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1.
BMC Rheumatol ; 6(1): 20, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35361289

RESUMO

BACKGROUND: Dermatomyositis belongs to an infrequent group of diseases predominantly found in patients older than 40 years old and is characterized by dermal and muscular findings. This disease presents itself as proximal, ascending and symmetric weakness and typical dermatosis with findings such as elevated muscle enzymes, altered electromyography and typical changes in muscle biopsy; as of today, the etiology of the disease in unknown. The COVID-19 vaccine has been a fundamental tactic to achieve control of the coronavirus (SARS CoV2), and it's clear that the benefits of getting the vaccine overweight the risks that might come along with it. Although rare, all adverse effects should be reported, this could help us to understand the elusive pathophysiology of inflammatory idiopathic myopathy. CASE PRESENTATION: In this text we will describe the case of a patient with dermatomyositis who was vaccinated against SARS CoV2 with BNT162b2 mRNA (Pfizer-BioNTech), showing a temporal relation between the vaccination and the beginning of her symptoms. We realized all the diagnostic approach to the suspected disease including electromyography, muscle biopsy and laboratory findings, corroborating the diagnosis. The patient received standard treatment for this disease (steroid therapy) and have a classic slow improvement. CONCLUSIONS: Although it´s not possible to confirm a direct correlation between the vaccine and the onset of the disease, we considered that there are enough data to suspect that this could be a trigger event and therefore should always be considered a possible cause for a case of inflammatory idiopathic myopathy.

2.
Braz. J. Pharm. Sci. (Online) ; 57: e181084, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1350225

RESUMO

Some antioxidant compounds have a pro-oxidant effect in the presence of transition metal ions, due to the reduction of Mn+ to M(n-1)+ with simultaneous formation of free radicals, which then promote DNA damage. In the present study, we evaluated the pUC19 DNA damage in a solution containing Cu(II) and ascorbic acid (AA) or S(IV) saturated with air by agarose gel electrophoresis. Our results showed that this damage decreases if AA and S(IV) are simultaneously added. This study also illustrates the importance of Cu(II) in this process, as no DNA damage was observed when AA or S(IV) were present in the absence of this metallic ion. Our data showed that DNA preservation depends on the concentration of AA and S(IV) and occurs when the [S(IV)]:[AA] ratio ranges from 1:1 to 20:1. Absorbance measurements and thermodynamic data show that no reaction occurs between AA and S(IV) when this mixture (pH 5.5) is added to pUC-19 DNA. The presence of dissolved oxygen may be the cause of AA consumption in the mixture of these two antioxidants, which subsequently decreases DNA damage.


Assuntos
Ácido Ascórbico/efeitos adversos , Sulfitos , Dano ao DNA , Cobre/farmacologia , Íons/efeitos adversos , Antioxidantes/efeitos adversos , Eletroforese em Gel de Ágar/instrumentação , Radicais Livres/farmacologia , Concentração de Íons de Hidrogênio
3.
J Food Sci Technol ; 55(4): 1331-1338, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29606747

RESUMO

An alternative method for quantification of the total reducing capacity (TRC) of processed ready-to-drink fruit juices (orange, grape, peach, mango, cashew, strawberry, apple and guava) is suggested. The spectrophotometric procedure is based on the reduction of Cu(II) to Cu(I) by antioxidants (present in the samples) in aqueous buffered solution (pH 7.0), containing 4,4'-dicarboxy-2,2'-biquinoline acid (H2BCA), yielding the [Formula: see text] complexes. The absorbance values at 558 nm (A558 nm) of the [Formula: see text] complexes obtained with juice samples were compared with A558 nm values of the same complexes obtained with a standard ascorbic acid solution and used to quantify and express the reducing capacity of each sample. Regarding orange juices a positive relationship between the TRC values using the [Formula: see text] complexes and the labelled ascorbic acid (AA) content along with the total polyphenol content (TPC) was measured. Grape juices showed the best positive correlation was verified between the TRC (with the [Formula: see text] complexes) and the TPC. While other fruit juices showed good agreement of TRC values with [Formula: see text] complexes and DPPH reagent. The proposed method may be applied to measure the TRC of beers and wines and also for biological samples like serum and follicular fluid.

4.
Saudi Pharm J ; 25(7): 961-966, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29158701

RESUMO

The DNA damage in the presence of dipyrone (used as its sodium salt, NaDip) and some transition metal ions in an air saturated ([O2] ≈ 0.25 mM) non-buffered solution at T = (25.0 ± 0.5)°C was investigated by agarose gel electrophoresis. As metal ions Cu2+, Fe3+, Ni2+ and Mn3+ were selected and evaluated in the present study because of the important role they play in a biological system. pUC19 plasmid DNA damage-induced by NaDip (80-600 µM) was observed in the presence of 100 µM Cu2+. The damage was proportional to the NaDip concentration provided that the order of addition of reagents (pUC19 plasmid DNA + Cu2+ + NaDip) is obeyed. Addition in the reaction medium of ligands for Cu2+ and Cu+, respectively EDTA and neocuproine, promoted total inhibition or reduction of the pUC19 plasmid DNA damage suggesting the involvement of the Cu2+/Cu+ cycle. Besides, the decrease in the pUC19 plasmid DNA damage after addition of catalase (1.0 × 10-4 mg µL-1) in the same reaction medium indicates that H2O2 is also involved in the damage process. In NaDip concentration range (80-600 µM), and under same the experimental conditions, it was not possible to conclude whether there was pUC19 plasmid DNA damage caused by 10 µM Fe3+. No damage was observed in the presence of Mn3+ or Ni2+. Although the technique used in this study is sensitive to detect the pUC19 plasmid DNA damage it was not possible to identify in which DNA base this damage occurs. Further studies with other techniques should be made to unambiguously identify the oxidative intermediates that are responsible for the DNA damage. As far as we know, this is the first study dealing with the pUC19 plasmid DNA damage-induced by NaDip in presence of copper, iron, nickel and manganese ions.

5.
Molecules ; 20(12): 22411-21, 2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26694328

RESUMO

A method for the determination of total reducing capacity (TRC) based on the reduction of Cu(II) to Cu(I) by antioxidants in a buffered solution (pH 7.0) containing 4,4'-dicarboxy-2,2'-biquinoline acid (BCA) was developed. Absorbance values at 558 nm characteristic of the Cu(I)/BCA complexes formed were used to determine the TRC of aqueous extracts of twelve Brazilian plants. The TRC values obtained with the suggested method correlated well with values obtained using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method (r² = 0.959). They were also compared with the total polyphenol content (using the Folin-Ciocalteu reagent) and the good agreement (r² = 0.919) indicates that the polyphenols should be responsible for this reducing capacity. The method proposed here (and successfully applied in plant extracts) can be used to measure the TRC of aqueous samples derived from other plants (e.g., teas, juices, beers and wines) and even in biological samples (e.g., serum, urine and follicular fluid). To achieve a structure-activity relationship of the proposed reaction, the reduction capability of 25 standard antioxidants (phenolic derivatives, flavonoids, stilbenoids, vitamins, etc.) was individually evaluated and the apparent molar absorptivity values (at 558 nm) obtained were compared and discussed.


Assuntos
Antioxidantes/análise , Complexos de Coordenação/química , Cobre/química , Plantas Medicinais/química , Polifenóis/análise , Quinolinas/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/química , Brasil , Soluções Tampão , Cátions Monovalentes , Humanos , Oxirredução , Picratos/química , Extratos Vegetais/química , Polifenóis/química , Polifenóis/isolamento & purificação , Soluções , Espectrofotometria , Água
6.
Phytochem Anal ; 26(2): 119-26, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25431184

RESUMO

INTRODUCTION: The growing interest in determination of anti-oxidant capacity through non-labour, effective and less costly methods encouraged the development of the spectrophotometric procedure presented in this study. OBJECTIVE: To investigate the reduction reaction of Fe(III) in 3-hydroxy-4-nitroso-2,7-naphthalenedisulphonic anion (NRS) medium as an alternative ferric reducing activity power (FRAP) assay for determining the total reduction capacity (RC). MATERIALS AND METHODS: The absorbance values at 730 nm were used to determine the RC of aqueous extracts of nine Brazilian plants. The results were compared with the values obtained with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and with the total polyphenol content (TPC). The RCs of phenolic derivatives, flavonoids, amino acids and other anti-oxidant compounds were determined. RESULTS: Paired t-test with RC values obtained with both assays (proposed FRAP and DPPH) showed no statistically significant difference. In addition, the RC values from the proposed FRAP assay are proportional to those found with TPC values (r =0.916). In addition, the conditional reduction potential of the Fe(III)/Fe(II) couple (0.685 V vs NHE (normal hydrogen electrode)) and the molar absorptivities at 730 nm of the Fe(NRS)(3)(3-) and Fe(NRS)(3)(4-) complexes (1.88 × 10(3) and 1.77 × 10(4) L/cm × mol, respectively) were calculated because these values were not available. CONCLUSION: The proposed assay is adequate for determination of the RC of plant extracts, and the results infer that other samples derived from plants (e.g. beers and wines) and even biological samples (e.g. serum and urine) also could be analysed.


Assuntos
Técnicas de Química Analítica/métodos , Compostos Férricos/química , Extratos Vegetais/química , Plantas/química , Aminoácidos/análise , Antioxidantes/análise , Compostos de Bifenilo/química , Brasil , Flavonoides/análise , Naftalenos/análise , Oxirredução , Picratos/química , Extratos Vegetais/isolamento & purificação , Polifenóis/análise , Espectrofotometria/métodos
7.
Nat Prod Commun ; 10(11): 1821-4, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26749806

RESUMO

Aqueous plant extracts contain polyphenols that reduce Fe3+ to Fe2+, which in the presence of excess 2,2'-bipyridine (bipy) yield the Fe(bipy)3(2+) complex (λmax = 521 nm). This reaction was used to quantify the total polyphenol content (TPC) of nineteen Brazilian medicinal species using pyrogallic acid (PA) as a standard. A calibration curve of absorbance values at 521 nm values vs. PA was linear from 0.378 to 3.03 mg L(-1) (r = 0.998; n = 8) with a limit of detection 0.16 mg L(-1). The TPC quantification using the proposed reaction was compared with values obtained with the Folin-Ciocalteu reagent, yielding good agreement (r = 0.965). For the same species the TPC obtained with the proposed method also resulted in good correlation (r = 0.773) with the antioxidant capacity values quantified using the 2,2-diphenyl-lI-picrylhydrazyl method. It was also found that Fe(bipy)3(2+) complexes can be used to calculate the reducing capability of polyphenols. The polyphenol structure, and the number and position of the hydroxyl group attached to the benzene ring modify this reductive capacity.


Assuntos
2,2'-Dipiridil/química , Antioxidantes/química , Compostos Ferrosos/química , Extratos Vegetais/química , Plantas Medicinais/química , Polifenóis/química , Brasil
8.
Montrichardia linifera (Araceae) biological potential, phytochemical prospection and polyphenol content / Montrichardia linifera is commonly known in Brazil as "aninga." In November 2008 and August 2009, we collected plant samples and extracted leaves and stems using hexane or dichloromethane and methanol to evaluate its biological and chemical potential, phytochemical profile and polyphenol content. Differences in the chemical composition of the collections were evident. In the first collection, the apolar extracts were the richest in metabolite composition while the polar extracts were the richest in the second collection. In general, extracts from Aug/2009 had higher antioxidant and cytotoxic activities than extracts from Nov/2008 and the stem and leaf extracts from the Aug/2009 collection showed the highest polyphenol content. As an insecticide against Sitophilus zeamais, the hexane extract of the leaves (Aug/2009) presented concentration-dependent insecticidal activity. Only the methanolic extract of stems and leaves (Aug/2009) presented a small inhibition halo (9 and 7 mm, respectively) against Aeromonas hydrophila when evaluating its antibacterial potential. The study demonstrates that, collection period is an important factor to consider in phytochemical and biological activity studies of M. linifera. / Potencial biológico, prospección fitoquímica y contenido de polifenoles de Montrichardia linifera (Araceae) / Potencial biológico, prospecção fitoquímica e teor de polifenóis de Montrichardia linifera (Araceae)
Univ. sci ; 19(3): 213-224, sep.-dic. 2014. ilus, tab
Artigo em Inglês | LILACS-Express | LILACS | ID: lil-735233

RESUMO

Montrichardia linifera es comúnmente conocida en Brasil como "aninga". Fue colectada dos veces (Nov/2008 y Ago/2009), y sus hojas y tallos fueron extraídos con hexano o diclorometano y metanol. El potencial biológico y químico, perfil fitoquímico y contenido de polifenoles de sus extractos fueron evaluados. Fueron encontradas diferencias en la composición química: de la primera colecta, los extractos apolares fueron más ricos, mientras que de la segunda colecta, los polares fueron los más ricos. Extractos de Ago/2009 mostraron, en general, actividades antioxidante y citotóxica mayores que los de Nov/2008. Los extractos de los tallos y hojas de Ago/2009 mostraron un mayor contenido de polifenoles. Cuanto al ensayo insecticida sobre Sitophilus zeamais, el extracto hexánico de las hojas (Ago/2009) presentó actividad insecticida concentración-dependiente. Cuando evaluado el potencial antibacteriano, apenas los extractos metanólicos de los tallos y hojas (Ago/2009) presentaron un halo de inhibición pequeño (9 y 7 mm, respectivamente) contra Aeromonas hydrophila. Este estudio muestra que el período de la colecta es un factor importante a ser considerado cuando los objetivos son estudios fitoquímicos y de actividades biológicas de M. linifera.


Montrichardia linifera é comumente conhecida no Brasil como "aninga". Foi coletada duas vezes (Nov/2008 e Ago/2009), e suas folhas e caules foram extraídos com hexano ou diclorometano e metanol. O potencial biológico e químico, perfil fitoquímico e teor de polifenóis de seus extratos foram avaliados. Foram encontradas diferenças na composição química: da primeira coleta, os extratos apolares forem mais ricos, enquanto que da segunda coleta, os polares foram os mais ricos. Extratos de Ago/2009 mostraram, em geral, atividades antioxidante e citotóxica maiores que os de Nov/2008. Os extratos dos caules e das folhas de Ago/2009 mostraram um maior teor de polifenois. Quanto ao ensaio inseticida sobre Sitophilus zçamais, o extrato hexânico das folhas (Ago/2009) apresentou atividade inseticida dependente da concentração. Quando avaliado o potencial antibacteriano, apenas os extratos metanólicos dos caules e folhas (Ago/2009) apresentaram um halo de inhibição pequeno (9 e 7 mm, respectivamente) contra Aeromonas hydrophila. Este estudo mostra que o período da coleta é um fator importante a ser considerado quando os objetivos são estudos fitoquímicos e de atividades biológicas de M. linifera.

9.
ABCS health sci ; 38(1): 8-16, jan.-set. 2013. graf, tab
Artigo em Português | LILACS | ID: lil-681441

RESUMO

OBJETIVO: Os chás de ervas são tradicionalmente utilizados na medicina popular em muitas regiões do Brasil. Os chás contêm compostos antioxidantes que combatem o stress oxidativo e seu consumo tem sido associado à diminuição dos níveis de colesterol, pressão arterial e até de doenças cardiovasculares. O objetivo deste estudo foi determinar a capacidade antioxidante total, o teor total de polifenóis, o consumo (scavenging) de H2O2 e a presença de outros grupos de compostos antioxidantes em 43 amostras de chás em sachets. MÉTODOS: O método CUPRAC (cupric ion reducing antioxidant capacity) foi utilizado para determinar a capacidade antioxidante total. O teor total de polifenóis foi obtido com o uso do reagente de Folin-Ciocalteu; o ensaio de scavenging baseou-se no consumo de solução de H2O2 após adição do chá; e a presença de flavonóides, carotenos e catequinas foi investigada por cromatografia em papel. RESULTADOS: A capacidade antioxidante total nas amostras analisadas seguiu a ordem: camomila > hortelã > carqueja >cidreira > boldo > verde > mate > preto > branco > erva doce. O teor total de polifenóis obedeceu à sequência: branco > hortelã > preto > mate > boldo > verde > camomila > carqueja > cidreira > erva doce. As divergências encontradas entre as amostras de um mesmo grupo de chá podem ser atribuídas à época da colheita, ao tipo de solo, local de plantio, variações climáticas e partes da planta utilizadas na elaboração dos sachets. CONCLUSÃO: Conclui-se que todas as amostras analisadas apresentaram capacidade antioxidante e consumo de H2O2. Em apenas uma delas não foi possível detectar flavonóides, carotenos ou catequinas.


OBJECTIVE: Tea leaves are traditionally used in folk medicine in many regions of Brazil. They contain antioxidant compounds that can protect against oxidative stress and their regular intake have been associated with decreased of cholesterol levels, blood pressure and, thereby, with the lowered risk of coronary heart disease. The objective of this study was to determine the total antioxidant capacity, the total polyphenols content,scavenging of H2O2 and presence of other groups of antioxidant compounds in 43 tea samples packed in bags. METHODS: The CUPRAC method (cupric ion reducing antioxidant capacity) was used to quantify the total antioxidant capacity. The polyphenols content was performed using the Folin-Ciocalteu reagent. The scavenging assay was based on the consumption of H2O2 after addition of tea; the presence of flavonoids, carotenes and catechins was evaluated by paper chromatography. RESULTS:The total antioxidant capacity found in tea samples followed the order: chamomile > mint > carqueja > balm > boldo > green > mate > black > white > fennel. For total polyphenol content the order was: white > mint > black > matte > boldo > green > chamomile > carqueja > balm > fennel. The differences found in the samples from the same kind of tea can be attributed to the harvest season, soil type, planting location, climate differencesand from the parts of the vegetal material used in the preparation of the tea bags. CONCLUSION: All samples analyzed presented antioxidant activity and ability to scavenge H2O2. It was not possible to detect flavonoids, carotenes and catechins in only one sample.


Assuntos
Antioxidantes , Bebidas , Carotenoides , Catequina , Chá , Flavonoides , Polifenóis
10.
Food Chem ; 138(2-3): 1325-32, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23411250

RESUMO

A critical study of the use of the Fe(III)/3-hydroxy-4-nitroso-2,7-naphthalenedisulfonic acid (NRS) complexes on the quantification of the polyphenols content in aqueous extracts of plants, expressed as pyrogallic acid, [PA], is presented. The reaction used is based on the reduction of Fe(III) to Fe(II) by [PA] in the presence of NRS in a buffered medium (Tris; pH 8.0) with formation of Fe(II)/NRS complexes. A calibration curve of absorbance (at 730 nm) vs. [PA] is linear (r=0.998; n=7) from 1.0 to 7.0 µmolL(-1) [PA]. LD and RSD were 0.5 µmolL(-1) and 2.5% (6.0 µmolL(-1) [PA], n=10), respectively. The influence of pH, type of buffer solution and interfering species possibly present in the samples were evaluated. Aqueous extracts of twelve medicinal plants used in the Brazilian folk medicine were analysed by using both Fe(III)/NRS complexes and the Folin-Ciocalteu reagent.


Assuntos
Técnicas de Química Analítica/métodos , Compostos Ferrosos/química , Naftalenossulfonatos/química , Extratos Vegetais/análise , Plantas Medicinais/química , Polifenóis/análise , Brasil
11.
J Agric Food Chem ; 57(23): 11061-6, 2009 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-19899763

RESUMO

A spectrophotometric method is proposed for the determination of the polyphenols content in aqueous extracts of plants. The method is based on the reduction of Cu(II) to Cu(I) by polyphenols, in the presence of bicinchoninic acid in a buffered medium (ammonium acetate, pH 7.0) with the formation of Cu(I)/BCA complexes. A calibration curve of absorbance (at 558 nm) vs tannic acid concentration is linear (r = 0.995; n = 7) with tannic acid from 0.1 to 0.7 micromol L(-1). The limit of detection and relative standard deviation were 40 nmol L(-1) (99% confidence level) and 3.8% (0.4 micromol L(-1) tannic acid, n = 7), respectively. For the aqueous extracts of Hamamelis virginiana L., Maytenus ilicifolia Mart. ex Reissek, Hydrocotyle bonariensis Lam, Annona muricata L., Myrciaria cauliflora (Mart.) O. Berg., Caesearia sylvestris Sw., Schinus terebinthifolia (Raddi), and Stryphnodendron adstringens (Mart.) Coville, the total polyphenol contents, expressed as tannic acid, were 3.5, 1.3, 2.0, 3.1, 15.4, 3.1, 9.1, and 6.9%, respectively.


Assuntos
Cobre/química , Flavonoides/química , Fenóis/química , Extratos Vegetais/química , Plantas Medicinais/química , Quinolinas/química , Espectrofotometria/métodos , Limite de Detecção , Oxirredução , Polifenóis
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