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1.
Braz. J. Pharm. Sci. (Online) ; 59: e19544, 2023. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1429970

RESUMO

Abstract A new series of N-Mannich bases of 2-Phenyl-5-benzimidazole sulfonic acid have been synthesized through amino methylation reaction with secondary amines. The two moieties were held together through a methylene bridge, which comes from formaldehyde (Formalin Solution 37%) used in the reaction. Chemical structures of the newly synthesized compounds have been confirmed using FT-IR, 1HNMR and 13CNMR. Different in vitro assays including Anti-oxidant, Enzyme inhibition, Anti-microbial and Cytotoxicity assay were performed to evaluate the biological potential with reference to the standard drug. Among the synthesized library, compound 3a shows maximum alpha-glucosidase inhibition with an IC50 value of 66.66 µg/ml, compound 3d was found most toxic with LC50 value of 10.17 µg/ml. ADME evaluation studies were performed with the help of Molinspiration online software. Docking calculations were also performed. Given the importance of the nucleus involved, the synthesized compound might find extensive medicinal applications as reported in the literature.


Assuntos
Benzimidazóis/agonistas , Bases de Mannich/análise , Antioxidantes/farmacologia , Ácidos Sulfônicos/efeitos adversos , Preparações Farmacêuticas/administração & dosagem , alfa-Glucosidases/efeitos adversos , Simulação de Acoplamento Molecular/instrumentação , Metilação
2.
Bol. latinoam. Caribe plantas med. aromát ; 20(4): 416-426, jul. 2021. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1369485

RESUMO

Reactive oxygen species are implicated in multiple pathological conditions including erectile dysfunction. This study evaluated the in vitro and in vivo antioxidant potential of the methanolic extracts of Inula glomerata and Salacia kraussii. The plant materials were pulverized and extracted with methanol. The phytochemical analysis, ability of the crude extracts to scavenge free radicals (ABTS, DPPH, NO.) in vitroas well as the total phenolic and flavonoid contents was investigated. In vivo, antioxidant potentials of the crude extracts (50/250 mg/kg body weight) were determined in an erectile dysfunction rat model. The phytochemical analysis revealed that both plants contain flavonoids, tannins, terpenoids, and alkaloids. The crude extracts at varying degree of efficiency, scavenged ABTS and DPPH radicals. The crude extracts at low concentrations (50 mg/kg b.w) significantly (p<0.05) diminished the level of malondialdehyde, augmented catalase activities and elevated glutathione levels. However, SOD activities were significantly boosted in a dose-dependent manner by the crude extracts. Therefore, I. glomerataand S. kraussiipossess antioxidant properties, hence, can serve as a therapeutic modality in the treatment of oxidative stress-induced erectile dysfunction.


Las especies reactivas de oxígeno están implicadas en múltiples condiciones patológicas, incluyendo la disfunción eréctil. Este estudio evaluó el potencial antioxidante in vitro e in vivo de extractos metanólicos de Inula glomeratay Salacia kraussii. Los materiales vegetales fueron pulverizados y extraídos con metanol. A estos extractos crudos se les llevó a cabo el análisis fitoquímico junto con el contenido total de fenólicos y flavonoides, así como se les investigó la capacidad in vitro para atrapar radicales (ABTS, DPPH, NO.). Los potenciales antioxidantes in vivo de los extractos crudos (50/250 mg/kg de peso corporal) se determinaron en un modelo en ratas con disfunción eréctil. El análisis fitoquímico reveló que ambas plantas contuvieron flavonoides, taninos, terpenoides y alcaloides. Los extractos crudos con un grado variable de eficiencia, atraparon a los radicales ABTS y DPPH. Los extractos crudos a bajas concentraciones (50 mg/kg p.c) significativamente (p<0.05) disminuyeron el nivel de malondialdehído, aumentaron las actividades de catalasa y elevaron los niveles de glutatión. Sin embargo, las actividades de SOD por los extractos crudos fueron significativamente dosis-dependientes. Así, los extractos de I. glomeratay S. kraussii mostraron propiedades antioxidantes, y por lo tanto, podrían servir como una alternativa terapéutica en el tratamiento de disfunción eréctil inducida por estrés oxidativo.


Assuntos
Animais , Ratos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Inula/química , Salacia/química , Antioxidantes/farmacologia , Antioxidantes/química , Ácidos Sulfônicos/metabolismo , Flavonoides/análise , Espécies Reativas de Oxigênio , Ratos Sprague-Dawley , Estresse Oxidativo/efeitos dos fármacos , Asteraceae/química , Celastraceae/química , Benzotiazóis/metabolismo , Compostos Fenólicos/análise , Compostos Fitoquímicos/análise , Óxido Nítrico/metabolismo
3.
Rev. Asoc. Odontol. Argent ; 104(2): 79-85, jun. 2016. ilus
Artigo em Espanhol | LILACS | ID: lil-790193

RESUMO

Objetivo: mostrar el efecto de un nuevo procedimiento de descontaminación del biofilm sobre los abscesos periodontales agudos y la periimplantitis. Casos clínicos: un absceso periodontal agudo y una periimplantitis fueron tratados mediante un material de descontaminación de los tejidos bucales. Este consiste en un concentrado acuoso con una mezcla de ácidos hidroxibencensulfónicos e hidroxymetho-xybencénicos y ácido sulfúrico, que se coloca en las bolsas periodontales y alrededor de los implantes. En ninguno de los casos se utilizaron antibióticos locales ni sistémicos. Todos los casos tratados cicatrizaron rápidamente, sin complicaciones. Los pacientes sintieron una leve molestia durante la aplicación del material, que desapareció completamente en pocos segundos. Conclusión: el procedimiento de desecación del biofilm parecería ser una técnica promisoria para el tratamiento de los abscesos periodontales agudos ylas periimplantitis, con la ventaja adicional de que se evita el uso de antibióticos locales y sistémicos.


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Abscesso Periodontal/tratamento farmacológico , Biofilmes , Descontaminação/métodos , Peri-Implantite/tratamento farmacológico , Administração Tópica , Ácidos Sulfônicos/uso terapêutico , Ácidos Sulfúricos/uso terapêutico , Bolsa Periodontal/tratamento farmacológico , Hidroxibenzoatos/uso terapêutico
4.
Biol. Res ; 48: 1-6, 2015. graf, tab
Artigo em Inglês | LILACS | ID: lil-734621

RESUMO

BACKGROUND: The present study was conducted in order to evaluate the fatty acid profile, anti-oxidant and anti-bacterial activities from the microwave aqueous extract of the leaves of three different varieties of Labisia pumila Benth. RESULTS: The chemical analysis of the extract showed that fatty acids (palmitic, palmitoleic, stearic, oleic, linoleic and α-linolenic) acid as the main components in three varieties of L. pumila leaves. Furthermore, the obtained results of the anti-oxidant revealed that L. pumila var. alata contained higher anti-oxidative activities compared to var. pumila and var. lanceolata. However, these values were lower than the tested anti-oxidant standards. On the other hand, the aqueous leaf extracts in all three varieties of L. pumila were also found to inhibit a variable degree of antibacterial activities against eight bacteria (four Gram-positive and four Gram-negative bacteria). CONCLUSIONS: In this study, it was observed the leaves of three varieties of L. pumila exhibited variable patterns of fatty acids and the microwave aqueous extraction possess anti-oxidant and anti-bacterial activities.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Ácidos Graxos/análise , Micro-Ondas , Primulaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Benzotiazóis/metabolismo , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Flavonoides/análise , Sequestradores de Radicais Livres/análise , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Primulaceae/classificação , Óxido Nítrico/metabolismo , Fenóis/análise , Folhas de Planta/química , Ácidos Sulfônicos/metabolismo
5.
Biol. Res ; 48: 1-11, 2015. graf, tab
Artigo em Inglês | LILACS | ID: biblio-950785

RESUMO

BACKGROUND: Atriplex laciniata L. was investigated for phenolic, flavonoid contents, antioxidant, anticholinesterase activities, in an attempt to explore its effectiveness in Alzheimer's and other neurological disorders. Plant crude methanolic extract (Al.MeF), subsequent fractions; n-hexane (Al.HxF), chloroform (Al.CfF), ethyl acetate (Al.EaF), aqueous (Al.WtF), Saponins (Al.SPF) and Flavonoids (Al.FLVF) were investigated for DPPH, ABTS and H2O2 free radical scavenging activities. Further these extracts were subjected to acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities using Ellman's assay. Phenolic and Flavonoid contents were determined and expressed in mg Gallic acid GAE/g and Rutin RTE/g of samples respectively. RESULTS: In DPPH free radicals scavenging assay, Al.FLVF, Al.SPF and Al.MeF showed highest activity causing 89.41 ± 0.55, 83.37 ± 0.34 and 83.37 ± 0.34% inhibition of free radicals respectively at 1 mg/mL concentration. IC50 for these fractions were 33, 83 and 82 µg/mL respectively. Similarly, plant extracts showed high ABTS scavenging potential, i.e. Al.FLVF (90.34 ± 0.55), Al.CfF (83.42 ± 0.57), Al.MeF (81.49 ± 0.60) with IC50 of 30, 190 and 70 µg/ml respectively. further, H2O2 percent scavenging was highly appraised in Al.FLVF (91.29 ±0.53, IC50 75), Al.SPF (85.35 ±0.61, IC50 70) and Al.EaF (83.48 ± 0.67, IC50 270 µg/mL). All fractions exhibited concentration dependent AChE inhibitory activity as; Al.FLVF, 88.31 ± 0.57 (IC50 70 µg/mL), Al.SPF, 84.36 ± 0.64 (IC50 90 µg/mL), Al.MeF, 78.65 ± 0.70 (IC50 280 µg/mL), Al.EaF, 77.45 ± 0.46 (IC50 270 µg/mL) and Al.WtF 72.44 ± 0.58 (IC50 263 µg/mL) at 1 mg/mL. Likewise the percent BChE inhibitory activity was most obvious in Al.FLVF 85.46 ± 0.62 (IC50 100 µg/mL), Al.CfF 83.49 ± 0.46 (IC50 160 µg/mL), Al.MeF 82.68 ± 0.60 (IC50 220 µg/mL) and Al.SPF 80.37 ± 0.54 (IC50 120 µg/mL). CONCLUSIONS: These results stipulate that A. laciniata is enriched with phenolic and flavonoid contents that possess significant antioxidant and anticholinestrase effects. This provide pharmacological basis for the presence of compounds that may be effective in Alzheimer's and other neurological disorders.


Assuntos
Saponinas/metabolismo , Flavonoides/metabolismo , Extratos Vegetais/farmacologia , Inibidores da Colinesterase/farmacologia , Atriplex/química , Doença de Alzheimer/tratamento farmacológico , Antioxidantes/farmacologia , Fenóis/análise , Fenóis/metabolismo , Acetilcolinesterase/metabolismo , Saponinas/isolamento & purificação , Espectrofotometria , Ácidos Sulfônicos/metabolismo , Flavonoides/análise , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Concentração Inibidora 50 , Benzotiazóis/metabolismo , Medicina Tradicional , Antioxidantes/isolamento & purificação
6.
Biol. Res ; 48: 1-17, 2015. graf, tab
Artigo em Inglês | LILACS | ID: biblio-950779

RESUMO

BACKGROUND: Excessive production of free radicals causes direct damage to biological molecules such as DNA, proteins, lipids, carbohydrates leading to tumor development and progression. Natural antioxidant molecules from phytochemicals of plant origin may directly inhibit either their production or limit their propagation or destroy them to protect the system. In the present study, Monodora myristica a non-timber forest product consumed in Cameroon as spice was screened for its free radical scavenging properties, antioxidant and enzymes protective activities. Its phenolic compound profile was also realized by HPLC. RESULTS: This study demonstrated that M. myristica has scavenging properties against DPPH',OH',NO', and ABTS'radicals which vary in a dose depending manner. It also showed an antioxidant potential that was comparable with that of Butylated Hydroxytoluene (BHT) and vitamin C used as standard. The aqueous ethanol extract of M. myristica barks (AEH); showed a significantly higher content in polyphenolic compounds (21.44 ± 0.24 mg caffeic acid/g dried extract) and flavonoid (5.69 ± 0.07 quercetin equivalent mg/g of dried weight) as compared to the other studied extracts. The HPLC analysis of the barks and leaves revealed the presence of several polyphenols. The acids (3,4-OH-benzoic, caffeic, gallic, O- and P- coumaric, syringic, vanillic), alcohols (tyrosol and OH-tyrosol), theobromine, quercetin, rutin, catechine and apigenin were the identified and quantified polyphenols. All the tested extracts demonstrated a high protective potential on the superoxide dismutase (SOD), catalase and peroxidase activities. CONCLUSION: Finally, the different extracts from M. myristica and specifically the aqueous ethanol extract reveal several properties such as higher free radical scavenging properties, significant antioxidant capacities and protective potential effects on liver enzymes.


Assuntos
Extratos Vegetais/farmacologia , Sequestradores de Radicais Livres/farmacologia , Especiarias , Annonaceae/química , Polifenóis/química , Antioxidantes/farmacologia , Peroxidases/efeitos dos fármacos , Picratos/metabolismo , Ácidos Sulfônicos/metabolismo , Superóxido Dismutase/efeitos dos fármacos , Flavonoides/análise , Compostos de Bifenilo/metabolismo , Técnicas In Vitro , Camarões , Extratos Vegetais/química , Catalase/efeitos dos fármacos , Florestas , Cromatografia Líquida de Alta Pressão , Radical Hidroxila/metabolismo , Folhas de Planta/química , Casca de Planta/química , Benzotiazóis/metabolismo , Óxido Nítrico/metabolismo
7.
Biol. Res ; 47: 1-10, 2014. graf, tab
Artigo em Inglês | LILACS | ID: biblio-950772

RESUMO

BACKGROUND: Based on the ethnomedicinal uses and the effective outcomes of natural products in various diseases, this study was designed to evaluate Isodon rugosus as possible remedy in oxidative stress, alzheimer's and other neurodegenerative diseases. Acetylecholinestrase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of crude methanolic extract (Ir.Cr), resultant fractions (n-hexane (Ir.Hex), chloroform (Ir.Cf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq)), flavonoids (Ir.Flv) and crude saponins (Ir.Sp) of I. rugosus were investigated using Ellman's spectrophotometric method. Antioxidant potential of I. rugosus was determined using DPPH, H2O2 and ABTS free radicals scavenging assays. Total phenolic and flavonoids contents of plant extracts were determined and expressed in mg GAE/g dry weight and mg RTE/g of dry sample respectively. RESULTS: Among different fractions Ir.Flv and Ir.Cf exhibited highest inhibitory activity against AChE (87.44 ± 0.51, 83.73 ± 0.64%) and BChE (82.53 ± 0.71, 88.55 ± 0.77%) enzymes at 1 mg/ml with IC50 values of 45, 50 for AChE and 40, 70 µg/ml for BChE respectively. Activity of these fractions were comparable to galanthamine causing 96.00 ± 0.30 and 88.61 ± 0.43% inhibition of AChE and BChE at 1 mg/ml concentration with IC50 values of 20 and 47 µg/ml respectively. In antioxidant assays, Ir.Flv, Ir.Cf, and Ir.EtAc demonstrated highest radicals scavenging activities in DPPH and H2O2 assays which were comparable to ascorbic acid. Ir.Flv was found most potent with IC50 of 19 and 24 µg/ml against DPPH and H2O2 radicals respectively. Whereas antioxidant activates of plant samples against ABTS free radicals was moderate. Ir.Cf, Ir.EtAc and Ir.Cr showed high phenolic and flavonoid contents and concentrations of these compounds in different fractions correlated well to their antioxidant and anticholinestrase activities. CONCLUSION: It may be inferred from the current investigations that the Ir.Sp, Ir.Flv and various fractions of I. rugosus are good sources of anticholinesterase and antioxidant compounds. Different fractions can be subjected to activity guided isolation of bioactive compounds effective in neurological disorders.


Assuntos
Saponinas/análise , Flavonoides/análise , Extratos Vegetais/química , Inibidores da Colinesterase/análise , Isodon/química , Antioxidantes/análise , Picratos/metabolismo , Acetilcolinesterase/efeitos dos fármacos , Saponinas/isolamento & purificação , Espectrofotometria/métodos , Ácidos Sulfônicos/metabolismo , Flavonoides/isolamento & purificação , Compostos de Bifenilo/metabolismo , Butirilcolinesterase/efeitos dos fármacos , Clorofórmio , Sequestradores de Radicais Livres/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Concentração Inibidora 50 , Isodon/classificação , Isodon/enzimologia , Componentes Aéreos da Planta/química , Misturas Complexas , Metanol , Benzotiazóis/metabolismo , Radicais Livres/análise , Hexanos , Peróxido de Hidrogênio/metabolismo , Medicina Tradicional , Acetatos
8.
Braz. dent. j ; 22(1): 37-40, 2011.
Artigo em Inglês | LILACS | ID: lil-582399

RESUMO

Most of the problems of endodontic origin have a bacterial etiological agent. Thus, there is a continued interest in seeking more effective chemical substances that can replace the camphorated paramonochiorophenol or antibiotics as intracanal medicaments. Among the possible substances, ozone has some interesting biological characteristics: bactericidal action, debriding effect, angiogenesis stimulation capacity and high oxidizing power. The purpose of this study was to chemically evaluate the presence of ozone in sunflower, castor, olive and almond oil, as well as in propylene glycol and byproducts of ozonation, such as formaldehyde. These compounds were ozonized, inserted into empty and sterile vials, and analyzed by testing the reaction between ozone and indigo, for determining the presence of ozone, and subjected to the chromotropic acid test for determining the presence of formaldehyde. It was observed complete absence of ozone in all samples tested and presence of formaldehyde. The bactericidal and healing action of ozonized oils could be attributed to products formed by the ozonation of mineral oils, such as formaldehyde, not to the ozone itself.


A maioria dos problemas de origem endodôntica tem um agente etiológico bacteriano. Assim, existe um interesse permanente em se buscar substâncias químicas mais efetivas e que possam substituir o PMCC ou os antibióticos como curativos de demora. Dentre as possíveis substâncias, o ozônio apresenta algumas características biológicas interessantes: ação bactericida, efeito debridante, estímulo a angiogênese, além do efeito oxidante. O propósito do presente estudo foi avaliar quimicamente a presença de ozônio nos óleos de girassol, rícino, oliva e amêndoas, além do propilenoglicol, bem como subproputos da ozonização, como formaldeído. Essas substâncias foram ozonizadas, inseridas em tubetes anestésicos vazios e esterilizados, e analisadas por meio do teste da reação entre ozônio e índigo, para determinação da presença de ozônio; e teste do ácido cromotrópico, para determinação da presença de formaldeído. Foi observado ausência total de ozônio em todas as amostras testadas, além da presença de formaldeído. A ação bactericida e curativa dos óleos ozonizados poderia ser atribuída aos produtos formados pela ozonização de óleos minerais, como o formaldeído, e não ao ozônio propriamente dito.


Assuntos
Ozônio/análise , Óleos de Plantas/química , Irrigantes do Canal Radicular/química , Colorimetria , Corantes/química , Formaldeído/análise , Indóis/química , Propilenoglicol/química , Ácidos Sulfônicos/química
9.
Braz. j. med. biol. res ; 41(6): 455-461, June 2008. graf
Artigo em Inglês | LILACS | ID: lil-485857

RESUMO

A novel, rapid and cost-effective trifluoperazine dihydrochloride (TFPH) decolorization assay is described for the screening of antioxidant activity. A chromogenic reaction between TFPH and potassium persulfate at low pH produces an orange-red radical cation with maximum absorption at 502 nm in its first-order derivative spectrum. TFPH was dissolved in distilled water to give a 100 mM solution. The TFPH radical cation solution was made by reacting 0.5 mL of the solution with K2S2O8 (final concentration: 0.1 mM) and diluting to 100 mL with 4 M H2SO4 solution. A linear inhibition of color production was observed with linearly increasing amounts of antioxidants, with correlation coefficients (R²) ranging from 0.999 to 0.983. The antioxidant capacity of standard solutions of an antioxidant was evaluated by comparing with the inhibition curve using Trolox as the standard. Comparison of antioxidant capacity determined with this newly developed TFPH assay and with the well-known 2,2'-azinobis-[3-ethylbenzthiazoline-6-sulfonic acid] (ABTS)-persulfate decolorization assay indicated the efficacy and sensitivity of the procedure. The proposed assay is less expensive (costs about US$4 per 100 assays) and requires only 20 min for preparation of radical cation solution in comparison with ABTS assay, in which almost 12-16 h are required for preparation of a stable ABTS radical cation solution. The present assay has the advantage over ABTS assay that it can be used to measure the antioxidant activity of the samples, which are naturally found at a pH as low as 1, because the radical cation itself has been stabilized at low pH.


Assuntos
Antioxidantes/análise , Benzotiazóis/química , Ácidos Sulfônicos/química , Trifluoperazina/química , Cátions , Indicadores e Reagentes , Reprodutibilidade dos Testes , Espectrofotometria/métodos , Fatores de Tempo
10.
Biol. Res ; 39(2): 229-236, 2006. ilus
Artigo em Inglês | LILACS | ID: lil-432425

RESUMO

Pre-eclampsia is a hypertensive disorder of pregnancy in which enzymatic antioxidant defenses fail and tissues are injured. This prospective case-control study evaluated whether pre-eclamptic women and their newborns show higher degrees of oxidative stress than normal pregnancies and sought to determine if this stress is related to clinical severity. Forty-four pre-eclamptic and thirty healthy pregnant women attending two hospitals in Valparaíso, Chile, were studied. The following plasmatic variables of antioxidant capacity were evaluated: glutathione peroxidase activity (GPx), total antioxidant capacity measured by oxidation of ABTS substrate (2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid), and superoxide dismutase activity (SOD). malondialdehide (MDA) was measured to evaluate lipoperoxidation. The evaluation was performed at diagnosis of pre-eclampsia, delivery, 30 days and 120 days post delivery. Newborns were studied at delivery through umbilical cord blood samples. Our analysis shows that antioxidant enzyme activity (SOD, GPx, ABTS) was significantly decreased, while lipoperoxidation (MDA) was increased in both pre-eclamptic groups compared to normal pregnant women (p<0.01). Statistically significant difference was found between mild and severe pre-eclamptic groups (p<0.01), for all biochemical markers studied. Therefore, the clinical severity of this pathology is closely related to the degree of oxidative stress.


Assuntos
Feminino , Humanos , Recém-Nascido , Gravidez , Peroxidação de Lipídeos , Estresse Oxidativo , Pré-Eclâmpsia/metabolismo , Benzotiazóis/sangue , Benzotiazóis/metabolismo , Biomarcadores/sangue , Estudos de Casos e Controles , Sangue Fetal/enzimologia , Glutationa Peroxidase/sangue , Glutationa Peroxidase/metabolismo , Estudos Prospectivos , Pré-Eclâmpsia/diagnóstico , Índice de Gravidade de Doença , Ácidos Sulfônicos/sangue , Ácidos Sulfônicos/metabolismo , Superóxido Dismutase/sangue , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico
11.
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
12.
Rev. chil. cienc. méd. biol ; 2(1): 19-23, 1992. tab, ilus
Artigo em Espanhol | LILACS | ID: lil-148303

RESUMO

El calcio y el magnesio son dos importantes cationes corporales, con funciones especializadas en los líquidos orgánicos. Existen numerosos métodos para la cuantificación de estos cationes. Se evaluaron los métodos colorimétricos de la O-cresolftaleína para calcio total y del calmagite para magnesio en suero sanguíneo de 64 individuos, comparándolos con espectrofotometría de absorción atómica. Las determinaciones colorimétricas mostraron buena estabilidad de color y adecuados valores de precisión diaria e interdiaria. Al analizar los espectros de absorción, se propone modoficar las longitudes de onda establecidas en ambos métodos colorimétricos. Los valores obtenidos para el calcio con la O-cresolftaleína, resultaron similares a los obtenidos con espectrofotometría de absorción atómica; en cambio para el magnesio las determinaciones con Calmagite fueron en promedio 8,7 por ciento más altos


Assuntos
Humanos , Adulto , Cálcio/sangue , Colorimetria , Espectrofotometria Atômica/métodos , Magnésio/sangue , Ácidos Sulfônicos , Kit de Reagentes para Diagnóstico/normas
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