mice.
Hasegawa A, Sasaki T, Islam J … +4 more , Tominaga T, Nochi T, Hara K, Tanemura K
J Toxicol Sci · 2023 · PMID 36858640 · Publisher ↗
Reportedly, antibiotics, which are frequently prescribed in children, have long-term effects owing to gut microbiota dysregulation. Tosufloxacin tosilate hydrate (TFLX) is the first orally administered new quinolone with...
Reportedly, antibiotics, which are frequently prescribed in children, have long-term effects owing to gut microbiota dysregulation. Tosufloxacin tosilate hydrate (TFLX) is the first orally administered new quinolone with high efficacy and broad-spectrum action approved as an antibacterial agent for pediatric use in Japan. However, studies on the effects of its early-stage administration are limited. Therefore, we aimed to analyze the later effects of its developmental administration by monitoring growth rate, neurobehavior, and gut microbiota in mice. The TFLX was administered via drinking water at a dose of up to 300 mg/kg for two consecutive weeks during the developmental period (4-6 weeks of age) or adulthood (8-10 weeks of age). Thereafter, the body weights of the mice were measured weekly to monitor growth rate. Behavioral tests were also conducted on 11-12-week-old mice to examine the neurobehavioral effects of the treatment. Further, to examine the effects of the treatment on microbiota, fecal samples were collected from the rectum of mice dissected at 12 weeks of age, and 16s rRNA analysis was conducted. Our results showed increased body weights after TFLX administration, without any long-term effects. Behavioral analysis suggested alterations in anxiety-like behaviors and memory recall dysregulation, and gut microbiota analysis revealed significant differences in bacterial composition. These findings indicated that TFLX administration during the developmental period affects mice growth rate, neurobehavior, and gut microbiota structure. This is the first study to report that TFLX is potentially associated with the risk of long effects.
Dexmedetomidine protects against Ropivacaine-induced neuronal pyroptosis via the Nrf2/HO-1 pathway.
Wang R, Liu P, Li F … +1 more , Qiao H
J Toxicol Sci · 2023 · PMID 36858639 · Publisher ↗
Dexmedetomidine (DEX) has been demonstrated to protect against ropivacaine (Ropi)-induced neuronal damages. This study was conducted to explore the protective role of DEX in Ropi-induced neuronal pyroptosis and provide a...
Dexmedetomidine (DEX) has been demonstrated to protect against ropivacaine (Ropi)-induced neuronal damages. This study was conducted to explore the protective role of DEX in Ropi-induced neuronal pyroptosis and provide a strategy to eliminate Ropi-induced neurotoxicity. The impacts of different concentrations of Ropi and DEX on neurotoxicity in SK-N-SH cells were evaluated by cell counting kit-8 assay and lactic dehydrogenase assay kits. Levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), NLR family pyrin domain containing 3 (NLRP3), cleaved Caspase-1, cleaved N-terminal gasdermin D, interleukin (IL)-1β, and IL-18 were measured by real-time quantitative PCR, Western blotting, and enzyme linked immunosorbent assay. The Nrf2 level after nuclear/cytoplasmic separation was quantified. SK-N-SH cells were treated with si-Nrf2, Nigericin (NLRP3 activator), and Zinc Protoporphyrin (HO-1 inhibitor) to validate the mechanism. Ropi reduced SK-N-SH cell viability in a concentration- and time-dependent manner. DEX treatment alleviated Ropi-induced toxicity and inhibited pyroptosis. Ropi increased the expression levels of Nrf2 and HO-1, and DEX further enhanced the increases and promoted Nrf2 nuclear translocation. Nrf2/HO-1 inhibition or NLRP3 activation both neutralized the inhibitory role of DEX in Ropi-induced pyroptosis of SK-N-SH cells. Overall, DEX promoted the Nrf2/HO-1 pathway to inhibit NLRP3 expression, thus alleviating Ropi-induced neuronal pyroptosis.
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