S. Shityakov, R. E. Salmas, Ellaine Salvador, N. Roewer, J. Broscheit, C. Förster
In this study, we investigated the cytotoxic effects of unmodified α-cyclodextrin (α-CD) and modified cyclodextrins, including trimethyl-β-cyclodextrin (TRIMEB) and hydroxypropyl-β-cyclodextrin (HPβCD), on immortalized murine microvascular endothelial (cEND) cells of the blood-brain barrier (BBB). A CellTiter-Glo viability test, performed on the cEND cells showed significant differences among the different cyclodextrins. After 24 hr of incubation, TRIMEB was the most cytotoxic, and HPβCD was non-toxic. α-CD and TRIMEB exhibited greater cytotoxicity in the Dulbecco's modified Eagle's medium than in heat-inactivated human serum indicating protective properties of the human serum. The predicted dynamic toxicity profiles (Td) for α-CD and TRIMEB indicated higher cytotoxicity for these cyclodextrins compared to the reference compound (dimethylsulfoxide). Molecular dynamics simulation of cholesterol binding to the CDs suggested that not just cholesterol but phospholipids extraction might be involved in the cytotoxicity. Overall, the results demonstrate that HPβCD has the potential to be used as a candidate for drug delivery vector development and signify a correlation between the in vitro cytotoxic effect and cholesterol binding of cyclodextrins.
{"title":"Evaluation of the potential toxicity of unmodified and modified cyclodextrins on murine blood-brain barrier endothelial cells.","authors":"S. Shityakov, R. E. Salmas, Ellaine Salvador, N. Roewer, J. Broscheit, C. Förster","doi":"10.2131/jts.41.175","DOIUrl":"https://doi.org/10.2131/jts.41.175","url":null,"abstract":"In this study, we investigated the cytotoxic effects of unmodified α-cyclodextrin (α-CD) and modified cyclodextrins, including trimethyl-β-cyclodextrin (TRIMEB) and hydroxypropyl-β-cyclodextrin (HPβCD), on immortalized murine microvascular endothelial (cEND) cells of the blood-brain barrier (BBB). A CellTiter-Glo viability test, performed on the cEND cells showed significant differences among the different cyclodextrins. After 24 hr of incubation, TRIMEB was the most cytotoxic, and HPβCD was non-toxic. α-CD and TRIMEB exhibited greater cytotoxicity in the Dulbecco's modified Eagle's medium than in heat-inactivated human serum indicating protective properties of the human serum. The predicted dynamic toxicity profiles (Td) for α-CD and TRIMEB indicated higher cytotoxicity for these cyclodextrins compared to the reference compound (dimethylsulfoxide). Molecular dynamics simulation of cholesterol binding to the CDs suggested that not just cholesterol but phospholipids extraction might be involved in the cytotoxicity. Overall, the results demonstrate that HPβCD has the potential to be used as a candidate for drug delivery vector development and signify a correlation between the in vitro cytotoxic effect and cholesterol binding of cyclodextrins.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125919084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lipopolysaccharide (LPS) has been confirmed to be the main inhibitor in osteogenic differentiation, posing a clinical challenge to bone healing, particularly for trauma followed by endotoxinemia/sepsis. However, the molecular mechanism remains ambiguous. miR-23b, which regulates multiple signaling pathways in inflammation, has been shown to be deregulated by LPS. In this study, we examined the LPS-mediated regulation on the expression of miR-23b and Smad 3 in preosteoblast MC3T3-E1 cells. Then we determined the regulation of miR-23b overexpression on the Smad 3 expression and on the LPS-mediated inhibition of bone morphogenetic protein-2 (BMP-2)-induced osteogenic differentiation. Our results demonstrated that LPS significantly downregulated the expression of miR-23b, while upregulating Smad 3 in MC3T3-E1 cells. However, the transfection with miR-23b mimics markedly downregulated the Smad 3 in both mRNA and protein levels, via the specific binding to the 3'-untranslated region (UTR) of Smad 3. Moreover, though LPS markedly downregulated the BMP-2-induced osteogenic differentiation of MC3T3-E1 cells by inhibiting the expression of alkaline phosphatase (ALP), Osteocalcin (OCN), Osteopontin (OPN) and Runt-related transcription factor 2 (RUNX2). The upregulated miR-23b reversed such downregulation of ALP, OCN, OPN and RUNX2 in the MC3T3-E1 cells which were treated both with LPS and BMP-2. In conclusion, our data indicates that miR-23b ameliorates the LPS-mediated inhibition of BMP-2-induced osteogenic differentiation in MC3T3-E1 cells, implying the protective role of miR-23b in the LPS-mediated inhibition of osteogenic differentiation and bone formation.
{"title":"miR-23b targets Smad 3 and ameliorates the LPS-inhibited osteogenic differentiation in preosteoblast MC3T3-E1 cells.","authors":"Hongzhi Liu, W. Hao, Xin Wang, H. Su","doi":"10.2131/jts.41.185","DOIUrl":"https://doi.org/10.2131/jts.41.185","url":null,"abstract":"Lipopolysaccharide (LPS) has been confirmed to be the main inhibitor in osteogenic differentiation, posing a clinical challenge to bone healing, particularly for trauma followed by endotoxinemia/sepsis. However, the molecular mechanism remains ambiguous. miR-23b, which regulates multiple signaling pathways in inflammation, has been shown to be deregulated by LPS. In this study, we examined the LPS-mediated regulation on the expression of miR-23b and Smad 3 in preosteoblast MC3T3-E1 cells. Then we determined the regulation of miR-23b overexpression on the Smad 3 expression and on the LPS-mediated inhibition of bone morphogenetic protein-2 (BMP-2)-induced osteogenic differentiation. Our results demonstrated that LPS significantly downregulated the expression of miR-23b, while upregulating Smad 3 in MC3T3-E1 cells. However, the transfection with miR-23b mimics markedly downregulated the Smad 3 in both mRNA and protein levels, via the specific binding to the 3'-untranslated region (UTR) of Smad 3. Moreover, though LPS markedly downregulated the BMP-2-induced osteogenic differentiation of MC3T3-E1 cells by inhibiting the expression of alkaline phosphatase (ALP), Osteocalcin (OCN), Osteopontin (OPN) and Runt-related transcription factor 2 (RUNX2). The upregulated miR-23b reversed such downregulation of ALP, OCN, OPN and RUNX2 in the MC3T3-E1 cells which were treated both with LPS and BMP-2. In conclusion, our data indicates that miR-23b ameliorates the LPS-mediated inhibition of BMP-2-induced osteogenic differentiation in MC3T3-E1 cells, implying the protective role of miR-23b in the LPS-mediated inhibition of osteogenic differentiation and bone formation.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121183346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Shirai, Shingo Arakawa, M. Teranishi, Kiyonori Kai
We previously reported that thioacetamide (TA)-induced hepatocellular necrosis was attenuated in mice fed a high-fat diet (HFD mice) compared with mice fed a normal rodent diet (ND mice). In this study, we investigated whether p38 mitogen-activated protein kinase (p38 MAPK) was involved in this attenuation. Western blot analysis revealed that hepatic phosphorylated p38 MAPK protein decreased at 8 and 24 hours (hr) after TA dosing in the HFD mice, while it decreased only at 24 hr in the ND mice in comparison to the time- and diet-matched, vehicle-treated mice. p38 MAPK regulates various biological functions including inflammation, therefore, hepatic metabolomics analysis focusing on pro-inflammatory lipid mediators was performed. At 24 hr after TA dosing, only one pro-inflammatory mediator, 12-hydroxyeicosatetraenoic acid (HETE), was higher in the HFD mice. On the other hand, in addition to 12-HETE, 15-HETE and 12-hydroxyeicosapentaenoic acid (HEPE) were higher and omega-3/omega-6 polyunsaturated fatty acids ratios were lower in the ND mice at 24 hr. These results of metabolomics indicated that less pro-inflammatory state was seen in HFD mice than in ND mice at 24 hr. Finally, to confirm whether the observed decrease in phosphorylated p38 MAPK could attenuate TA-induced hepatocellular necrosis, we showed that SB203580 hydrochloride, an inhibitor of p38 MAPK, partially attenuated TA-induced hepatic necrosis in ND mice. Collectively, these results suggest that a prompt decrease in phosphorylation of p38 MAPK after TA administration is one of the factors that attenuate TA-induced hepatic necrosis in HFD mice.
{"title":"Decreased hepatic phosphorylated p38 mitogen-activated protein kinase contributes to attenuation of thioacetamide-induced hepatic necrosis in diet-induced obese mice.","authors":"M. Shirai, Shingo Arakawa, M. Teranishi, Kiyonori Kai","doi":"10.2131/jts.41.245","DOIUrl":"https://doi.org/10.2131/jts.41.245","url":null,"abstract":"We previously reported that thioacetamide (TA)-induced hepatocellular necrosis was attenuated in mice fed a high-fat diet (HFD mice) compared with mice fed a normal rodent diet (ND mice). In this study, we investigated whether p38 mitogen-activated protein kinase (p38 MAPK) was involved in this attenuation. Western blot analysis revealed that hepatic phosphorylated p38 MAPK protein decreased at 8 and 24 hours (hr) after TA dosing in the HFD mice, while it decreased only at 24 hr in the ND mice in comparison to the time- and diet-matched, vehicle-treated mice. p38 MAPK regulates various biological functions including inflammation, therefore, hepatic metabolomics analysis focusing on pro-inflammatory lipid mediators was performed. At 24 hr after TA dosing, only one pro-inflammatory mediator, 12-hydroxyeicosatetraenoic acid (HETE), was higher in the HFD mice. On the other hand, in addition to 12-HETE, 15-HETE and 12-hydroxyeicosapentaenoic acid (HEPE) were higher and omega-3/omega-6 polyunsaturated fatty acids ratios were lower in the ND mice at 24 hr. These results of metabolomics indicated that less pro-inflammatory state was seen in HFD mice than in ND mice at 24 hr. Finally, to confirm whether the observed decrease in phosphorylated p38 MAPK could attenuate TA-induced hepatocellular necrosis, we showed that SB203580 hydrochloride, an inhibitor of p38 MAPK, partially attenuated TA-induced hepatic necrosis in ND mice. Collectively, these results suggest that a prompt decrease in phosphorylation of p38 MAPK after TA administration is one of the factors that attenuate TA-induced hepatic necrosis in HFD mice.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116162223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Fujie, Yukino Segawa, Eiko Yoshida, T. Kimura, Y. Fujiwara, C. Yamamoto, M. Satoh, H. Naka, T. Kaji
Metallothionein (MT) plays a central role in cellular defense against heavy metals and oxidative stress. Since the induction of MT requires the activation of metal response element (MRE)-binding transcription factor-1 (MTF-1) by binding of zinc ions, inorganic zinc is regarded as a typical MT inducer. However, in a previous report, we showed that inorganic zinc could not induce MT in vascular endothelial cells. While it is suggested that endothelial MT presents mechanisms different from those of other cell types, these remain unclear. In this study, we investigated whether the induction of endothelial MT expression involves the Nrf2-ARE pathway using copper(II) bis(diethyldithiocarbamate), termed Cu10, using a culture system of bovine aortic endothelial cells. Cu10 induced MT-1/2 protein expression and increased the expression of mRNAs for MT-1A, MT-1E, and MT-2, MT isoforms expressed in the cells. Cu10 activated not only the MTF-1-MRE, but also the Nrf2-ARE pathway. MTF-1 knockdown resulted in the repression of Cu10-induced MT-1 and -2 expression. Cu10-induced MT-1 expression was down-regulated by Nrf2 knockdown. However, MT-2 expression was not affected by Nrf2 knockdown. These results suggest that the expression of endothelial MT is up-regulated by the Nrf2-ARE pathway as well as by the MTF-1-MRE pathway. Moreover, MT-1 regulation mechanisms differ from that of MT-2. Specifically, the present data support the hypothesis that MT-1 participates in the biological defense system, while MT-2 mainly regulates intracellular zinc metabolism.
{"title":"Induction of metallothionein isoforms by copper diethyldithiocarbamate in cultured vascular endothelial cells.","authors":"T. Fujie, Yukino Segawa, Eiko Yoshida, T. Kimura, Y. Fujiwara, C. Yamamoto, M. Satoh, H. Naka, T. Kaji","doi":"10.2131/jts.41.225","DOIUrl":"https://doi.org/10.2131/jts.41.225","url":null,"abstract":"Metallothionein (MT) plays a central role in cellular defense against heavy metals and oxidative stress. Since the induction of MT requires the activation of metal response element (MRE)-binding transcription factor-1 (MTF-1) by binding of zinc ions, inorganic zinc is regarded as a typical MT inducer. However, in a previous report, we showed that inorganic zinc could not induce MT in vascular endothelial cells. While it is suggested that endothelial MT presents mechanisms different from those of other cell types, these remain unclear. In this study, we investigated whether the induction of endothelial MT expression involves the Nrf2-ARE pathway using copper(II) bis(diethyldithiocarbamate), termed Cu10, using a culture system of bovine aortic endothelial cells. Cu10 induced MT-1/2 protein expression and increased the expression of mRNAs for MT-1A, MT-1E, and MT-2, MT isoforms expressed in the cells. Cu10 activated not only the MTF-1-MRE, but also the Nrf2-ARE pathway. MTF-1 knockdown resulted in the repression of Cu10-induced MT-1 and -2 expression. Cu10-induced MT-1 expression was down-regulated by Nrf2 knockdown. However, MT-2 expression was not affected by Nrf2 knockdown. These results suggest that the expression of endothelial MT is up-regulated by the Nrf2-ARE pathway as well as by the MTF-1-MRE pathway. Moreover, MT-1 regulation mechanisms differ from that of MT-2. Specifically, the present data support the hypothesis that MT-1 participates in the biological defense system, while MT-2 mainly regulates intracellular zinc metabolism.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"332 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134429739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kanae Umeda, Y. Kotake, Masatsugu Miyara, K. Ishida, S. Sanoh, S. Ohta
GluR2, an α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subunit, plays important roles in neuronal survival. We previously showed that exposure of cultured rat cortical neurons to several chemicals decreases GluR2 protein expression, leading to neuronal toxicity. Methoxychlor, the bis-p-methoxy derivative of dichlorodiphenyltrichloroethane, and fenvalerate, a synthetic pyrethroid chemical, have been used commercially as agricultural pesticides in several countries. In this study, we investigated the effects of long-term methoxychlor and fenvalerate exposure on neuronal glutamate receptors. Treatment of cultured rat cortical neurons with 1 or 10 µM methoxychlor and fenvalerate for 9 days selectively decreased GluR2 protein expression; the expression of other AMPA receptor subunits GluR1, GluR3, and GluR4 did not change under the same conditions. Importantly, the decreases in GluR2 protein expression were also observed on the cell surface membrane where AMPA receptors typically function. In addition, both chemicals decreased neuronal viability, which was blocked by pretreatment with 1-naphtylacetylspermine, an antagonist of GluR2-lacking AMPA receptors, and MK-801, an N-methyl-d-aspartate (NMDA) receptor antagonist. These results suggest that long-term exposure to methoxychlor and fenvalerate decreases GluR2 protein expression, leading to neuronal death via overactivation of GluR2-lacking AMPA and NMDA receptors.
{"title":"Methoxychlor and fenvalerate induce neuronal death by reducing GluR2 expression.","authors":"Kanae Umeda, Y. Kotake, Masatsugu Miyara, K. Ishida, S. Sanoh, S. Ohta","doi":"10.2131/jts.41.255","DOIUrl":"https://doi.org/10.2131/jts.41.255","url":null,"abstract":"GluR2, an α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subunit, plays important roles in neuronal survival. We previously showed that exposure of cultured rat cortical neurons to several chemicals decreases GluR2 protein expression, leading to neuronal toxicity. Methoxychlor, the bis-p-methoxy derivative of dichlorodiphenyltrichloroethane, and fenvalerate, a synthetic pyrethroid chemical, have been used commercially as agricultural pesticides in several countries. In this study, we investigated the effects of long-term methoxychlor and fenvalerate exposure on neuronal glutamate receptors. Treatment of cultured rat cortical neurons with 1 or 10 µM methoxychlor and fenvalerate for 9 days selectively decreased GluR2 protein expression; the expression of other AMPA receptor subunits GluR1, GluR3, and GluR4 did not change under the same conditions. Importantly, the decreases in GluR2 protein expression were also observed on the cell surface membrane where AMPA receptors typically function. In addition, both chemicals decreased neuronal viability, which was blocked by pretreatment with 1-naphtylacetylspermine, an antagonist of GluR2-lacking AMPA receptors, and MK-801, an N-methyl-d-aspartate (NMDA) receptor antagonist. These results suggest that long-term exposure to methoxychlor and fenvalerate decreases GluR2 protein expression, leading to neuronal death via overactivation of GluR2-lacking AMPA and NMDA receptors.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127792924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yui Nakajima, Hirotoshi Iguchi, Shinji Kamisuki, F. Sugawara, T. Furuichi, Y. Shinoda
Citrinin, a natural mycotoxin that is found in fermented foods, is known as a cytotoxin and nephrotoxin. Exposure to high doses of citrinin result in apoptosis; however, the effects of low doses are not fully understood. Glutamate excitotoxicity is responsible for neuronal death in acute neurological disorders including stroke, trauma and other neurodegenerative diseases. Here, we show the neuroprotective effect of low doses of citrinin against glutamate-induced excitotoxicity. We examined the effect of citrinin exposure on glutamate-induced cell death in cultured rat cortical neurons under two conditions: simultaneous treatment with citrinin 0.1 to 1,000 nM and glutamate (30 μM) for 1, 3 hr; the same simultaneous treatment for 3 hr after pretreatment with citrinin for 21 hr. Both the MTT and immunocytochemical assay showed significant neuroprotective effects at several doses and exposure times tested. All concentrations of citrinin tested showed no remarkable cell death following 14-day exposure, and no marked alterations to synapses. These data suggest that low doses of citrinin can be used as a neuroprotective agent against glutamate-induced excitotoxicity without additional harmful cellular alterations.
{"title":"Low doses of the mycotoxin citrinin protect cortical neurons against glutamate-induced excitotoxicity.","authors":"Yui Nakajima, Hirotoshi Iguchi, Shinji Kamisuki, F. Sugawara, T. Furuichi, Y. Shinoda","doi":"10.2131/jts.41.311","DOIUrl":"https://doi.org/10.2131/jts.41.311","url":null,"abstract":"Citrinin, a natural mycotoxin that is found in fermented foods, is known as a cytotoxin and nephrotoxin. Exposure to high doses of citrinin result in apoptosis; however, the effects of low doses are not fully understood. Glutamate excitotoxicity is responsible for neuronal death in acute neurological disorders including stroke, trauma and other neurodegenerative diseases. Here, we show the neuroprotective effect of low doses of citrinin against glutamate-induced excitotoxicity. We examined the effect of citrinin exposure on glutamate-induced cell death in cultured rat cortical neurons under two conditions: simultaneous treatment with citrinin 0.1 to 1,000 nM and glutamate (30 μM) for 1, 3 hr; the same simultaneous treatment for 3 hr after pretreatment with citrinin for 21 hr. Both the MTT and immunocytochemical assay showed significant neuroprotective effects at several doses and exposure times tested. All concentrations of citrinin tested showed no remarkable cell death following 14-day exposure, and no marked alterations to synapses. These data suggest that low doses of citrinin can be used as a neuroprotective agent against glutamate-induced excitotoxicity without additional harmful cellular alterations.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122582832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evaluation of oral mucosal irritation is required by regulatory agencies when the intended clinical route of the drug candidate is intraoral administration. In this study, we investigated whether it was possible to evaluate oral mucosal irritation in rats by an intraoral instillation which was thought to mimic the clinical route of gargle products. Although no oral mucosal irritation was observed in the animals instilled with 0.5% and 4% sodium dodecyl sulfate (SDS, an anionic detergent) solutions for 10 days, instillation of 15% SDS solution for 4 days induced oral mucosal irritation macro- and microscopically, and this was evaluated as moderate irritant. It was suggested that the oral mucosal irritation test by intraoral instillation in rats could be a simple and useful method mimicking the clinical route of gargle products.
{"title":"A simple method for oral mucosal irritation test by intraoral instillation in rats.","authors":"H. Kimoto, Y. Ito, S. Matsumoto, E. Hosoki","doi":"10.2131/jts.41.233","DOIUrl":"https://doi.org/10.2131/jts.41.233","url":null,"abstract":"Evaluation of oral mucosal irritation is required by regulatory agencies when the intended clinical route of the drug candidate is intraoral administration. In this study, we investigated whether it was possible to evaluate oral mucosal irritation in rats by an intraoral instillation which was thought to mimic the clinical route of gargle products. Although no oral mucosal irritation was observed in the animals instilled with 0.5% and 4% sodium dodecyl sulfate (SDS, an anionic detergent) solutions for 10 days, instillation of 15% SDS solution for 4 days induced oral mucosal irritation macro- and microscopically, and this was evaluated as moderate irritant. It was suggested that the oral mucosal irritation test by intraoral instillation in rats could be a simple and useful method mimicking the clinical route of gargle products.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124828288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Zaid, Fatimazahra Marhoume, N. Senhaji, K. Kojok, Hicham Boufous, A. Naya, M. Oudghiri, Youssef Darif, N. Habti, S. Zouine, Fekhaoui Mohamed, A. Chait, Abdellah Bagri
Paraphenylene daimine (PPD) is an aromatic amine that is widely used in several industrial products; however, its toxicity has been reported in several cases of cardiac arrests. As platelets play a key role in cardiovascular diseases, we aimed to determine the impact of PPD in vitro and in vivo on platelet function. Our findings demonstrated that platelet activation and aggregation were strongly enhanced by PPD. Treatment with PPD primed human platelets that became more reactive in response to low doses of collagen. Furthermore, PPD exacerbated thrombus formation in rats in comparison with those untreated. Our results suggest that PPD is an important platelet primer predisposing platelets to promote thrombus formation in response to vascular injury. This should prompt the authorities to consider controlling the marketing of this product.
{"title":"Paraphenylene diamine exacerbates platelet aggregation and thrombus formation in response to a low dose of collagen.","authors":"Y. Zaid, Fatimazahra Marhoume, N. Senhaji, K. Kojok, Hicham Boufous, A. Naya, M. Oudghiri, Youssef Darif, N. Habti, S. Zouine, Fekhaoui Mohamed, A. Chait, Abdellah Bagri","doi":"10.2131/jts.41.123","DOIUrl":"https://doi.org/10.2131/jts.41.123","url":null,"abstract":"Paraphenylene daimine (PPD) is an aromatic amine that is widely used in several industrial products; however, its toxicity has been reported in several cases of cardiac arrests. As platelets play a key role in cardiovascular diseases, we aimed to determine the impact of PPD in vitro and in vivo on platelet function. Our findings demonstrated that platelet activation and aggregation were strongly enhanced by PPD. Treatment with PPD primed human platelets that became more reactive in response to low doses of collagen. Furthermore, PPD exacerbated thrombus formation in rats in comparison with those untreated. Our results suggest that PPD is an important platelet primer predisposing platelets to promote thrombus formation in response to vascular injury. This should prompt the authorities to consider controlling the marketing of this product.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115623141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Yoshioka, Haruki Usuda, T. Nonogaki, S. Onosaka
Carbon tetrachloride (CCl4) is commonly used as a chemical inducer of experimental liver injury. Several compounds have been demonstrated to attenuate the hepatic damage caused by sublethal doses of CCl4. However, rescue from lethal toxicity of CCl4 has not been reported. In the present study, we evaluated the protective effect of metallothionein (MT), an endogenous scavenger of free radicals, on CCl4-induced lethal toxicity of mice. To induce MT production in male ddY mice, we administered Zn (as ZnSO4) at 50 mg/kg as a once-daily subcutaneous injection for 3 days prior to a single intraperitoneal administration of 4 g/kg CCl4. Animals were observed for mortality every 3 hr for 24 hr after CCl4 injection. Liver damage was assessed by determining (in a subset of these mice) blood levels of alanine aminotransferase (ALT; a marker of liver injury) and liver histopathology at 6 hr after CCl4 injection. Our results showed that three times pretreatment with Zn yielded > 40-fold induction of hepatic MT protein levels compared to control group. Zn pretreatment completely abolished the CCl4-induced mortality of mice. We also found that pretreatment of mice with Zn significantly decreased the ALT levels and reduced the histological liver damage as assessed at 6 hr post-CCl4. These findings suggest that prophylaxis with Zn protects mice from CCl4-induced acute hepatic toxicity and mortality, presumably by induction of radical-scavenging MT.
{"title":"Carbon tetrachloride-induced lethality in mouse is prevented by multiple pretreatment with zinc sulfate.","authors":"H. Yoshioka, Haruki Usuda, T. Nonogaki, S. Onosaka","doi":"10.2131/jts.41.55","DOIUrl":"https://doi.org/10.2131/jts.41.55","url":null,"abstract":"Carbon tetrachloride (CCl4) is commonly used as a chemical inducer of experimental liver injury. Several compounds have been demonstrated to attenuate the hepatic damage caused by sublethal doses of CCl4. However, rescue from lethal toxicity of CCl4 has not been reported. In the present study, we evaluated the protective effect of metallothionein (MT), an endogenous scavenger of free radicals, on CCl4-induced lethal toxicity of mice. To induce MT production in male ddY mice, we administered Zn (as ZnSO4) at 50 mg/kg as a once-daily subcutaneous injection for 3 days prior to a single intraperitoneal administration of 4 g/kg CCl4. Animals were observed for mortality every 3 hr for 24 hr after CCl4 injection. Liver damage was assessed by determining (in a subset of these mice) blood levels of alanine aminotransferase (ALT; a marker of liver injury) and liver histopathology at 6 hr after CCl4 injection. Our results showed that three times pretreatment with Zn yielded > 40-fold induction of hepatic MT protein levels compared to control group. Zn pretreatment completely abolished the CCl4-induced mortality of mice. We also found that pretreatment of mice with Zn significantly decreased the ALT levels and reduced the histological liver damage as assessed at 6 hr post-CCl4. These findings suggest that prophylaxis with Zn protects mice from CCl4-induced acute hepatic toxicity and mortality, presumably by induction of radical-scavenging MT.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129616865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To identify the sheep red blood cell (SRBC) surface immune-responsive peptides, immuno-reactive fraction of SRBC was detected by SDS-PAGE and western blot analysis with antisera from SRBC-immunized rats. Then the most intense immuno-reactive band on SDS-PAGE was subjected to nanoLC-ESI-MS/MS analysis, and 17 proteins were identified including membrane proteins of erythrocytes such as band 3 anion transport protein isoform 1 (Anion exchange protein 1; AE-1, CD233), Ammonium transporter Rh type A (Rh type A glycoprotein, CD241) and Ankyrin-1 (ANK-1), Spectrin beta chain. Among them, plasma protein AE-1 (CD233) and Rh type A glycoprotein (CD241) have transmembrane domain and correspond to extracellular region in their sequences. These extracellular regions of the plasma membrane proteins are supposed to be major immune-responsive peptides of SRBC in rats. These peptides are promising for the construction of an ELISA system which does not require the processing of SRBC membrane ghosts.
{"title":"Identification of sheep red blood cell (SRBC) surface immune-responsive peptides detected by antisera from SRBC-immunized rats.","authors":"H. Yamanaka, M. Takeyoshi","doi":"10.2131/jts.41.13","DOIUrl":"https://doi.org/10.2131/jts.41.13","url":null,"abstract":"To identify the sheep red blood cell (SRBC) surface immune-responsive peptides, immuno-reactive fraction of SRBC was detected by SDS-PAGE and western blot analysis with antisera from SRBC-immunized rats. Then the most intense immuno-reactive band on SDS-PAGE was subjected to nanoLC-ESI-MS/MS analysis, and 17 proteins were identified including membrane proteins of erythrocytes such as band 3 anion transport protein isoform 1 (Anion exchange protein 1; AE-1, CD233), Ammonium transporter Rh type A (Rh type A glycoprotein, CD241) and Ankyrin-1 (ANK-1), Spectrin beta chain. Among them, plasma protein AE-1 (CD233) and Rh type A glycoprotein (CD241) have transmembrane domain and correspond to extracellular region in their sequences. These extracellular regions of the plasma membrane proteins are supposed to be major immune-responsive peptides of SRBC in rats. These peptides are promising for the construction of an ELISA system which does not require the processing of SRBC membrane ghosts.","PeriodicalId":231048,"journal":{"name":"The Journal of toxicological sciences","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127281837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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