RESUMO
Calcitriol, the active metabolite of vitamin D, has been widely studied for its preventive and therapeutic activity against several cancers including oral squamous cell carcinoma (OSCC). However, the impact of dietary vitamin D supplementation on initiation and progression of OSCC is unclear. To address this gap in knowledge, we conducted preclinical trials using the 4-nitroquinoline-1-oxide 4NQO carcinogen model of oral carcinogenesis. Female C57BL/6 mice were maintained on one of three vitamin D diets [25 IU, 100 IU, 10,000 IU] and exposed to 4NQO in drinking water for 16 weeks followed by regular water for 10 weeks. Body weight measurements obtained through the study duration did not reveal any differences between the three diets. Animals on 100 IU diet showed lower incidence of high-grade dysplasia/OSCC and higher CD3 + T cells compared to animals on 25 IU and 10,000 IU diets. Serum 25OHD3 levels were highest in animals on 10,000 IU diet at week 0 prior to carcinogen exposure but showed â¼50 % reduction at week 26. Histologic evaluation revealed highest incidence of OSCC in animals maintained on 10,000 IU diet. Animals on 100 IU and 10,000 IU diets showed higher vitamin D receptor VDR and CYP24A1 immunostaining in high-grade dysplastic lesions and OSCC compared to normal tongue. Validation studies performed in a 4NQO-derived OSCC model showed that short-term treatment of animals on a 25 IU diet with calcitriol significantly inhibited tumor growth compared to controls but did not affect tumor growth in animals on reference diet 1000 IU. Collectively, our results highlight the complex dynamics between vitamin D status and oral carcinogenesis. Our observations also suggest that therapeutic benefits of short-term calcitriol treatment may be more pronounced in vitamin D deficient hosts.
Assuntos
Carcinoma de Células Escamosas/dietoterapia , Neoplasias Bucais/dietoterapia , Receptores de Calcitriol/genética , Vitamina D3 24-Hidroxilase/genética , Vitamina D/genética , 4-Nitroquinolina-1-Óxido/toxicidade , Animais , Peso Corporal , Calcitriol/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/patologia , Suplementos Nutricionais/efeitos adversos , Modelos Animais de Doenças , Progressão da Doença , Humanos , Camundongos , Neoplasias Bucais/sangue , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/patologia , Vitamina D/sangue , Deficiência de Vitamina D/dietoterapia , Deficiência de Vitamina D/genética , Deficiência de Vitamina D/patologiaRESUMO
BACKGROUND/AIM: The aim of this study was to evaluate the chemoprotective potential of grape skin extract following rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide (4NQO). MATERIALS AND METHODS: Male Wistar rats were distributed into four groups (n=5, per group): Control Group: free access to commercial diet and drinking water for 12 weeks; 4NQO Group: received 4NQO diluted in drinking water daily, for 12 weeks; Grape Skin Extract Group: free access to water and received grape skin extract incorporated with diet for 12 weeks; 4NQO + Grape Skin Extract Group: received 4NQO in drinking water daily and grape extract incorporated with diet for 12 weeks. RESULTS: Animals treated with grape skin extract revealed a significant reduction in epithelial dysplasia. Also, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and ki-67 immunoexpression was reduced in animals treated with grape skin extract. Western blot analysis showed a significant decrease of p-NFκB p50 and MyD88 protein expression in the groups treated with grape skin extract. Copper-zinc superoxide dismutase, manganese superoxide dismutase, and catalase gene expression did not present any statistically significant differences (p>0.05). CONCLUSION: Grape skin extract displayed chemopreventive activity in oral carcinogenesis assays as depicted by its antioxidant, anti-proliferative and anti-inflammatory properties.
Assuntos
Carcinogênese/efeitos dos fármacos , Neoplasias Bucais/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Vitis/química , 4-Nitroquinolina-1-Óxido/toxicidade , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Catalase/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/patologia , Extratos Vegetais/química , Ratos , Superóxido Dismutase/genética , Superóxido Dismutase-1/genéticaRESUMO
Abstract Salacia crassifolia (Mart. Ex. Schult.) G. Don. is a bush which belongs to Celastraceae family and occurs specially in Brazilian Cerrado. Its leaves, stem, seeds and fruits are popularly used for several medicinal purposes, such as antitumoral, antirheumatic, anti-inflammatory and antimicrobial. In this study, the mutagenic and antimutagenic activities of S. crassifolia stem bark fractions (hexane, ethyl acetate and hydroalcoholic) were evaluated by the Ames mutagenicity assay in Salmonella typhimurium TA98 and TA100 strains. By the obtained results, all S. crassifolia fractions did not significantly increase the number of prototrophic revertants for histidine (His+) in both S. typhimurium strains tested (p > 0.05), suggesting absence of mutagenicity. Regarding antimutagenicity, the fractions ethyl acetate and hydroalcoholic significantly decreased the number of His+ revertants colonies induced by positive control for strain TA98 (p < 0.05), demonstrating protection against mutagenicity induced by 4-nitroquinolile1-oxide, whereas the hexane fraction did not show antimutagenic effect in this strain. In the TA100 strain, all fractions of S. crassifolia protected DNA against the harmful action of sodium azide, and the hexane fraction exhibited the greatest protection in this work. Thus, it's possible conclude that the fractions of S. crassifolia tested in this study could be used in chemoprevention.
Resumo Salacia crassifolia (Mart. Ex. Schult.) G. Don. é uma árvore que pertence à família Celastraceae e ocorre especialmente no Cerrado Brasileiro. Suas folhas, caule, sementes e frutos são popularmente utilizados para vários fins medicinais, tais como antitumoral, antirreumático, anti-inflamatório e antimicrobiano. Neste estudo, nós avaliamos as atividades mutagênica e antimutagênica de frações da casca do caule de S. crassifolia (hexânica, acetato de etila e hidroalcoólica) pelo ensaio de mutagenicidade de Ames em Salmonella typhimurium, cepas TA98 e TA100. Pelos resultados obtidos todas as frações de S. crassifolia não aumentaram significativamente o número de revertentes prototróficas para histidina (His+) em ambas as cepas de S. typhimurium testadas (p > 0.05), sugerindo ausência de mutagenicidade. Em relação à antimutagenicidade, as frações acetate de etila e hidroalcoólica reduziram significativamente o número de colônias revertentes His+ induzidas pelo controle positive para a cepa TA98 (p < 0.05), demonstrando sua ação protetora contra a mutagenicidade induzida por 4-nitroquinolile1-oxide, enquanto a fração hexânica não demonstrou efeito antimutagênico nesta cepa. Na cepa TA100, todas as frações de S. crassifolia protegeram o DNA contra a ação lesiva de azida sódica, e a fração hexânica exibiu a maior proteção desse trabalho. Assim, concluímos que as frações de S. crassifolia testadas neste estudo poderiam ser utilizadas em quimioprevenção.
Assuntos
Antimutagênicos/farmacologia , Salacia/química , Mutagênicos/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Extratos Vegetais/toxicidade , Extratos Vegetais/farmacologia , Testes de Mutagenicidade , 4-Nitroquinolina-1-Óxido/toxicidadeRESUMO
Salacia crassifolia (Mart. Ex. Schult.) G. Don. is a bush which belongs to Celastraceae family and occurs specially in Brazilian Cerrado. Its leaves, stem, seeds and fruits are popularly used for several medicinal purposes, such as antitumoral, antirheumatic, anti-inflammatory and antimicrobial. In this study, the mutagenic and antimutagenic activities of S. crassifolia stem bark fractions (hexane, ethyl acetate and hydroalcoholic) were evaluated by the Ames mutagenicity assay in Salmonella typhimurium TA98 and TA100 strains. By the obtained results, all S. crassifolia fractions did not significantly increase the number of prototrophic revertants for histidine (His+) in both S. typhimurium strains tested (p > 0.05), suggesting absence of mutagenicity. Regarding antimutagenicity, the fractions ethyl acetate and hydroalcoholic significantly decreased the number of His+ revertants colonies induced by positive control for strain TA98 (p < 0.05), demonstrating protection against mutagenicity induced by 4-nitroquinolile1-oxide, whereas the hexane fraction did not show antimutagenic effect in this strain. In the TA100 strain, all fractions of S. crassifolia protected DNA against the harmful action of sodium azide, and the hexane fraction exhibited the greatest protection in this work. Thus, it's possible conclude that the fractions of S. crassifolia tested in this study could be used in chemoprevention.
Assuntos
Antimutagênicos/farmacologia , Mutagênicos/toxicidade , Salacia/química , 4-Nitroquinolina-1-Óxido/toxicidade , Testes de Mutagenicidade , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genéticaRESUMO
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, and tobacco is one of the most common factors for HNSCC of the oral cavity. We have previously observed that bitter melon (Momordica charantia) extract (BME) exerts antiproliferative activity against several cancers including HNSCC. In this study, we investigated the preventive role of BME in 4-nitroquinoline 1-oxide (4-NQO) carcinogen-induced HNSCC. We observed that BME feeding significantly reduced the incidence of 4-NQO-induced oral cancer in a mouse model. Histologic analysis suggested control 4-NQO-treated mouse tongues showed neoplastic changes ranging from moderate dysplasia to invasive squamous cell carcinoma, whereas no significant dysplasia was observed in the BME-fed mouse tongues. We also examined the global transcriptome changes in normal versus carcinogen-induced tongue cancer tissues, and following BME feeding. Gene ontology and pathway analyses revealed a signature of biological processes including "immune system process" that is significantly dysregulated in 4-NQO-induced oral cancer. We identified elevated expression of proinflammatory genes, s100a9, IL23a, IL1ß and immune checkpoint gene PDCD1/PD1, during oral cancer development. Interestingly, BME treatment significantly reduced their expression. Enhancement of MMP9 ("ossification" pathway) was noted during carcinogenesis, which was reduced in BME-fed mouse tongue tissues. Our study demonstrates the preventive effect of BME in 4-NQO-induced carcinogenesis. Identification of pathways involved in carcinogen-induced oral cancer provides useful information for prevention strategies. Together, our data strongly suggest the potential clinical benefits of BME as a chemopreventive agent in the control or delay of carcinogen-induced HNSCC development and progression. Cancer Prev Res; 11(4); 191-202. ©2017 AACRSee related editorial by Rao, p. 185.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Carcinoma de Células Escamosas/prevenção & controle , Modelos Animais de Doenças , Fenômenos do Sistema Imunitário/efeitos dos fármacos , Momordica charantia/química , Neoplasias Bucais/prevenção & controle , Extratos Vegetais/farmacologia , Animais , Apoptose , Carcinógenos/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/patologia , Proliferação de Células , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/imunologia , Neoplasias Bucais/patologia , Células Tumorais CultivadasRESUMO
Geraniol, an acyclic monoterpene found in lemon grass and aromatic herb oil, has been shown to exert antitumor and antioxidant activities against various cancer types. The objective of this study was to investigate the potential chemoprotective role of geraniol against 4-nitroquinoline-1-oxide (4NQO)-induced oral carcinogenesis in male Wistar rats and furthermore to study anti-inflammatory mechanisms of action through possible NF-κB signaling. 4NQO was administered to rats at the dose of 50 ppm through drinking water to induce tongue cancer in 20 weeks. 4NQO provoked inflammation by upregulating the expressions of the p65 subunit nuclear factor kappa-ß (NF-κB) in the nucleus, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Additionally, staining for immature and mature mast cells in cancer niche by toluidine blue staining and alcian blue-safranin staining showed more accumulation. Co-treatment of geraniol 200 mg/kg b.w. showed a significant decrease in the level of p65 NF-κB in the nucleus, and this might be due to the inhibition of NF-κB activation/translocation into nucleus, which was further confirmed by decreased immature and mature mast cell density and the expression of inflammatory downstream mediators such as TNF-α, IL-1ß, COX-2, and iNOS. Collectively, our results suggested that geraniol as a potential anti-inflammatory agent having the capability to obstruct 4NQO initiated NF-κB activation and modulated the expression of inflammatory mediators.
Assuntos
Anticarcinógenos/uso terapêutico , Carcinógenos/toxicidade , Regulação para Baixo/efeitos dos fármacos , NF-kappa B/metabolismo , Quinolonas/toxicidade , Terpenos/farmacologia , Neoplasias da Língua/prevenção & controle , 4-Nitroquinolina-1-Óxido/toxicidade , Monoterpenos Acíclicos , Animais , Contagem de Células Sanguíneas , Western Blotting , Inflamação/complicações , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Ratos , Ratos Wistar , Neoplasias da Língua/induzido quimicamente , Neoplasias da Língua/complicações , Neoplasias da Língua/metabolismoRESUMO
EMS1 (chromosome eleven, band q13, mammary tumor and squamous cell carcinoma-associated gene 1) gene amplification and the concomitant cortactin overexpression have been reported to associate with poor prognosis and tumor metastasis. In this study, we examined cortactin expression by immunohistochemistry in human oral tumors and murine tongue tumors which were induced by the carcinogen 4-nitroquinoline 1-oxide (4-NQO). The immunostaining results show over- to moderate expression of cortactin in 85% (104/122) of oral squamous cell carcinoma (OSCC) tissues and in all 15 leukoplakia tissues examined. Further, statistical analysis indicates that cortactin overexpression appears to be a predictor for shorter survival and poorer prognosis in OSCC patients. In an animal model, cortactin is shown to upregulate in infiltrating squamous cell carcinoma, papilloma, and epithelia with squamous hyperplasia, indicating that cortactin induction is an early event during oral carcinogenesis. It is suggested that cortactin expression is mediated in the progression of pre-malignancy to papilloma, based on earlier cortactin induction in pre-malignancy preceding cyclin D1 in papilloma. In conclusion, cortactin overexpression is frequently observed in human OSCC and mouse tongue tumors. Thus, cortactin may have an important role in the development of oral tumors in human and mice. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 799-812, 2017.
Assuntos
Carcinoma de Células Escamosas/patologia , Cortactina/metabolismo , Neoplasias Bucais/patologia , 4-Nitroquinolina-1-Óxido/toxicidade , Adulto , Animais , Areca/química , Areca/metabolismo , Carcinogênese , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Cortactina/genética , Ciclina D1/metabolismo , Modelos Animais de Doenças , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Leucoplasia/metabolismo , Leucoplasia/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Neoplasias Bucais/metabolismo , Neoplasias Bucais/mortalidade , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Reação em Cadeia da Polimerase , Prognóstico , Modelos de Riscos Proporcionais , Neoplasias da Língua/induzido quimicamente , Neoplasias da Língua/metabolismo , Neoplasias da Língua/patologia , Regulação para Cima/efeitos dos fármacosRESUMO
Despite many years of studies, the debate on genotoxic effects of radiofrequency electromagnetic fields (RF-EMF) continues. To systematically evaluate genotoxicity of RF-EMF, this study examined effects of RF-EMF on DNA damage and cellular behavior in different neurogenic cells. Neurogenic A172, U251, and SH-SY5Y cells were intermittently (5 min on/10 min off) exposed to 1800 MHz RF-EMF at an average specific absorption rate (SAR) of 4.0 W/kg for 1, 6, or 24 h. DNA damage was evaluated by quantification of γH2AX foci, an early marker of DNA double-strand breaks. Cell cycle progression, cell proliferation, and cell viability were examined by flow cytometry, hemocytometer, and cell counting kit-8 assay, respectively. Results showed that exposure to RF-EMF at an SAR of 4.0 W/kg neither significantly induced γH2AX foci formation in A172, U251, or SH-SY5Y cells, nor resulted in abnormal cell cycle progression, cell proliferation, or cell viability. Furthermore, prolonged incubation of these cells for up to 48 h after exposure did not significantly affect cellular behavior. Our data suggest that 1800 MHz RF-EMF exposure at 4.0 W/kg is unlikely to elicit DNA damage or abnormal cellular behaviors in neurogenic cells. Bioelectromagnetics. 38:175-185, 2017. © 2016 Wiley Periodicals, Inc.
Assuntos
Dano ao DNA , Campos Eletromagnéticos/efeitos adversos , Glioblastoma/patologia , Neuroblastoma/patologia , 4-Nitroquinolina-1-Óxido/toxicidade , Ciclo Celular , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Dano ao DNA/efeitos dos fármacos , Glioblastoma/genética , Histonas/genética , Humanos , Testes de Mutagenicidade/instrumentação , Testes de Mutagenicidade/métodos , Neuroblastoma/genética , Ondas de RádioRESUMO
BACKGROUND: 4-nitroquinoline 1-oxide (4-NQO) is a mutagen known to be responsible for causing cancer by generating oxidative stress in humans. Oroxylum indicum (L.) possesses various bioactive compounds with antioxidant properties. In this connection, the present study aims to analyze the alleviation of 4-NQO induced oxidative stress in albino Wistar rats using O. indicum (L.) leaf extract. METHODS: O. indicum (L.) belonging to the family Bignoniaceae, has anticancer and anti-inflammatory properties. In this study, we observed severe oxidative stress in 4-NQO induced albino Wistar rats when compared to untreated control. Alleviation of this condition was seen after the oral administration of O. indicum (L.) leaf extract at 50, 100, and 200 mg/kg body weight. RESULTS: 4-NQO (50 ppm) administration in drinking water resulted in the generation of reactive oxygen species (ROS) leading to cellular damage, lipid peroxidation and imbalance in antioxidant status. Administration of O. indicum (L.) leaf extract has alleviated the level of 4-NQO induced oxidative stress by increasing the antioxidant status and decreasing the elevation of liver markers in serum. CONCLUSIONS: Results clearly suggest that O. indicum (L.) leaf extract when administered orally in a dose dependent manner has the ability to overcome the oxidative stress induced by 4-NQO with hepatoprotective and lipid protective properties.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Antioxidantes/farmacologia , Bignoniaceae/química , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , 4-Nitroquinolina-1-Óxido/química , Animais , Antioxidantes/química , Glicemia/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Lipídeos/sangue , Fígado/efeitos dos fármacos , Masculino , Extratos Vegetais/química , Folhas de Planta/química , Ratos , Ratos WistarRESUMO
The aim of this study was to evaluate the antigenotoxic and antioxidant potential of shikonin (SH), acetylshikonin (ACS) and Arnebia euchroma callus extract (EXT). The antigenotoxic activity was investigated by the umu-test as the inhibition of the SOS system induction caused by genotoxic chemical agents - 4-nitroquinoline oxide and 2-aminoanthracene. Moreover the ability of SH, ACS and EXT to prevent photogenotoxicity triggered by chlorpromazine under UVA irradiation was measured. The cytotoxicity of EXT toward V79 Chinese hamster cell line was additionally assessed. Shikonin and acetylshikonin had no effect on 4-NQO induced genotoxicity whereas EXT demonstrated an unclear effect. The protection against 2AA induced genotoxicity was observed for all tested substances. The highest protection was demonstrated for EXT with inhibition of 66%. SH and ACS reduced 2AA genotoxicity with inhibition of about 60%. Under UVA the strongest and dose-dependent activity was observed for EXT. Acetylshikonin was a weak anti-photogenotoxin whereas shikonin had no clear effect. EXT was highly cytotoxic toward the V79 cell line - the cells' morphology was affected seriously and apoptosis was impacted. The antioxidant activity of SH, ACS and EXT was studied by means of electron paramagnetic resonance spectroscopy using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. All three samples exhibited radical scavenging properties.
Assuntos
Antraquinonas/farmacologia , Antioxidantes/farmacologia , Boraginaceae , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Naftoquinonas/farmacologia , Extratos Vegetais/farmacologia , 4-Nitroquinolina-1-Óxido/toxicidade , Animais , Antracenos/toxicidade , Linhagem Celular , Clorpromazina/toxicidade , Cricetinae , Cricetulus , Masculino , Testes de Mutagenicidade , Ratos , Ratos Sprague-DawleyRESUMO
Several studies have shown that apple (Malus sp.) has many components able to exert chemopreventive activity. The aim of this study was to evaluate the chemopreventive potential of apple extract following medium-term oral carcinogenesis assay induced by 4-nitroquinoline 1-oxide (4NQO) by means of histopathological analysis and gene expression of antioxidant enzymes, such as CuZnSOD, MnSOD and catalase. A total of 30 male Wistar rats were distributed into five groups, as follows (n = 6 per group): Group 1 - negative control group (non-treated group); Group 2 - received 4NQO during 8 weeks in drinking water and treated with apple extract by gavage between the 1st and 4th weeks daily (initiation phase); Group 3 - received 4NQO for 8 weeks in drinking water and treated with apple extract by gavage between the 5th and 8th weeks daily (promotion phase); Group 4 - received apple extract by gavage for eight consecutive weeks only; and Group 5 - received 4NQO for 8 weeks in drinking water daily. Histopathological analysis revealed that apple extract protect oral lesions induced by 4NQO at initiation or promotion phase. Higher gene expression of CuZnSOD and MnSOD enzymes were noticed in groups treated with apple extract as well. Taken together, our results demonstrate that the apple extract is able to modulate medium-term oral carcinogenesis assay as a result of antioxidant activity.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Anticarcinógenos/farmacologia , Antioxidantes/farmacologia , Carcinógenos/toxicidade , Malus/química , Extratos Vegetais/farmacologia , Neoplasias da Língua/prevenção & controle , Animais , Água Potável/química , Células Epiteliais/patologia , Frutas/química , Masculino , Ratos , Ratos Wistar , Sementes/química , Superóxido Dismutase/metabolismo , Neoplasias da Língua/induzido quimicamenteRESUMO
Preventive measures against oral carcinogenesis are urgently warranted to lower the high morbidity and mortality associated with this malignancy worldwide. Here, we investigated the chemopreventive efficacy of grape seed extract (GSE) and resveratrol (Res) in 4-nitroquinoline-1-oxide (4NQO)-induced tongue tumorigenesis in C57BL/6 mice. Following 8 weeks of 4NQO exposure (100 µg/ml in drinking water), mice were fed with either control AIN-76A diet or diet containing 0.2% GSE (w/w) or 0.25% Res (w/w) for 8 subsequent weeks, while continued on 4NQO. Upon termination of the study at 16 weeks, tongue tissues were histologically evaluated for hyperplasia, dysplasia, and papillary lesions, and then analyzed for molecular targets by immunohistochemistry. GSE and Res feeding for 8 weeks, moderately decreased the incidence, but significantly prevented the multiplicity and severity of 4NQO-induced preneoplastic and neoplastic lesions, without any apparent toxicity. In tongue tissues, both 4NQO + GSE and 4NQO + Res treatment correlated with a decreased proliferation (BrdU labeling index) but increased apoptotic death (TUNEL-positive cells) as compared to the 4NQO group. Furthermore, tongue tissues from both the 4NQO + GSE and 4NQO + Res groups showed an increase in activated metabolic regulator phospho-AMPK (Thr172) and decreased autophagy flux marker p62. Together, these findings suggest that GSE and Res could effectively prevent 4NQO-induced oral tumorigenesis through modulating AMPK activation, and thereby, inhibiting proliferation and inducing apoptosis and autophagy, as mechanisms of their efficacy.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Proteínas Quinases Ativadas por AMP/metabolismo , Anticarcinógenos/uso terapêutico , Carcinógenos/toxicidade , Carcinoma de Células Escamosas/prevenção & controle , Extrato de Sementes de Uva/uso terapêutico , Estilbenos/uso terapêutico , Neoplasias da Língua/prevenção & controle , Proteínas Quinases Ativadas por AMP/análise , Animais , Apoptose/efeitos dos fármacos , Carcinogênese/induzido quimicamente , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/patologia , Feminino , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Endogâmicos C57BL , Resveratrol , Língua/efeitos dos fármacos , Língua/patologia , Neoplasias da Língua/induzido quimicamente , Neoplasias da Língua/patologiaRESUMO
Genotoxicity assessments were conducted on male Sprague Dawley rats treated with 5-fluorouracil (5-FU) and 4-nitroquinoline-1-oxide (4NQO) as part of an international validation trial of the Pig-a mutant phenotype assay. Rats were orally exposed to 0, 11.5, 23, or 46 mg/kg/day 5-FU for three consecutive days (Days 1-3); blood was sampled on Days -1, 4, 15, 29, and 45. Pig-a mutant phenotype reticulocyte (RET(CD59-)) and mutant phenotype erythrocyte (RBC(CD59-)) frequencies were determined on Days -1, 15, 29, and 45, and percent micronucleated reticulocytes (%MN-RET) were measured on Day 4. Rats were treated with 4NQO for 28 consecutive days by oral gavage, at doses of 1.5, 3, or 6 mg/kg/day. RBC(CD59-) and RET(CD59-) frequencies were determined on Days -1, 15, and 29, and MN-RET were quantified on Day 29. Whereas 5-FU was found to increase %MN-RET, no significant increases were observed for RBC(CD59-) or RET(CD59-) at any of the time points studied. The high dose of 4NQO (6 mg/kg/day) was observed to markedly increase RBC(CD59-) and RET(CD59-) frequencies, and this same dose level caused a weak but significantly elevated increase in MN-RET (approximately twofold). Collectively, the results provide additional support for the combination of Pig-a mutation and MN-RET into acute and 28-day repeat-dose studies.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Antígenos CD59/genética , Fluoruracila/toxicidade , Testes para Micronúcleos/métodos , Animais , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Masculino , Mutação , Ratos Sprague-Dawley , Reticulócitos/efeitos dos fármacos , Testes de Toxicidade Aguda/métodosRESUMO
Reconstructed 3D human epidermal skin models are being used increasingly for safety testing of chemicals. Based on EpiDerm™ tissues, an assay was developed in which the tissues were topically exposed to test chemicals for 3h followed by cell isolation and assessment of DNA damage using the comet assay. Inter-laboratory reproducibility of the 3D skin comet assay was initially demonstrated using two model genotoxic carcinogens, methyl methane sulfonate (MMS) and 4-nitroquinoline-n-oxide, and the results showed good concordance among three different laboratories and with in vivo data. In Phase 2 of the project, intra- and inter-laboratory reproducibility was investigated with five coded compounds with different genotoxicity liability tested at three different laboratories. For the genotoxic carcinogens MMS and N-ethyl-N-nitrosourea, all laboratories reported a dose-related and statistically significant increase (P < 0.05) in DNA damage in every experiment. For the genotoxic carcinogen, 2,4-diaminotoluene, the overall result from all laboratories showed a smaller, but significant genotoxic response (P < 0.05). For cyclohexanone (CHN) (non-genotoxic in vitro and in vivo, and non-carcinogenic), an increase compared to the solvent control acetone was observed only in one laboratory. However, the response was not dose related and CHN was judged negative overall, as was p-nitrophenol (p-NP) (genotoxic in vitro but not in vivo and non-carcinogenic), which was the only compound showing clear cytotoxic effects. For p-NP, significant DNA damage generally occurred only at doses that were substantially cytotoxic (>30% cell loss), and the overall response was comparable in all laboratories despite some differences in doses tested. The results of the collaborative study for the coded compounds were generally reproducible among the laboratories involved and intra-laboratory reproducibility was also good. These data indicate that the comet assay in EpiDerm™ skin models is a promising model for the safety assessment of compounds with a dermal route of exposure.
Assuntos
Ensaio Cometa/normas , Epiderme/efeitos dos fármacos , 4-Nitroquinolina-1-Óxido/toxicidade , Cicloexanonas/toxicidade , Dano ao DNA , Avaliação Pré-Clínica de Medicamentos/normas , Etilnitrosoureia/toxicidade , Humanos , Ensaio de Proficiência Laboratorial , Metanossulfonato de Metila/toxicidade , Modelos Biológicos , Mutagênicos/toxicidade , Nitrofenóis/toxicidade , Fenilenodiaminas/toxicidade , Reprodutibilidade dos Testes , Técnicas de Cultura de TecidosRESUMO
In this study, we evaluated chemopreventive efficacy of Antitumor B, a Chinese herbal mixture of six plants (Sophora tonkinensis, Polygonum bistorta, Prunella vulgaris, Sonchus arvensis L., Dictamnus dasycarpus, and Dioscorea bulbifera) on the development of 4-nitroquinoline-1-oxide (4NQO) induced oral squamous cell carcinomas in A/J mice. Antitumor B, delivered through diet, inhibited 4NQO-induced oral cancer development by 59.19%. The reduction of cell proliferation appears to be associated with efficacy of Antitumor B against 4NQO-induced oral cancer in A/J mice. The expression of epidermal growth factor receptor (EGFR) and phosphorylated EGFR (Tyr1173) were down-regulated by Antitumor B. Tissue distribution of Antitumor B was determined using obacunone, matrine, and maackiain as marker chemicals. We found significant amounts of obacunone, matrine, and maackiain in the blood after 1-wk treatment. The concentrations of these three compounds did not increase further at 18 wk, suggesting that plasma concentrations had reached a steady-state level at 1 wk. There was no significant body weight loss and there was no other obvious sign of toxicity in Antitumor B-treated mice. These results suggest that Antitumor B is a promising agent for human oral cancer chemoprevention.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma de Células Escamosas/prevenção & controle , Medicamentos de Ervas Chinesas/uso terapêutico , Neoplasias Bucais/prevenção & controle , 4-Nitroquinolina-1-Óxido/toxicidade , Alcaloides/sangue , Animais , Benzoxepinas/sangue , Biomarcadores/sangue , Carcinógenos/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/efeitos dos fármacos , Quimioprevenção , Receptores ErbB/biossíntese , Limoninas/sangue , Masculino , Camundongos , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/tratamento farmacológico , Fosforilação , Pterocarpanos/sangue , Quinolizinas/sangue , Tirosina/metabolismo , MatrinasRESUMO
4-Nitroquinoline 1-oxide (4-NQO) a potent oral carcinogen, widely used for induction of oral carcinogenesis, has been found to induce lipid peroxidation in vivo and in vitro. Green tea contains a high content of polyphenols, which are potent antioxidants. Thus green tea polyphenols (GTP) might be expected play a protective role against 4-NQO induced lipid peroxidation and bone marrow toxicity. In the present study, a dose of 200 mg of GTP/kg b.wt/day was given orally for a week, simultaneously animals received 0.2 ml of 0.5% 4-NQO in propylene glycol (5 mg/ml) injected intramuscularly for three times/week. Oxidants and antioxidants such as malendialdehyde (MDA) and thiols, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) were significantly decreased in 4-NQO induced animals except MDA, and these parameters were brought back to near normalcy on treatment with GTP. The results suggest that GTP treatment offers significant protection against 4-NQO induced lipid peroxidation and bone marrow toxicity and might be a promising potential candidate for prevention of mutations leading to cancer.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Medula Óssea/efeitos dos fármacos , Carcinógenos/toxicidade , Dano ao DNA/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Polifenóis/farmacologia , Chá/química , Animais , Medula Óssea/patologia , Catalase/metabolismo , Adutos de DNA/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Técnicas Imunoenzimáticas , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
Sesame oil could be considered as a potent antioxidant and dietary supplement. It possesses antimutagenic, anti-inflammatory and anti-cardiac toxicity. In the view of available findings, the current study focused on determining the protective effects of sesame oil on 4-Nitroquinoline-1-oxide (4-NQO) -induced oxidative DNA damage and lipid peroxidation (LPO) in rats. Seven groups of Wistar albino rats each with 6 either sex were used. Groups were given vehicle control and sesame oil alone orally and 4-NQO (30 mg/kg) by intraperitoneal injection. Following the four dose levels (1, 2, 4, and 8 ml/kg orally), sesame oil plus 4-NQO were also tested. After 24 hours of 4-NQO injection, blood samples were drawn by venipuncture. DNA damage (8-hydroxy-2-deoxy guanosine; 8-OHdG) and LPO were estimated. LPO from the 4-NQO-treated group was 2.5-fold higher than that of the control LPO. Pretreatment with sesame oil reduced this by 16-61%. 8-OHdG DNA damage from 4-NQO was found to be 3-fold higher than that of controls. Pretreatment with sesame oil effectively protected against DNA damage in a dose-dependent fashion. This study indicates that the antioxidant, sesame oil, effectively protected DNA damage and LPO induced by 4-NQO.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Antioxidantes/farmacologia , Dano ao DNA/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Óleo de Gergelim/farmacologia , Animais , Feminino , Peroxidação de Lipídeos/fisiologia , Masculino , Malondialdeído/sangue , Oxirredução , Estresse Oxidativo/fisiologia , Ratos , Ratos WistarRESUMO
Dietary zinc (Zn) deficiency is implicated in the pathogenesis of human oral-esophageal cancers. In rats, Zn deficiency causes increased cell proliferation and cyclooxygenase-2 (COX-2) overexpression and enhances oral carcinogenesis by 4-nitroquinoline 1-oxide (NQO). Zn replenishment reverses all these effects. We questioned whether Zn has antitumor efficacy in a Zn-sufficient animal by investigating in Zn-sufficient rats (i) the efficacy of Zn supplementation on the progression of tongue squamous cell carcinogenesis induced by drinking water exposure to high (20-30 p.p.m.) and low (10 p.p.m.) doses of NQO and (ii) the modulating effects of Zn supplementation on biomarker expression in tongue lesions by immunohistochemistry. In rats exposed to high doses of NQO, Zn supplementation significantly reduced the incidence of papillomas from 100 to 64.7% (P=0.018) and invasive carcinomas from 93.8 to 52.9% (P=0.017). In rats exposed to low doses of NQO, where only minimally invasive carcinomas developed, Zn supplementation significantly reduced tumor multiplicity, incidence of tumors (1-2 mm), hyperplasia, dysplasia, papillomas and progression to carcinoma. Immunohistochemical analysis of carcinomas showed that Zn supplementation caused a shift to a less proliferative/aggressive cancer phenotype by reducing cell proliferation, stimulating apoptosis and decreasing expression of the key tumor markers cyclin D1, p53 and COX-2. Additionally, Zn supplementation significantly reduced cell proliferation in non-lesional tongue squamous epithelia, thereby suppressing tumor development. Together, the results demonstrate that Zn supplementation has chemopreventive efficacy against oral carcinogenesis in nutritionally complete animals. Our data suggest that Zn supplementation may be efficacious in the chemoprevention of human oral cancer.
Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Neoplasias da Língua/prevenção & controle , Zinco/administração & dosagem , Animais , Apoptose , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/prevenção & controle , Proliferação de Células , Suplementos Nutricionais , Masculino , Ratos , Ratos Sprague-Dawley , Neoplasias da Língua/induzido quimicamente , Neoplasias da Língua/patologia , Zinco/sangueRESUMO
Chemoprevention of head and neck squamous cell carcinoma (HNSCC), a disease associated with high mortality rates and frequent occurrence of second primary tumor (SPT), is an important clinical goal. The epidermal growth factor receptor (EGFR)-signal transducer and activator of transcription (STAT)-3 signaling pathway is known to play a key role in HNSCC growth, survival, and prognosis, thereby serving as a potential therapeutic target in the treatment of HNSCC. In the current study, the 4-nitroquinoline-1-oxide (4-NQO)-induced murine model of oral carcinogenesis was utilized to investigate the chemopreventive activities of compounds that target the EGFR-STAT3 signaling pathway. This model mimics the process of oral carcinogenesis in humans. The drugs under investigation included erlotinib, a small molecule inhibitor of the EGFR, and guggulipid, the extract of an Ayurvedic medicinal plant, which contains guggulsterone, a compound known to inhibit STAT3. Dietary administration of guggulipid failed to confer protection against oral carcinogenesis. On the other hand, the mice placed on erlotinib-supplemented diet exhibited a 69% decrease (P < 0.001) in incidence of preneoplastic and neoplastic lesions compared with mice on the control diet. Immunostaining of dysplastic lesions demonstrated modest decreases in STAT3 levels, with both drug treatments, that were not statistically significant. The results of the present study provide the basis for exploring the efficacy of erlotinib for prevention of HNSCC in a clinical setting.
Assuntos
Carcinoma de Células Escamosas/prevenção & controle , Modelos Animais de Doenças , Receptores ErbB/antagonistas & inibidores , Neoplasias Bucais/prevenção & controle , Inibidores de Proteínas Quinases/uso terapêutico , Quinazolinas/uso terapêutico , Fator de Transcrição STAT3/antagonistas & inibidores , 4-Nitroquinolina-1-Óxido/toxicidade , Ração Animal , Animais , Carcinógenos/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Commiphora , Receptores ErbB/metabolismo , Cloridrato de Erlotinib , Feminino , Técnicas Imunoenzimáticas , Camundongos , Camundongos Endogâmicos CBA , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Extratos Vegetais/administração & dosagem , Gomas Vegetais/administração & dosagem , Fator de Transcrição STAT3/metabolismo , Transdução de SinaisRESUMO
Olive leaf extract provides nutritional support for detoxification at the cellular level, when the body is under stress. The present study aimed to evaluate the chemopreventive effect of oleuropein-rich extract (ORE) on 4-NQO-induced rat tongue carcinogenesis. Eighty male F344 rats, 6 weeks age were divided into 5 groups (10 animals each for groups 1 and 2 and 20 each for groups 3, 4, and 5). Group 1 served as an untreated control. Group 2 was given ORE-containing diet alone. Rats of groups 3, 4, and 5 were given daily 20 ppm 4-NQO in drinking water for 8 weeks. Group 4 was fed diets containing ORE, concomitantly with the time of carcinogen exposure and continued 1 week after its stoppage. Group 5 was fed diets mixed with ORE starting 1 week after cessation of 4-NQO treatment. The experiment was terminated when the rats aged 37 weeks, and all animals were euthanized. The tongues were carefully inspected for pathological lesions, excised, and were processed for c-Met and Ki-67 immunohistochemical examination. The gross inspection, histopathological and immunohistochemical results of the present study showed a beneficial regression effect of ORE on tumor progression, especially when it was administered concomitantly with 4-NQO rather than when given after the stoppage of the carcinogenic material. In conclusion, ORE has a chemopreventive role in tongue squamous cell carcinoma, and further studies are needed to explore the molecular mechanisms of its tumor suppressive effect at this level.