Physicochemical characterization and antioxidant activity of decolorized Moringa oleifera Lam leaf flour

BACKGROUND: Maringa oleifera leaves are rich in antioxidant substances; however, when lyophilized leaves were used in flour form in meat products, they presented no antioxidant effect and even accelerated the oxidation process of the product. Thus, the objective of this study was to evaluate the effect of chlorophyll extraction on the physicochemical composition and antioxidant activity of Moringa leaves. METHODS: Moringa leaves were dried and ground in order to obtain uniform flour. A treatment using chlorophyll extraction (decolorized) was tested versus a control treatment(non-decolorized) for proximate composition, instrumental color, and antioxidant activity using ANOVA followed by Tukey'stest. RESULTS: Higher crude fiber, ash, and protein contents were observed for decolorized flour (19.41 and 38.13%, 11.87 and14.02%, and 28.81 and 31.33%, respectively) when compared to those for the control. Chlorophyll extraction significantly affected (p< 0.05) the instrumental color of the leaves flour. The half maximal effective concentration (EC50) of both decolorized and control flour was 3.74 and 4.30 mg/L, respectively. The equivalent of antioxidant per gramof non-decolorized leaves was higher than that observed for the decolorized leaves (0.36 and 0.32 g/g DPPH, respectively). The antioxidant activity (AA%) of the extract from non-decolorized leaves was higher in the concentrations of 5 and 2.5 mg/0.1 mL, while the decolorized leaves was higher in the extract concentration 5 and 2 mg/0.1 ml. CONCLUSION: The decolorization process affected the chemical composition and color of Moringa oleifera leaves flours however did not improve its antioxidant activity

Comparative antioxidant and bioavailability studies of Vitamin C in Phyllanthus emblica Linn. and its combinations with Piper nigrum Linn. and Zingiber officinale Roscoe

ABSTRACT Phyllanthus emblica Linn. (amla) is used in Ayurveda, the ancient Indian system of medicine and its major constituent is vitamin C which has effective free radical scavenging property. The purpose of this study was to evaluate the in vitro antioxidant activity and the bioavailability profile of vitamin C in amla and its combinations with piperine and ginger in comparison to synthetic vitamin C using New Zealand rabbits. In vitro antioxidant activity studies of synthetic vitamin C, amla, amla with piperine and amla with ginger were carried out using different models such as 2,2-Diphenyl-1-picrylhydrazyl, Nitric Oxide, Hydrogen peroxide scavenging methods, Total reductive capability and Oxygen Radical Absorbance Capacity estimation. The study results showed that synthetic vitamin C, amla, amla with piperine and amla with ginger possess significant in vitro antioxidant activity. For bioavailability studies, synthetic vitamin C, amla, amla with piperine and amla with ginger 100 mg/kg, were administered orally and the serum samples were analyzed by HPLC at 0, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours. Bioavailability studies revealed that amla with piperine combination has higher concentration of vitamin C when compared to synthetic vitamin C. This is probably due to presence of piperine, which is a bioavailability enhancer. The present study supports the fact that amla with piperine combination can be an alternative to synthetic vitamin C.

RESUMO Phyllanthus emblica Linn. (amla) é utilizada na medicina Ayurveda, medicina da Índia antiga e seu principal constituinte é a vitamina C, que possui propriedade sequestrante de radicais livres. O propósito deste estudo foi avaliar a atividade antioxidante in vitro e o perfil de biodisponibilidade da vitamina C na amla e suas combinações com piperina e gengibre em comparação com a vitamina C sintética, utilizando coelhos da Nova Zelândia. Os estudos de atividade antioxidante in vitro de vitamina C sintética, amla, amla com piperina e amla com gengibre foram realizados utilizando-se diferentes modelos para sequestrantes, como 2,2-difenil-1-picrilidrazil, óxido nítrico, peróxido de hidrogênio, capacidade redutiva total e a estimativa da capacidade de absorvância do radical oxigênio. Os resultados do estudo mostraram que vitamina C sintética, amla, amla com piperina e amla com gengibre possuem atividade antioxidante in vitro significativa. Para os estudos de biodisponibilidade, administraram-se oralmente vitamina C sintética, amla, amla com piperina e amla com gengibre 100 mg/kg e as amostras de soro foram analisadas por CLAE em 0, 1, 2, 3, 4, 6, 8, 10, 12 e 24 horas. Os estudos de biodisponibilidade revelaram que a associação de amla com piperina tem maior concentração de vitamina C, quando comparada com a vitamina C sintética. Este efeito é provavelmente devido à presença de piperina, que é intensificador de biodisponibilidade. O presente estudo apoia o fato de que a associação de amla e piperina pode ser uma alternativa para a vitamina C sintética.

Effect of mitochondrial potassium channel on the renal protection mediated by sodium thiosulfate against ethylene glycol induced nephrolithiasis in rat model

Purpose: Sodium thiosulfate (STS) is clinically reported to be a promising drug in preventing nephrolithiasis. However, its mechanism of action remains unclear. In the present study, we investigated the role of mitochondrial KATP channel in the renal protection mediated by STS. Materials and Methods: Nephrolithiasis was induced in Wistar rats by administrating 0.4% ethylene glycol (EG) along with 1% ammonium chloride for one week in drinking water followed by only 0.75% EG for two weeks. Treatment groups received STS, mitochondrial KATP channel opener and closer exclusively or in combination with STS for two weeks. Results: Animals treated with STS showed normal renal tissue architecture, supported by near normal serum creatinine, urea and ALP activity. Diazoxide (mitochondria KATP channel opening) treatment to the animal also showed normal renal tissue histology and improved serum chemistry. However, an opposite result was shown by glibenclamide (mitochondria KATP channel closer) treated rats. STS administered along with diazoxide negated the renal protection rendered by diazoxide alone, while it imparted protection to the glibenclamide treated rats, formulating a mitochondria modulated STS action. Conclusion: The present study confirmed that STS render renal protection not only through chelation and antioxidant effect but also by modulating the mitochondrial KATP channel for preventing urolithiasis.

Characterization and biological activities of extracellular melanin produced by Schizophyllum commune (Fries).

Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment was characterized by biochemical tests and further, confirmed by UV, IR, EPR, NMR and MALDI-TOF Mass Spectra. Extracellular melanin, at 100 µg/ml, showed significant antibacterial activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas fluorescens and antifungal activity against Trichophyton simii and T. rubrum. At a concentration of 50 µg/ml, melanin showed high free radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl) indicating its antioxidant potential. It showed concentration dependent inhibition of cell proliferation of Human Epidermoid Larynx Carcinoma Cell Line (HEP-2). This study has demonstrated characterization of melanin from basidiomycetes mushroom fungus, Schizophyllum commune and its applications.

Synthesis and DPPH scavenging assay of reserpine analogues, computational studies and in silico docking studies in AChE and BChE responsible for Alzheimer's disease

Alzheimer's disease (AD) is a fast growing neurodegenerative disorder of the central nervous system and anti-oxidants can be used to help suppress the oxidative stress caused by the free radicals that are responsible for AD. A series of selected synthetic indole derivatives were biologically evaluated to identify potent new antioxidants. Most of the evaluated compounds showed significant to modest antioxidant properties (IC50 value 399.07 140.0±50 µM). Density Functional Theory (DFT) studies were carried out on the compounds and their corresponding free radicals. Differences in the energy of the parent compounds and their corresponding free radicals provided a good justification for the trend found in their IC50 values. In silico, docking of compounds into the proteins acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are well known for contributing in AD disease, was also performed to predict anti-AD potential.

A doença de Alzheimer (DA) é uma doença neurodegenerativado sistema nervoso central, em rápido crescimento, e antioxidantes ajudam a suprimir o estresse oxidativo causado por radicais livres, responsávies pela DA. Avaliou-se, biologicamente, série de derivados sintéticos de indol selecionados para identificar novos antioxidantes. A maioria dos compostos avaliados apresentou de significativa a boa propriedade antioxidante (valor de IC50 399,07140.0 ± 50 µM). Eftuaram-se estudos de Teoria do Funcional de Densidade (DFT) com os compostos e os seus correspondentes radicais livres. As diferenças de energia entre os compostos protótipos e os radicais livres correspondentes proporcionaram boa justificativa para a tendência encontrada nos seus valores de IC50. O ancoramento in silico dos compostos com a acetilcolinesterase (AChE) e com a butirilcolinesterase (BChE), que contribuem para a DA, foi, também, realizado para prever o seu potencial anti-DA.

Representações sociais de educação em saúde em tempos de AIDS / Social representations of health education in a time of AIDS / Representaciones sociales de educación para la salud en la era del SIDA

Estudo qualitativo e descritivo, cujo objetivo foi identificar e analisar as representações sociais de educação em saúde à pessoa vivendo com HIV entre profissionais de saúde. Os cenários foram três serviços de atenção à DST/HIV/AIDS, em Belém-PA, Brasil, e 37 profissionais de saúde participaram da pesquisa. A coleta de dados deu-se em 2012-2013 por meio de entrevista em profundidade; a análise utilizou o software Alceste 4.10. Com base no conjunto dos resultados foi possível vislumbrar que a educação em saúde pode ser compreendida a partir de categorias: a configuração do agir educativo; as condições sine qua non: educação no trabalho e estrutura da unidade; o processo pedagógico. Conclui-se que as representações sociais configuram-se como orientação-informação para precaução-prevenção e revelam-se no movimento do agir persistente ao emergente, o que suscita uma educação em saúde permanente para se chegar à integralidade nos serviços.

This is a qualitative and descriptive study, which aimed at identifying and analyzing social representations of health education to HIV patients among health professionals. The setting included three healthcare DST/HIV/AIDS services in Belém-PA, Brazil, and 37 health professionals participated in the study. Data collection was conducted in 2012-2013 on the basis of in-depth interviews and analysis was made on Alceste 4.0 software. Final results indicated that health education can be comprehended in light of categories: educational action; sine qua non: education and training at work, and unit structure; teaching-learning process. Conclusions show that social representations are set as guidance-information for precaution-prevention and that they come forth along continuous and emerging action flow, bringing about permanent health education to ensure healthcare services in full.

Estudio cualitativo y descriptivo, que objetivó identificar y analizar las representaciones sociales de educación en salud a la persona viviendo con HIV entre profesionales de salud. Los escenarios fueron tres servicios de atendimiento al DST/HIV/ SIDA, en Belém-PA, Brasil, y 37 profesionales de salud participaran del estudio. La colecta de datos se dio en 2012-2013, por medio de entrevista en profundidad y el análisis utilizo el software Alceste 4.10. Con base en el conjunto de los resultados fue posible vislumbrar que la educación en salud puede ser comprendida a partir de categorías: la configuración del acto educativo; las condiciones sine qua non: educación en el trabajo y estructura de la unidad; el proceso pedagógico. Se concluye que las representaciones sociales se configuran como orientación-información para precaución-prevención y se revelan en el movimiento del acto persistente al emergente, lo que suscita una educación en salud permanente para llegarse a la integralidad en los servicios.

Comparative evaluation of serum superoxide dismutase and glutathione levels in periodontally diseased patients: An interventional study.

Background: Periodontal disease is an immune-inflammatory disease characterized by connective tissue breakdown, loss of attachment, and alveolar bone resorption. Under normal physiological conditions, a dynamic equilibrium is maintained between the reactive oxygen species (ROS) and antioxidant defense capacity. Oxidative stress occurs when this equilibrium shifts in favor of ROS. Oxidative stress is thought to play a causative role in the pathogenesis of periodontal diseases. Aim: The present study was designed to estimate and compare the superoxide dismutase (SOD) and glutathione (GSH) levels in the serum of periodontitis, gingivitis, and healthy individuals before and after nonsurgical periodontal therapy. Materials and Methods: The present study was conducted in the Department of Periodontics, A. B. Shetty Memorial Institute of Dental Sciences, Deralakatte, Mangalore. The study was designed as a single blinded interventional study comprising 75 subjects, inclusive of both sexes and divided into three groups of 25 patients each. Patients were categorized into chronic periodontitis, gingivitis, and healthy. The severity of inflammation was assessed using gingival index and pocket probing depth. Biochemical analysis was done to estimate the SOD and GSH levels before and after nonsurgical periodontal therapy. Results obtained were then statistically analyzed using ANOVA test and paired t-test. Results: The results showed a higher level of serum SOD and GSH in the healthy group compared to the other groups. The difference was found to be statistically significant (P < 0.0001). The post-treatment levels of SOD were statistically higher than the pre-treatment levels in periodontitis and gingivitis group.

Urinary excretion of L-carnitine, acetyl-L-carnitine, propionyl-L-carnitine and their antioxidant activities after single dose administration of L-carnitine in healthy subjects

The urine excretion of L-carnitine (LC), acetyl-L-carnitine (ALC) and propionyl-Lcarnitine (PLC) and their relations with the antioxidant activities are presently unknown. Liquid L-carnitine (2.0 g) was administered orally as a single dose in 12 healthy subjects. Urine concentrations of LC, ALC and PLC were detected by HPLC. Superoxide dismutase (SOD), total antioxidative capacity (T-AOC), malondialdehyde (MDA) and nitrogen monoxidum (NO) activities were measured by spectrophotometric methods. The 0~2 h, 2~4 h, 4~8 h, 8~12 h, 12~24 h excretion of LC was 53.13±31.36 µmol, 166.93±76.87 µmol, 219.92±76.30 µmol, 100.48±23.89 µmol, 72.07±25.77 µmol, respectively. The excretion of ALC was 29.70±14.43 µmol, 80.59±32.70 µmol, 109.85±49.21 µmol, 58.65±18.55 µmol, and 80.43±35.44 µmol, respectively. The urine concentration of PLC was 6.63±4.50 µmol, 15.33±12.59 µmol, 15.46±6.26 µmol, 13.41±11.66 µmol and 9.67±7.92 µmol, respectively. The accumulated excretion rate of LC was 6.1% within 24h after its administration. There was also an increase in urine concentrations of SOD and T-AOC, and a decrease in NO and MDA. A positive correlation was found between urine concentrations of LC and SOD (r = 0.8277) or T-AOC (r = 0.9547), and a negative correlation was found between urine LC excretions and NO (r = -0.8575) or MDA (r = 0.7085). In conclusion, a single oral LC administration let to a gradual increase in urine L-carnitine excretion which was associated with an increase in urine antioxidant enzymes and the total antioxidant capacities. These data may be useful in designing therapeutic regimens of LC or its analogues in the future.

A excreção urinária de L-carnitina (LC), acetil-L-carnitina (ALC) e propionil-L-carnitine (PLC) e as suas relações com as atividades antioxidantes são presentemente desconhecidos. Líquido de L-carnitina (2,0 g) foi administrada por via oral como uma dose única em 12 indivíduos saudáveis. As concentrações urinárias de LC, PLC e ALC foram detectados por HPLC. Atividades superóxido dismutase (SOD), a capacidade antioxidante total (T-AOC), malondialdeído (MDA) e óxido nítrico (NO) foram medidas por métodos espectrofotométricos. O 0~2 h, 2~4 h, 4~8 h, 8~12 h, 12~24 h excreção de LC foi 53,13±31.36 µmol, 166,93±76.87 µmol, 219,92±76.30 µmol, 100,48±23.89 µmol, 72,07±25.77 µmol, respectivamente. A excreηão de ALC foi 29,70±14.43 µmol, 80,59±32.70 µmol, 109,85±49.21 µmol, 58,65±18.55 µmol, e 80,43±35.44 µmol, respectivamente. A concentraηão de urina de PLC foi 6,63±4.50 µmol, 15,33±12.59 µmol, 15,46±6.26 µmol, 13,41±11.66 µmol e 9,67±7.92 µmol, respectivamente. A taxa de excreηão acumulada de LC foi de 6,1% 24 horas após sua administração. Houve também um aumento nas concentrações de urina de SOD e T-COA e diminuição de NO e de MDA. Correlação positiva foi encontrada entre as concentrações de urina de LC e SOD (r = 0,8277) ou T-AOC (r = 0,9547) e correlação negativa entre a excreção de LC e NO (r = -0,8575) ou MDA (r = 0,7085). Em conclusão, a administração oral única de LC leva ao aumento gradual na excreção urinária de L-carnitina, que foi associada com o aumento das enzimas antioxidantes na urina e as capacidades antioxidantes totais. Estes dados podem ser úteis no futuro para o planejamento de esquemas terapêuticos de LC ou os seus análogos, no futuro.

Development, characterization and antioxidant activity of polysorbate based O/W emulsion containing polyphenols derived from Hippophae rhamnoides and Cassia fistula

The objective of this study was to develop a pharmaceutical O/W emulsion containing plant-derived polyphenol extracts and evaluate its stability and antioxidant activity. O/W emulsions were prepared using ionic surfactant polysorbate 80 (Tween 80®). The odorwas adjusted with few drops of blue sea fragrance. DPPH (1,1-diphenyl-2-picrylhydrazyl) assay was used to evaluate the antioxidant activity of the plant extracts alone and emulsions containing these extracts. Physical stability was assessed by submitting the emulsions to storage at 8 ºC, 25 ºC, 40 ºC and 40 ºC + 70% RH (relative humidity) for two months. Various physical characteristics of emulsions monitored, include color, creaming, liquefaction, centrifugation and pH. Brookfield rotational rheometer was used to determined viscosities and rheological behavior of emulsions. Different types of emulsion were determined microscopically, while pH values of emulsions were measured by a pH meter. Electrical conductivity data confirmed that the outer phase was water. Samples presented an acceptable pH value for an external topical use. Shear thinning behaviour was observed for all emulsions. The polyphenol-rich-plant-derived extracts alone and the extract containing emulsions showed good antioxidant activities. This research confirmed that the method used was suitable for preparing emulsions with Hippophae rhamnoids and Cassia fistula extracts, suggesting that those emulsions are suitable for topical use.

O presente estudo objetivou o desenvolvimento de uma emulsão farmacêutica óleo-água contendo extratos de plantas ricos em polifenóis, a comparação à sua formulação-controle e a avaliação de sua estabilidade, assim como de sua capacidade antioxidante. Extrato concentrado de Hippophae rhamnoids e Cassia fistula foi encapsulado no interior da fase oleosa da emulsão O/W. As emulsões foram preparadas usando o tensoativo iônico monooleato sorbital de polioxietileno (Tween 80®). O odor foi ajustado pela adição de algumas gotas de fragrância azul do mar. O ensaio do DPPH (1,1-difenil-2-picrilidrazil) foi utilizado para avaliar a atividade antioxidante dos extratos de plantas sozinhos e nas emulsões contendo os extratos. A estabilidade física foi avaliada submetendo os cremes a diferentes temperaturas de estocagem, como a 8 ºC, 25 ºC e 40 ºC e a 40% + 70% de umidade relativa por um período de 2 meses. As características físicas das emulsões foram monitoradas por 2 meses incluindo cor, cremosidade, liquefação, centrifugação e pH. O reômetro rotacional de Brookfield foi utilizado para determinar a viscosidade e o comportamento reológico das emulsões. O programa Rheocalc Brookfield foi utilizado para análise dos dados. As características organolépticas também foram avaliadas. O tipo de emulsão foi determinado microscopicamente, enquanto o pH das emulsões foi avaliado por meio de um pHmetro. A estabilidade farmacêutica esperada das emulsões foi alcançada dentro dos dois meses de estudo. Os resultados da condutividade elétrica confirmaram que a fase externa da emulsão era composta de água. O pH das amostras estava dentro da normalidade para uso tópico. A emulsão apresentou boa fragrância e pode ser retirada da pele com água após a aplicação, características desejáveis em emulsões O/W. Os extratos vegetais ricos em polifenóis isolados ou nas emulsões apresentaram boa atividade antioxidante. Nossos estudos confirmaram que o método utilizado foi adequado para preparar a emulsão semi-sólida contendo extratos de Hippophae rhamnoids e Cassia fistula. Nossos achados sugerem que emulsões contendo extratos de Hippophae rhamnoids e Cassia fistula são adequados para o uso tópico.

Señalización de la angiotensina II, a través de la producción de radicales libres en estructuras del sistema nervioso: papel en el estres agudo y crónico / Angiotensin II signaling, through the production of free radicals in structures of the nervous system: role in acute and chronic stress

Existen evidencias que apoyan la participación de las especies reactivas de oxígeno en las cascadas de señalización y transducción intracelular de la angiotensina II. La ANG II es importante en el mantenimiento de la homeostasis corporal, regulando la presión arterial y el metabolismo de fluidos y electrolitos. Se sabe que en la periferia, la ANG II es capaz de estimular a la NAD(P)H oxidasa con la subsiguiente producción de ERO. El anión superóxido es metabolizado secuencialmente por las enzimas antioxidantes como la superóxido dismutasa, la catalasa y la glutatión peroxidasa. A su vez, las especies reactivas de oxígeno son capaces de activar a las proteínas kinasas activadas por mitógenos, las cuales se encuentran asociadas al crecimiento y la diferenciación celular. Se evaluó la posible participación de las especies reactivas de oxígeno en el mecanismo de señalización intracelular mediado por el receptorAT1en el hipotálamo, el órgano subfornicaly médula suprarrenal de la rata. Nuestros resultados demostraron que la estimulación del tejido nervioso con ANG II in vitroincrementó la actividad de la enzimas antioxidante. Al evaluar el papel del receptor AT1, la NAD(P)H oxidasa, el anión superóxido y la proteína kinasa C; así como la activación de las ERK1/2 en la señalización de la ANG II en el hipotálamo, OSF y MSR, demostramos que el bloqueo del receptor AT1con losartán, la interferencia del ensamblaje de la NAD(P)H oxidasa con apocinina, el secuestro de anión superóxido empleando un mimético de la SOD, tempol,y la inhibición de la PKC con cheleritrina, bloquearon completamente el efecto que produce la ANG II sobre las enzimas antioxidantes in vitro.Igualmente, la activación de la ERK1/2 inducida por la ANG II fue reducida por APO y LOS a nivel hipotalámico. Adicionalmente, el bloqueo del receptor AT2hipotalámico con PD123319, no bloqueo sino que mas bien potenció la respuesta de las enzimas antioxidantes y la activación de las ERK1/2 inducida por la ANG II, lo que desenmascaró el efecto contra regulatorio del receptor AT2sobre la acción de la ANG II mediada por el receptor AT1. Se sabe que durante el estrés el sistema renina angiotensina circulante y cerebral se encuentra estimulado, por lo tanto el incremento de la ANG II endógena debería desencadenar vías de señalización similares a las reportadas in vitro. Efectivamente, nuestros hallazgos demostraron que tanto,el estrés agudo inducido por la inmovilización forzada,como el estrés crónico en ratas espontáneamente hipertensas incrementaron la actividad de las enzimas antioxidantes en las tres estructuras cerebrales estudiadas. Este efecto es mediado por la vía del receptor AT1, la estimulación de la NAD(P)H oxidasa y la producción de anión superóxido ya que el tratamiento in vivo con LOS, APO y TEM fue capaz de bloquear completamente el incremento de la actividad de las enzimas antioxidantes inducidas por el estrés y por ende por la ANG II endógena.A nivel de la MSR demostramos, por primera vez, que la estimulación del receptor AT2 esta asociada a la estimulación de la NAD(P)H oxidasa, ya que la APOy el PD 123319 fueron capaces de bloquear el incremento de la actividad de las enzimas antioxidantes inducida por la ANG II. Demostrando así, que el receptor AT1en la MSR contrarregula la acción de la ANG II a través del receptor AT2.En conclusión, nuestros resultados indican que a nivel del sistema nervioso las especies reactivas de oxígeno participan en la cascada de señalización intracelular de la ANG II, y ejercen un importante papel en la respuesta al estrés y la hipertensión.

Caracterización de un modelo de diabetes tipo 2 en ratas y evaluación del papel de la angiotensina II y las especies reactivas de oxígeno en la resistencia neuronal a la insulina / Characterization of a type 2 diabetes model in rats and evaluation of the role of angiotensin II and reactive oxygen species in neuronal insulin resistance

La regulación ejercida por la insulina central en individuos diabéticos ha sido muy poco estudiada. La angiotensina II promueve el estrés oxidativo y la resistencia a la insulina. Dada la co-localización del receptor AT1 de la angiotensina II y el RI a nivel hipotalámico, en este trabajo, decidimos evaluar el efecto de la angiotensina II sobre las acciones centrales de la insulina en condiciones diabéticas, a través de un modelo animal de DM2 en ratas Sprague-Dawley, así como el posible efecto protector del tratamiento crónico con Valsartán. El modelo fue caracterizado y validado a través de la medición de diversos parámetros metabólicos, usando técnicas enzimáticas e inmunoenzimáticas. Los efectos de la angiotensina II sobre la señalización y acciones biológicas de la insulina a nivel hipotalámico fueron evaluadas in vivo e in vitro, mediante western blot, así como los cambios en los niveles de glicemia en las ratas tratadas ICV con ANG II y/o insulina. Fue evaluado además, el estado oxidativo a nivel hipotalámico, mediante la determinación de enzimas antioxidantes, así como el estado inflamatorio sistémico, mediante la determinación fluorométrica de citoquinas plasmáticas. El modelo experimental desarrollado mimetizó las características fenotípicas de la DM2. El valsartán previno parcialmente la resistencia a la insulina. En condiciones normales, se demostró que la angiotensina es capaz de inhibir la señalización de la insulina a nivel hipotalámico por un mecanismo dependiente de ERO. En condiciones diabéticas, hay una disminución basal de la activación de las proteínas de señalización de la insulina, la cual fue prevenida por el tratamiento con valsartán. El efecto hipoglicemiante inducido por la insulina central fue significativamente reducido en condiciones diabéticas. El tratamiento ICV con angiotensina II antagonizó los efectos hipoglicemiantes de la insulina central y este efecto fue potenciado en condiciones diabéticas. El valsartán bloquea la acción inducida por la ANG II ICV en todos los grupos. Los resultados demuestran que existe un estado de resistencia a la insulina en nuestro modelo de DM2, evidente tanto a nivel molecular como fisiológico, el cual es potenciado por la angiotensina y prevenido parcialmente por el tratamiento crónico con valsartán.

Potential of antioxidant enzymes in depicting drought tolerance of wheat (Triticum aestivum L.).

In an effort to determine the biochemical markers for identifying genotypes before sowing for drought tolerance, changes in activities of antioxidant enzymes were determined in the seedlings of five drought-tolerant and five drought-sensitive wheat (Triticum aestivum L.) genotypes, each with different genetic background growing under normal and water deficit conditions induced by 6% mannitol. In comparison with non-stressed seedlings, the catalase (CAT) activity was upregulated by more than 50% in the roots of water-stressed seedlings in drought-tolerant genotypes. Water deficit stress also led to the upregulation of ascorbate peroxidase (APX) in the endosperms and glutathione reductase (GR), CAT and peroxidase (POD) in the shoots of stressed seedlings in drought-tolerant genotypes. Superoxide dismutase (SOD) activity was very low in roots and shoots and showed non-significant increase under water-stress in tolerant genotypes. Out of five specified enzyme activities (CAT in roots and shoots, APX in endosperms, GR and POD in shoots), if any three are upregulated in the specified tissues under water deficit conditions, the genotype is likely to be drought-tolerant. Wheat seedlings with low GR and APX activities and high POD activity in shoots with a low ratio of GR activity of shoot to root of non-stressed seedlings are likely to perform better under rainfed conditions. The observed data showed that status of antioxidant enzymes could provide a meaningful tool for depicting drought tolerance of a wheat genotype.

Biodisponibilidade, distribuição tecidual e atividade antioxidante do extrato hidroetanólico de Ilex paraguariensis hidrolisado e não hidrolisado / Bioavailability, tissue distribution and antioxidant activity of hydrolyzed and non hydrolyzed hydroethanolic extract of Ilex paraguariensis

Ilex paraguariensis (erva mate) é uma planta amplamente usada na América Latina sob a forma de infusão aquosa. Dentre as propriedades atribuídas a esta planta encontra-se a atividade antioxidante que sugere um papel importante desta droga vegetal na prevenção e tratamento de doenças associadas ao estresse oxidativo como a aterosclerose, fotocarcinogênese e fotoenvelhecimento, entre outras. No entanto alguns compostos presentes nesta planta se encontram sob a forma esterificada, o que poderia dificultar a sua adequada absorção. Uma maneira de aumentar a biodisponibilidade de antioxidantes em extratos vegetais é promover a sua hidrólise visando à liberação dos compostos ativos. O objetivo deste trabalho foi estudar comparativamente o extrato hidroetanólico de Ilex paraguariensis antes e após hidrólise enzimática quanto à composição fitoquímica, atividade antioxidante in vitro e in vivo, biodisponibilidade de compostos antioxidantes e distribuição tecidual destes compostos em animais de experimentação. Para tanto o extrato foi obtido por percolação etanol: água (50 por cento v/v) e sua hidrólise realizada por reação enzimática. A caracterização fitoquímica foi realizada por cromatografia líquida de alta eficiência (CLAE) e espectrofotometria e a atividade antioxidante dos extratos pelos métodos de DPPH e ORAC. Para os ensaios in vivo os extratos (hidrolisado e não hidrolisado) foram administrados oralmente (por gavage) a ratos Wistar machos em sistema de dose única ou doses repetidas (30 dias). Coletou-se o sangue, pele, fígado e cérebro, analisando-se a concentração dos compostos de interesse e a atividade antioxidante destes tecidos pelo método de ORAC. O extrato apresentou boa atividade antioxidante e conteúdo fenólico, sendo que estes valores não foram significativamente alterados pela hidrólise. No entanto, a hidrólise possibilitou uma maior absorção dos compostos de interesse, aumentando a atividade antioxidante plasmática.

Ilex paraguariensis (yerba mate) is a plant broadly used in Latin America as an aqueous infusion. Among its biological properties is the antioxidant activity, which suggests a important role in prevention and treatment of oxidative stress associated diseases, such as atheroclerosis, photocarcinogenesis and photoaging among other. However some of the compounds responsible for that activity are, in crude plant extract, under esterified form, which could make absorption more difficult. An approach to increase the bioavailability of antioxidants from plant extracts is to submit the extract to hydrolysis in order to release the active compounds. The goal of this work was comparatively evaluate the hydroethanolic extract of Ilex paraguariensis before and after enzimatic hydrolysis concerning phytochemical composition, in vivo and in vitro antioxidant activity, bioavailability and tissue distribution of antioxidant compounds in rats. The extract was obtained by percolation with ethanol:water (50 percent v/v) and the hydrolysis performed by enzymatic reaction. The phytochemical characterization was performed by high performance liquid chromatography (HPLC) and spectrophotometry and the antioxidant activity by DPPH and ORAC methods. Hydrolyzed and non hydrolyzed extracts were given orally (by gavage) to male Wistar rats in single and multiple dose (30 days) regimen. Blood, skin, liver and brain were removed, and the concentration of antioxidant compounds and antioxidant activity by ORAC method were evaluated. The crude hydroethanolic extract showed antioxidant activity and phenolic content, but these values were not significantly changed by hydrolysis. However the hydrolysis increased the absorption of the compounds and the plasma antioxidant activity.

Inhibition of DNA virus: herpes-1 (HSV-1) in cellular culture replication, through an antioxidant treatment extracted from rosemary spice / A inibição do vírus DNA: herpes-1 (HSV-1) na replicação de cultura celular, através de um tratamento antioxidante extraídos de especiarias alecrim

This work aimed to evaluate antiviral properties in antioxidants from spices. Phenolic compounds extracted from rosemary (Rosmarinus officinallis, L) by hot water, had their antioxidant activity determined by spectrophotometry using β carotene/linoleic acid system. The rosemary extract was evaluated by antiviral assay of Herpes Virus type-1 (HSV-1) replication in VERO cells, in the presence or absence of the spice. 10,000 TCID50/mL of the HSV-1 was kept for 3 h at 4º C, with 300 ppm of rosemary extract, and 100 ppm of butyl hydroxyl toluene (BHT). Then, these viruses were inoculated in VERO cells incubated at 37º C in CO2-5 percent, for seven days. Daily, they were examined and the end point was based on 100 percent of CPE in virus control (without antioxidants). The HSV-1 replication inhibition percentage (IP) measured the antiviral action from antioxidants, showing viral reductions of the 82.0, 82.5 percent, in the presence of rosemary and rosemary + BHT, respectively. As an extension, cell test corresponded to the similar viral decrease (IP = 85.0 and 86.3 percent) in both aforementioned situations. Results lead to conclude that phenolic compounds from rosemary revealed an antiviral action on herpesvirus-1.

Neste estudo foi avaliada a ação antiviral de antioxidantes de especiaria. Extrato aquoso de alecrim (Rosmarinus officinalis, L), que apresentou atividade antioxidante através de espectrofotometria usando o sistema β caroteno/ácido linoléico, foi avaliado em ensaios com vírus herpes-1 na replicação em células VERO. Nestes ensaios foram utilizados 10.000 TCID50 por cento/mL do vírus HSV-1, mantidos em contato com 300 ppm do extrato de alecrim e com 100 ppm de butil hidroxi tolueno (BHT), durante 3h a 4ºC. Esses vírus, em seguida, foram inoculados em células VERO incubadas a 37 ºC/5 por cento de CO2 por sete dias. Pelo efeito citopático (ECP) e o "end point" de ECP do controle de vírus (sem antioxidante), foi possível observar que houve reduções na replicação viral de 82 e 82,5 por cento na presença do alecrim e do alecrim + BHT, respectivamente. Nessa situação,avaliou-se ainda a redução da adsorção viral às células, que apresentou índices similares de 85,0 e 86,3 por cento de redução na capacidade da adsorção. Estas reduções no desempenho do HSV foram medidas pela fórmula de porcentagem de inibição da replicação viral (PI). Os resultados levam a concluir que os compostos fenólicos do alecrim apresentam ação antiviral sobre o HSV-1.

Effects of N-acetyl-L-cysteine and Glutathione on Antioxidant Status of Human Serum and 3T3 Fibroblasts

The effectiveness of several sulfhydryl compounds in the treatment of paraquat intoxication has been previously tested based on their antioxidant ability. However, practical guidelines for their clinical use remain to be determined. As a preliminary pharmacokinetic study on sulfhydryl compounds, we attempted to establish the optimal concentration of N-acetyl-L-cysteine, glutathione, superoxide dismutase, and catalase. We measured the antioxidant effect of these antioxidants in normal pooled plasma and on intracellular reactive oxygen species (ROS) induced by paraquat. N-acetyl-L-cysteine begins to suppress the production of ROS in plasma at concentrations as low as 5 mM, with the suppression being maximal at 40 mM. In the same way, glutathione increased the total antioxidant status in plasma at concentrations of 5-40 mM in a dose-dependent manner. Complete suppression of ROS in plasma induced by exposure to 500 micrometer paraquat for 40 min was observed when using 40 mM N-acetyl-L-cysteine and 5 mM glutathione. These concentrations are comparable with 50 units of catalase, which reduced ROS at concentrations of 5-100 units. Further pharmacokinetic study into the systemic administration of these antioxidants is necessary, using effective concentrations of 5-40 mM for both N-acetyl-L-cysteine and glutathione, and 1-50 units of catalase.

Estudio comparativo de la utilización biologica de beta-caroteno sintético y de fuentes naturales en ratas / Comparative study of the biological utilization of beta-carotene from synthetic and natural sources in rats

The purpose of this study was to evaluate the change in concentration of retinol and beta-carotene (BC) in blood serum and liver tissue of rats, after supplementation with synthetic BC and commonly consumed carotenoid-rich vegetables (carrot and spinach). Weanling male Wistar rats were randomly assigned in four groups of 16 rats each. The four groups of rats were supplemented according to the following feeding treatments: 1) Control group (0G), 0.2 mL corn oil; 2) Pure BC group (BCG), 60 micrograms RE in 0.2 mL corn oil; 3) Carrot group (CG), 60 micrograms RE in 0.2 mL corn oil; 4) Spinach group (SG), 60 micrograms RE in 0.2 mL corn oil. Analysis of retinol and BC contents in serum and liver was performed by HPLC procedures. The variance analysis showed no significant differences (a = 0.05) in the increase of weight of the animals and in the increase of retinol and BC levels in serum and in liver of the four treatments during the four weeks of supplementation. The correlation analysis between levels of retinol and BC in serum and in liver showed no relation between these two parameters. A regression analysis of liver BC levels in the four treatments showed the following slopes of the regression lines: BCG, 0.909; CG, 0.451; SG, 0.444, and 0G, 0.203. These results indicate that the highest BC absorption was in the BCG treatment, whereas the BC absorption in the CG and SG treatments was approximately one half.

Radicales libres y antioxidantes en la prevención de enfermedades, III: evidencias clínico epidemiológicas de los riesgos y beneficios asociados al consumo de antioxidantes en la prevención de enfermedades cardiovasculares / Free radicals and antioxidants in disease prevention, III: clinical and epidemiological evidences of the risks and benefits associated with antioxidant consumption in cardiovascular disease prevention

La presente actualización constituye la tercera parte de una serie de artículos publicados en esta revista sobre radicales libres y antioxidantes en nutrición, salud y patologá humana. En los artículos referidos, los autores han realizado una detallada descripción y discusión de los principales mecanismos de generación de radicales libres en el organismo, de sus acciones tanto biológicas como deletéreas, y de aquellos mecanismos de defensa antioxidante encargados de la remoción de dichas especies radicalarias. De estas revisiones se ha desprendido que, si bien la formación controlada de radicales libres es un evento continuo de carácter fisiológico, la existencia de un desbalance a favor de la generación de especies radicalarias respecto a la velocidad con que dichas especies son removidas (estrés oxidativo) puede conducir a la oxidación masiva de susbtratos biológicos. Se estableció que si bien el estrés oxidativo per se no es sinonimo de daño, la cronicidad de este evento a nivel celular/tisular puede estar involucrado en la etiogénesis y/o en el desarrollo de numerosas patologías entre las que destacan las enfermedades cardiovasculares y diversos tipos de cáncer. Esto último ha constituido la base racional para intentar establecer asociaciones entre el nivel de ingesta de antioxidantes dietarios y la prevención de dichas enfermedaes. En esta tercera revisión, centrándose en enfermedades cardiovasculares, los autores han intentado recoger en forma concisa las princiipales evidencias científicas, de carácter epidemiológico y clínico, en torno a los potenciales beneficios y riesgos asociados al consumo de antioxidantes (ya sea dietario o como suplemento)

Radicales libres y antioxidantes en la prevención de enfermedades: II, mecanismos de defensa antioxidante / Free radicals and antioxidants in disease prevention: II, antioxidante defense mechanisms

La generación de radicales libres y de otras especies reactivas del oxígeno (ERO) constituye un evento continuo y fisiológico. Si bien dichas especies cumplen funciones biológicas fundamentales, su producción excesiva relativa a su velocidad de remoción puede conducir a diversas formas de daño celular. En la primera parte de esta revisión se mencionaron los mecanismos de defensa antioxidante del organismo que son determinantes en el mantenimiento del delicado balance entre la generación y la remoción de especies radicalarias. El presente trabajo describe y discute los principales mecanismos antioxidantes, de naturaleza enzimática o no, encargados de inhibir la presencia de niveles de ERO potencialmente tóxicos para la célula. Se describen las enzimas superóxido dismutasa, encargada de la remoción de anión superóxido, y las enzimas con actividad peroxidásica (catalasa, glutation peroxidasa). Junto a estos mecanismos enzimáticos, se describe las funciones biológicas que cumplen las vitaminas E y C, y los carotenos como antioxidantes de carácter no enzimático. Se pone énfasis en la importancia que tiene la ingesta adecuada de alimentos en el aporte de micronutrientes para mantener el necesario equilibrio entre los sistemas de defensa antioxidantes y los generadores de especies radicalarias. Finalmente, se revisan los potenciales beneficios y riesgos del uso de preparados en base a polifenoles como suplementos antioxidantes de carácter no fisiológico