RESUMEN
OBJECTIVES: Previous studies have shown that pingyangmycin (PYM; bleomycin A5) can induce two distinct modes of cell death (necrosis, apoptosis). At high concentrations, PYM can be considered as an apoptosis mimetic drug. In this study, we explored the possibility that the membrane-modifying agent verapamil might affect the transport function of PYM through the plasma membrane, resulting in inducing apoptosis of tumor cells at low concentration of PYM. METHODS: Cytotoxicity, flow cytometry and DNA fragmentation assays were used to detect the interaction of verapamil and PYM in human oral carcinoma cell line KB cells. RESULTS: Our results indicated that verapamil can enhance the cytotoxicity of PYM against KB cells with the non-toxic doses (P<0.05). The cell viability at a concentration of 500 microg ml-1 of PYM was 35+/-2% compared with control and 10 microg ml-1 verapamil decreased the cell viability lower to 28+/-1%. In addition, because of the synergistic effect of verapamil, KB cells apoptosis was found to be induced when treated with a lower concentration of PYM (50 microg ml-1) for 24 h by flow cytometry and DNA fragmentation assays. CONCLUSIONS: Verapamil was found to enhance PYM-induced cytotoxicity and apoptosis in KB cells. The responsiveness of PYM might be explained by the effective accumulation of PYM by verapamil in KB cells mediated by the inhibition of PYM efflux function of the cells.
Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Apoptosis/efectos de los fármacos , Bleomicina/análogos & derivados , Bloqueadores de los Canales de Calcio/administración & dosificación , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias de la Boca/tratamiento farmacológico , Verapamilo/administración & dosificación , Bleomicina/administración & dosificación , Carcinoma de Células Escamosas/patología , Supervivencia Celular/efectos de los fármacos , Fragmentación del ADN/efectos de los fármacos , Sinergismo Farmacológico , Citometría de Flujo , Humanos , Células KB , Neoplasias de la Boca/patologíaRESUMEN
AIM: The purpose of this study was to determine the cytotoxicity of three different types of root canal sealer on human periodontal ligament (PDL) cells and a permanent hamster cell line (V79 cells). METHODOLOGY: Set specimens from two resin based sealers (AH26 and AHPlus), three zinc oxide-eugenol-based sealers (Canals, Endomethasone and N2) and one calcium hydroxide-based sealer (Sealapex) were eluted with culture medium for 1, 2, 3 and 7 days. Cytotoxicity was judged using tetrazolium bromide reduction assay on human primary PDL cells and V79 cells derived from a Chinese hamster. RESULTS: The results showed that elutes from resin-based, zinc oxide-eugenol-based, and calcium hydroxide-based sealers were cytotoxic to primary human PDL cultures and V79 cells. Calcium hydroxide-based sealer was the least toxic sealer amongst the chemicals tested in both cultures. The cytotoxic response decreased in an order of N2 > Endomethasone > AH26 > AHplus > Canals > Sealapex. CONCLUSIONS: The sensitivity of toxicity depended on the materials tested and the cell culture system used. Thus, the use of both permanent and primary cells is recommended for screening of the cytotoxic effects of root canal sealers. In addition, the results confirmed that root canal sealers constantly dissolve when exposed to an aqueous environment for extended periods, possibly causing moderate or severe cytotoxic reactions. Use of calcium hydroxide-based material as a root canal sealer initially may result in a more favourable response to periradicular tissues.
Asunto(s)
Administración Tópica , Hidróxido de Calcio/toxicidad , Hidrocortisona , Ligamento Periodontal/efectos de los fármacos , Cementos de Resina/toxicidad , Materiales de Obturación del Conducto Radicular/toxicidad , Timol/análogos & derivados , Cemento de Óxido de Zinc-Eugenol/toxicidad , Análisis de Varianza , Animales , Antiinflamatorios/toxicidad , Bismuto/toxicidad , Células Cultivadas , Cricetinae , Dexametasona/toxicidad , Combinación de Medicamentos , Resinas Epoxi/toxicidad , Fibroblastos/efectos de los fármacos , Formaldehído/toxicidad , Humanos , Metenamina/toxicidad , Ligamento Periodontal/citología , Salicilatos/toxicidad , Plata/toxicidad , Estadísticas no Paramétricas , Timol/toxicidad , Titanio/toxicidadRESUMEN
OBJECTIVE: The objective of this study was to examine the effects of sodium hypochlorite (NaOCl) and chlorhexidine (CHx) on cultured human periodontal ligament (PDL) cells in vitro. STUDY DESIGN: The effects of irrigation solutions on human PDL cells were evaluated by propidium iodide fluorescence cytotoxicity assay, protein synthesis assay, and mitochondrial activity. RESULTS: Both NaOCl and CHx were cytotoxic to human PDL cells in a concentration- and contact time-dependent manner. In addition, CHx inhibited protein synthesis in human PDL cells. Although NaOCl displayed cellular cytotoxicity, it showed no protein inhibition in the PDL cells. Furthermore, both NaOCl and CHx exhibited an inhibitory effect on mitochondrial activity on human PDL cells. CONCLUSIONS: This study suggests that these irrigation fluids may cause detrimental effects on vital tissues. Its clinical significance, however, needs to be evaluated further because concentration used, exposure time to the agent, and exposure surface area are important factors affecting the resulting effect.
Asunto(s)
Antiinfecciosos Locales/toxicidad , Clorhexidina/toxicidad , Ligamento Periodontal/efectos de los fármacos , Irrigantes del Conducto Radicular/toxicidad , Hipoclorito de Sodio/toxicidad , Células Cultivadas , Relación Dosis-Respuesta a Droga , Fluorescencia , Humanos , Mitocondrias/efectos de los fármacos , Ligamento Periodontal/citología , Inhibidores de la Síntesis de la Proteína/toxicidadRESUMEN
To date there has been very little data on the cytotoxic response of different cell lines to root canal sealers. The objective of this study was to determine the cytocompatibility of three different extracts of root canal sealers and to compare the cytotoxic response of these materials on two different primary human oral fibroblasts (derived from gingiva and buccal mucosa) and one permanent hamster cell line (V79 cells). Cytotoxicity was judged using an assay of tetrazolium bromide reduction. The results showed that root canal sealers (AH plus, Canals, and N2) were cytotoxic to primary human oral fibroblast cultures and V79 cells. It was found that N2 was the most toxic root canal sealer among those tested in all cultures. The toxicity decreased in an order of N2 > AH plus approximately = Canals. The sensitivity of toxicity depended on the materials tested and the cell culture system used.
Asunto(s)
Fibroblastos/efectos de los fármacos , Encía/efectos de los fármacos , Mucosa Bucal/efectos de los fármacos , Materiales de Obturación del Conducto Radicular/toxicidad , Análisis de Varianza , Animales , Línea Celular/efectos de los fármacos , Colorimetría , Colorantes , Cricetinae , Cricetulus , Combinación de Medicamentos , Resinas Epoxi/toxicidad , Eugenol/toxicidad , Formaldehído/toxicidad , Encía/citología , Humanos , Mucosa Bucal/citología , Sales de Tetrazolio , Tiazoles , Óxido de Zinc/toxicidad , Cemento de Óxido de Zinc-Eugenol/toxicidadRESUMEN
Areca quid chewing has been linked to oral submucous fibrosis and oral cancer. Arecoline, a major areca nut alkaloid, is considered to be the most important etiologic factor in the areca nut. In order to elucidate the pathobiological effects of arecoline, cytotoxicity assays, cellular glutathione S-transferase (GST) activity and lipid peroxidation assay were employed to investigate cultured human buccal mucosal fibroblasts. To date, there is a large proportion of areca quid chewers who are also smokers. Furthermore, nicotine, the major product of cigarette smoking, was added to test how it modulated the cytotoxicity of arecoline. At a concentration higher than 50 microg/ml, arecoline was shown to be cytotoxic to human buccal fibroblasts in a dose-dependent manner by the alamar blue dye colorimetric assay (P<0.05). In addition, arecoline significantly decreased GST activity in a dose-dependent manner (P<0.05). At concentrations of 100 microg/ml and 400 microg/ml, arecoline reduced GST activity about 21% and 46%, respectively, during a 24 h incubation period. However, arecoline at any test dose did not increase lipid peroxidation in the present human buccal fibroblast test system. The addition of extracellular nicotine acted synergistically on the arecoline-induced cytotoxicity. Arecoline at a concentration of 50 microg/ml caused about 30% of cell death over the 24 h incubation period. However, 2.5 mM nicotine enhanced the cytotoxic response and caused about 50% of cell death on 50 microg/ml arecoline-induced cytotoxicity. Taken together, arecoline may render human buccal mucosal fibroblasts more vulnerable to other reactive agents in cigarettes via GST reduction. The compounds of tobacco products may act synergistically in the pathogenesis of oral mucosal lesions in areca quid chewers. The data presented here may partly explain why patients who combined the habits of areca quid chewing and cigarette smoking are at greater risk of contracting oral cancer.
Asunto(s)
Arecolina/efectos adversos , Carcinógenos/efectos adversos , Fibroblastos/efectos de los fármacos , Mucosa Bucal/efectos de los fármacos , Nicotina/efectos adversos , Oxazinas , Xantenos , Análisis de Varianza , Areca/efectos adversos , Bisbenzimidazol , Técnicas de Cultivo de Célula , Muerte Celular/efectos de los fármacos , Cocarcinogénesis , Colorimetría , Colorantes , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Inhibidores Enzimáticos/efectos adversos , Colorantes Fluorescentes , Glutatión Transferasa/antagonistas & inhibidores , Humanos , Peroxidación de Lípido/efectos de los fármacos , Mucosa Bucal/citología , Plantas Medicinales , Factores de Riesgo , Fumar/efectos adversos , Espectrometría de Fluorescencia , Estadística como AsuntoRESUMEN
Betel nut chewing, like cigarette smoking, is a popular oral habit which impinges on the daily lives of a population of approximately 200 million. People who chew betel nuts have a higher prevalence of periodontal diseases than those who do not. Many of the undesirable effects of betel nuts have been attributed to arecoline, a major component of the particular alkaloid in betel nuts. In this in vitro study, we have focused on the effects of arecoline and the role it could play in periodontal breakdown via its direct effects on human gingival fibroblasts. Human gingival fibroblasts were derived from three healthy individuals undergoing crown-lengthening procedures. We found that arecoline is cytotoxic to human gingival fibroblasts at a concentration higher than 50 micrograms/ml by depleting intracellular thiols and inhibiting mitochondrial activity (P < 0.05). In addition, the cells displayed a marked arrest at G2/M phase in a dose-dependent manner. Repeated and long-term exposure to arecoline could impair the gingival fibroblast functions. As they are cytotoxic, the use of betel nut products in conjunction with periodontal therapy may interfere with optimal healing and/or lead to further periodontal breakdown.
Asunto(s)
Arecolina/toxicidad , Agonistas Colinérgicos/toxicidad , Fibroblastos/efectos de los fármacos , Encía/efectos de los fármacos , Oxazinas , Xantenos , Adulto , Análisis de Varianza , Areca , Arecolina/administración & dosificación , Bisbenzimidazol , Células Cultivadas , Agonistas Colinérgicos/administración & dosificación , Cromatografía Líquida de Alta Presión , Colorimetría , Colorantes , Relación Dosis-Respuesta a Droga , Fibroblastos/citología , Colorantes Fluorescentes , Fase G2/efectos de los fármacos , Encía/citología , Glutatión/antagonistas & inhibidores , Humanos , Mitocondrias/efectos de los fármacos , Mitosis/efectos de los fármacos , Plantas Medicinales , Estadística como Asunto , Compuestos de Sulfhidrilo/antagonistas & inhibidoresRESUMEN
BACKGROUND, AIMS: The habit of betel nut chewing impinges on the daily lives of approximately 200 million people. Betel quid chewers have a higher prevalence of periodontal diseases than non-chewers. This study examined the pathobiological effects of arecoline, a major component of the betel nut alkaloids, on human periodontal ligament fibroblasts (PDLF) in vitro. METHOD: Cell viability, proliferation, protein synthesis, and cellular thiol levels were used to investigate the effects of human PDLF exposed to arecoline levels of 0 to 200 microg/ml. In addition, nicotine was added to test how it modulated the effects of arecoline. RESULTS: Arecoline significantly inhibited cell proliferation in a dose-dependent manner. At concentrations of 10 and 30 microg/ml, arecoline suppressed the growth of PDLF by 20% and 50% (p < 0.05), respectively. Arecoline also decreased protein synthesis in a dose-dependent manner during a 24-h culture period. A 100 microg/ ml concentration level of arecoline significantly inhibited protein synthesis to only 50% of that in the untreated control (p < 0.05). Moreover, arecoline significantly depleted intracellular thiols in a dose-dependent manner. At concentrations of 25 microg/ml and 100 microg/ml, arecoline depleted about 18% and 56% of thiols (p < 0.05), respectively. This suggests that arecoline itself might augment the destruction of periodontium associated with betel nut use. Furthermore, the addition of nicotine acted with a synergistic effect on the arecoline-induced cytotoxicity. At a concentration of 60 microg/ml, arecoline suppressed the growth of PDLF by about 33% and 5 mM nicotine enhanced the arecoline-induced cytotoxic response to cause about 66% cell death. CONCLUSION: During thiol depletion, arecoline may render human PDLF more vulnerable to reactive agents within cigarettes. Taken together, people who combine habits of betel nut chewing with cigarette smoking could be more susceptible to periodontium damage than betel nut chewing alone.
Asunto(s)
Arecolina/efectos adversos , Fibroblastos/efectos de los fármacos , Nicotina/efectos adversos , Ligamento Periodontal/efectos de los fármacos , Areca/efectos adversos , Arecolina/administración & dosificación , Muerte Celular , División Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Colorantes , Susceptibilidad a Enfermedades , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Sinergismo Farmacológico , Fibroblastos/citología , Fibroblastos/metabolismo , Humanos , Nicotina/administración & dosificación , Ligamento Periodontal/citología , Ligamento Periodontal/metabolismo , Plantas Medicinales , Biosíntesis de Proteínas , Proteínas/efectos de los fármacos , Estadística como Asunto , Compuestos de Sulfhidrilo/análisis , Sales de Tetrazolio , TiazolesRESUMEN
PURPOSE: The objective of this study was to determine the cytocompatibility of three different extracts of denture base resins and to compare the cytotoxic effect of these materials on a human oral epithelial KB cell line and primary human oral fibroblasts derived from buccal mucosa. MATERIALS AND METHODS: Set specimens from a heat-cured resin, a self-cured resin, and a light-cured resin were eluted with culture medium for 1, 3, and 5 days. Cytotoxicity was judged using tetrazolium bromide reduction assay. RESULTS: The eluates from self-cured, heat-cured, and light-cured denture base resins were cytotoxic to primary human buccal fibroblast cultures and KB cells. Self-cured resin was the most toxic denture base material among the chemicals tested in all cultures. The cytotoxicity decreased in the order of self-cured resin > heat-cured resin > light-cured resin for KB cells. The rank for buccal fibroblast cells was self-cured resin > heat-cured resin > light-cured resin. CONCLUSION: The influence of the cytotoxicity depended on the materials tested and the cell culture system used. The use of both permanent and primary cells is recommended for a better screening of the cytotoxic effects of denture base resins.
Asunto(s)
Resinas Acrílicas/toxicidad , Materiales Dentales/toxicidad , Bases para Dentadura , Mucosa Bucal/efectos de los fármacos , Análisis de Varianza , Línea Celular , Células Cultivadas , Colorantes , Medios de Cultivo , Células Epiteliales/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Humanos , Células KB/efectos de los fármacos , Mucosa Bucal/patología , Reproducibilidad de los Resultados , Estadística como Asunto , Sales de Tetrazolio , TiazolesRESUMEN
The inactivation of tumor suppressor gene (TSG) is important during multistage carcinogenesis. The p53 TSG is frequently mutated in oral squamous cell carcinomas. These mutations can serve as very specific markers for the presence of tumor cells in a background of normal cells. In this study, 10 oral squamous cell carcinoma patients and 27 normal dental students were collected from Chung Shan Medical and Dental College Hospital, Taichung, Taiwan. Extractions of DNA from saliva were obtained. Exon 4 and intron 6 within the p53 gene were amplified with polymerase chain reactions (PCRs) followed by DNA sequence analysis. DNA sequence analysis of PCR products revealed that five of eight (62.5%) tumor saliva samples and five of 27 (18. 52%) healthy saliva samples contained p53 exon 4 codon 63 mutations. These results were significantly different by using Chi-square test (P<0.05). The majority of the base substitutions were C deletions. Probable hot spots for the mutation were identified at exon 4 codon 63, which has not been observed before in head and neck cancers. Our study indicated that mutation of p53 codon 63 in saliva might be a molecular marker for oral squamous cell carcinomas. In addition, the amount of DNA recovered from saliva in most cases is sufficiently large and its quality suitable to enable PCR amplification which could be used in the search for mutations. The protocol described is rapid, cheap, and easy to perform, and may be useful for epidemiological studies for oral carcinogenesis.
Asunto(s)
Carcinoma de Células Escamosas/genética , Genes p53/genética , Neoplasias de la Boca/genética , Saliva/química , Adulto , Carcinoma de Células Escamosas/diagnóstico , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Codón , Marcadores Genéticos , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADNRESUMEN
Pingyangmycin (PYM; Bleomycin A(5)), an antitumour antibiotic is currently used during anticancer therapy. Previous experiments demonstrated that the therapeutic efficiency of PYM for treatment of malignant tumours is considered to be related to its ability to cause DNA strand breaks in vitro. However, very little is known about the interaction of PYM with the target cells, and it is still unclear how PYM enters the cells. In this study, cell death induced by PYM was studied in a human squamous cell carcinoma cell line (KB cells). In order to determine if cell death occurred by necrosis (reproductive cell death) or apoptosis (programmed cell death), KB cells were exposed to different concentrations of PYM and evaluated by biochemical and morphological criteria. Our results indicate that KB cells displayed an arrest in the G(2)-M phase of the cell cycle and became enlarged and polynucleated before dying at the low concentrations of PYM. In contrast, when cells were exposed to high concentrations of PYM, morphological changes identical to those usually associated with apoptosis were observed as well as internucleosomal digestion of genomic DNA. In conclusion, we demonstrate that PYM is able to induce two distinct modes of cell death depending on the doses of PYM.
Asunto(s)
Antibióticos Antineoplásicos/uso terapéutico , Apoptosis , Bleomicina/análogos & derivados , Carcinoma de Células Escamosas/tratamiento farmacológico , Apoptosis/genética , Bleomicina/uso terapéutico , Carcinoma de Células Escamosas/patología , Fragmentación del ADN/efectos de los fármacos , ADN de Neoplasias/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Células KB/efectos de los fármacos , Células KB/patología , NecrosisRESUMEN
Perforation of a tooth structure resulting in communication of the pulp space with periodontium occasionally occurs during endodontic therapy. For the best prognosis, the perforation area must be sealed as soon as possible. Because these materials will be in direct contact with periodontal tissues, their cytotoxic potential must be evaluated before clinical use. The purpose of this study was to determine the cytocompatibility of three perforation repair materials (amalgam, resin, and glass ionomer). Cultured human periodontal ligament (PDL) cells were used to evaluate the cellular response resulting from these materials by cell viability and proliferation assays. Twenty-seven 5 x 4 mm cylinders of each material were fabricated for this study. All tested materials were cytotoxic to human PDL cells. Both types of material and time affected cell viability and proliferation. Resin exhibited the most cytotoxic effects followed by glass ionomer and amalgam during a 14-day incubation period. Amalgam and glass ionomer slightly inhibited cell viability and growth in the first 24 hr, compared with the control. Amalgam or glass ionomer may initially react more favorably to PDL cells than resin. The present model of cultured human PDL cells is simple, relatively cheap, and easily established and propagated under standardized conditions in any laboratory. Furthermore, this method allows long-term observation of human cellular reactions and thus might be a preliminary screening test for initial biocompatibility of dental materials.
Asunto(s)
Resinas Compuestas/toxicidad , Amalgama Dental/toxicidad , Cementos de Ionómero Vítreo/toxicidad , Ligamento Periodontal/efectos de los fármacos , Análisis de Varianza , Células Cultivadas/efectos de los fármacos , Restauración Dental Permanente/efectos adversos , Humanos , Ensayo de Materiales , Ligamento Periodontal/citología , Pruebas de ToxicidadRESUMEN
Phenolic compounds are widely used in clinical dentistry as sedatives for the dental pulp, as disinfectants for caries, and as root canal medications. The pathobiological effects of various phenolic compounds on human dental pulp fibroblasts were investigated with Hoechst 33258 fluorescence assay and DNA precipitation assay. All phenolic compounds showed cytotoxicity in Hoechst 33258 fluorescence assay by inhibiting cellular DNA in a concentration-dependent manner. The 50% inhibition concentrations required to decrease the cellular DNA contents by guaiacol, phenol, eugenol, and thymol were 9.8, 4.5, 0.9, and 0.5 mM, respectively. However these phenolic compounds did not cause DNA single-strand breaks in cultured human pulp fibroblasts. These results indicate that phenolic compounds are cytotoxic agents but are without genotoxic effects on human pulp fibroblasts in vitro. However care should be taken to reduce the possibility of pulpal as well as periapical irritations from inadvertent extrusion of these substances in clinical usage.
Asunto(s)
Pulpa Dental/efectos de los fármacos , Fenoles/toxicidad , Irrigantes del Conducto Radicular/toxicidad , Bisbenzimidazol , Células Cultivadas , Daño del ADN , Replicación del ADN/efectos de los fármacos , Pulpa Dental/citología , Relación Dosis-Respuesta a Droga , Eugenol/toxicidad , Fibroblastos/efectos de los fármacos , Colorantes Fluorescentes , Guayacol/toxicidad , Humanos , Concentración 50 Inhibidora , Timol/toxicidadRESUMEN
Epidemiological studies have demonstrated a clear association between betel nut chewing and an increased risk for oral mucosal lesions. Arecoline, the most abundant betel alkaloid, is considered the most important etiologic factor in betel nuts. In addition, most betel nut chewers are also smokers. In order to elucidate the potential toxicological implications of interactions of arecoline and peroxynitrite (a reaction product of cigarette smoking), cell viability, and cellular levels of glutathione (GSH) were investigated, using cultured human buccal mucosal fibroblasts. At a concentration higher than 0.8 mM, arecoline was cytotoxic to buccal mucosal fibroblasts in a concentration- and time-dependent manner. Arecoline also depleted intracellular GSH in a dose-dependent manner (P<0.05). The addition of extracellular peroxynitrite acted as a synergistic effect on the arecoline-induced cytotoxicity (P<0.05). Furthermore, at a concentration of 0.8 mM, arecoline depleted intracellular GSH by about 42%, while 2 mM peroxynitrite enhanced the arecoline-depleted GSH level further to 86% as compared with the control. During GSH depletion, arecoline may render the human buccal mucosal fibroblasts more vulnerable to other reactive agents within cigarette smoking. Taken together, we suggest that people who combine the habits of betel nut chewing with cigarette smoking could be more susceptible to oral mucosal damage than betel quid chewing alone.
Asunto(s)
Arecolina/toxicidad , Colinérgicos/toxicidad , Mucosa Bucal/efectos de los fármacos , Nitratos/toxicidad , Oxidantes/toxicidad , Células Cultivadas , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Glutatión/metabolismo , Humanos , Cinética , Mucosa Bucal/citología , Mucosa Bucal/metabolismoRESUMEN
Arecoline, a major betel nut alkaloid, has been detected in saliva obtained during betel nut chewing in concentrations up to 140 micrograms/ml, corresponding to 0.9 mM. Arecoline in the millimolar concentration range might participate in the initiation and/or progression of periodontal disease during the long-term effects of betel nut chewing. In this study, cell growth, cell proliferation, assessment of cytoplasmic enzyme lactate dehydrogenase (LDH) and collagen synthesis were used to investigate the effects of human gingival fibroblasts exposed to arecoline levels of 0-200 micrograms/ml. Control culture exhibited a normal monolayer of long spindle-shaped fibroblast morphology. Arecoline-treated human gingival fibroblasts showed a more rounded appearance and detached at the higher concentrations. At concentrations higher than 75 micrograms/ml, many cells had detached from the surface of the petri dish and numerous floating cells could be seen under the inverted microscope. At a concentrations higher than 25 micrograms/ml, arecoline inhibited cell growth, proliferation and collagen synthesis and increased LDH leakage in a dose-dependent manner (P < 0.05). These results indicate that arecoline is a cytotoxic agent to human gingival fibroblasts. Repeated and long-term exposure to arecoline could impair gingival fibroblast function. Betel quid chewers might be more susceptible to destruction of the periodontium and less responsive to a regeneration procedures during periodontal therapy.
Asunto(s)
Areca/efectos adversos , Arecolina/toxicidad , Fibroblastos/efectos de los fármacos , Encía/efectos de los fármacos , Extractos Vegetales/toxicidad , Plantas Medicinales , Análisis de Varianza , División Celular/efectos de los fármacos , Células Cultivadas , Colágeno/biosíntesis , Fibroblastos/metabolismo , Encía/citología , Humanos , L-Lactato Deshidrogenasa/análisisRESUMEN
To date, there has been very little research into the possible effects of endodontic therapy on regeneration of a lost periodontal attachment. The objective of this study was to examine the effects of the endodontic medication, camphorated parachlorophenol (CMCP), on human periodontal ligament cells in vitro. The cytotoxic effects of CMCP were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay and cell proliferation using a [3H]thymidine incorporation assay. CMCP inhibited the human periodontal ligament cells viability and proliferation in a dose-dependent manner (p < 0.05). These data indicate that the use of CMCP in a root canal could cause periodontium damage. Although this study was conducted in vitro, the findings suggest that it may not be advisable to use CMCP as an interim medication when a periodontal surgical procedure, especially an attempt at regeneration or a new attachment procedure, is being considered in tissues adjacent to the endodontically involved tooth.
Asunto(s)
Antiinfecciosos Locales/toxicidad , Alcanfor/toxicidad , Clorofenoles/toxicidad , Ligamento Periodontal/efectos de los fármacos , Irrigantes del Conducto Radicular/toxicidad , División Celular/efectos de los fármacos , Células Cultivadas , Colorimetría , Desinfectantes Dentales/toxicidad , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Humanos , Ligamento Periodontal/citologíaRESUMEN
The antitumour antibiotic pingyangmycin (PYM; bleomycin A5) was isolated from many components of bleomycin (BLM) produced by Streptomyces pingyangensisn. PYM has a similar chemical structure to that of BLM but the terminal amine moiety is different. Therefore, it would be of significance to demonstrate the antitumour effect and action mechanism of PYM on cultivated tumour cells. In this study, we used the cell growth curve, plating efficiency, and DNA synthesis inhibition assay to demonstrate the cytotoxicity of PYM on cultured KB cells. In the meantime, the morphological variations of drug-treated cells were also observed. In addition, we used the DNA precipitation assay, a simple and rapid assay, for detecting DNA damage caused by PYM on cultured KB cells for potential genotoxicity. Our results indicate that the effect of PYM significantly inhibits the cell growth, colonyforming ability, and DNA synthesis of KB cells in a dose-dependent manner. Furthermore, when treated with 5 micrograms/ml of PYM for 24 h on cultured KB cells, DNA strand breaks can be induced (P < 0.05). Therefore, it is considered that the action mechanism of PYM is due to its ability to inhibit the synthesis of DNA and split the DNA chains.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Bleomicina/análogos & derivados , Carcinoma de Células Escamosas/patología , Neoplasias de la Boca/patología , Bleomicina/farmacología , División Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Daño del ADN , ADN de Neoplasias/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Células Tumorales Cultivadas/efectos de los fármacos , Ensayo de Tumor de Célula MadreRESUMEN
Betel quid chewing has been linked to oral submucous fibrosis and oral cancer. Cytotoxicity and genotoxicity assays were used to investigate the pathobiological effects of arecoline on cultured human buccal fibroblasts. Arecoline increased double-stranded polynucleic acid at the concentration of 0.1 to 10 micrograms/ml in a concentration-dependent manner. At a concentration higher than 50 micrograms/ml, arecoline was cytotoxic to cultured fibroblasts and the cytotoxicity was dose-dependent. No genotoxicity for arecoline was found even at a concentration of 400 micrograms/ml. On the other hand, 600 micrograms/ml glutathione (GSH) and 200 micrograms/ml glycyrrhizin could prevent the arecoline-induced cytotoxicity. These results indicate that arecoline is a cytotoxic agent and no genotoxicity was found to human buccal fibroblasts. Furthermore, increasing consumption of GSH- and glycyrrhizin-rich foods may reduce the oral diseases associated with betel quid chewing.