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1.
Molecules ; 26(19)2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34641628

RESUMO

This work aims to assess the recently established anti-inflammatory and antioxidant potential of melatonin of plant origin extracted from the plant matrix as a phytomelatonin complex (PHT-MLT), and compare its activity with synthetic melatonin (SNT-MLT) when used on its own or with vitamin C. For this purpose, a COX-2 enzyme inhibitory activity test, an antiradical activity in vitro and on cell lines assays, was performed on both PHT-MLT and SNT-MLT products. COX-2 inhibitory activity of PHT-MLT was found to be ca. 6.5 times stronger than that of SNT-MLT (43.3% and 6.7% enzyme inhibition, equivalent to the activity of acetylsalicylic acid in conc. 30.3 ± 0.2 and 12.0 ± 0.3 mg/mL, respectively). Higher antiradical potential and COX-2 inhibitory properties of PHT-MLT could be explained by the presence of additional naturally occurring constituents in alfalfa, chlorella, and rice, which were clearly visible on the HPLC-ESI-QTOF-MS fingerprint. The antiradical properties of PHT-MLT determined in the DPPH test (IC50 of 21.6 ± 1 mg of powder/mL) were found to originate from the presence of other metabolites in the 50% EtOH extract while SNT-MLT was found to be inactive under the applied testing conditions. However, the antioxidant studies on HaCaT keratinocytes stimulated with H2O2 revealed a noticeable activity in all samples. The presence of PHT-MLT (12.5, 25 and 50 µg/mL) and vitamin C (12.5, 25 and 50 µg/mL) in the H2O2-pretreated HaCaT keratinocytes protected the cells from generating reactive oxygen species. This observation confirms that MLT-containing samples affect the intracellular production of enzymes and neutralize the free radicals. Presented results indicated that MLT-containing products in combination with Vitamin C dosage are worth to be considered as a preventive alternative in the therapy of various diseases in the etiopathogenesis, of which radical and inflammatory mechanisms play an important role.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Ciclo-Oxigenase 2/metabolismo , Queratinócitos/citologia , Melatonina/farmacologia , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Antioxidantes/síntese química , Antioxidantes/química , Ácido Ascórbico/farmacologia , Linhagem Celular , Regulação para Baixo , Sinergismo Farmacológico , Radicais Livres/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/efeitos adversos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Melatonina/síntese química , Melatonina/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia
2.
Methods Mol Biol ; 2202: 33-42, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32857343

RESUMO

Production of reactive oxygen species (ROS) in the mitochondria plays multiple roles in physiology, and excessive production of ROS leads to the development of various pathologies. ROS in the mitochondria are generated by various enzymes, mainly in the electron transporvt chain, and it is important to identify not only the trigger but also the source of free radical production. It is important to measure mitochondrial ROS in live, intact cells, because activation of ROS production could be initiated by changes in extramitochondrial processes which could be overseen when using isolated mitochondria. Here we describe the approaches, which allow to measure production of ROS in the matrix of mitochondria in live cells. We also demonstrate how to measure kinetic changes in lipid peroxidation in mitochondria of live cells. These methods could be used for understanding the mechanisms of pathology in a variety of disease models and also for testing neuro- or cardioprotective chemicals.


Assuntos
Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Imagem Individual de Molécula/métodos , Animais , Radicais Livres/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Modelos Biológicos , Estresse Oxidativo
3.
Environ Sci Pollut Res Int ; 25(3): 2614-2622, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29130132

RESUMO

Arsenic (As) is a well-known contaminant of global groundwater. Its exposure causes several hazardous effects on animals and human via oxidative stress. The present study examined the effect of polydatin (PD) on free radical overproduction in rats exposed to As. Thirty-five male rats randomly allocated into five equal groups. To the control group, physiological saline was given orally and to the second group only 100 mg/L As was given by drinking water for 60 days. The other groups were treated with As (100 mg/L) and PD orally at 50, 100, and 200 mg/kg/day, respectively. Treatment with As enhanced malondialdehyde level but decreased glutathione level in blood, liver, kidney, brain, lung, and heart of rats. Also, As decreased superoxide dismutase and catalase activities of erythrocyte, liver, kidney, brain, lung, and heart in rats. Furthermore, As treatment gave rise to increased DNA damage and gene expressions of interleukin 1 beta (IL-1ß), nuclear factor kappa beta (NFκB), p53, and tumor necrosis factor-α (TNF-α) in the lung, brain, kidney, and liver. However, treatment of PD ameliorated As-exposed lipid peroxidation, antioxidant enzymes activities, DNA damage, gene expressions, and histopathological changes in tissues. In conclusion, PD has a dose-dependent protective effect on lipid peroxidation and antioxidant defense mechanism in rats against As exposure.


Assuntos
Arsênio/toxicidade , Dano ao DNA/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Radicais Livres/metabolismo , Expressão Gênica/efeitos dos fármacos , Glucosídeos/farmacologia , Estilbenos/farmacologia , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Eritrócitos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar
4.
J Oral Pathol Med ; 45(10): 753-757, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26876359

RESUMO

BACKGROUND: Oxidative DNA damage leads to abnormalities in endogenous cellular processes and constitutes a direct link between free radicals, antioxidants and squamous cell carcinoma (SCC). Oxygen radical absorbance capacity (ORAC) method is used to measure antioxidant capacity versus oxygen free radicals. There is no report on the application of ORAC to evaluate salivary antioxidant capacity in patients with head and neck SCC. This study investigated the relation between total antioxidant capacity of saliva, measured with ORAC method, and the incidence, location, size and histopathological grading of SCC. METHODS: Salivary antioxidant capacity was assessed in 30 male and female patients with histopathologically confirmed oral and laryngeal SCC. Histopathological grading of SCC was based on WHO classification. RESULTS: Mean ORAC in patients with SCC was higher than the mean value in the control group. Statistically significant difference was observed in the study group versus the control group. No significant differences were observed for ORAC values in relation to histopathological grading, tumour size and spread to lymph nodes. CONCLUSIONS: The obtained results can advocate local compensatory mechanism in saliva in response to increased oxidative stress associated with primary tumour. ORAC can become an additional factor in head and neck SCC prognosis, but further investigation is required.


Assuntos
Antioxidantes/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Saliva/metabolismo , Idoso , Antioxidantes/química , Carcinoma de Células Escamosas/genética , Dano ao DNA , Feminino , Radicais Livres/química , Radicais Livres/metabolismo , Neoplasias de Cabeça e Pescoço/genética , Humanos , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patologia , Masculino , Pessoa de Meia-Idade , Oxirredução , Capacidade de Absorbância de Radicais de Oxigênio , Saliva/química , Carcinoma de Células Escamosas de Cabeça e Pescoço
5.
J Therm Biol ; 44: 35-40, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25086971

RESUMO

The mechanism of the rate of living-free radical theory suggests that higher rate of oxidative metabolism results from greater rate of mitochondria oxidative phosphorylation, leading to a consequent increase in production of free radicals. However, the relation between metabolic rate and oxidative stress is tissue dependent in animals acclimated to cold temperatures. Here we examined oxidative stress, reflected by changes of antioxidant activity and other related markers, in striped hamsters acclimated to moderate cold (15°C), room (23°C) or warm temperature (30°C) for 6 weeks, by which either higher or lower metabolic rate was induced experimentally. Energy intake and the rate of metabolism and nonshivering thermogenesis were increased at 15°C, but decreased at 30°C compared with that at 23°C. Effects of temperatures on the markers of both oxidative stress and antioxidant activities were rarely significant. The percentages of positive correlation between the 11 tissues (brain, BAT, liver, heart, lung, kidneys, stomach, small and large intestine, caecum and skeletal muscle) were 14.5% (8/55) for catalase (CAT), 7.3% (4/55) for the capacity of inhibition of hydroxyl free radical (CIH), 5.5% (3/55) for activities of superoxide dismutase (SOD), 1.8% (1/55) for total antioxidant capacity (T-AOC), 4.3% (2/46) for H2O2 and 11.1% (4/36) for the capacity of inhibition of hydroxyl free radical (CIH). This indicated that the tissue-dependent changes of both oxidative stress and antioxidant activity were less consistent among the different tissues. Finally the data from this study were less consistent with the prediction of the mechanism of the rate of living-free radical theory.


Assuntos
Aclimatação/fisiologia , Metabolismo Basal , Temperatura Corporal , Temperatura Baixa , Estresse Oxidativo , Termogênese , Animais , Catalase/metabolismo , Cricetinae , Radicais Livres/metabolismo , Especificidade de Órgãos , Superóxido Dismutase
6.
Integr Cancer Ther ; 13(4): 351-67, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24363284

RESUMO

Cancer is the final outcome of a plethora of events. Targeting the proliferation or inducing programmed cell death in a proliferating population is a major standpoint in the cancer therapy. However, proliferation is regulated by several cellular and immunologic processes. This study reports the inhibition of proliferation by augmenting immune surveillance, silencing acute inflammation, and inducing p53-mediated apoptosis of skin cancer by 3 promising medicinal extracts. We used the well-characterized model for experimental skin carcinogenesis in mice for 32 weeks to study the chemopreventive effect of the methanolic extracts of Trigonella foenumgraecum, Eclipta alba, and Calendula officinalis. All 3 extracts reduced the number, incidence, and multiplicity of tumors, which was confirmed by the pathologic studies that showed regressed tumors. There was a significant reduction in the PCNA+ nuclei in all treatment groups 32 weeks after the initiation. Mechanistic studies revealed that proliferative population in tumors is diminished by the restoration of the endogenous antioxidant defense, inhibition of the stress-related signal-transducing element NFκB, reduction of inflammation, enhancement of immunosurveillance of the genetically mutated cells, along with silencing of the cell cycle progression signals. Finally, all 3 medicinal extracts induced stable expression of p53 within the tumors, confirmed by the CFDA-Cy3 apoptosis assay. Results of our study confirm that these extracts not only limit the rate of proliferation by inhibition of the processes integral to cancer development but also induce stable cytoplasmic expression of p53-mediated apoptosis, leading to fewer and regressed tumors in mice.


Assuntos
Calendula , Eclipta , Fitoterapia , Extratos Vegetais/uso terapêutico , Neoplasias Cutâneas/prevenção & controle , Trigonella , Proteína Supressora de Tumor p53/efeitos dos fármacos , 9,10-Dimetil-1,2-benzantraceno , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quimioprevenção/métodos , Feminino , Radicais Livres/metabolismo , Vigilância Imunológica/efeitos dos fármacos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/prevenção & controle , Células de Langerhans/efeitos dos fármacos , Camundongos , NF-kappa B/antagonistas & inibidores , Antígeno Nuclear de Célula em Proliferação/análise , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/patologia , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/química , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol , Proteína Supressora de Tumor p53/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-23665483

RESUMO

A simple and fast procedure is described for evaluating the antioxidant activity of hydrophilic and hydrophobic compounds by using the peroxyoxalate-chemiluminescence (PO-CL) reaction of Bis(2,4,6-trichlorophenyl) oxalate (TCPO) with hydrogen peroxide in the presence of di(tert-butyl)2-(tert-butylamino)-5-[(E)-2-phenyl-1-ethenyl]3,4-furandicarboxylate as a highly fluorescent fluorophore. The IC50 values of the well-known antioxidants were calculated and the results were expressed as gallic equivalent antioxidant capacity (GEAC). It was found that the proposed method is free of physical quenching and oxidant interference, for this reason, proposed method is able to determine the accurate scavenging activity of the antioxidants to the free radicals. Finally, the proposed method was applied to the evaluation of antioxidant activity of complex real samples such as soybean oil and sunflower oil (as hydrophobic samples) and honey (as hydrophilic sample). To the best of our knowledge, this is the first time that total antioxidant activity can be determined directly in soybean oil, sunflower oil and honey (not in their extracts) using PO-CL reactions.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Radicais Livres/metabolismo , Medições Luminescentes/métodos , Oxalatos/química , Corantes Fluorescentes/química , Helianthus/química , Mel/análise , Peróxido de Hidrogênio/química , Interações Hidrofóbicas e Hidrofílicas , Luminescência , Medições Luminescentes/economia , Óleos de Plantas/química , Óleo de Soja/química
8.
Free Radic Biol Med ; 63: 236-42, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23707455

RESUMO

The analytical validation of a possible biomarker is the first step in the long translational process from basic science to clinical routine. Although the chemokine-like cytokine macrophage migration inhibitory factor (MIF) has been investigated intensively in experimental approaches to various disease conditions, its transition into clinical research is just at the very beginning. Because of its presence in preformed storage pools, MIF is the first cytokine to be released under various stimulation conditions. In the first proof-of-concept studies, MIF levels correlated with the severity and outcome of various disease states. In a recent small study with acute coronary syndrome patients, elevation of MIF was described as a new factor for risk assessment. When these studies are compared, not only MIF levels in diseased patients differ, but also MIF levels in healthy control groups are inconsistent. Blood MIF concentrations in control groups vary between 0.56 and 95.6 ng/ml, corresponding to a 170-fold difference. MIF concentrations in blood were analyzed by ELISA. Other than the influence of this approach due to method-based variations, the impact of preanalytical processing on MIF concentrations is unclear and has not been systematically studied yet. Before large randomized studies are performed to determine the impact of circulating MIF on prognosis and outcome and before MIF is characterized as a diagnostic marker, an accurate protocol for the determination of reproducible MIF levels needs to be validated. In this study, the measurement of MIF in the blood of healthy volunteers was investigated focusing on the potential influence of critical preanalytical factors such as anticoagulants, storage conditions, freeze/thaw stability, hemolysis, and dilution. We show how to avoid pitfalls in the measurement of MIF and that MIF concentrations are highly susceptible to preanalytical factors. MIF serum concentrations are higher than plasma concentrations and show broader ranges. MIF concentrations are higher in samples processed with latency than in those processed directly and strongly correlate with hemoglobin in plasma. Neither storage temperature nor storage length or dilution or repeated freezing and thawing influenced MIF concentrations in plasma. Preanalytical validation of MIF is essential. In summary, we suggest using plasma and not serum samples when determining circulating MIF and avoiding hemolysis by processing samples immediately after blood drawing.


Assuntos
Movimento Celular/genética , Radicais Livres/metabolismo , Fatores Inibidores da Migração de Macrófagos/sangue , Macrófagos/metabolismo , Síndrome Coronariana Aguda/sangue , Adulto , Biomarcadores , Feminino , Congelamento , Humanos , Masculino , Pessoa de Meia-Idade
9.
Carbohydr Polym ; 90(2): 921-9, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22840021

RESUMO

The extracellular polysaccharide produced by a newly isolated strain Pseudomonas fluorescens WR-1 was purified and characterized and its production was optimized using response surface methodology. The results showed that the strain WR-1 produced one kind of EPS that was composed of arabinose, glucose and uronic acid. The molecular weight of the EPS was determined to be 6.78 × 10(6)Da. The preferable culture conditions for EPS production were pH 7.0, temperature 28°C for 72 h with peptone and maltose as best N and C sources, respectively. The model predicted that the maximum EPS production (39.6 gL(-1)) was appeared with maltose 48.65 gL(-1), Mn(2+) 1118 µM and Zn(2+) 901 µM. The EPS also showed good H(2)O(2) scavenging activity while moderate free radical scavenging activity and reductive ability were determined. The EPS from WR-1 may be a new source of natural antioxidants with potential value for health, food and industry.


Assuntos
Antioxidantes/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/farmacologia , Pseudomonas fluorescens/química , Antioxidantes/química , Antioxidantes/farmacologia , Calibragem , Fracionamento Químico , Indústria Farmacêutica/métodos , Indústria Farmacêutica/normas , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Radicais Livres/metabolismo , Peróxido de Hidrogênio/metabolismo , Peso Molecular , Oxirredução/efeitos dos fármacos , Polissacarídeos Bacterianos/química
10.
J Med Toxicol ; 8(3): 281-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22407514

RESUMO

According to previous animal studies, aluminium phosphides (AlPs) may induce oxidative stress leading to generation of free radicals and alteration in antioxidant defense system. This study was conducted to evaluate the existence and degree of oxidative stress in patients with acute AlP ingestion. A total of 44 acute AlP ingested patients as well as 44 age- and sex-matched controls were included. All patients had acute poisoning symptoms with AlP at the time of presentation and had blood samples analyzed for lipid peroxidation, total antioxidant capacity and total thiol. Our findings showed that there is a significant increase in lipid peroxidation in AlP ingested group along with a reduction in total antioxidant capacity and total thiols groups. These clinical data confirm previous experimental models that showed AlP exposure might significantly augment lipoperoxidative damage with simultaneous alterations in the antioxidant defense system. Hence, our findings might justify use of antioxidants in treatment of acute AlP poisoning which needs to be clarified by additional clinical trials.


Assuntos
Compostos de Alumínio/intoxicação , Biomarcadores/sangue , Estresse Oxidativo/efeitos dos fármacos , Fosfinas/intoxicação , Adulto , Antioxidantes/análise , Estudos de Casos e Controles , Feminino , Radicais Livres/metabolismo , Humanos , Irã (Geográfico) , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Compostos de Sulfidrila/sangue
11.
Free Radic Biol Med ; 52(7): 1242-52, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22306582

RESUMO

With increasing evidence showing the involvement of oxidative stress induced by free radicals in the development of various diseases, the role of radical-scavenging antioxidants has received much attention. Although many randomized controlled clinical trials do not support the beneficial effects of indiscriminate supplementation of antioxidants, more recent studies suggest that antioxidants such as vitamin E may be effective for prevention and treatment of some diseases when given to the right subjects at the right time. Many studies on the antioxidant capacity assessed by various available methods showed inconsistent results and the assessment of antioxidant capacity has been the subject of extensive studies and arguments. This study was performed to elucidate the basic chemistry required for the development of a reliable method for the assessment of antioxidant capacity for radical scavenging in vitro. In this study, the capacity of α-tocopherol and its related compounds, ascorbic acid, and uric acid for scavenging radicals was assessed from their effects on the rate of decay of hydrophilic and lipophilic probes with various reactivities toward free radicals induced by hydrophilic and lipophilic radicals in homogeneous solution and heterogeneous micelle systems. Fluorescein, pyranine, and pyrogallol red were used as hydrophilic probes, and BODIPY and N,N-diphenyl-p-phenylenediamine were used as lipophilic probes. We show that the rate and amount of radical scavenging by antioxidants, termed the antioxidant radical absorbance capacity, could be assessed by an appropriate combination of radical initiator and probe. This method was applied to the assessment of radical-scavenging capacity of human plasma, wine, and green tea powder.


Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/análise , Radicais Livres/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Chá , Vinho , Humanos , Técnicas In Vitro
12.
Cytometry A ; 79(6): 405-25, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21595013

RESUMO

Mitochondria are most important organelles in the survival of eukaryotic aerobic cells because they are the primary producers of ATP, regulators of ion homeostasis or redox state, and producers of free radicals. The key role of mitochondria in the generation of primordial ATP for the survival and proliferation of eukaryotic cells has been proven by extensive biochemical studies. In this context, it is crucial to understand the complexity of the mitochondrial compartment and its functionality and to develop experimental tools allowing the assessment of its nature and its function and metabolism. This review covers the role of the mitochondria in the cell, focusing on its structure, the mechanism of the mitochondrial respiratory chain, the maintenance of the transmembrane potential and the production of reactive oxygen species. The main probes used for mitochondrial compartment monitoring are described. In addition, various applications using mitochondrial-specific probes are detailed to illustrate the potential of flow and image cytometry in the study of the mitochondrial compartment. This review contains a panel of tools to explore mitochondria and to help researchers design experiments, determine the approach to be employed, and interpret their results.


Assuntos
Citometria de Fluxo/métodos , Corantes Fluorescentes , Mitocôndrias/metabolismo , Imagem Molecular/métodos , Trifosfato de Adenosina/biossíntese , Animais , Transporte de Elétrons , Fluorescência , Corantes Fluorescentes/análise , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Radicais Livres/metabolismo , Humanos , Mamíferos , Potencial da Membrana Mitocondrial , Camundongos , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
13.
J Drugs Dermatol ; 10(3): 262-7, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21369642

RESUMO

While there is at least one standardized test available for evaluating the antioxidant capacity of cosmetic formulations, the authors proposed a new in vivo method to determine kinetics of squalene (SQ) photo-oxidation products (squalene monohydroperoxide, SQmOOH) as a reliable method with which to evaluate antioxidant capacity of a cosmetic formulation. Topical antioxidant formulation was applied on the foreheads of 30 volunteers. Sebum samples were collected before application of topical antioxidant and after one hour, three hours and five hours from the application of topical antioxidant. One half of the sebutape was irradiated and SQmOOH/SQ ratios in the skin lipid were analyzed using HPLC method. These results showed protective action of the topical antioxidant formulation against skin lipid peroxidation with a significant reduction of the quantity of SQmOOH (P<0.0001). Determination of the kinetics of squalene peroxidation is a reliable in vivo method in the evaluation of antioxidant capacity of cosmetic formulations.


Assuntos
Antioxidantes/administração & dosagem , Cosméticos , Peroxidação de Lipídeos/efeitos dos fármacos , Sebo/metabolismo , Administração Tópica , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Testa , Radicais Livres/metabolismo , Humanos , Oxirredução/efeitos dos fármacos , Sebo/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/metabolismo , Esqualeno/análogos & derivados , Esqualeno/metabolismo , Fatores de Tempo , Resultado do Tratamento , Raios Ultravioleta
14.
Philos Trans R Soc Lond B Biol Sci ; 365(1557): 3443-54, 2010 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-20921044

RESUMO

Ageing is a complex multifactorial process involving a progressive physiological decline that, ultimately, leads to the death of an organism. It involves multiple changes in many components that play fundamental roles under healthy and pathological conditions. Simultaneously, every organism undergoes accumulative 'wear and tear' during its lifespan, which confounds the effects of the ageing process. The scenario is complicated even further by the presence of both age-dependent and age-independent competing causes of death. Various manipulations have been shown to interfere with the ageing process. Calorie restriction, for example, has been reported to increase the lifespan of a wide range of organisms, which suggests a strong relation between energy metabolism and ageing. Such a link is also supported within the main theories for ageing: the free radical hypothesis, for instance, links oxidative damage production directly to energy metabolism. The Dynamic Energy Budgets (DEB) theory, which characterizes the uptake and use of energy by living organisms, therefore constitutes a useful tool for gaining insight into the ageing process. Here we compare the existing DEB-based modelling approaches and, then, discuss how new biological evidence could be incorporated within a DEB framework.


Assuntos
Envelhecimento/metabolismo , Metabolismo Energético , Modelos Biológicos , Animais , Evolução Biológica , Restrição Calórica , Radicais Livres/metabolismo , Humanos
15.
J Oral Sci ; 52(3): 369-75, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20881328

RESUMO

The aim of this study was to assess the radioprotective effects of sodium selenite on parotid glands in rats by ultrastructural analysis of acinar cells. Four experimental groups were assessed; control, irradiated, selenium, and selenium/irradiated. The sodium selenite dose was 0.5 mg/kg, administered intraperitoneally 24 h before irradiation in the head and neck region with a single 15-Gy dose of gamma radiation. At 4, 8, 12, 48 and 72 h after irradiation, all animals were sacrificed and the parotid glands were removed. Radiation caused cellular changes from 4 h, and the organelles that presented the greatest alterations were the mitochondria and the secretion glands; nuclear alterations were also observed. Sodium selenite was found to have a radioprotective action, as the selenium/irradiated group presented with less damage when compared to the irradiated group. However, sodium selenite caused cellular alterations that were evident after 8 h, but with less damage when compared to those caused by radiation, which demonstrates a favorable risk-benefit for its use as a radioprotector. Thus, this research shows that sodium selenite has an effective radioprotective action in the parotid gland, which may contribute to the reduction of the adverse effects brought by the radiotherapy.


Assuntos
Glândula Parótida/efeitos da radiação , Protetores contra Radiação/uso terapêutico , Selenito de Sódio/uso terapêutico , Animais , Radicais Livres/metabolismo , Masculino , Glândula Parótida/ultraestrutura , Dosagem Radioterapêutica , Ratos , Ratos Wistar
16.
Indian J Biochem Biophys ; 47(2): 96-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20521622

RESUMO

Reactive oxygen species (ROS) produced as a part of cellular metabolism can interact with biological macromolecules such as DNA, proteins and lipids and interfere with their normal functions, leading to the loss of cellular viability. ROS have been implicated in many pathophysiological conditions including cancer. In the present study, the damage caused by ROS and the effect of radiation in head and neck squamous cell carcinoma (HNSCC) patients were assessed in the erythrocytes by analyzing the superoxide dismutase (SOD) and catalase (CAT) activities, and levels of total thiols (T-SH) and malondialdehyde (MDA, a marker for lipid peroxidation). Blood samples were collected before the start of treatment and after the completion of radiotherapy. Both SOD and CAT activities were decreased in untreated patients, but elevated in patients after treatment. The T-SH levels were also depleted in untreated HNSCC patients, but elevated non-significantly after radiation therapy (p>0.05). The levels of MDA showed a significant increase in both untreated patients and after radiation therapy when compared with normal subjects (p<0.05). Thus, the present study indicated that the free radical-mediated damage was aggravated in untreated HNSCC patients, but the levels of antioxidants returned to baseline or nearly so after the treatment with radiation therapy.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/radioterapia , Radicais Livres/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/radioterapia , Estresse Oxidativo/efeitos da radiação , Lesões por Radiação/metabolismo , Carcinoma de Células Escamosas/enzimologia , Estudos de Casos e Controles , Catalase/metabolismo , Neoplasias de Cabeça e Pescoço/enzimologia , Humanos , Masculino , Malondialdeído/metabolismo , Pessoa de Meia-Idade , Compostos de Sulfidrila/metabolismo , Superóxido Dismutase/metabolismo
17.
Biosci Biotechnol Biochem ; 74(3): 531-5, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20208356

RESUMO

The oxidation of lipids, proteins, and DNA induced by reactive oxygen species has been implicated in the development of various diseases, and the role of antioxidants has received much attention. Free-radical scavenging antioxidants play an important role in the defense network in vivo, and assessment of the capacity of antioxidants has been the subject of extensive studies and controversy, but there is no universal method by which antioxidant capacity can be measured accurately. In the present study, the assessment of the antioxidant capacity of natural fruit extracts was examined for radical scavenging and inhibition of lipid peroxidation. It was found that the capacity of fruit extracts for scavenging of both hydrophilic and lipophilic free radicals and for antioxidation can be assessed from the effect on the probe decay and the inhibition of plasma lipid peroxidation respectively. The importance of these two factors in the assessment of antioxidant capacity is discussed.


Assuntos
Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Frutas/química , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Radicais Livres/metabolismo , Humanos , Estresse Oxidativo
18.
Free Radic Res ; 44(3): 304-12, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20088711

RESUMO

Photo-instability of common UV-filters is a well documented phenomenon. This study develops a method for concomitant measurement of photostability and photo-induced ROS generation in cosmetic formulations. Oil-in-water formulations containing three common UV filters (OMC, BMDBM, EHT), individually or combined, were further supplemented with phosphatidylcholine and exposed to UVA. All filters show spectral decrease after UVA exposure. OMC and EHT do not induce significant lipid-peroxidation (as measured by TBARS production) while BMDBM does. In the latter case, this is reduced when BMDBM is combined with OMC but not with EHT. Neither OMC nor EHT stabilize BMDBM with respect to loss of absorbance. ROS-generation assessed via TBARS formation was supported by EPR experiments. The UV-induced changes in UV-filter performance, as monitored in the model formulations and in commercial sunscreens, demonstrate that this is a simple and effective method for stability assessment of sunscreen filters under conditions of use.


Assuntos
Técnicas de Laboratório Clínico , Fotólise/efeitos da radiação , Espécies Reativas de Oxigênio/efeitos da radiação , Protetores Solares/efeitos da radiação , Cosméticos/análise , Cosméticos/efeitos da radiação , Estabilidade de Medicamentos , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres/metabolismo , Radicais Livres/efeitos da radiação , Espécies Reativas de Oxigênio/análise , Protetores Solares/análise , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Raios Ultravioleta
19.
Hemoglobin ; 33(5): 386-97, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19814684

RESUMO

Tissue damage caused by oxidative stress is a common characteristic of many conditions involving different major organs such as the brain, heart, liver and kidneys. The treatment of such conditions using classical antioxidants is not in most cases sufficient or effective because it lacks specificity and has a low therapeutic index. Increased evidence from in vitro, in vivo and clinical studies suggest that deferiprone (L1) can be used as a potent pharmaceutical antioxidant by mobilizing labile iron and copper and/or inhibiting their catalytic activity in the formation of free radicals and oxidative stress in tissue damage. The high therapeutic index, tissue penetration, rapid iron binding and clearance of the iron complex, and the low toxicity of L1, support its application as an antioxidant pharmaceutical for adjuvant, alternative or main therapy, especially in conditions where other treatments have failed. Substantial clinical improvement and reversal in most cases of the tissue damage has been observed in cardiomyopathy in thalassemia, diabetic nephropathy and glomerulonephritis in kidney disease, Friedreich's Ataxia and Fanconi Anemia patients. In contrast to L1, both deferoxamine (DFO) and deferasirox (DFRA) have major disadvantages in their use in non iron loading conditions due to toxicity implications. Further studies in the above and other conditions and optimization of the L1 therapy in each individual will increase the prospects of the application and role of L1 as a universal antioxidant pharmaceutical.


Assuntos
Antioxidantes/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Piridonas/uso terapêutico , Talassemia/tratamento farmacológico , Animais , Benzoatos/uso terapêutico , Terapia por Quelação , Cobre/metabolismo , Deferasirox , Deferiprona , Desferroxamina/uso terapêutico , Radicais Livres/metabolismo , Humanos , Ferro/metabolismo , Sobrecarga de Ferro/complicações , Medição de Risco , Sideróforos/uso terapêutico , Triazóis/uso terapêutico
20.
J Diet Suppl ; 5(2): 147-63, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-22432431

RESUMO

OBJECTIVE: Immense interest has been generated in recent years for the development of drugs of herbal origin for the mitigation of deleterious effects of environmental pollutants like ionizing radiation, mainly to protect against radiation leakages resulting from mishaps in nuclear reactors, deliberate use of dirty bombs, etc. METHOD: The radio modifying effects of a fractionated extract of the high-altitude Himalayan plant species Rhodiola imbricata, along with its electron-donation potential, super-oxide ion scavenging (IC50 ≤ 0.025 mg/ml), nitric oxide (NO) scavenging potential (IC(50) = 0.5 mg/ml), and antihemolytic activity were evaluated in the present study. Reducing power, superoxide ion (O(2)(•-)), and nitric oxide scavenging ability of the fractionated extract increased in a dose-dependent manner. Rhodiola imbricata also exhibited antihemolytic potential preventing radiation-induced membrane degeneration of human erythrocytes. CONCLUSION: Thus, it can be stated that Rhodiola imbricata provides protection against gamma radiation via multifarious mechanisms that act in a synergistic manner. Rhodiola imbricata is widely used as a nutraceutical supplement in the trans-Himalayan region nations, and the current study shows that Rhodiola has immense potential for alleviation of biological damage in a radiation environment.


Assuntos
Eritrócitos/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Fármacos Hematológicos/farmacologia , Extratos Vegetais/farmacologia , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/farmacologia , Rhodiola , Ácido Ascórbico/farmacologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/efeitos da radiação , Relação Dose-Resposta a Droga , Eritrócitos/efeitos da radiação , Sequestradores de Radicais Livres/uso terapêutico , Radicais Livres/metabolismo , Fármacos Hematológicos/uso terapêutico , Humanos , Fitoterapia , Extratos Vegetais/uso terapêutico , Lesões por Radiação/sangue , Radiação Ionizante , Protetores contra Radiação/uso terapêutico
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