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1.
Biol. Res ; 47: 1-11, 2014. graf, tab
Artigo em Inglês | LILACS | ID: biblio-950720

RESUMO

BACKGROUND: Unstable generation of free radicals in the body are responsible for many degenerative diseases. A bloom forming algae Euglena tuba growing abundantly in the aquatic habitats of Cachar district in the state of Assam in North-East India was analysed for its phytochemical contents, antioxidant activity as well as free radical scavenging potentials. RESULTS: Based on the ability of the extract in ABTS•+ radical cation inhibition and Fe3+ reducing power, the obtained results revealed the prominent antioxidant activity of the algae, with high correlation coefficient of its TEAC values to the respective phenolic and flavonoid contents. The extract had shown its scavenging activity for different free radicals and 41.89 ± 0.41 µg/ml, 5.83 ± 0.07 µg/ml, 278.46 ± 15.02 µg/ml and 223.25 ± 4.19 µg/ml were determined as the IC50 values for hydroxyl, superoxide, nitric oxide and hypochlorous acid respectively, which are lower than that of the corresponding reference standards. The phytochemical analysis also revealed that the phenolics, flavonoids, alkaloids, tannins and carbohydrates are present in adequate amount in the extract which was confirmed by HPLC analysis. CONCLUSIONS: The results showed that 70% methanol extract of the algae possesses excellent antioxidant and free radical scavenging properties.


Assuntos
Animais , Masculino , Camundongos , Extratos Celulares/química , Sequestradores de Radicais Livres/metabolismo , Substâncias Redutoras/metabolismo , Euglena/química , Antioxidantes/metabolismo , Oxirredução , Fenóis/análise , Ácido Ascórbico/análise , Taninos/análise , Flavonoides/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Cromanos/metabolismo , Cromatografia Líquida de Alta Pressão , Metanol , Alcaloides/análise , Microalgas , Glucose/análise , Índia
2.
Clinics ; 67(2): 135-143, 2012. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-614637

RESUMO

OBJECTIVE: Human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. The beneficial effects of vitamin E in aging have been established, but studies to determine the mechanisms of these effects are ongoing. This study determined the molecular mechanism of γ-tocotrienol, a vitamin E homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes. METHODS: Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer. RESULTS: The cell cycle was arrested in the G0/G1 phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G0/G1 phase and increased cell populations in the G2/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts. CONCLUSION: γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.


Assuntos
Humanos , Antioxidantes/farmacologia , Senescência Celular/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Cromanos/farmacologia , Fibroblastos/efeitos dos fármacos , Vitamina E/análogos & derivados , beta-Galactosidase/análise , Análise de Variância , Biomarcadores/análise , Células Cultivadas , Senescência Celular/genética , Ciclo Celular/genética , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Diploide , Fibroblastos/citologia , Fibroblastos/metabolismo , /genética , /metabolismo , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 1 da Matriz/metabolismo , RNA Mensageiro/metabolismo , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Regulação para Cima/efeitos dos fármacos , Vitamina E/farmacologia , beta-Galactosidase/metabolismo
3.
Acta cir. bras ; 21(supl.4): 69-73, 2006. tab, graf
Artigo em Inglês | LILACS | ID: lil-440783

RESUMO

PURPOSE: To evaluate the effects of intraluminal injection of glutamine on the serum trolox equivalent antioxidant capacity in an experimental model of ischemia-reperfusion of the liver observing the applicability of modifications on the original assay method. METHODS: Thirty Wistar rats underwent laparotomy to perform a 20 cm blind sac of small bowel and occlusion of the hepatic hilo for 30 minutes and reperfusion for 5 minutes. Into the gut sac it was injected glutamine (glutamine group, n=10) or distilled water (control group, n=10). Ten other animals (sham group) underwent laparotomy without artery occlusion. Blood samples were collected for trolox equivalent antioxidant capacity assays in different temperature conditions, reagent quantities and time for spectrophotometer readings. RESULTS: Total antioxidant capacity was significantly greater in glutamine group than in both control group (1,60[1,55-1,77] vs 1,44[1,27-1,53]) and sham group (1,60[1,55-1,77] vs 1,48[1,45-1,59]). CONCLUSION: Glutamine enhanced serum antioxidant capacity. The assay technique consistently reflected the changes in the antioxidant defenses in this experimental model.


OBJETIVO: Avaliar em um modelo experimental de isquemia-reperfusão hepática os efeitos da injeção intraluminal de glutamina na capacidade anti-oxidante total em equivalência ao trolox (TEAC) do plasma, verificando a aplicabilidade de modificações ao método original de dosagem. MÉTODOS: Trinta ratos Wistar foram submetidos a laparotomia e confecção de uma alça fechada de 20 cm de comprimento envolvendo o intestinal delgado distal seguido do clampeamento do hilo hepático por 30 minutos e reperfusão por 5 minutos. Na alça fechada foi injetada glutamina (grupo glutamina; n=10) ou água destilada (grupo controle; n=10). Em dez animais (grupo sham) não foi realizado clampeamento hilar. Coletou-se sangue para dosagem da capacidade antioxidante total em equivalência ao trolox em condições modificadas de temperatura, proporções relativas dos reagentes e tempo de leitura sob espectrofotometria. RESULTADOS: A capacidade antioxidante total foi significantemente maior (p<0.05) no grupo glutamina que no grupo controle (1,60[1,55-1,77] vs 1,44[1,27-1,53]) e grupo sham (1,60[1,55-1,77] vs 1,48[1,45-1,59]). Não houve diferenças estatísticas entre o grupo controle e o grupo sham. CONCLUSÃO: A glutamina melhorou a capacidade anti-oxidante total plasmática. O método de dosagem refletiu consistentemente alterações na defesa anti-oxidante nesse modelo experimental.


Assuntos
Animais , Masculino , Ratos , Antioxidantes/metabolismo , Cromanos/sangue , Glutamina/farmacologia , Intestino Delgado/efeitos dos fármacos , Fígado/irrigação sanguínea , Traumatismo por Reperfusão/tratamento farmacológico , Antioxidantes/química , Cromanos/química , Modelos Animais de Doenças , Distribuição Aleatória , Ratos Wistar
4.
Braz. j. med. biol. res ; 33(8): 961-6, Aug. 2000. tab, graf
Artigo em Inglês | LILACS | ID: lil-265854

RESUMO

The vasorelaxant effects of SR 47063 (4-(2-cyanimino-1,2-dihydropyrid-1-yl)-2,2-dimethyl-6-nitrochromene), a new K+-channel opener structurally related to levcromakalim, were examined in isolated human saphenous vein (HSV) and rat aorta (RA). HSV or RA rings were precontracted with either KCl or noradrenaline and cumulative relaxant concentration-response curves were obtained for SR 47063 (0.1 nM to 1 µM) in the presence or absence of 3 µM glibenclamide. SR 47063 potently relaxed HSV and RA precontracted with 20 mM (but not 60 mM) KCl or 10 µM noradrenaline in a concentration-dependent manner, showing slightly greater activity in the aorta. The potency of the effect of SR 47063 on HSV and RA was 12- and 58-fold greater, respectively, than that reported for the structurally related K+-channel opener levcromakalim. The vasorelaxant action of SR 47063 in both blood vessels was strongly inhibited by 3 µM glibenclamide, consistent with a mechanism of action involving ATP-dependent K+-channels


Assuntos
Humanos , Animais , Masculino , Ratos , Aorta/efeitos dos fármacos , Cromanos/farmacologia , Veia Safena/efeitos dos fármacos , Vasodilatadores/farmacologia , Cromanos/antagonistas & inibidores , Glibureto/farmacologia , Norepinefrina , Ratos Wistar , Vasodilatadores/antagonistas & inibidores
5.
Biol. Res ; 33(2): 71-77, 2000. tab
Artigo em Inglês | LILACS | ID: lil-443676

RESUMO

Three different methodologies frequently employed to evaluate the indexes that report the antioxidant capabilities of pure compounds and/or complex mixtures of antioxidants are applied to a series of mono- and polyphenols, as well as to two wine (red and white) samples. These methodologies are based on the bleaching of a stable radical, the effect of the additive upon luminol chemiluminescence induced by peroxyl radicals, and the effect of the additive upon the bleaching of the fluorescence from a dye molecule. Widely different responses are obtained from the different methodologies. These differences are interpreted in terms of the different factors (stoichiometric factors and/or reactivities) that determines the indexes evaluated by these different methodologies.


Assuntos
Antioxidantes/química , Cromanos/química , Espectrometria de Fluorescência/métodos , Medições Luminescentes , Peróxidos/química , Vinho/análise , Flavonoides , Luminol , Fenóis , Fatores de Tempo
6.
Braz. j. med. biol. res ; 29(2): 175-83, Feb. 1996. graf, tab
Artigo em Inglês | LILACS | ID: lil-161667

RESUMO

The 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation can be generated by incubation of ABTS and 2,2'-azo-bis(2-amidinopropane) at 45 degrees Celsius. The ABTS radical cation is stable for several minutes at room temperature and reacts quantitatively and instantaneously with several antioxidants, such as Trolox, ascorbic acid, uric acid, cysteine, glutathione and bilirubin. In contrast, the ABTS radical cation reacts slowly with albumin. When serum is added to a solution of the ABTS radical cation, the bleaching of the radical follows biphasic kinetics, with a fast decay followed by a slow decay that takes place within several minutes. The fast decay is primarily due to uric acid, while the slow decay is related to the protein content of the sample. We propose that this procedure can provide an independent and simultaneous evaluation of the low molecular weight and protein antioxidants present in biological samples such as serum.


Assuntos
Humanos , Masculino , Feminino , Ácidos Sulfônicos/metabolismo , Antioxidantes/farmacologia , Indicadores e Reagentes/metabolismo , Ácido Ascórbico/sangue , Ácido Úrico/sangue , Bilirrubina/sangue , Cromanos/farmacologia , Cisteína/sangue , Glutationa/sangue , Temperatura , Fatores de Tempo
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