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Journal ArticleDOI

Radicais Livres e Antioxidantes: Proteção ou Perigo?

02 Jul 2015-Journal of Health Science (UNOPAR Científica. Ciências Biológicas e da Saúde)-Vol. 16, Iss: 3

AbstractO presente estudo consiste numa revisao bibliografica sobre o papel dos radicais livres e antioxidantes no organismo humano e na qualidade de vida. Para tanto, realizou-se uma pesquisa bibliografica, no periodo de 25 de Abril a 20 de Maio de 2013, atraves de consultas nas bases de dados: Bireme, SciELO, LILACS, Pubmed e Google Academico, alem de livros que abordassem a tematica em estudo. Os descritores pesquisados foram: radicais livres, antioxidante, sistema de defesa e qualidade de vida. Como criterios de inclusao foram selecionados artigos publicados nos idiomas portugues ou ingles, entre os anos de 2002 e 2012. A producao de especies reativas – radicais livres e parte integrante do metabolismo e esta presente em condicoes normais, notadamente nos processos fisiologicos envolvidos na producao de energia, regulacao do crescimento celular, fagocitose, sinalizacao intracelular e sintese de substâncias importantes, tais como hormonios e enzimas. Para contrabalancar essa producao e seus potenciais efeitos negativos, o organismo dispoe de um sistema antioxidante. Nas situacoes em que surge um desequilibrio entre os sistemas pro e antioxidante, com predominio dos pro-oxidantes, ocorre o estresse oxidativo que, por sua vez, pode originar danos, como envelhecimento precoce, doencas cardiovasculares ou neurodegenerativas, influenciando negativamente na qualidade de vida. A inclusao dos antioxidantes na dieta e a pratica regular de atividade fisica sao de grande importância para a diminuicao do risco do desenvolvimento de doencas associadas ao acumulo de radicais livres, alem de influenciarem positivamente na qualidade de vida.

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27 Mar 2020
Abstract: A exposicao prolongada ao estresse e um dos principais fatores que tem sido associados com a progressao de processos patologicos relacionado as vias oxidativas associadas a depressao. Fundamentado na demonstracao de que o Trans-anetol e a Eletroacupuntura isoladamente apresentam efeitos moduladores na producao de enzimas antioxidativas e reducao de fatores inflamatorios, este estudo visa avaliar o efeito da eletroacupuntura (100Hz) e do Trans-anetol como adjuvante no estresse oxidativo induzido por estresse cronico moderado imprevisivel (ECMI) a partir de parâmetros hematologicos e hepaticos. Tratou-se de um estudo prospectivo, controlado e comparativo utilizando 42 ratos sadios, machos (Rattus norvegicus: var. albinus, Rodentia, Mammalia), aprovados pelo comite de etica para uso de animais da Comite de Etica e Pesquisa (CEPA), do Departamento de Fisiologia e Farmacologia da Universidade Federal do Ceara (UFC) para uso de animais experimentais sob o n° 21/2016. Os animais foram submetidos ECMI durante seis (6) semanas, para o desenvolvimento de um quadro similar a depressao, constatado por Teste de Preferencia a Sacarose, seguido por tratamento em 12 dias com Salina (G1), Eletroacupuntura 100 Hz nos acupontos VB34, E36 e R3 por 15 minutos em dias alternados (G2), Trans-anetol 1,0 mg/kg/dia por gavagem diariamente (G3) e Terapia combinada com Eletroacupuntura 100 Hz e Trans-anetol (G4). Foram coletadas amostras de sangue e de figado para analise bioquimica de Transaminase glutâmico-oxalacetica (TGO) e Transaminase glutâmico piruvica (TGP) serico, mieloperoxidase hepatica (MPO) serico e hepatico, TBARS serico e hepatico, glutationa reduzida (GSH) serica e hepatica. Os animais apresentaram anedonia confirmada pelo Teste de Preferencia a Sacarose com reducao significativa de 60% (37,75 ± 4,77) preferencia a sacarose. O ECMI promoveu ainda impacto de 39,6% sobre o ganho de peso, ja o tratamento promoveu aumento medio de 19,2%. Quanto aos parâmetros bioquimicos foi evidenciado reducao de TGO e TGP apenas com a terapia conjunta (G4) de 32,46% (53,27 ± 7,73) e 14,37% (45,09 ± 4,09), respectivamente, sem significância. A MPO reduziu significativamente G2- 39,87% (4,87 ± 0,79), G3 - 60,0% (3,25±0,74) e G4 - 78,76% (1,72 ± 0,50); assim como TBARS no plasma tambem reduziu G2- 39,13%(0,14 ± 0,04), G3 - 60,86% (0,09 ± 0,02) e G4- 91,30% (0,02 ± 0,01) acompanhada tambem pela reducao no figado G2 - 46,51%(0,24 ± 0,04), G3- 55,81%(0,19 ± 0,03) e G4 - 74,41%(0,12 ±0,02); a glutationa serica, por sua vez, teve acrescimo de G2- 59,33% (105,94 ± 3,25), G3 - 121,92%(140,39 ± 4,89) e G4- 228,09%(216,32 ± 4,73) assim como no figado G2-21,67%(105,06±3,25), G3 - 40,05%(140,39 ± 4,89) e G4 -90,04% (216,32 ± 4,73). Conclui-se, entao, que o tratamento com eletroacupuntura (100Hz) e/ou anetol em animais submetidos a ECMI promove protecao local e sistemica sobre o estresse oxidativo, alem de reduzir o estado inflamatorio geral. Alem disso, o tratamento conjunto apresenta efeito potencializador ao tratamento isolado, sendo a terapia combinada mais promissora como possibilidade terapeutica na depressao

7 citations


Journal ArticleDOI
Abstract: Objective: To evaluate the effects of passive inhalation of cigarette smoke on the respiratory system of guinea pigs Methods: Male guinea pigs were divided into two groups: control and passive smoking, the latter being exposed to the smoke of ten cigarettes for 20 min in the morning, afternoon and evening (30 cigarettes/day) for five days After that period, inflammatory parameters were studied by quantifying mesenteric mast cell degranulation, as well as oxidative stress, in BAL fluid In addition, we determined MIP, MEP, and mucociliary transport (in vivo), as well as tracheal contractility response (in vitro) Results: In comparison with the control group, the passive smoking group showed a significant increase in mast cell degranulation (1975 ± 377% vs 4253 ± 042%; p < 0001) and in the levels of reduced glutathione (2939 ± 1921 vs 7237 ± 6743 nM/g of tissue; p < 005); as well as a significant reduction in mucociliary clearance (p < 005), which caused significant changes in pulmonary function (in MIP and MEP; p < 005 for both) and airway hyperreactivity Conclusions: Passive inhalation of cigarette smoke caused significant increases in mast cell degranulation and oxidative stress This inflammatory process seems to influence the decrease in mucociliary transport and to cause changes in pulmonary function, leading to tracheal hyperreactivity

4 citations


Journal ArticleDOI
TL;DR: The results showed that the copaiba extract was able to reverse the oxidative stress caused by solid Ehrlich tumor, probably due to the presence of antioxidant compounds, and had potential antineoplasic effect after a 30-day treatment.
Abstract: Copaifera multijuga, commonly known as copaiba, is popularly used in the form of tea for various conditions due to the presence of antioxidant substances in its composition, which protect cells against damage caused by free radicals. Its oleoresin is also used as an anti-inflammatory and antitumoral agent. The present study investigated the antioxidant effect of the ethanolic extract of copaiba stem bark on Swiss mice inoculated with solid Ehrlich tumors. Mice were inoculated subcutaneously with 1x106 Ehrlich’s tumor cells and treated via gavage with ethanolic extract of copaiba for thirty days, with doses varying between 100 and 200 mg kg-1. Biochemical analyses of enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST)], non-enzymatic antioxidants [reduced glutathione (GSH) and ascorbic acid (ASA)], substances reactive to thiobarbituric acid (TBARS) and protein carbonylation (carbonyl) in different tissues were significantly affected. The extract administered at 200 mg kg-1 presented higher antioxidant capacity in the liver, increased CAT, GST, GSH and decreased TBARS, as well as increased CAT activity and protein carbonylation in brain tissue. The results showed that the copaiba extract was able to reverse the oxidative stress caused by solid Ehrlich tumor, probably due to the presence of antioxidant compounds, and had potential antineoplasic effect after a 30-day treatment.

3 citations


Cites background from "Radicais Livres e Antioxidantes: Pr..."

  • ...The continuous production of free radicals during metabolic processes has led to the development of many antioxidant defense mechanisms to limit and prevent cell damage (Vasconcelos et al. 2014)....

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Journal ArticleDOI
30 Dec 2017
TL;DR: The use of Caryocar brasiliense Camb in dietes is beneficial to the population in general, because it has antioxidant action, which decreases oxidative damage, can delay the early cells aging and prevent the neurodegenerative diseases development.
Abstract: O cerrado e um patrimonio de recursos naturais renovaveis, com especies frutiferas, com caracteristicas peculiares e intensas. O Caryocar brasiliense Camb. possui atividade antioxidante, conforme estudos realizados, o consumo de pequi regularmente pode agir de forma a minimizar esse desequilibrio, com a diminuicao do nivel de radicais livres no organismo humano. As doencas neurodegenerativas levam a perda de funcao e estrutura neuronal, sendo um grave problema de saude publica, o numero de casos cresce a cada ano. Estas doencas sao associadas ao desequilibrio entre a producao de radicais livres e antioxidantes. O presente estudo teve a finalidade de discutir sobre a importância da utilizacao do Caryocar brasiliense camb. como agente antioxidante, que pode ser utilizado na prevencao da doenca de Alzheimer e doenca de Parkinson, caracterizadas como doencas neurodegenerativas. Esta investigacao foi caracterizada como pesquisa bibliografica, a coleta foi realizada nas bases eletronicas, para avaliacao inicial foi realizada leitura dos resumos, com finalidade de selecionar aqueles que melhor se adequaram ao objetivo da pesquisa. A utilizacao do Caryocar brasiliense Camb. na alimentacao e benefico para a populacao, de uma forma geral, por apresentar acao antioxidante, o que diminui os danos oxidativos, podendo retardar o envelhecimento precoce das celulas e evitar o desenvolvimento das doencas neurodegenerativas.Palavras-chave: Populacao. Antioxidante. Doencas neurodenerativas.AbstractThe cerrado is a heritage of renewable natural resources, with fruit species, with peculiar and intense characteristics. The Caryocar brasiliense Camb., has antioxidant activity, according to studies carried out, the consumption of pequi regularly can act in a way to minimize this imbalance, with the reduction of the level of free radicals in the human organism. Neurodegenerative diseases, leads to loss of function and neuronal structure, is a serious public health problem and the number of cases grows each year. These are associated with the imbalance between the production of free radicals and antioxidants. The present study had the purpose of discussing the importance of the use of Caryocar brasiliense camb., as an antioxidant agent that can be used in the prevention of Alzheimer’s disease and Parkinson’s disease, characterized as neurodegenerative diseases. This research was characterized as a bibliographical research, the collection was performed in the electronic databases, for the initial evaluation, the abstracts were read, with the purpose of selecting those that best fit the research objective. The use of Caryocar brasiliense Camb in dietes is beneficial to the population in general, because it has antioxidant action, which decreases oxidative damage, can delay the early cells aging and prevent the neurodegenerative diseases development.Keywords: Population. Antioxidant. Neurodegenerative diseases.

1 citations


Journal ArticleDOI
01 Jan 2018
TL;DR: It could be concluded that tooth bleaching decreases the bond strength to bleached enamel and 5% grape seed extract applied after dental bleaching improves the bonded strength between the restorative material and the bleachedEnamel.
Abstract: Objective: The aim of this study was to evaluate the effect of different concentrations of a natural antioxidant (grape seed extract) on the bond strength of the restorative material to the bleached enamel. Methods: Forty fragments of healthy bovine incisors were randomly divided into four groups (n = 10): Group I: no bleaching; Group II: Bleaching with 35% hydrogen peroxide (HP) and without post-treatment; Group III: Bleaching with 35% HP + 5% grape seed extract; and Group IV: Bleaching with 35% HP + 10% grape seed extract. The bond strength at the adhesive interface was evaluated using the shear test (MPa). The data were analyzed by the analysis of variance (ANOVA) and Tukey test ( =0.05%). The fracture types were also analyzed and classified into: adhesive, cohesive or mixed. Results: Only Group III (bleached + 5% grape seed extract) had a significant increase (p<0.001) in bond strength values when compared to Group II bleached, without post-treatment). All groups showed a predominance of the adhesive type of fracture. Conclusion: It could be concluded that tooth bleaching decreases the bond strength to bleached enamel and 5% grape seed extract applied after dental bleaching improves the bond strength between the restorative material and the bleached enamel.

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