RESUMO
Gap junctional intercellular communication (GJIC) is considered a key biological mechanism to maintain homeostasis in cell differentiation and growth. In addition, as another major signaling pathway associated with cell proliferation and differentiation, Wnt/ß-catenin signaling appears to trigger several cellular responses against injury. The purpose of the present study was to investigate the effects of a known toxic agent, benzo[a]pyrene (BaP), on the regulation and interaction between GJIC and Wnt/ß-catenin signaling. BaP treatment resulted in GJIC inhibition and decreases the major GJIC protein connexin 43 (Cx43) in WB-F344 rat liver epithelial cells. We also found BaP-mediated downregulation of Wnt/ß-catenin signaling related to the PI3K-Akt pathway. To identify the relationship between GJIC and Wnt/ß-catenin signaling, we treated WB-F344 cells with the Wnt agonist CHIR99021 and found that it inhibited GJIC while causing a significant reduction in Cx43 expression at both the mRNA and protein levels, through the repression of promoter activity. This Wnt agonist-mediated GJIC inhibition was confirmed using a small interfering RNA directed against the Wnt antagonist Dact2, indicating that Wnt/ß-catenin signaling negatively regulates GJIC. Despite the inverse correlation between Wnt/ß-catenin signaling and Cx43 promoter activation as indicated by downregulation of ß-catenin nuclear translocation and upregulation of Cx43 promoter activation involving HNF3ß, BaP treatment decreased the Cx43 protein expression, which was associated with protein degradation, possibly through protein kinase C activation. In conclusion, our results revealed the mechanism of BaP-induced inhibition of GJIC and Wnt/ß-catenin signaling. More importantly, linking Wnt/ß-catenin signaling to Cx protein expression will have profound implications in understanding the relationships among different major signaling pathways associated with cell proliferation and differentiation in toxicity.
Assuntos
Conexina 43 , beta Catenina , Ratos , Animais , Conexina 43/metabolismo , Conexina 43/farmacologia , Ratos Endogâmicos F344 , beta Catenina/metabolismo , Via de Sinalização Wnt , Fosfatidilinositol 3-Quinases/metabolismo , Junções Comunicantes/metabolismo , Pirenos/metabolismo , Pirenos/farmacologia , Proteínas Nucleares/metabolismoRESUMO
This study was performed to improve production efficiency at the level of recipient pig and donor nuclei of transgenic cloned pigs used for xenotransplantation. To generate transgenic pigs, human endothelial protein C receptor (hEPCR) and human thrombomodulin (hTM) genes were introduced using the F2A expression vector into GalT-/-/hCD55+ porcine neonatal ear fibroblasts used as donor cells and cloned embryos were transferred to the sows and gilts. Cloned fetal kidney cells were also used as donor cells for recloning to increase production efficiency. Pregnancy and parturition rates after embryo transfer and preimplantation developmental competence were compared between cloned embryos derived from adult and fetal cells. Significantly higher parturition rates were shown in the group of sows (50.0 vs. 4.1%), natural oestrus (20.8 vs. 0%), and ovulated ovary (16.7 vs. 5.6%) compared with gilt, induced and non-ovulated, respectively (P < 0.05). When using gilts as recipients, final parturitions occurred in only the fetal cell groups and significantly higher blastocyst rates (15.1% vs. 21.3%) were seen (P < 0.05). Additionally, gene expression levels related to pluripotency were significantly higher in the fetal cell group (P < 0.05). In conclusion, sows can be recommended as recipients due to their higher efficiency in the generation of transgenic cloned pigs and cloned fetal cells also can be recommended as donor cells through correct nuclear reprogramming.
Assuntos
Clonagem de Organismos , Técnicas de Transferência Nuclear , Animais , Animais Geneticamente Modificados , Blastocisto , Feminino , Fibroblastos , Gravidez , Sus scrofa , SuínosRESUMO
Taurodeoxycholate (TDCA) inhibits various inflammatory responses suggesting potential clinical application. However, the toxicity of TDCA has not been evaluated in detail in vivo. We investigated the acute toxicity and 4-week repeated-dose toxicity of TDCA following intravenous infusion under Good Laboratory Practice regulations. In the sighting study of acute toxicity, one of two rats (one male and one female) treated with 300 mg/kg TDCA died with hepatotoxicity, suggesting that the approximate 50% lethal dose of TDCA is 300 mg/kg. Edema and discoloration were observed at the injection sites of tails when rats were infused with 150 mg/kg or higher amount of TDCA once. In 4-week repeated-dose toxicity study, no treatment-related mortality or systemic changes in hematology and serum biochemistry, organ weights, gross pathology, or histopathology were observed. However, the tail injection site showed redness, discharge, hardening, and crust formation along with histopathological changes such as ulceration, edema, fibrosis, and thrombosis when rats were infused with 20 mg/kg TDCA. Taken together, TDCA induced no systemic toxicity or macroscopic lesions at the injection site at a dose of 10 mg/kg/day, which is 33 times higher than the median effective dose observed in a mouse sepsis model. These findings suggest that TDCA might have a favorable therapeutic index in clinical applications.
Assuntos
Colagogos e Coleréticos/toxicidade , Ácido Taurodesoxicólico/toxicidade , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Colagogos e Coleréticos/administração & dosagem , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Feminino , Infusões Intravenosas , Dose Letal Mediana , Masculino , Ratos , Ratos Sprague-Dawley , Ácido Taurodesoxicólico/administração & dosagem , Testes de Toxicidade Aguda , Testes de Toxicidade SubagudaRESUMO
Sodium taurodeoxycholate (TDCA) has been investigated for various inflammatory disorders such as sepsis. We recently evaluated nonclinical safety profile of TDCA using rats infused intravenously. As a series of preclinical safety investigations, we further conducted toxicity studies with TDCA delivered to dogs via intravenous administration under Good Laboratory Practice regulation in this study. In dose range-finding study (dose escalation study), dogs given with TDCA at a dose of 150 mg/kg showed marked changes in clinical signs, hematology, and serum biochemistry. And biochemical markers of liver damage and local skin lesions were observed following intravenous infusion of 100 mg/kg TDCA, suggesting that 100 mg/kg was chosen as the highest dose of TDCA for 4-week repeated-dose toxicity study using dogs. Despite no treatment-related significant changes in body weight, food consumption, ophthalmoscopy, and urinalysis, skin lesions were observed at the injection site of animals administered with higher than 50 mg/kg of TDCA along with biochemical and histopathological changes associated with liver injury. However, most of off-target effects were found to be reversible since these were recovered after stopping TDCA infusion. These findings indicate that the no-observed-adverse-effect-level (NOAEL) for TDCA in dogs was considered to be 5 mg/kg/d. Taken together, our results provide important toxicological profiles regarding the safe dose of TDCA for drug development or clinical application.
Assuntos
Anti-Inflamatórios/toxicidade , Ácido Taurodesoxicólico/toxicidade , Animais , Anti-Inflamatórios/administração & dosagem , Cães , Relação Dose-Resposta a Droga , Feminino , Masculino , Nível de Efeito Adverso não Observado , Ácido Taurodesoxicólico/administração & dosagem , Testes de Toxicidade Aguda , Testes de Toxicidade SubagudaRESUMO
In vivo animal studies are required by regulatory agencies to investigate drug safety before clinical trials. In this review, we summarize the process of selecting a relevant non-rodent species for preclinical studies. The dog is the primary, default non-rodent used in toxicology studies with multiple scientific advantages, including adequate background data and availability. Rabbit has many regulatory advantages as the first non-rodent for the evaluation of reproductive and developmental as well as local toxicity. Recently, minipigs have increasingly replaced dogs and rabbits in toxicology studies due to ethical and scientific advantages including similarity to humans and breeding habits. When these species are not relevant, nonhuman primates (NHPs) can be used as the available animal models, especially in toxicology studies investigating biotherapeutics. Particularly, based on the phylogenetic relationships, the use of New-World marmosets can be considered before Old-World monkeys, especially cynomolgus with robust historical data. Importantly, the use of NHPs should be justified in terms of scientific benefits considering target affinity, expression pattern, and pharmacological cross-reactivity. Strict standards are required for the use of animals. Therefore, this review is helpful for the selection of appropriate non-rodent in regulatory toxicology studies by providing sufficient regulatory, ethical, and scientific data for each species.
Assuntos
Modelos Animais , Toxicologia/métodos , Animais , Projetos de Pesquisa , Toxicologia/éticaRESUMO
Despite a major role of experimental animals in development of biomedical research, there has been historical controversy surrounding animal research. Along with a strategy of 3Rs, various in vitro methods have been suggested to replace potentially painful animal experiments. In this review, we summarize the use of stem cells as an alternative of animal experimentation in predictive toxicology. There have been continuing researches on stem cells and stem cell-derived tissue-specific cells to develop alternative methods/biomarkers for animal toxicity testing including developmental toxicity, genotoxicity, and tissue-specific toxicity. Along with unique abilities of stem cells including self-renewal, infinite proliferation, and differentiation into multiple lineages, human stem cell-based in vitro systems have been proven valuable to increase predictive power of toxicology through providing with better scientific information related to toxic risks in humans without inter-species variability. In particular, stem cells including induced pluripotent stem cell-based system for personalized toxicological assessment could be a better option as an in vitro model system in comparison with immortalized cells with abnormal phenotype or primary cells with small quantity and batch-to-batch variation. This review will be useful for understanding the current status and future direction in using stem cells as an alternative non-animal method for predictive toxicology.
Assuntos
Células-Tronco/efeitos dos fármacos , Testes de Toxicidade/métodos , Toxicologia/métodos , Experimentação Animal , Alternativas aos Testes com Animais/métodos , Animais , Diferenciação Celular/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Especificidade da Espécie , Células-Tronco/citologiaRESUMO
BACKGROUND: Safety concerns exist for corneal recipients under immunosuppression. We report long-term safety results of porcine corneal xenotransplantation under immunosuppression in nonhuman primates. METHODS: Systemic monitoring data from 49 Chinese rhesus macaques that received pig corneal transplant between 2009 and 2018 were retrospectively reviewed. The recipients were divided into 4 groups depending on the systemic immunosuppressants used: (a) conventional steroid group; costimulation blockade groups ([b] anti-CD154 antibody, [c] anti-CD40 antibody); and (d) commercially available immunosuppressants (anti-CD20 antibody, tacrolimus, basiliximab) group. We compared results of general condition monitoring; hematologic, biochemical, and electrolyte tests; and Rhesus Cytomegalovirus infection monitoring. RESULTS: All recipients recovered from early weight loss. White blood cell counts significantly decreased at 6 months in the steroid and anti-CD154 groups. Abnormal liver and kidney function and electrolyte imbalance were not observed in all groups. The mean value of Rhesus Cytomegalovirus DNA copies was consistently lower than 200 copies/mL, and antibody titers did not change over time in all groups. Tacrolimus-associated thrombotic microangiopathy was developed in one case, which resolved after discontinuation of tacrolimus. In 2017, a simian varicella virus outbreak led to clinical signs in 5 that received immunosuppressive therapies, of which 3 died. CONCLUSION: Costimulatory blockade-based and anti-CD20 antibody/tacrolimus-based immunosuppressive therapies seem to be comparably safe with steroid therapy in nonhuman primates receiving corneal xenotransplantation, as they did not reactivate Rhesus Cytomegalovirus and maintained manageable systemic status. Although reactivation is rare, antiviral prophylaxis for simian varicella virus should be considered in immunocompromised hosts.
Assuntos
Xenoenxertos/efeitos dos fármacos , Terapia de Imunossupressão , Imunossupressores/farmacologia , Tacrolimo/uso terapêutico , Tempo , Animais , Transplante de Córnea/métodos , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Humanos , Tolerância Imunológica/efeitos dos fármacos , Terapia de Imunossupressão/métodos , Transplante das Ilhotas Pancreáticas/métodos , Macaca mulatta/imunologia , Suínos , Transplante Heterólogo/métodosRESUMO
Ecklonia cava (EC) is known to have antioxidant, anti-inflammatory, antidiabetic, and anticancer properties. Despite its wide use and beneficial properties, comprehensive toxicological information regarding EC extract is currently limited. Therefore, the purpose of this study was to investigate acute toxicity, subchronic toxicity, and genotoxicity of enzymatic EC extract according to test guidelines published by Organization for Economic Cooperation and Development. The acute oral LD50 values of this EC extract administered to rats and dogs were estimated to be more than 3000 mg/kg BW. In an oral 13-week toxicity study, changes in body weights of rats exposed to the EC extract up to 3000 mg/kg BW were found to be normal. In addition, repeated doses of EC extract failed to influence any systematic parameters of treatment-related toxic symptoms such as food/water consumption, mortality, urinalysis, hematology, serum biochemistry, organ weight, or histopathology. These results indicated that the no-observed-adverse-effect level for the EC extract was 3000 mg/kg/day for male and female rats. Data obtained from Ames test, chromosome aberration assay, and micronucleus assay indicated that EC extract was not mutagenic or clastogenic. Taken together, these results support the safety of enzymatic EC extract as a potential therapeutic for human consumption against various diseases.
Assuntos
Laminaria/química , Extratos Vegetais/efeitos adversos , Administração Oral , Animais , Cães , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Testes de Mutagenicidade/métodos , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Testes de Toxicidade Aguda/métodos , Testes de Toxicidade Subcrônica/métodosRESUMO
Cinnamomum cassia has been widely used as a natural product to treat diseases in Asia due to its diverse pharmacological functions including anti-inflammatory, anti-oxidant, anti-microbial, anti-diabetic, and anti-tumor effects. Despite its ethnomedicinal benefits, little information regarding its toxicity is currently available. The aim of this study was to evaluate its potential long-term toxicity and genotoxicity in compliance with test guidelines of the Organization for Economic Cooperation and Development. A 13-week repeat-dose oral toxicity study revealed that body weights of rats were normal after receiving cinnamon extract at up to 2000â¯mg/kg. High-dose intake of cinnamon extract (2000â¯mg/kg) showed potential nephrotoxicity and hepatotoxicity to both males and females as evidenced by obvious increases of kidney/liver weight along with a small but statistically elevation of total cholesterol level. Overall findings from genetic toxicity testing battery including Ames test, in vitro mammalian cell micronucleus assay, and in vivo bone marrow micronucleus assay indicated that cinnamon extract was not mutagenic or clastogenic. In conclusion, cinnamon extract may possess potential nephrotoxicity and hepatotoxicity at dose higher than its recommended daily safe dose. Further study is needed to clarify the mechanism involved in its induction of liver and kidney injury.
Assuntos
Cinnamomum aromaticum , Extratos Vegetais/toxicidade , Animais , Feminino , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Testes de Mutagenicidade , Tamanho do Órgão/efeitos dos fármacos , Casca de Planta , Ratos Endogâmicos F344 , Testes de Toxicidade Aguda , Testes de Toxicidade SubcrônicaRESUMO
BACKGROUND: Seed of mature Croton tiglium Linne, also known as Tiglium seed (TS), has been widely used as a natural product due to its several health beneficial properties including anti-tumor and antifungal activities. Despite its ethnomedicinal beneficial properties, toxicological information regarding TS extract, especially its long-term toxicity, is currently limited. Therefore, the objective of the present study was to evaluate acute and subchronic toxicity of TS extract in rats after oral administration following test guidelines of the Organization for Economic Cooperation and Development (OECD). METHODS: Toxicological properties of TS extract were evaluated by toxicity assays to determine its single-dose acute toxicity (125, 250, 500, 1000, or 2000 mg/kg), 14-day repeated-dose toxicity (125, 250, 500, 1000, or 2000 mg/kg) and 13-week repeated-dose toxicity (31.25, 62.5, 125, 250, and 500 mg/kg) in Sprague-Dawley rats and F344 rats. Hematological, serum biochemical, and histopathological parameters were analyzed to determine its median lethal dose (LD50) and no-observed-adverse-effect-level (NOAEL). RESULTS: Oral single dose up to 2000 mg/kg of TS extract resulted in no mortalities or abnormal clinical signs. In 13-week toxicity study, TS extract exhibited no dose-related changes (mortality, body weight, food/water consumption, hematology, clinical biochemistry, organ weight, or histopathology) at dose up to 500 mg/kg, the highest dosage level suggested based on 14-day repeat-dose oral toxicity study. CONCLUSION: Acute oral LD50 of TS extract in rats was estimated to be greater than 2000 mg/kg. NOAEL of TS extract administered orally was determined to be 500 mg/kg/day in both male and female rats. Results from these acute and subchronic toxicity assessments of TS extract under Good Laboratory Practice regulations indicate that TS extract appears to be safe for human consumption.
Assuntos
Croton/química , Extratos Vegetais/toxicidade , Sementes/química , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Masculino , Tamanho do Órgão/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Testes de ToxicidadeRESUMO
Artemisia capillaris (AC) has been used as an alternative therapy in obesity, atopic dermatitis, and liver diseases through several biological activity including anti-steatotic, antioxidant, and anti-inflammatory activities. Despite its ethnomedicinal benefits, no sufficient background information is available about the long-term safety and genotoxicity of the AC extract. Therefore, the present study was carried out to investigate the 13-week subchronic toxicity and genotoxicity of the AC extract according to the test guidelines published by the Organization for Economic Cooperation and Development. In the 13-week toxicity study using doses of 25, 74, 222, 667, and 2000 mg/kg body weight, oral administration of the AC extract in male and female rats did not result in any significant adverse effects in food/water consumption, body weight, mortality, hematology, serum biochemistry, organ weight and histopathology. Accordingly, the no-observed-adverse-effect level in rats of both genders was established for the AC extract at 2000 mg/kg/day, the highest dose level tested. In addition, the AC extract was not genotoxic in a battery of tests including Ames test, in vitro chromosome aberration assay and in vivo micronucleus assay. In conclusion, we demonstrated that the AC extract is considered as a safe traditional medicine for human consumption.
Assuntos
Artemisia/química , Extratos Vegetais/toxicidade , Administração Oral , Animais , Peso Corporal , Ingestão de Líquidos , Ingestão de Alimentos , Feminino , Masculino , Testes para Micronúcleos , Nível de Efeito Adverso não Observado , Tamanho do Órgão , Extratos Vegetais/administração & dosagem , Ratos , Ratos Sprague-Dawley , Testes de Toxicidade SubcrônicaRESUMO
Koji products have been considered as an effective fermented food consumed in East Asia with many health benefits. Particularly, rice koji with Aspergillus terreus (RAT) has been reported to be able to prevent hyperlipidemia and hepatic steatosis through regulating cholesterol synthesis. Despite its biological activities, there is a lack of comprehensive information to give an assurance of its safety. Therefore, the objective of this study was to perform a series of toxicological studies (repeated dose oral toxicity and genotoxicity) according to test guidelines published by the Organization for Economic Cooperation and Development. Along with acute toxicity study using rats and beagle dogs, a 13-week toxicity study revealed no clear RAT-related toxic changes, including body weight, mortality, hematology, serum biochemistry, organ weight, and histopathology after oral administration at doses of 500, 1000, and 2000 mg/kg BW. The no-observed-adverse-effect level of RAT was considered to be more than 2000 mg/kg BW/day in rats of both genders. In addition, potential genotoxicity was evaluated using a standard battery of tests (Ames test, chromosome aberration assay, and micronucleus assay) which revealed that RAT showed no genotoxicity. Accordingly, these results suggest that RAT is a safe and non-toxic functional food for human consumption at proper dose.
Assuntos
Aspergillus oryzae , Nível de Efeito Adverso não Observado , Oryza/microbiologia , Oryza/toxicidade , Administração Oral , Animais , Cães , Humanos , Testes para Micronúcleos , Testes de Mutagenicidade , Ratos , Testes de Toxicidade SubcrônicaRESUMO
Ixeris dentata (Thunb. Ex Thunb.) Nakai (ID) exhibits various physiological activities, and its related plant derived-products are expected to represent promising cancer therapeutic agents. However, the anticancer effects of ID extract on breast cancer cells classified as estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are still unknown. In this study, we investigated the anti-cancer effects and analyzed the molecular mechanism of ID extract in T47D, MCF-7 (ER-, PR-positive, HER2-negative), SK-BR-3(ER-, PR-negative, HER2-positive), and MDA-MB-231 (Triple-negative) through in vitro studies. Additionally, we examined its anti-tumor effects through in vivo studies. Our findings indicated that ID extract-induced apoptosis was mediated via various survival pathways on four breast cancer cells by identifying the factors including Bcl-2 family, phospho-Akt and phospho-nuclear factor-κB (NF-κB). Based on in vitro findings that induced apoptosis via Akt-NF-κB signaling, we investigated the effects of ID extract on mice bearing MDA-MB-231 cells. The results showed that ID extract significantly decreased MDA-MB-231 tumor volume and weight via inducing apoptosis by suppressing phospho-Akt. Overall, these results indicate that ID extract induces apoptosis through the Akt-NFκB signaling pathway in MDA-MB-231 breast cancer cells and tumors, and it may serve as a therapeutic agent for triple-negative human breast cancer.
Assuntos
Apoptose/efeitos dos fármacos , Asteraceae/química , Neoplasias da Mama/patologia , NF-kappa B/metabolismo , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Administração Oral , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Feminino , Antígeno Ki-67/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Extratos Vegetais/administração & dosagem , Extratos Vegetais/toxicidadeRESUMO
For cells to exit from pluripotency and commit to a lineage, the circuitry of a core transcription factor (CTF) network must be extinguished in an orderly manner through epigenetic modifications. However, how this choreographed epigenetic remodeling at active embryonic stem cell (ESC) genes occurs during differentiation is poorly understood. In this study, we demonstrate that C-terminal binding protein 2 (Ctbp2) regulates nucleosome remodeling and deacetylation (NuRD)-mediated deacetylation of H3K27 and facilitates recruitment of polycomb repressive complex 2 (PRC2)-mediated H3K27me3 in active ESC genes for exit from pluripotency during differentiation. By genomewide analysis, we found that Ctbp2 resides in active ESC genes and co-occupies regions with ESC CTFs in undifferentiated ESCs. Furthermore, ablation of Ctbp2 effects inappropriate gene silencing in ESCs by sustaining high levels of H3K27ac and impeding H3K27me3 in active ESC genes, thereby sustaining ESC maintenance during differentiation. Thus, Ctbp2 preoccupies regions in active genes with the NuRD complex in undifferentiated ESCs that are directed toward H3K27me3 by PRC2 to induce stable silencing, which is pivotal for natural lineage commitment.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Epigênese Genética/fisiologia , Histonas/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Fosfoproteínas/metabolismo , Proteínas Repressoras/metabolismo , Oxirredutases do Álcool , Animais , Linhagem Celular , Montagem e Desmontagem da Cromatina/fisiologia , Proteínas Correpressoras , Proteínas de Ligação a DNA/genética , Histonas/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Nucleossomos/genética , Nucleossomos/metabolismo , Fosfoproteínas/genética , Proteínas Repressoras/genéticaRESUMO
In vitro testing methods for classifying sensitizers could be valuable alternatives to in vivo sensitization testing using animal models, such as the murine local lymph node assay (LLNA) and the guinea pig maximization test (GMT), but there remains a need for in vitro methods that are more accurate and simpler to distinguish skin sensitizers from non-sensitizers. Thus, the aim of our study was to establish an in vitro assay as a screening tool for detecting skin sensitizers using the human keratinocyte cell line, HaCaT. HaCaT cells were exposed to 16 relevant skin sensitizers and 6 skin non-sensitizers. The highest dose used was the dose causing 75% cell viability (CV75) that we determined by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The levels of extracellular production of interleukin-1α (IL-1α) and IL-6 were measured. The sensitivity of IL-1α was 63%, specificity was 83% and accuracy was 68%. In the case of IL-6, sensitivity: 69%, specificity: 83% and accuracy: 73%. Thus, this study suggests that measuring extracellular production of pro-inflammatory cytokines IL-1α and IL-6 by human HaCaT cells may potentially classify skin sensitizers from non-sensitizers. Copyright © 2015 John Wiley & Sons, Ltd.
Assuntos
Interleucina-1alfa/metabolismo , Interleucina-6/metabolismo , Queratinócitos/efeitos dos fármacos , Pele/efeitos dos fármacos , Xenobióticos/toxicidade , Alternativas aos Testes com Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dermatite Alérgica de Contato/patologia , Humanos , Interleucina-1alfa/genética , Irritantes/toxicidade , Queratinócitos/metabolismo , Ensaio Local de Linfonodo , Pele/citologia , Pele/metabolismo , Sais de Tetrazólio/metabolismo , Tiazóis/metabolismoRESUMO
As a well-known traditional medicine, Angelica gigas (AG) and its active constituents, including decursin and decursinol, have been shown to possess several health beneficial properties such as anti-bacterial, immunostimulating, anti-tumor, neuroprotective, anti-nociceptive and anti-amnestic activities. However, there is lack of toxicity studies to assess potential toxicological concerns, especially long-term toxicity and genotoxicity, regarding the AG extract. Therefore, the safety of AG extract was assessed in subchronic toxicity and genotoxicity assays in accordance with the test guidelines published by the Organization for Economic Cooperation and Development. In a subchronic toxicity study for 13 weeks (125, 250, 500, 1000 and 2000 mg/kg body weight, delivered by gavage), data revealed no significant adverse effects of the AG extract in food consumption, body weight, mortality, hematology, biochemistry, necropsy, organ weight and histopathology throughout the study in male and female rats. These results suggest that no observed adverse effect level of the AG extract administered orally was determined to be greater than 2000 mg/kg/day, the highest dose tested. In addition, a battery of tests including Ames test, in vitro chromosome aberration assay and in vivo micronucleus assay suggested that the AG extract was not genotoxic. In conclusion, the AG extract appears to be safe as a traditional medicine for oral consumption.
Assuntos
Angelica , Extratos Vegetais/toxicidade , Animais , Linhagem Celular , Cricetulus , Feminino , Masculino , Camundongos Endogâmicos ICR , Testes de Mutagenicidade , Nível de Efeito Adverso não Observado , Raízes de Plantas , Ratos Endogâmicos F344 , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Testes de Toxicidade Subaguda , Testes de Toxicidade SubcrônicaRESUMO
Although Sophorae radix (SR) has been traditionally used as a treatment for various clinical symptoms, a comprehensive investigation of its safety has not yet been carried out. Therefore, we present an evaluation of the toxicity of the SR extract that was performed according to the Organization for Economic Cooperation and Development test guidelines for subchronic toxicity and genotoxicity. In an oral subchronic study for 13 weeks, the repeated treatment of rats with 429 or 1500 mg/kg of the SR extract induced a dose-related change in body weight. In particular, the SR extract was observed to exert a significant increase in liver weight along with an increase in serum alkaline phosphatase and alanine transaminase. A small but statistically significant reductions in red blood cell, hemoglobin, and hematocrit levels in the SR extract-treated rats suggest the possibility that anemia, accompanied by liver injury, was at least partially induced. These findings indicate the no-observed-adverse-effect-level for the SR extract was considered to be 10mg/kg/d. And, the data obtained from the chromosome aberration assay showed that SR extract might be considered to be a weak clastogen although no significant micronucleus induction was observed in vivo. Despite the benefits that SR extract can exhibit, this study indicates that SR extract may possess hepatotoxic and genotoxic potential.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Aberrações Cromossômicas/induzido quimicamente , Testes de Mutagenicidade , Extratos Vegetais/toxicidade , Sophora , Testes de Toxicidade Subcrônica , Administração Oral , Anemia/sangue , Anemia/induzido quimicamente , Animais , Biomarcadores/sangue , Peso Corporal/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Masculino , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Testes de Mutagenicidade/métodos , Nível de Efeito Adverso não Observado , Fitoterapia , Extratos Vegetais/administração & dosagem , Plantas Medicinais , Ratos Endogâmicos F344 , Medição de Risco , Fatores de TempoRESUMO
The rhizomes of Cimicifuga species, including Cimicifuga heracleifolia (CH), have been widely used as antipyretic, analgesic, and anti-inflammatory agents in oriental countries. However, information regarding its toxicity, especially long-term toxicity and genotoxicity, is limited. Therefore, we performed the subchronic toxicity and genotoxicity assays of the CH extract in accordance with the test guidelines published by the Organization for Economic Cooperation and Development. In a 13-week repeat-dose oral toxicity study, the CH extract did not influence body weight, food/water consumption, mortality, clinical signs, and urinalysis throughout the study. Noteworthy, the CH extract groups exhibited increased liver weights along with serum alanine transaminase activity rise at doses of 667 and 2000 mg/kg in females. No-observed-adverse-effect-level of the CH extract administered orally was concluded to be 2000 mg/kg body weight/day for male rats and 222 mg/kg body weight/day for female rats. The CH extract did not exert a mutagenic or clastogenic effect in Ames test, in vitro chromosome aberration assay and in vivo micronucleus assay. Overall findings of the subchronic toxicity study indicate for the first time that the CH extract may possess hepatotoxic potential in female rats, suggesting that further mechanistic studies should be performed to have more conclusive results on hepatotoxic potential of the CH extract.
Assuntos
Cimicifuga/efeitos adversos , Extratos Vegetais/efeitos adversos , Animais , Peso Corporal/efeitos dos fármacos , Aberrações Cromossômicas/induzido quimicamente , Relação Dose-Resposta a Droga , Feminino , Masculino , Testes para Micronúcleos/métodos , Testes de Mutagenicidade/métodos , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Testes de Toxicidade Subcrônica/métodosRESUMO
Genkwa Flos (GF) is a well-known traditional medicine that is used to treat tumors and to relieve inflammation-related symptoms. GF tends to be taken in repeated doses for a long period of time, and although many reports on the toxicity of raw GF have led to a processing method to remove the toxicity, little information is currently available with regards to the toxic effects of subchronic exposure to processed GF (PGF). The aim of this study was to assess the possible genotoxicity and subchronic toxicity of PGF extract in accordance with the test guidelines published by the Organization for Economic Cooperation and Development. A 13-week repeat-dose oral toxicity study was carried out with rats, and the change in body weight observed in rats receiving PGF extract was normal. It is worth noting that the PGF extract groups exhibited an obvious increase in liver weight along with a significant increase in serum alkaline phosphatase activity at doses of 667 and 2000mg/kg, providing evidence of hepatotoxic potential. More importantly, the results of the Ames test indicated that the PGF extract presented a mutagenic potential. Altogether, these results are the first to determine the subchronic toxicity and genotoxicity of the PGF extract, indicating that when GF is used for medicinal purposes, the period of use should be considered despite the manner in which the extract is processed.
Assuntos
Daphne , Mutagênicos/toxicidade , Extratos Vegetais/toxicidade , Ácido Acético/química , Fosfatase Alcalina/sangue , Flores/química , Fígado/efeitos dos fármacos , Fígado/patologia , Testes de Mutagenicidade , Tamanho do Órgão/efeitos dos fármacos , Testes de Toxicidade Subaguda , Testes de Toxicidade SubcrônicaRESUMO
Although silicon dioxide (SiO2), silver (Ag) and iron oxide (Fe2O3) nanoparticles are widely used in diverse applications from food to biomedicine, in vivo toxicities of these nanoparticles exposed via the oral route remain highly controversial. To examine the systemic toxicity of these nanoparticles, well-dispersed nanoparticles were orally administered to Sprague-Dawley rats daily over a 13-week period. Based on the results of an acute toxicity and a 14-day repeated toxicity study, 975.9, 1030.5 and 1000 mg kg(-1) were selected as the highest dose of the SiO2 , Ag and Fe2O3 nanoparticles, respectively, for the 13-week repeated oral toxicity study. The SiO2 and Fe2O3 nanoparticles did not induce dose-related changes in a number of parameters associated with the systemic toxicity up to 975.9 and 1000 mg kg(-1) , respectively, whereas the Ag nanoparticles resulted in increases in serum alkaline phosphatase and calcium as well as lymphocyte infiltration in liver and kidney, raising the possibility of liver and kidney toxicity induced by the Ag nanoparticles. Compared with the SiO2 and Fe2O3 nanoparticles showing no systemic distribution in all tissues tested, the Ag concentration in sampled blood and organs in the Ag nanoparticle-treated group significantly increased with a positive and/or dose-related trend, meaning that the systemic toxicity of the Ag nanoparticles, including liver and kidney toxicity, might be explained by extensive systemic distribution of Ag originating from the Ag nanoparticles. Our current results suggest that further study is required to identify that Ag detected outside the gastrointestinal tract were indeed a nanoparticle form or ionized form.