RESUMO
Lipid rafts display a lateral heterogeneity forming membrane microdomains that hold a fundamental role on biological membranes and are indispensable to physiological functions of cells. Oxidative stress in cellular environments may cause lipid oxidation, changing membrane composition and organization, thus implying in effects in cell signaling and even loss of homeostasis. The individual contribution of oxidized lipid species to the formation or disruption of lipid rafts in membranes still remains unknown. Here, we investigate the role of different structures of oxidized phospholipids on rafts microdomains by carefully controlling the membrane composition. Our experimental approach based on fluorescence microscopy of giant unilamellar vesicles (GUV) enables the direct visualization of the impact of hydroperoxidized POPC lipid (referred to as POPCOOH) and shortened chain lipid PazePC (1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine) on phase separation. We found that the molecular structure of oxidized lipid is of paramount importance on lipid mixing and/or demixing. The hydrophobic mismatch promoted by POPCOOH coupled to its cylindrical molecular shape favor microdomains formation. In contrast, the conical shape of PazePC causes disarrangement of lipid 2D organized platforms. Our findings contribute to better unraveling how oxidized phospholipids can trigger formation or disruption of lipid rafts. As a consequence, phospholipid oxidation may indirectly affect association or dissociation of key biomolecules in the rafts thus altering cell signaling and homeostasis.
Assuntos
Bicamadas Lipídicas/metabolismo , Microdomínios da Membrana/efeitos dos fármacos , Microdomínios da Membrana/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidilcolinas/farmacologia , Bicamadas Lipídicas/química , Peroxidação de Lipídeos/fisiologia , Microdomínios da Membrana/química , Oxidantes Fotoquímicos/química , Oxidantes Fotoquímicos/farmacologia , Oxirredução , Fosfatidilcolinas/química , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Fosforilcolina/metabolismo , Lipossomas Unilamelares/química , Lipossomas Unilamelares/metabolismoRESUMO
PURPOSE:: To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated. METHODS:: Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles. RESULTS:: There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups. CONCLUSIONS:: We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.
Assuntos
Dissulfetos/sangue , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Enxerto Vascular , Animais , Antibacterianos/farmacologia , Contagem de Colônia Microbiana , Citocinas/sangue , Homeostase/efeitos dos fármacos , Masculino , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Distribuição Aleatória , Ratos Wistar , Valores de Referência , Reprodutibilidade dos Testes , Albumina Sérica/análise , Fatores de Tempo , Transplantes/microbiologia , Resultado do Tratamento , Vancomicina/farmacologia , Doenças Vasculares/microbiologiaRESUMO
Abstract: Purpose: To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated. Methods: Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles. Results: There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups. Conclusions: We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.
Assuntos
Animais , Masculino , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Dissulfetos/sangue , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Enxerto Vascular , Valores de Referência , Fatores de Tempo , Doenças Vasculares/microbiologia , Albumina Sérica/análise , Vancomicina/farmacologia , Contagem de Colônia Microbiana , Distribuição Aleatória , Reprodutibilidade dos Testes , Citocinas/sangue , Resultado do Tratamento , Ratos Wistar , Transplantes/microbiologia , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Homeostase/efeitos dos fármacos , Antibacterianos/farmacologiaRESUMO
Here, we proposed that volatile organic compounds (VOC), specifically methyl salicylate (MeSA), mediate the formation of calcium oxalate crystals (COC) in the defence against ozone (O3) oxidative damage. We performed experiments using Croton floribundus, a pioneer tree species that is tolerant to O3 and widely distributed in the Brazilian forest. This species constitutively produces COC. We exposed plants to a controlled fumigation experiment and assessed biochemical, physiological, and morphological parameters. O3 induced a significant increase in the concentrations of constitutive oxygenated compounds, MeSA and terpenoids as well as in COC number. Our analysis supported the hypothesis that ozone-induced VOC (mainly MeSA) regulate ROS formation in a way that promotes the opening of calcium channels and the subsequent formation of COC in a fast and stable manner to stop the consequences of the reactive oxygen species in the tissue, indeed immobilising the excess calcium (caused by acute exposition to O3) that can be dangerous to the plant. To test this hypothesis, we performed an independent experiment spraying MeSA over C. floribundus plants and observed an increase in the number of COC, indicating that this compound has a potential to directly induce their formation. Thus, the tolerance of C. floribundus to O3 oxidative stress could be a consequence of a higher capacity for the production of VOC and COC rather than the modulation of antioxidant balance. We also present some insights into constitutive morphological features that may be related to the tolerance that this species exhibits to O3.
Assuntos
Oxalato de Cálcio/metabolismo , Respiração Celular/efeitos dos fármacos , Croton/metabolismo , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Compostos Orgânicos Voláteis/metabolismo , Antioxidantes/metabolismo , Cálcio/metabolismo , Croton/efeitos dos fármacos , OxirreduçãoRESUMO
UNLABELLED: Ozone is an important disinfecting agent, however its influence on enamel adhesion has not yet been clarified. OBJECTIVE: Evaluate the influence of ozone pretreatment on the shear strength of an etch-and-rinse and a self-etch system to enamel and analyze the respective failure modes. MATERIAL AND METHODS: Sixty sound bovine incisors were used. Specimens were randomly assigned to four experimental groups (n=15): Group G1 (Excite® with ozone) and group G3 (AdheSE® with ozone) were prepared with ozone gas from the HealOzone unit (Kavo®) for 20 s prior to adhesion, and groups G2 (Excite®) and G4 (AdheSE®) were used as control. Teeth were bisected and polished to simulate a smear layer just before the application of the adhesive systems. The adhesives were applied according to the manufacturer's instructions to a standardized 3 mm diameter surface, and a composite (Synergy D6, Coltene Whaledent) cylinder with 2 mm increments was build. Specimens were stored in 100% humidity for 24 h at 37°C and then subjected to a thermal cycling regimen of 500 cycles. Shear bond tests were performed with a Watanabe device in a universal testing machine at 5 mm/min. The failure mode was analyzed under scanning electron microscope. Means and standard deviation of shear bond strength (SBS) were calculated and difference between the groups was analyzed using ANOVA, Kolmogorov-Smirnov, Levene and Bonferroni. Chi-squared statistical tests were used to evaluate the failure modes. RESULTS: Mean bond strength values and failure modes were as follows: G1--26.85±6.18 MPa (33.3% of adhesive cohesive failure); G2--27.95±5.58 MPa (53.8% of adhesive failures between enamel and adhesive); G3--15.0±3.84 MPa (77.8% of adhesive failures between enamel and adhesive) and G4--13.1±3.68 MPa (36.4% of adhesive failures between enamel and adhesive). CONCLUSIONS: Shear bond strength values of both adhesives tested on enamel were not influenced by the previous application of ozone gas.
Assuntos
Resinas Acrílicas/química , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Metacrilatos/química , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Resistência ao Cisalhamento , Animais , Bovinos , Resinas Compostas/química , Esmalte Dentário/química , Falha de Restauração Dentária , Adesivos Dentinários/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Ácidos Fosfóricos/química , Distribuição Aleatória , Propriedades de SuperfícieRESUMO
Ozone is an important disinfecting agent, however its influence on enamel adhesion has not yet been clarified. Objective: Evaluate the influence of ozone pretreatment on the shear strength of an etch-and-rinse and a self-etch system to enamel and analyze the respective failure modes. Material and Methods: Sixty sound bovine incisors were used. Specimens were randomly assigned to four experimental groups (n=15): Group G1 (Excite® with ozone) and group G3 (AdheSE® with ozone) were prepared with ozone gas from the HealOzone unit (Kavo®) for 20 s prior to adhesion, and groups G2 (Excite®) and G4 (AdheSE®) were used as control. Teeth were bisected and polished to simulate a smear layer just before the application of the adhesive systems. The adhesives were applied according to the manufacturer's instructions to a standardized 3 mm diameter surface, and a composite (Synergy D6, Coltene Whaledent) cylinder with 2 mm increments was build. Specimens were stored in 100% humidity for 24 h at 37°C and then subjected to a thermal cycling regimen of 500 cycles. Shear bond tests were performed with a Watanabe device in a universal testing machine at 5 mm/min. The failure mode was analyzed under scanning electron microscope. Means and standard deviation of shear bond strength (SBS) were calculated and difference between the groups was analyzed using ANOVA, Kolmogorov-Smirnov, Levene and Bonferroni. Chi-squared statistical tests were used to evaluate the failure modes. Results: Mean bond strength values and failure modes were as follows: G1- 26.85±6.18 MPa (33.3% of adhesive cohesive failure); G2 - 27.95±5.58 MPa (53.8% of adhesive failures between enamel and adhesive); G3 - 15.0±3.84 MPa (77.8% of adhesive failures between enamel and adhesive) and G4 - 13.1±3.68 MPa (36.4% of adhesive failures between enamel and adhesive). Conclusions: Shear bond strength values of both adhesives tested on enamel were not influenced by the previous application of ozone gas.
Assuntos
Animais , Bovinos , Resinas Acrílicas/química , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Metacrilatos/química , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Resistência ao Cisalhamento , Resinas Compostas/química , Falha de Restauração Dentária , Esmalte Dentário/química , Adesivos Dentinários/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Ácidos Fosfóricos/química , Distribuição Aleatória , Propriedades de SuperfícieRESUMO
Ozone is a known oxidant present in the atmosphere and is commercially produced by simple ozonizer machines. It is a powerful antimicrobial agent in its gaseous and aqueous forms. Ozone readily dissolves in water and retains its antimicrobial property even in the dissolved state. In this study, the effect of 0.1 ppm ozonated water was analyzed on 24-hour supragingival plaque (SP) samples in situ. SP was collected from the two most posterior teeth in the contra-lateral quadrants before and after a 30-second rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). The plaque was used to count the number of total bacteria, total anaerobic bacteria, Streptococcus mutans, and Candida albicans on selective agar media. The statistical analysis of the number of colony forming units (CFUs) obtained demonstrated a significant antimicrobial effect of ozonated water on the total bacteria (p = 0.01) and anaerobes (p = 0.02). A reduction in the post-rinse CFU count for Streptococcus mutans was also observed, but the effect was not statistically significant (p = 0.07). The Candida species was only grown from one sample. Ozonated water at the 0.1 ppm concentration was effective in reducing the load of 24-hour plaque bacteria, but it did not eliminate them completely.
Assuntos
Anti-Infecciosos/farmacologia , Candida albicans/efeitos dos fármacos , Placa Dentária/microbiologia , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Streptococcus mutans/efeitos dos fármacos , Água/farmacologia , Adolescente , Adulto , Análise de Variância , Contagem de Colônia Microbiana , Humanos , Fatores de Tempo , Adulto JovemRESUMO
Ozone is a known oxidant present in the atmosphere and is commercially produced by simple ozonizer machines. It is a powerful antimicrobial agent in its gaseous and aqueous forms. Ozone readily dissolves in water and retains its antimicrobial property even in the dissolved state. In this study, the effect of 0.1 ppm ozonated water was analyzed on 24-hour supragingival plaque (SP) samples in situ. SP was collected from the two most posterior teeth in the contra-lateral quadrants before and after a 30-second rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). The plaque was used to count the number of total bacteria, total anaerobic bacteria, Streptococcus mutans, and Candida albicans on selective agar media. The statistical analysis of the number of colony forming units (CFUs) obtained demonstrated a significant antimicrobial effect of ozonated water on the total bacteria (p = 0.01) and anaerobes (p = 0.02). A reduction in the post-rinse CFU count for Streptococcus mutans was also observed, but the effect was not statistically significant (p = 0.07). The Candida species was only grown from one sample. Ozonated water at the 0.1 ppm concentration was effective in reducing the load of 24-hour plaque bacteria, but it did not eliminate them completely.
Assuntos
Adolescente , Adulto , Humanos , Adulto Jovem , Anti-Infecciosos/farmacologia , Candida albicans/efeitos dos fármacos , Placa Dentária/microbiologia , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Streptococcus mutans/efeitos dos fármacos , Água/farmacologia , Análise de Variância , Contagem de Colônia Microbiana , Fatores de TempoRESUMO
In endotoxic shock, variations are known to occur in different biochemical parameters of oxidative stress. Ozone oxidative preconditioning (OOP) is a good candidate to restore the redox balance on different tissue. This investigation examined the effect of OOP on different biomarkers of oxidative stress in hepatic tissue of mice treated with lipopolysaccharide (LPS). LPS doses of 30 mg/kg were administered intraperitoneally (i.p.) and pretreatment with ozone/oxygen mixture (OOM) was applied i.p. at 0.2, 0.4, and 1.2 mg/kg once daily during 5 days before LPS injection. The mice were euthanized under ether atmosphere at different times, 1 and 24 h after LPS injection. Hepatic tissue from all animals was taken for biochemical determinations of oxidative stress parameters such as thiobarbituric acid reactive substances (TBARS) content and activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST). The results demonstrated that OOP reduces levels of TBARS content and increases the activity of GPx in hepatic tissue. In conclusion, OOP was able to recover the redox balance and in this way to protect the animals against the oxidative damage induced by endotoxemia.
Assuntos
Fígado/efeitos dos fármacos , Oxidantes Fotoquímicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ozônio/farmacologia , Choque Séptico/metabolismo , Animais , Biomarcadores/metabolismo , Endotoxinas/toxicidade , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oxidantes Fotoquímicos/uso terapêutico , Oxirredução , Ozônio/uso terapêutico , Choque Séptico/tratamento farmacológico , Substâncias Reativas com Ácido TiobarbitúricoRESUMO
OBJECTIVE AND DESIGN: Reactive oxygen species, and also reactive species of nitrogen such as nitric oxide, play an important role in the pathogenesis of peritonitis and septic shock. Ozone oxidative preconditioning (OOP) has shown protective effects in various experimental models of peritonitis in rats and endotoxic shock in mice. Currently, strong evidence is available that this protective effect of OOP is due to its action on the balance between endogenous antioxidants and pro-oxidants, which is favorable for anti-oxidant defense. The aim of this research was to elucidate whether or not OOP is able to reduce nitrite levels in blood serum of mice treated with lipopolysaccharide (LPS). We used an experimental model of endotoxic shock induced by LPS in mice in which the animals were pre-treated with ozone/oxygen mixture for 5 days (once daily), with injection of LPS 24 h thereafter to induce endotoxic shock. RESULTS: Mice pretreated with OOP showed a significant decrease in nitrite levels with all three doses tested [0.2 mg/kg (50.91%), 0.4 mg/kg (47.3%) and 1.2 mg/kg (34.6%)]. CONCLUSIONS: Ozone oxidative preconditioning significantly reduced nitrite levels in blood serum of mice with endotoxic shock induced by LPS. We propose that OOP merits further testing in studies as a potential alternative treatment to reduce nitrite levels in patients with sepsis syndrome and septic shock.
Assuntos
Lipopolissacarídeos/toxicidade , Nitritos/sangue , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Choque Séptico/sangue , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Dexametasona/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
We synthesized and determined the production of reactive oxygen species (ROS) as 1O2, *-O2, *OH, H2O2 during the photolysis with UV-A light of three antibacterial quinolones and their naphthyl ester derivatives. Singlet oxygen and ROS dose-dependant generation from norfloxacin (1), enoxacin (2), ciprofloxacin (3) and their respective naphthyl ester derivatives 4-6 were detecting in cell-free systems by the histidine assay and by luminol-enhanced chemiluminescence (LCL). Both the electronic absorption and emission spectra were quantified and their photostability determined. The antibacterial activity in darkness and under irradiation of compounds 4, 5 and 6 was tested on E. coli and compared with their parent drugs.
Assuntos
Antibacterianos/farmacologia , Fluoroquinolonas/farmacologia , Naftalenos/farmacologia , Oxidantes Fotoquímicos/farmacologia , Antibacterianos/efeitos da radiação , Ciprofloxacina/farmacologia , Ciprofloxacina/efeitos da radiação , Meios de Cultura , Enoxacino/farmacologia , Enoxacino/efeitos da radiação , Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Fluoroquinolonas/efeitos da radiação , Histidina/análise , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Luminescência , Norfloxacino/farmacologia , Norfloxacino/efeitos da radiação , Oxidantes/química , Fotólise , Fármacos Fotossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Raios UltravioletaRESUMO
AIM: To determine the antimicrobial efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in human root canals infected by Enterococcus faecalis. METHODOLOGY: Thirty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. Eppendorf tubes were connected to the coronal portion of the teeth. Urethane hoses were attached to the tubes and to the entrance of a peristaltic pump. The exit of the apparatus corresponded to the apical portion of the root canals. The test irrigating solutions were ozonated water, gaseous ozone, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine that circulated at a constant flow of 50 mL min(-1) for 20 min. Samples from the root canals were collected and immersed in 7 mL Letheen Broth (LB), followed by incubation at 37 degrees C for 48 h. Bacterial growth was analysed by turbidity of the culture medium and subculture on a specific nutrient broth. A 0.1 mL inoculum obtained from LB was transferred to 7 mL of brain heart infusion and incubated at 37 degrees C for 48 h. Bacterial growth was checked by turbidity of the culture medium carried out in triplicate. RESULTS: No solution used as an irrigant over a 20-min contact time demonstrated an antimicrobial effect against E. faecalis. CONCLUSION: The irrigation of infected human root canals with ozonated water, 2.5% NaOCl, 2% chlorhexidine and the application of gaseous ozone for 20 min was not sufficient to inactivate E. faecalis.
Assuntos
Anti-Infecciosos Locais/farmacologia , Doenças da Polpa Dentária/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Irrigantes do Canal Radicular/farmacologia , Clorexidina/farmacologia , Contagem de Colônia Microbiana , Enterococcus faecalis/crescimento & desenvolvimento , Humanos , Testes de Sensibilidade Microbiana , Nefelometria e Turbidimetria , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Hipoclorito de Sódio/farmacologia , Água/química , Água/farmacologiaRESUMO
The aim of this study was to analyze the effect of nutritional condition and simulated exposure to ozone on Glutathione (GSH), the activity of Na+/K+ ATPase and lipid peroxidation in rat brain. Male Wistar rats were fed with 7% and 23% protein diets. Two groups were formed for each nutritional condition: one group was exposed for 15 successive days to 0.75 ppm of ozone and the other to air. Subsequently, the brain was dissected in cortex, hemispheres, cerebellum, and brainstem to measure the activity of thiobarbituric acid reactive substances (TBARS), ATPase, and levels of GSH. The activity of Na+/K+ ATPase increased in cerebellum of well-nourished rats exposed to ozone, while total ATPase and TBARS decreased in all studied areas in the malnourished groups. The levels of GSH decreased significantly (P < 0.05) in the brain of rats fed with 7% of protein diet and exposed to ozone but increased in rats fed with normal diet and exposed to ozone. These results suggest that malnutrition causes alterations in the values of Na+/K+ ATPase, total ATPase, GSH, and lipid peroxidation, while ozone contributes to these modifications. As a consequence, both variables are involved in oxidative stress in the rat brain.
Assuntos
Encéfalo/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Estado Nutricional/fisiologia , Oxidantes Fotoquímicos/farmacologia , Estresse Oxidativo , Ozônio/farmacologia , Animais , Biomarcadores , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Glutationa/metabolismo , Masculino , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
BACKGROUND: Cellular events in cisplatin-mediated nephrotoxicity include apoptosis induction, decreased protein synthesis, changes in the subcellular redistribution of Bax mitochondrial dysfunction, DNA injury, increased lipid peroxidation, depletion of glutathione and decrease in enzymatic activity of renal antioxidant enzymes. In previous papers we have shown that intra-rectal (i.r.) ozone/oxygen mixture protected and induced a significant recovery in cisplatin-induced renal damage and was related to a significant increase in the antioxidant system in renal tissue. METHODS: This study was undertaken to examine the effect of the ir applications of ozone/oxygen mixture in the renal expression pattern of Bax proteins in rats treated with cisplatin. A group of male Sprague-Dawley rats was pretreated with 15 i.r. applications of ozone/oxygen (1.1 mg/kg) before intraperitoneal injection of cisplatin (6 mg/kg). Another group was treated with five i.r. applications of ozone/oxygen mixture after cisplatin administration. Serum creatinine was measured thereafter. Subcellular distribution of Bax in renal tissue was analyzed by immunohistochemistry. RESULTS: Ozone pretreatment prevented the increase in serum creatinine levels and completely inhibited the acute tubular necrosis induced by cisplatin in renal tissue, diminishing the expression of Bax. Ozone treatment after cisplatin application reduced the increase in serum creatinine levels and the renal necrosis, inducing a lesser decrease of the Bax expression in cisplatin-treated kidneys. CONCLUSIONS: Expression of Bax in renal tissue seems to play an important role in the protection and recovery in cisplatin-nephrotoxicity achieved by ozone/oxygen mixture.
Assuntos
Antineoplásicos , Cisplatino , Rim/efeitos dos fármacos , Oxidantes Fotoquímicos/farmacologia , Oxigênio/metabolismo , Ozônio/farmacologia , Proteína X Associada a bcl-2/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Antioxidantes/metabolismo , Cisplatino/farmacologia , Cisplatino/toxicidade , Creatinina/sangue , Humanos , Rim/metabolismo , Rim/patologia , Masculino , Oxidantes Fotoquímicos/metabolismo , Oxirredução , Ozônio/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
Ozone oxidative preconditioning is a prophylactic approach, which favors the antioxidant-prooxidant balance for preservation of the cell redox state by increasing antioxidant endogenous systems in both in vivo and in vitro experimental models. The aim of this study was to analyze the effect of ozone oxidative preconditioning on the level of tumor necrosis factor-alpha (TNF-alpha) in the serum of mice treated with lipopolysaccaride (LPS). Pretreatment with an ozone/oxygen gaseous mixture was administered intraperitoneally (0.2, 0.4 and 1.2 mg/kg) or by rectal application (0.2 and 0.4 mg/kg) once daily during five days before LPS (0.1 mg/kg, intraperitoneal). TNF-alpha was measured by cytotoxicity on L-929 cells. One hour after LPS injection, a significant mean increase of TNF-alpha in mouse serum was observed. Ozone/oxygen gaseous mixture reduced serum TNF-alpha levels in a dose-dependent manner. Statistically significant decreases in TNF-alpha levels after LPS injection were observed either with ozone intraperitoneal applications at 0.2 (78 %), 0.4 (98.5 %) and 1.2 (98.6 %) mg/ kg or by rectal application at 0.2 (46.2 %) and 0.4 (97.4 %) mg/kg. These results indicate that ozone oxidative preconditioning inhibits TNF-alpha production.
Assuntos
Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Choque Séptico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Administração Retal , Animais , Injeções Intraperitoneais , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , OxirreduçãoRESUMO
Many studies indicate that oxygen free-radical formation after reoxygenation of liver may initiate the cascade of hepatocellular injury. It has been demonstrated that controlled ozone administration may promote an oxidative preconditioning or adaptation to oxidative stress, preventing the damage induced by reactive oxygen species (ROS) and protecting against liver ischaemia-reperfusion (I/R) injury. On the basis of those results we postulated that ozone treatment in our experimental conditions has biochemical parameters similar to the ischaemic preconditioning (IscheP) mechanism. Four groups of rats were classified as follows: (1) sham-operated animals subjected to anaesthesia and laparotomy, plus surgical manipulation; (2) I/R animals were subjected to 90 min of right-lobe hepatic ischaemia, followed by 90 min of reperfusion; (3) IscheP, previous to the I/R period (as in group 2): animals were subjected to 10 min of ischaemia and 10 min of reperfusion; (4) ozone oxidative preconditioning (OzoneOP), previous to the I/R period (as in group 2): animals were treated with ozone by rectal insufflation 1 mg kg (-1). The rats received 15 ozone treatments, one per day, of 5-5.5 ml at the ozone concentration of 50 microg ml (-1). The following parameters were measured: serum transaminases (AST, ALT) and 5'-nucleotidase (5 '-NT), with morphological determinations, as indicators or hepatocellular injury; total sulfhydryl groups, calcium levels and calpain activity as mediators which take part in xanthine deshydrogenase (XDH) conversion to xanthine oxidase (XO) (reversible and irreversible forms, respectively); XO activities and malondialdehyde + 4-hydroyalkenals as indicators of increased oxidative stress. AST, ALT levels were attenuated in the IscheP (130 +/- 11.4 and 75 +/- 5.7 U l (-1)) with regard to the I/R group (200 +/- 22 and 117 +/- 21.7 U l (-1)) while the OzoneOP maintained both of the enzyme activities ( 89.5 +/- 12.6 and 43.7 +/- 10 U l (-1)) without statistical differences (P< 0.05) in comparison with the sham-operated ( 63.95 +/- 11 and 19.48 +/- 3.2 U l (-1)). Protective effects of both the preconditioning settings on the preservation of total sylfhydryl groups (IscheP: 6.28 +/- 0.07, OzoneOP: 6.34 +/- 0.07 micromol mg prot (-1)), calcium concentrations (IscheP: 0.18 +/- 0.09, OzoneOP: 0.20 +/- 0.06 micromol mg prot (-1)), and calpain activity (IscheP: 1.04 +/- 0.58, OzoneOP: 1.41 +/- 0.79 U mg prot (-1)) were observed. Both of the preconditionings attenuated the increase of total XO associated to I/R injury. Generation of malondialdehyde + 4 hydroxyalkenals was prevented by IscheP and OzoneOP without statistical differences between the two protective procedures. These results provide evidence that both of the preconditioning settings share similar biochemical mechanisms of protection in the parameters which were measured. Although there were no differences from a biochemical point of view between Ischaemic and OzoneOPs, the histological results showed a more effective protection of OzoneOP than IscheP in our experimental conditions.
Assuntos
Precondicionamento Isquêmico , Circulação Hepática/fisiologia , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Cálcio/metabolismo , Calpaína/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Testes de Função Hepática , Masculino , Proteínas/metabolismo , Ratos , Ratos Wistar , Compostos de Sulfidrila/metabolismo , Xantina Desidrogenase/metabolismo , Xantina Oxidase/metabolismoRESUMO
Ozone has been used as a therapeutical agent and beneficial effects have been observed. However so far only a few biochemical and pharmacodynamic mechanisms have been elucidated. We demonstrate that controlled ozone administration may promote an oxidative preconditioning or adaptation to oxidative stress, preventing the damage induced by reactive oxygen species (ROS). Taking into account that diabetes is a disorder associated with oxidative stress, we postulate that ozone treatment in our experimental conditions might protect antioxidant systems and maintain, at a physiological level, other markers of endothelial cell damage associated with diabetic complications. Five groups of rats were classified as follows: (1) control group treated only with physiological saline solution; (2) positive control group using streptozotocin (STZ) as a diabetes inductor; (3) ozone group, receiving 10 treatments (1.1 mg kg(-1)), one per day after STZ-induced diabetes; (4) oxygen group (26 mg kg(-1)), one per day, as in group 3 but using oxygen only; (5) control ozone group, as group 3, but without STZ. The ozone treatment improved glycemic control and prevented oxidative stress, the increase of aldose reductase, fructolysine content and advanced oxidation protein products. Nitrite and nitrate levels were maintained without changes with regard to non-diabetic control. The results of this study show that repeated administration of ozone in non-toxic doses might play a role in the control of diabetes and its complications.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Oxidantes Fotoquímicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ozônio/uso terapêutico , Animais , Biomarcadores/análise , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Glicosilação/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Nitratos/metabolismo , Óxido Nítrico/biossíntese , Nitritos/metabolismo , Oxidantes Fotoquímicos/uso terapêutico , Oxirredução/efeitos dos fármacos , Ozônio/administração & dosagem , Proteínas/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
By-products of lipoperoxidation reactions may be associated with the genesis or the progression of several diseases as arteriosclerosis, diabetes and cancer, among many others. Acrolein, at first a widely distributed environmental pollutant, is currently known as a compound capable of being generated as a result of metabolic reactions within biological systems, highly toxic and the most electrophilic of the alpha, beta-unsaturated aldehydes formed during lipoperoxidation. In the present study: 1. The separation of acrolein and malondialdehyde was achieved at alkaline pH with the use of high voltage capillary electrophoresis in uncoated fused-silica capillaries. 2. It was demonstrated how the oxidation of fatty acids (arachidonic/linoleic) with ozone generates, in dose-dependent form, acrolein as one of the by-products of the lipoperoxidation process. The oxidation of open human erythrocyte membranes with ozone also generated acrolein. 3. After aldolic condensation, aldol-acrolein derivative has a positive reaction with 2-thiobarbituric acid (TBA) and shows a maximum absorption at 498 nm. This novel characteristic is used in its identification after the separation of the by-products. 4. It is possible to suggest that in the classic reaction of the denominated thiobarbituric acid reactive substances (TBARS), when used as an indicator of the degree of peroxidation in biological systems, a portion of acrolein could be present but dwarfed by the TBA-MDA adduct.
Assuntos
Acroleína/metabolismo , Ácidos Graxos Insaturados/metabolismo , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Acroleína/isolamento & purificação , Relação Dose-Resposta a Droga , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Oxirredução , Tiobarbitúricos/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Polysomnographic studies were done at hourly intervals during 0.00, 0.35, 0.75 and 1.50 ppm of ozone (O3) exposure. We found a significant decrease in paradoxical sleep after 2 h and an increase in slow wave sleep after 12 h at all concentrations of O3. High resolution liquid chromatography demonstrated an increase in 5-HT concentration in the rat pons, in a roughly stepwise fashion as the O3 concentration increased. We propose that reaction products derived from O3 exposure, such as prostaglandins, could be affecting those physiological and biochemical mechanisms critical for the generation and maintenance of the sleep-wake cycle.