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Effect of methionine load on homocysteine levels, lipid peroxidation and DNA damage in rats receiving ethanol

JORDAO JÚNIOR, Alceu Afonso; DOMENICI, Fernanda Aparecida; LATARO, Renata Cristina; PORTARI, Guilherme Vannucchi; VANNUCCHI, Helio
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
65.76%
Changes in the metabolism of methionine can cause hyperhomocysteinemia, inducing a triad of atherosclerosis, hypertension, and increased oxidative stress. The generation of free radicals and oxidative damage to DNA is important in the liver damage caused by ethanol. In this study, the effect of methionine overload associated or otherwise with acute administration of ethanol on homocysteine values, damage to DNA, lipoperoxidation and vitamin E was evaluated. Thirty rats were divided into 3 groups: Group Ethanol 24 hours (EG24), Group Methionine 24 hours (MG24), and Group Methionine and Ethanol 24 hours (MEG24). TBARS, vitamin E, GS and, homocysteine values were determined and the Comet assay was carried out. Increased GSH, vitamin E and homocysteine levels were observed for MEG24, and increased TBARS were observed in EG24. The Comet assay showed an increase in DNA damage in EG24 and DNA protection in MEG24. The administration of ethanol decreased antioxidant levels and increased TBARS, indicating the occurrence of oxidative stress with possible DNA damage. The combination of methionine and ethanol had a protective effect against the ethanol-induced damage, but increased the levels of homocysteine.; Alterações no metabolismo da metionina podem ocasionar hiper-homocisteinemia...

Comportamento redox e detecção voltamétrica de neurotransmissores, nitrito, derivados purínicos e nitrofural em sensores eletroquímicos à base de carbono; Redox behavior and voltammetric detection of neurotransmitters, nitrite, and purine derivatives in nitrofural electrochemical sensors base carbon

Silva, Robson Pinho da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/10/2012 PT
Relevância na Pesquisa
65.86%
Sistemas químicos capazes de produzir radicais livres OH• e O2•-, responsáveis por danos no DNA, foram estudados em diversos tipos de eletrodos de carbono previamente modificados. Nitrofural, RNO2, foi reduzido mono eletronicamente ao seu respectivo nitro ânion radical, RNO2•-, em eletrodo de pasta de carbono modificado superficialmente com um filme de guanina. O nitro ânion radical atacou a guanina imobilizada na superfície do eletrodo e, esta interação in situ, resultou na formação de cátions radicais de guanina (G+•), que ao interagirem com a guanina (G), foram identificados pelo pico de oxidação em voltametria pulso diferencial, VPD, nas formas diméricas de guanina na região positiva de potencial. Os outros sistemas estudados se referem ao desenvolvimento de novos eletrodos de carbono modificados ou ainda a utilização procedimentos de modificações desenvolvidas anteriormente, para a detecção de várias moléculas de importância biológica. O ácido ascórbico (AA), ácido úrico (AU), xantina (XA) e hipoxantina (HX) foram detectados simultaneamente em eletrodo de grafite pirolítico, previamente modificado em solução de dopamina (EGPD), utilizando VPD. Os picos de oxidação, obtidos por voltametria cíclica foram detectados em 51; 393; 765 e 1080 mV vs Ag / AgCl...

Preliminary in vitro and ex vivo evaluation of afzelin, kaempferitrin and pterogynoside action over free radicals and reactive oxygen species

Vellosa, José Carlos Rebuglio; Regasini, Luis Octavio; Belló, Caroline; Schemberger, Josiane Aparecida; Khalil, Najeh Maissar; Morandim-Giannetti, Andreia De Araújo; Bolzani, Vanderlan da Silva; Brunetti, Iguatemy Lourenço; Oliveira, Olga Maria Mascar
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
85.85%
Biological activities of flavonoids have been extensively reviewed in literature. The biochemical profile of afzelin, kaempferitrin, and pterogynoside acting on reactive oxygen species was investigated in this paper. The flavonoids were able to act as scavengers of the superoxide anion, hypochlorous acid and taurine chloramine. Although flavonoids are naturally occurring substances in plants which antioxidant activities have been widely advertised as beneficial, afzelin, kaempferitrin, and pterogynoside were able to promote cytotoxic effect. In red blood cells this toxicity was enhanced, depending on flavonoids concentration, in the presence of hypochlorous acid, but reduced in the presence of 2,20 -azo-bis(2-amidinopropane) free radical. These flavonoids had also promoted the death of neutrophils, which was exacerbated when the oxidative burst was initiated by phorbol miristate acetate. Therefore, despite their well-known scavenging action toward free radicals and oxidants, these compounds could be very harmful to living organisms through their action over erythrocytes and neutrophils.

Profile of Maytenus aquifolium action over free radicals and reactive oxygen species

Vellosa,José Carlos Rebuglio; Barbosa,Vanessa de Frias; Khalil,Najeh Maissar; Santos,Vânia Aparecida de Freitas Formenton Macedo dos; Furlan,Maysa; Brunetti,Iguatemy Lourenço; Oliveira,Olga Maria Mascarenhas de Faria
Fonte: Divisão de Biblioteca e Documentação do Conjunto das Químicas da Universidade de São Paulo Publicador: Divisão de Biblioteca e Documentação do Conjunto das Químicas da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2007 EN
Relevância na Pesquisa
85.9%
Reactive oxygen species (ROS) and free radical species have been implicated in initiating, accompanying or causing many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Maytenus species have long been used, in several countries, as traditional medicines against gastric ulcers, dyspepsia and others gastric problems and for their anti-inflammatory properties. In this study, Maytenus aquifolium (Celastraceae) root bark ethanol extract was assessed for its ability to scavenge free radicals and reactive oxygen species. The results were expressed as percentage inhibition of the active species. The extract was efficient against studied reactive species: DPPH radical (obtained inhibition = 35.5 ± 1.3 %), ABTS•+ (IC50 = 0.0036 ± 0.0003 mg/mL), HOCl (IC50 = 0.002 ± 0.0001 mg/mL ), O2•- (obtained inhibition = 36.0 ± 2.1 %), and NO• (obtained inhibition = 18.3 ± 0.4 %).

Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile

Vellosa,José Carlos Rebuglio; Khalil,Najeh Maissar; Gutierres,Vânia Ortega; Santos,Vânia Aparecida de Freitas Formenton Macedo dos; Furlan,Maysa; Brunetti,Iguatemy Lourenço; Oliveira,Olga Maria Mascarenhas de Faria
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2009 EN
Relevância na Pesquisa
65.96%
Reactive oxygen species (ROS) and free radical species have been implicated in initiating or accompanying many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Salacia species have long been used, in several countries, as traditional medicines against certain diseases and for their anti-inflammatory properties. In this study, Salacia campestris Walp (Hippocrateaceae) root bark ethanol extract (ScEtOH) was assessed for its ability to scavenge free radicals and reactive oxygen species; the results were expressed as percentage inhibition of the active species. ScEtOH was efficient against studied species: DPPH radical (obtained inhibition = 30%), ABTS•+ (IC50 = 1.8±0.8 μg/mL), HOCl (IC50 = 1.7 ± 0.1 μg/mL), O2•- (obtained inhibition = 32%), and NO• (obtained inhibition = 18 %). Peroxidase activity inhibition was evaluated through the guaiacol oxidation reaction catalyzed by hemin, HRP and myeloperoxidase (MPO); data showed that ScEtOH at 10 μg/mL led to 54 and 51% of inhibition, respectively, for the hemin and HRP systems. In the MPO system...

Effect of methionine load on homocysteine levels, lipid peroxidation and DNA damage in rats receiving ethanol

Jordao Júnior,Alceu Afonso; Domenici,Fernanda Aparecida; Lataro,Renata Cristina; Portari,Guilherme Vannucchi; Vannucchi,Helio
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
65.76%
Changes in the metabolism of methionine can cause hyperhomocysteinemia, inducing a triad of atherosclerosis, hypertension, and increased oxidative stress. The generation of free radicals and oxidative damage to DNA is important in the liver damage caused by ethanol. In this study, the effect of methionine overload associated or otherwise with acute administration of ethanol on homocysteine values, damage to DNA, lipoperoxidation and vitamin E was evaluated. Thirty rats were divided into 3 groups: Group Ethanol 24 hours (EG24), Group Methionine 24 hours (MG24), and Group Methionine and Ethanol 24 hours (MEG24). TBARS, vitamin E, GS and, homocysteine values were determined and the Comet assay was carried out. Increased GSH, vitamin E and homocysteine levels were observed for MEG24, and increased TBARS were observed in EG24. The Comet assay showed an increase in DNA damage in EG24 and DNA protection in MEG24. The administration of ethanol decreased antioxidant levels and increased TBARS, indicating the occurrence of oxidative stress with possible DNA damage. The combination of methionine and ethanol had a protective effect against the ethanol-induced damage, but increased the levels of homocysteine.

Free radical generation and lipid peroxidation among the dry cell industry workers exposed to carbon

Reddy, K. K.; Reddy, T. P. K.; Somasekharaiah, B. V.; Kumari, K. Soorya
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
Publicado em /01/1998 EN
Relevância na Pesquisa
65.86%
A total of 75 healthy male dry cell industry workers exposed to carbon for 5, 8 and 10 years were compared with 48 controls matched for age and economic status with respect to free radical generation, lipid peroxidation and antioxidant levels. Lymphocytes were seperated from the whole blood and used for estimation of free radicals and antioxidants. Plasma lipid peroxidation products were estimated in the form of thiobarbituric acid reactive substances. Significant increase in free radical generation and lipid peroxidation products were observed in carbon exposed population than controls, and the increase was found to be significant with increase in the period of exposure. The levels of antioxidants i.e., superoxide dismutase (SOD) and catalase were found to decrease with the increase in exposure to carbon in industrial workers. These results suggest that exposure to carbon augments free radical generation, lipid peroxidation and promotes decline in antioxidant enzymes.

Changes in antioxidant enzyme levels and DNA damage during aging

Reddy, K. K.; Reddy, T. P. K.; Somasekharaiah, B. V.; Kumarl, K. Soorya
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
Publicado em /01/1998 EN
Relevância na Pesquisa
65.97%
Multiple mechanisms underlie the human aging process, but interest continues in the role that free radicals and antioxidants may play. The concentrations of lymphocyte free radical generation (O2−& H2O2), DNA damage and antioxidant enzyme levels (glutathione Stransferase, superoxide dismutase and catalase) were evaluated in 110 healthy individuals with an age range of 20–80 years. The antioxidant enzyme levels were significantly less in very old age when compared to young. Moreover, the levels of free radical concentration and DNA damage were increased in the same age group with respect to younger group. Cigarette smoking had a positive relation with free radicals and DNA damage, and inverse relation with antioxidants. On the other hand, body mass was found to have positive relation with free radical generation only. The data indicate that depletion of antioxidant enzyme levels would render the older people more susceptible to free radical stress and DNA damage.

Platelet protein damage by free radicals and glycationin vitro: The pathological consequences

Goswami, K.; Bhatla, B. D.; Shankar, R.
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
Publicado em /08/2000 EN
Relevância na Pesquisa
105.83%
Modification of platelet proteins by free radicals and glycation has been studied in the present work, as anin vitro model. The results of the two parameters, SDS-PAGE and carbonylation study are quite corroborative. We observed that the inducers like ferrous sulphate, ascorbate (mainly in supraphysiological concentration) and glucose attack the protein in a dose dependent manner, of which ferrous sulphate is most potent. Proteins from aged and degenerative conditions like malignancy and diabetes mellitus have suffered greater damage than normal adult and foetal proteins. The individual life expectancy in terms of biological versus chronological age may also be worked out from the individual stress level.

Free Radicals, Antioxidants in Disease and Health

Pham-Huy, Lien Ai; He, Hua; Pham-Huy, Chuong
Fonte: Master Publishing Group Publicador: Master Publishing Group
Tipo: Artigo de Revista Científica
Publicado em /06/2008 EN
Relevância na Pesquisa
56.03%
Free radicals and oxidants play a dual role as both toxic and beneficial compounds, since they can be either harmful or helpful to the body. They are produced either from normal cell metabolisms in situ or from external sources (pollution, cigarette smoke, radiation, medication). When an overload of free radicals cannot gradually be destroyed, their accumulation in the body generates a phenomenon called oxidative stress. This process plays a major part in the development of chronic and degenerative illness such as cancer, autoimmune disorders, aging, cataract, rheumatoid arthritis, cardiovascular and neurodegenerative diseases. The human body has several mechanisms to counteract oxidative stress by producing antioxidants, which are either naturally produced in situ, or externally supplied through foods and/or supplements. This mini-review deals with the taxonomy, the mechanisms of formation and catabolism of the free radicals, it examines their beneficial and deleterious effects on cellular activities, it highlights the potential role of the antioxidants in preventing and repairing damages caused by oxidative stress, and it discusses the antioxidant supplementation in health maintenance.

Antioxidants in Endodontics: A Strategic Review

Patel, Shyam; Hans, Manoj Kumar; Chander, Subhash; Ahluwalia, Amrit Singh
Fonte: JCDR Research and Publications (P) Limited Publicador: JCDR Research and Publications (P) Limited
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.11%
Over the past few decades, the free radicals and antioxidants have attracted tremendous importance in the field of dentistry. Depending on the level of free radicals in the body, they can either be harmful or helpful. Antioxidants are the substances that interact with and stabilize free radicals thereby protecting cells from the damage caused by free radicals. The indigenous antioxidants may be useful in preventing the harmful effects of oxidative stress. The present article presents a review on the free radicals formation, their role in disease pathogenesis, antioxidants and their potential role in endodontics.

Synthetic Studies of Azulenyl and Pseudoazulenyl Nitrones

Kolhe, Amolkumar
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
76.08%
Free radicals have been implicated in various pathological conditions such as, stroke, aging and ischemic heart disease (IHD), as well as neurodegenerative diseases like Alzheimer’s, Parkinson’s, and Huntington’s disease. The role of antioxidants in protection from the harmful effects of free radicals has long been recognized. Trapping extremely reactive free radicals and eliminating them from circulation has been shown to be effective in animal models. Nitrone-based free radical traps have been extensively explored in biological systems. Examples include nitrones such as PBN, NXY-059, MDL-101,002, DMPO and EMPO. However, these nitrones have extremely high oxidation potentials as compared to natural antioxidants such as Vitamin E (á-tocopherol), and glutathione. Becker et al. (1995) synthesized novel azulenyl nitrones, which were shown to have oxidation potentials much lower than that of any of the previously reported nitrone based spin traps. Another azulenyl nitrone derivative, stilbazulenyl nitrone (STAZN), was shown to have an even lower oxidation potential within the range of natural antioxidants. STAZN, a second generation free radical trap, was found to be markedly superior than the two most studied nitrones, PBN and NXY-059...

Studies on the antiperoxide and antihaemolytic action of polyamines using human erythrocytes

Chetan, Chethana; Prabhu, Ashok; D'Souza, Vivian; Rao, Shrinivas B.
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
Publicado em /08/2000 EN
Relevância na Pesquisa
65.71%
Blood RBC's were used to study the role of polyamines, putrescine, spermidine and spermine individually as antioxidants against the peroxidative action of H2O2 which leads to haemolysis of erythrocytes. Results indicated that putrescine did not act as antioxidant at all concentrations used in our studies. However, spermidine and spermine suppressed peroxidative changes in RBC's due to the action of H2O2 and this suppression was greater with higher concentration of these individual polyamines used, separately. Further, all the three polyamines decreased haemolysis of erythrocytes at all concentrations studied. The action of putrescine to suppress haemolysis of RBC's without showing antioxidant property hypothetically suggests that these properties of respective polyamines may have independent mechanism of action.

Free radicals, antioxidants and functional foods: Impact on human health

Lobo, V.; Patil, A.; Phatak, A.; Chandra, N.
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
66.12%
In recent years, there has been a great deal of attention toward the field of free radical chemistry. Free radicals reactive oxygen species and reactive nitrogen species are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states. A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger a number of human diseases. Hence application of external source of antioxidants can assist in coping this oxidative stress. Synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole have recently been reported to be dangerous for human health. Thus, the search for effective, nontoxic natural compounds with antioxidative activity has been intensified in recent years. The present review provides a brief overview on oxidative stress mediated cellular damages and role of dietary antioxidants as functional foods in the management of human diseases.

DPPH and oxygen free radicals as pro-oxidant of biomolecules

Miranda, Dante; Montoya, Margarita; Holst, Marianne; Cortés Troncoso, Juan; Molina Berríos, Alfredo; González Lira, Víctor Manuel; Jara Sandoval, José; Palma, Karina; Letelier Muñoz, María Eugenia
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artículo de revista
EN
Relevância na Pesquisa
75.92%
Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), a stable nitrogen synthetic radical, is used to evaluate the antioxidant capacity of medicinal herbal products; however, the structural changes that this radical provoke on the herbal active principles are not clear yet. In this work, we compared the redox reactivity of oxygen free radicals and DPPH radical on phospholipids and protein thiol groups present in rat liver microsomes. Cu2+/ascorbate was used as generator system of oxygen free radical and as antioxidant, an extract of Buddleja globosa’s leaves. Cu2+/ascorbate provoked microsomal lipid peroxidation, microsomal thiols oxidation and oxygen consumption; all of these phenomena were inhibited by B. globosa extract. On the other hand, DPPH was bleached in different extension by the herbal extract and phosphatidyl choline; beside, DPPH decreased microsomal thiols content, but this phenomenon were not prevented by the herbal extract. Furthermore, DPPH did not induce oxygen consumption and neither modified the oxygen consumption induced by Cu2+/ascorbate. Distinct redox mechanisms may explain the differences between the reactivity of DPPH and oxygen free radicals on biomolecules...

Mathematical and computational modeling for describing the basic behavior of free radicals and antioxidants within epithelial cells

Garcia, Alvaro Juan Ojeda
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/01/2012
Relevância na Pesquisa
95.85%
The traditional methods of the biology, based on illustrative descriptions and linear logic explanations, are discussed. This work aims to improve this approach by introducing alternative tools to describe and represent complex biological systems. Two models were developed, one mathematical and another computational, both were made in order to study the biological process between free radicals and antioxidants. Each model was used to study the same process but in different scenarios. The mathematical model was used to study the biological process in an epithelial cells culture; this model was validated with the experimental data of Anne Hanneken's research group from the Department of Molecular and Experimental Medicine, published by the journal Investigative Ophthalmology and Visual Science in July 2006. The computational model was used to study the same process in an individual. The model was made using C++ programming language, supported by the network theory of aging.; Comment: 4 pages, 5 figures. Treball de Recerca, gener de 2012

Effect of methionine load on homocysteine levels, lipid peroxidation and DNA damage in rats receiving ethanol

Jordao Júnior, Alceu Afonso; Domenici, Fernanda Aparecida; Lataro, Renata Cristina; Portari, Guilherme Vannucchi; Vannucchi, Helio
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/12/2009 ENG
Relevância na Pesquisa
65.76%
Alterações no metabolismo da metionina podem ocasionar hiper-homocisteinemia, quadro indutivo de aterosclerose, hipertensão e aumento do estresse oxidativo. A geração de radicais livres e dano oxidativo ao DNA são importantes na injúria hepática provocada pelo etanol. Neste estudo avaliaram-se os efeitos da sobrecarga de metionina associada ou não à administração aguda de etanol sobre valores de homocisteína, dano ao DNA, lipoperoxidação e vitamina E. Foram utilizados 30 ratos Wistar distribuídos em 3 Grupos: Grupo Etanol 24 horas (GE24), Grupo Metionina 24 horas (GM24) e Grupo Metionina e Etanol 24 horas (GME24). Realizaram-se determinações hepáticas de SRATB, vitamina E, GSH, homocisteína e Teste do Cometa e determinações plasmáticas de GSH e homocisteína. Valores aumentados de GSH, vitamina E e homocisteína foram observados para o GME24, e de SRATB no GE24. O Teste do Cometa mostrou aumento do dano ao DNA no GE24 e proteção ao DNA no GME24. A administração de etanol diminuiu os níveis de antioxidantes e aumentou o de SRATB, indicando ocorrência de estresse oxidativo, podendo ocasionar dano ao DNA. A presença da metionina associada com o etanol agiu como protetora contra os danos do etanol, mas aumentou os níveis de homocisteína.; Changes in the metabolism of methionine can cause hyperhomocysteinemia...

Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile

Vellosa, José Carlos Rebuglio; Khalil, Najeh Maissar; Gutierres, Vânia Ortega; Santos, Vânia Aparecida de Freitas Formenton Macedo do; Furlan, Maysa; Brunetti, Iguatemy Lourenço; Oliveira, Olga Maria Mascarenhas de Faria
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/03/2009 ENG
Relevância na Pesquisa
65.96%
Espécies reativas do oxigênio (ERO) e radicais livres estão relacionados ao início ou à exacerbação de muitas doenças em organismos vivos; existindo portanto uma necessidade contínua por moléculas antioxidantes que inativem as ERO e radicais livres. Muitos estudos com extratos brutos de plantas têm demonstrado propriedades antioxidantes e seqüestradoras de radicais livres. Espécies de Salacia são utilizadas, em muitos países, como remédio tradicional contra certas doenças e por suas propriedades antiinflamatórias. Neste estudo, o extrato bruto etanólico da casca da raiz da Salacia campestris Walp (Hippocrateaceae) foi avaliado quanto à sua habilidade em seqüestrar radicais livres e espécies reativas do oxigênio; os resultados são expressos como porcentagem de inibição das espécies ativas. ScEtOH mostrou-se eficiente frente as espécies estudadas: radical DPPH (inibição obtida = 30%), ABTS•+ (IC50 = 1,8±0,8 μg/mL), HOCl (IC50 = 1,7 ± 0,1 μg/mL), O2•- (inibição obtida = 32%), and NO• (inibição obtida = 18%). A inibição da atividade peroxidásica foi avaliada através da oxidação do guaiacol catalisada pela hemina, HRP e mieloperoxidase (MPO); os dados mostram que 10 μg/mL de ScEtOH promovem 54 e 51% de inibição...

Perfil de ação da Maytenus aquifolium sobre radicais livres e espécies reativas do oxigênio; Profile of Maytenus aquifolium action over free radicals and reactive oxygen species

Vellosa, José Carlos Rebuglio; Barbosa, Vanessa de Frias; Khalil, Najeh Maissar; Santos, Vânia Aparecida de Freitas Formenton Macedo do; Furlan, Maysa; Brunetti, Iguatemy Lourenço; Oliveira, Olga Maria Mascarenhas de Faria
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 01/09/2007 ENG
Relevância na Pesquisa
85.9%
Espécies Reativas do Oxigênio (ERO) e radicais livres têm tido implicações na iniciação e evolução de muitas doenças ou nas causas das mesmas em organismos vivos; há portanto, necessidade contínua por moléculas antioxidantes para inativar ERO/radicais livres. Estudos sobre extratos brutos de plantas têm demonstrado suas ações antioxidante e seqüestradora de radicais livres. Espécies do gênero Maytenus são utilizadas, em vários países, como medicamentos tradicionais no combate a úlceras gástricas, dispepsia e outras desordens gástricas, bem como por suas propriedades antiinflamatórias. Neste estudo, o extrato bruto etanólico da raiz da Maytenus aquifolium (Celastraceae) foi avaliado quanto à sua habilidade em seqüestrar radicais livres e outras espécies reativas do oxigênio. Os resultados são expressos como porcentagem de inibição das espécies ativas. O extrato foi eficiente contra as espécies estudadas: radical DPPH (inibição alcançada = 35,5 ± 1,3 %), ABTS•+ (IC50 = 0,0036 ± 0,0003 mg/mL), HOCl (IC50 = 0,002 ± 0,0001 mg/mL ), O2•- (inibição alcançada = 36,0 ± 2,1 %), and NO· (inibição alcançada = 18,3 ± 0,4 %).; Reactive oxygen species (ROS) and free radical species have been implicated in initiating...

Metabólitos secundários vegetais e benefícios antioxidantes

Pereira, Renata Junqueira; Cardoso, Maria das Graças
Fonte: Journal of Biotechnology and Biodiversity Publicador: Journal of Biotechnology and Biodiversity
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 03/12/2012 POR
Relevância na Pesquisa
66.06%
Known to mankind since primitive man, the plants are used for food and to cure diseases. It is evident that a diet with essential nutrients and bioactive substances plays an important role on preventing and curing chronic diseases. Free radicals production occurs in the body, such as a physiological process. Substantial evidences had shown that free radicals and other oxidants are responsible for aging, autoimmune diseases, inflammatory diseases and degenerative diseases as cancer, cardiovascular disease, liver disease, cataracts, immunologic decline and brain dysfunctions. Antioxidants protect the body, being able to intercept free radicals from cellular metabolism or exogenous sources, avoiding cellular integrity losses and injuries. Fresh vegetables contain numerous phytochemicals, plant metabolites, especially phenolic compounds, nitrogen compounds, carotenoids, ascorbic acid and tocopherols. These compounds have significant antioxidant activity, and are associated with lower incidence and mortality from chronic diseases, especially cancer, in humans. Key-words: antioxidants, free radicals, secondary metabolites