RESUMO
Diphenyl diselenide (DPDS) is an electrophilic reagent used in the synthesis of a variety of pharmacologically active organoselenium compounds. Studies have shown its interesting pharmacodinamic properties, as antioxidant, antimutagenic and antitumoral effects. Here we report the antigenotoxic properties of DPDS against tamoxifen (TAM)-induced oxidative DNA damage in MCF-7 cultured cell line. We determined the cytotoxicity by lactate dehydrogenase (LDH) leakage assay and evaluated oxidative DNA damage by modified comet assay employing the enzymes formamidopyrimidine DNA-glycosylase (Fpg) and endonuclease III (Endo III). Our results demonstrate that the cellular effects of DPDS appear to be complex and concentration-dependent. The present findings show that DPDS is not genotoxic (at concentrations lower than 2.0µmol/L) in MCF-7 cells, as observed in the modified comet assay. Moreover, DPDS protects against TAM-induced oxidative DNA damage, probably by its antioxidant activity, without interfering with its cytotoxicity. In this manner, the treatment with low concentrations of DPDS, a synthetic organoselenium compound, could be used as a potent antigenotoxic agent to prevent the risk of cancer induction triggered by tamoxifen hormone therapy. Thereby, more studies concerning the toxicity of DPDS and its structural derivatives are still necessary for future safe therapeutic application and development of novel chemopreventive compounds for combined therapy in breast cancer.
Assuntos
Antimutagênicos/farmacologia , Antineoplásicos Hormonais/toxicidade , Derivados de Benzeno/farmacologia , Compostos Organosselênicos/farmacologia , Tamoxifeno/toxicidade , Antimutagênicos/administração & dosagem , Antimutagênicos/toxicidade , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Antioxidantes/toxicidade , Derivados de Benzeno/administração & dosagem , Derivados de Benzeno/toxicidade , Neoplasias da Mama/patologia , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Humanos , Células MCF-7 , Compostos Organosselênicos/administração & dosagem , Compostos Organosselênicos/toxicidade , Estresse Oxidativo/efeitos dos fármacosRESUMO
Axinella corrugata lectin 1 (ACL-1) was purified from aqueous extracts of the marine sponge, Axinella corrugata. ACL-1 strongly agglutinates native rabbit erythrocytes. The hemagglutination is inhibited by N-acetyl derivatives, particularly N, N', N"-triacetylchitotriose, N-acetyl-D-glucosamine, N-acetyl-D-mannosamine and N-acetyl-D-galactosamine. We investigated the capacity of biotinylated ACL-1 to stain several transformed cell lines including breast (T-47D, MCF7), colon (HT-29), lung (H460), ovary (OVCAR-3) and bladder (T24). ACL-I may bind to both monosaccharides and oligosaccharides of tumor cells, N-acetyl-D-galactosamine, and N-acetyl-D- glucosamine glycan types. The lectins are useful, not only as markers and diagnostic parameters, but also for tissue mapping in suspicious neoplasms. In addition, they provide a better understanding of neoplasms at the cytological and molecular levels. Furthermore, the use of potential metastatic markers such as lectins is crucial for developing successful tools for therapy against cancer. We observed that biotinylated ACL-I stains tumor cells and may hold potential as a probe for identifying transformed cells and for studying glycan structures synthesized by such cells.
Assuntos
Axinella/química , Lectinas/química , Neoplasias/química , Coloração e Rotulagem/métodos , Animais , Biotinilação , Linhagem Celular Tumoral , Cromatografia de Afinidade/métodos , Neoplasias/patologia , Coelhos , RatosRESUMO
Kaurane diterpenes are considered important compounds in the development of new highly effective anticancer chemotherapeutic agents. Genotoxic effects of anticancer drugs in non-tumour cells are of special significance due to the possibility that they induce secondary tumours in cancer patients. In this context, we evaluated the genotoxic and mutagenic potential of the natural diterpenoid kaurenoic acid (KA), i.e. (-)-kaur-16-en-19-oic acid, isolated from Xylopia sericeae St. Hill, using several standard in vitro and in vivo protocols (comet, chromosomal aberration, micronucleus and Saccharomyces cerevisiae assays). Also, an analysis of structure-activity relationships was performed with two natural diterpenoid compounds, 14-hydroxy-kaurane (1) and xylopic acid (2), isolated from X. sericeae, and three semi-synthetic derivatives of KA (3-5). In addition, considering the importance of the exocyclic double bond (C16) moiety as an active pharmacophore of KA cytotoxicity, we also evaluated the hydrogenated derivative of KA, (-)-kauran-19-oic acid (KAH), to determine the role of the exocyclic bond (C16) in the genotoxic activity of KA. In summary, the present study shows that KA is genotoxic and mutagenic in human peripheral blood leukocytes (PBLs), yeast (S. cerevisiae) and mice (bone marrow, liver and kidney) probably due to the generation of DNA double-strand breaks (DSB) and/or inhibition of topoisomerase I. Unlike KA, compounds 1-5 and KAH are completely devoid of genotoxic and mutagenic effects under the experimental conditions used in this study, suggesting that the exocyclic double bond (C16) moiety may be the active pharmacophore of the genetic toxicity of KA.
Assuntos
Diterpenos/química , Diterpenos/toxicidade , Mutagênicos/toxicidade , Extratos Vegetais/toxicidade , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Testes de Mutagenicidade , Relação Estrutura-AtividadeRESUMO
The genotoxic effect of two tanshinones isolated from roots of Hyptis martiussi Benth (Labiatae) was studied using V79 (Chinese hamster lung) cells by the alkaline comet assay and micronucleus test. Tanshinones were incubated with the cells at concentrations of 1, 3, 6 and 12 microg/mL for 3 h. Tanshinones were shown to be quite strongly genotoxic against V79 cells at all tested concentrations. The data obtained provide support to the view that tanshinones has DNA damaging activity in cultured V79 cells under the conditions of the assays.
Assuntos
Antioxidantes/uso terapêutico , Intoxicação por Tetracloreto de Carbono/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Flavonoides/uso terapêutico , Animais , Análise Química do Sangue , Intoxicação por Tetracloreto de Carbono/patologia , Catalase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/patologia , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
The pharmacology of synthetic organoselenium compounds indicates that they can be used as antioxidants, enzyme inhibitors, neuroprotectors, anti-tumor and anti-infectious agents, and immunomodulators. In this review, we focus on the effects of diphenyl diselenide (DPDS) in various biological model organisms. DPDS possesses antioxidant activity, confirmed in several in vitro and in vivo systems, and thus has a protective effect against hepatic, renal and gastric injuries, in addition to its neuroprotective activity. The activity of the compound on the central nervous system has been studied since DPDS has lipophilic characteristics, increasing adenylyl cyclase activity and inhibiting glutamate and MK-801 binding to rat synaptic membranes. Systemic administration facilitates the formation of long-term object recognition memory in mice and has a protective effect against brain ischemia and on reserpine-induced orofacial dyskinesia in rats. On the other hand, DPDS may be toxic, mainly because of its interaction with thiol groups. In the yeast Saccharomyces cerevisiae, the molecule acts as a pro-oxidant by depleting free glutathione. Administration to mice during cadmium intoxication has the opposite effect, reducing oxidative stress in various tissues. DPDS is a potent inhibitor of d-aminolevulinate dehydratase and chronic exposure to high doses of this compound has central effects on mouse brain, as well as liver and renal toxicity. Genotoxicity of this compound has been assessed in bacteria, haploid and diploid yeast and in a tumor cell line.
Assuntos
Animais , Camundongos , Ratos , Antioxidantes/farmacologia , Derivados de Benzeno/farmacologia , Compostos Organosselênicos/farmacologia , Sintase do Porfobilinogênio/antagonistas & inibidores , Saccharomyces cerevisiae/efeitos dos fármacos , Derivados de Benzeno/toxicidade , Modelos Biológicos , Testes de Mutagenicidade , Compostos Organosselênicos/toxicidadeRESUMO
Programmed cell death (PCD) is present during the development of multicellular organisms and occurs from embryogenesis to death. In females of Boophilus microplus, the mass of several organs is reduced after the detachment from the host. In order to better characterize the cell death process that eliminates unnecessary tissues, the degeneration of salivary glands, ovaries and synganglia was investigated using DNA fragmentation in agarose gel, comet and TUNEL assays, and apoptosis activation pathway by the caspase assay. DNA fragmentation and enzymatic activity of caspase-3 were observed in salivary glands and ovaries at 48 and 72h after tick removal from the host; in synganglia these parameters were maintained at low levels upon 48h. The results obtained suggest that there is a refined control of tissue maintenance through apoptosis.
Assuntos
Apoptose/fisiologia , Ixodidae/fisiologia , Oviposição/fisiologia , Animais , Fragmentação do DNA , Feminino , Gânglios/citologia , Ovário/citologia , Glândulas Salivares/citologiaRESUMO
The pharmacology of synthetic organoselenium compounds indicates that they can be used as antioxidants, enzyme inhibitors, neuroprotectors, anti-tumor and anti-infectious agents, and immunomodulators. In this review, we focus on the effects of diphenyl diselenide (DPDS) in various biological model organisms. DPDS possesses antioxidant activity, confirmed in several in vitro and in vivo systems, and thus has a protective effect against hepatic, renal and gastric injuries, in addition to its neuroprotective activity. The activity of the compound on the central nervous system has been studied since DPDS has lipophilic characteristics, increasing adenylyl cyclase activity and inhibiting glutamate and MK-801 binding to rat synaptic membranes. Systemic administration facilitates the formation of long-term object recognition memory in mice and has a protective effect against brain ischemia and on reserpine-induced orofacial dyskinesia in rats. On the other hand, DPDS may be toxic, mainly because of its interaction with thiol groups. In the yeast Saccharomyces cerevisiae, the molecule acts as a pro-oxidant by depleting free glutathione. Administration to mice during cadmium intoxication has the opposite effect, reducing oxidative stress in various tissues. DPDS is a potent inhibitor of delta-aminolevulinate dehydratase and chronic exposure to high doses of this compound has central effects on mouse brain, as well as liver and renal toxicity. Genotoxicity of this compound has been assessed in bacteria, haploid and diploid yeast and in a tumor cell line.
Assuntos
Antioxidantes/farmacologia , Derivados de Benzeno/farmacologia , Compostos Organosselênicos/farmacologia , Sintase do Porfobilinogênio/antagonistas & inibidores , Saccharomyces cerevisiae/efeitos dos fármacos , Animais , Derivados de Benzeno/toxicidade , Camundongos , Modelos Biológicos , Testes de Mutagenicidade , Compostos Organosselênicos/toxicidade , RatosRESUMO
Glutathione S-transferases (GSTs) are enzymes that act in excretion of physiologic and xenobiotic substances, protecting cells against chemical toxicity and stress. In this work, we characterized the enzymatic activity of GST in eggs and larvae of cattle tick Boophilus microplus, on different days after oviposition and eclosion. The results showed that the GST activity varied depending on the time elapsed after oviposition and eclosion. Molecules involved in mechanism of protection from oxidative stress are correlated with the increase in GST activity. The oxygen consumption kinetics showed a positive correlation with the increase in GST activity during embryogenesis. A high content of thiobarbituric acid reactive substances were observed in egg and larva extracts, indicating that ticks face high oxidative stress during embryogenesis and aging. In eggs and larvae, GST activity can be correlated to kinetic parameters of oxidative stress such as catalase and glutathione. In addition, GST activity showed strong positive correlation with lipid peroxidation, an indication that it plays a role in oxidant defences in eggs.
Assuntos
Ixodidae/metabolismo , Peroxidação de Lipídeos , Óvulo/metabolismo , Estresse Oxidativo , Consumo de Oxigênio , Amitrol (Herbicida)/farmacologia , Animais , Catalase/antagonistas & inibidores , Catalase/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Larva/metabolismoRESUMO
Copaiba oil extracted from the Amazon traditional medicinal plant Copaifera langsdorffii is rich in kaurenoic acid (ent-kaur-16-en-19-oic acid), a diterpene that has been shown to exert anti-inflammatory, hypotensive, and diuretic effects in vivo and antimicrobial, smooth muscle relaxant and cytotoxic actions in vitro. This study evaluated its potential genotoxicity against Chinese hamster lung fibroblast (V79) cells in vitro, using the Comet and the micronucleus assays. Kaurenoic acid was tested at concentrations of 2.5, 5,10, 30 and 60 microg/mL. The positive control was the methylmethanesulfonate (MMS). The duration of the treatment of V79 cells with these agents was 3h. The results showed that unlike MMS, kaurenoic acid (2.5, 5, and 10 microg/mL) failed to induce significantly elevated cell DNA damage or the micronucleus frequencies in the studied tests. However, exposure of V79 cells to higher concentrations of kaurenoic acid (30 and 60 microg/mL) caused significant increases in cell damage index and frequency. The data obtained provide support to the view that the diterpene kaurenoic acid induces genotoxicity.
Assuntos
Antineoplásicos Alquilantes/toxicidade , Dano ao DNA/efeitos dos fármacos , Diterpenos/toxicidade , Fabaceae , Animais , Antineoplásicos Alquilantes/uso terapêutico , Ensaio Cometa , Cricetinae , Cricetulus , Diterpenos/uso terapêutico , Relação Dose-Resposta a Droga , Fabaceae/química , Neoplasias Pulmonares/tratamento farmacológico , Metanossulfonato de Metila/toxicidade , Testes para Micronúcleos , Testes de Mutagenicidade , Fitoterapia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/toxicidade , Células Tumorais CultivadasRESUMO
4,5,6-Trichloroguaiacol (4,5,6-TCG) is a recalcitrant organochlorine compound produced during pulp bleaching and a potential environmental hazard in paper mill effluents. We report here the identification by biochemical tests and molecular biological analysis, using 16S ribotyping, of a 4,5,6-TCG-degrading bacterium, identified as a strain of Bacillus subtilis that is most closely related according to the phylogenetic analysis to B. subtilis strain Lactipan (alignment score 99%). Biodegradation of 4,5,6-TCG by this organism in a mineral salts medium was shown to occur only when the inoculum was composed of cells in the stationary phase of growth and to be accelerated by an additional carbon source, such as glucose, sucrose, glycerol or molasses. An additional nitrogen source (as ammonium sulfate) did not affect the rate of 4,5,6-TGC removal. No plasmids were detected in the bacterial cells. This is the first strain of B. subtilis which degrades chlorophenols and shows that 4,5,6-TCG is not degraded by cometabolism and that the gene encoding this characteristic is probably located on the chromosome. The lack of requirement for additional nitrogen source, the ability to enhance biodegradation by adding cheap carbon sources such as molasses, and the fact the trait is likely to be stable since it is encoded on the cell chromosome, are all characteristics that make the organism an attractive possibility for treatment of wastes and environments polluted with organochlorine compounds.
Assuntos
Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Poluição Ambiental/prevenção & controle , Guaiacol/análogos & derivados , Guaiacol/metabolismo , Filogenia , Sequência de Bases , Biodegradação Ambiental , Carbono/metabolismo , Análise por Conglomerados , Primers do DNA , DNA Ribossômico/genética , Eletroforese , Dados de Sequência Molecular , Análise de Sequência de DNA , Espectrofotometria UltravioletaRESUMO
OBJECTIVES: A genetic test for susceptibility of periodontal disease has been introduced. A positive test indicates a risk factor for more severe periodontal destruction. The prevalence of genotype positive subjects has been reported around 30%. In a Mexican population, we have found a 26% prevalence of genotype positive individuals. Few studies have reported the response to therapy in these individuals. The purpose of this study was to assess the response to mucogingival surgery in an otherwise periodontally healthy Hispanic population. MATERIALS AND METHODS: 22 subjects (7 male and 15 female) with a mean age of 45 years participated. They were treated 3 years prior for the treatment of Types I and II recession defects using connective tissue grafts. No other active periodontal treatment was required, except for preventive maintenance. A full-mouth clinical evaluation was performed which included assessment of gingival inflammation and measurements of probing pocket depth and clinical attachment levels. Mean values per patient were determined. A finger stick blood sample was collected using specially provided DNA filter paper, let dried, and mailed for processing. RESULTS: Results indicated that 5 out of the 22 subjects were genotype positive. The genotype positive subjects presented the following values: GI 1.13+/-0.17, PPD 2.48+/-0.46, and CAL 3.38+/-0.66. The values for the genotype negative subjects were GI 1.06+/-0.14, PPD 2.38+/-0.31 and CAL 3.11+/-0.53. No statistical significant differences were found when both groups were compared (p>0.05). Furthermore, the treatment of the localized recessions was effective and provided similar amount of coverage in genotype positive and negative subjects. However, more genotype negative subjects showed complete coverage of the recession than genotype positive individuals. CONCLUSIONS: Within the limits of this study it is concluded that (1) periodontal health can be maintained with proper preventive maintenance irrespective of the genotype present, (2) the mean response to mucogingival surgery to cover localized gingival recessions is similar irrespective of the IL-1 periodontal genotype, however, full coverage is achieved more frequently in genotype negative subjects.
Assuntos
Retração Gengival/cirurgia , Interleucina-1/genética , Periodonto/metabolismo , Polimorfismo Genético/genética , Adolescente , Adulto , Idoso , Tecido Conjuntivo/transplante , Feminino , Seguimentos , Predisposição Genética para Doença/genética , Técnicas Genéticas , Genótipo , Gengiva/transplante , Retração Gengival/classificação , Gengivite/classificação , Humanos , Masculino , México , Pessoa de Meia-Idade , Perda da Inserção Periodontal/classificação , Doenças Periodontais/genética , Doenças Periodontais/prevenção & controle , Índice Periodontal , Bolsa Periodontal/classificação , Fatores de Risco , Estatística como Assunto , População Branca/genéticaRESUMO
Morphological and functional changes caused by diabetes in the accessory sex organs and especially the prostate have been reported by several investigators. The aim of the present study was to examine the possible deleterious effects of experimentally induced diabetes on the secretory epithelium of the ventral prostate of mice. Sixteen adult male C57BL/6J mice were divided into two groups. The diabetic group received a streptozotocin injection of 75 mg/kg, while the control group received only 0.1 ml citrate buffer, i.p. After 30 days, the diabetic state was ascertained, the animals were sacrificed and the ventral lobe of the prostate was collected for histological and ultrastructural examination. The results showed reduction in glandular epithelium cell height, increased numbers of cytoplasmic vacuoles and thickening of the extracellular matrix. In conclusion, experimental diabetes has harmful effects on the secretory epithelial cells of the ventral lobe of the prostate of mice.
Assuntos
Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Próstata/patologia , Próstata/ultraestrutura , Doenças Prostáticas/etiologia , Doenças Prostáticas/patologia , Animais , Diabetes Mellitus Experimental/fisiopatologia , Epitélio/patologia , Epitélio/fisiopatologia , Epitélio/ultraestrutura , Matriz Extracelular/patologia , Matriz Extracelular/ultraestrutura , Glicosúria/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Próstata/fisiopatologia , Doenças Prostáticas/fisiopatologia , Urinálise/estatística & dados numéricos , Vacúolos/patologia , Vacúolos/ultraestruturaRESUMO
No presente trabalho foi desenvolvida metodologia para determinaçäo de traços de sulfatos em material particulado atmosférico. Foi também estudada a viabilidade de utilizaçäo da titulaçäo potenciométrica com AgNO3 na determinaçäo de cloretos no mesmo tipo de matriz ambiental. Comprovou-se que pela utilizaçäo deste método gráfico, pode-se chegar à determinaçäo de até 10 M de cloretos, quando se emprega o método da adiçäo prévia de padräo, com erro relativo de l5,1%. Empregando-se esse método foram determinados íons cloreto em material particulado atmosférico coletado na regiäo da área metropolitana de Säo Paulo, na faixa de 0,5 a 2,0 ug/m3, com coeficiente de variaçäo de 20 e 8% respectivamente, para a menor e a maior concentraçäo.
Assuntos
Cloretos , Poluição Ambiental/análise , Sulfatos , MétodosRESUMO
Foi feita uma análise para orientar a determinaçäo dos riscos a saúde e medidas de controle necessárias para a utilizaçäo da nova mistura combustível no Brasil