Ilex paraguariensis: the effect of genotypes and growth phase on biomass, secondary metabolism and antioxidant activity of in vitro cultivated calli / Ilex paraguariensis: el efecto de los genotipos y la fase de crecimiento sobre la biomasa, metabolismo secundario y la actividad antioxidante de los callos cultivados in vitro

Yerba mate ( Ilex paraguariensis ) produces several secondary metabolites of interest to the phar maceutical industry, such as chlorogenic acids and methylxanthines. These compounds have been produced in vitro by callus culture from different species. However, for I. paraguariensis , no studies upon the production of these compounds in vitro have been p erformed to date. In this work, we show that the concentration of secondary metabolites from I. paraguariensis callus is possible and highly dependent on the callus growth phase. We observed that the best phase for the production of secondary compounds in calli of yerba mate is the stationary growth phase on both genotypes tested. In this phase, higher levels of phenolic compounds, chlorogenic acid and 3,5 - dicaffeoylquinic acid and greater antioxidant activity were observed. Chlorogenic acid and 3,5 - dicaffe oylquinic acid presented positive correlation with antioxidant activity. For the first time, secondary compounds were reported in yerba mate calli cultivated in vitro .

La yerba mate ( Ilex paraguariensis ) produce varios metabolitos secundarios de interés para la industria farmacéutica, como los ácidos clorogénicos y las metilxantinas. Estos compuestos se han producido in vitro mediante cultivo de ca llos de diferentes especies. Sin embargo, para I. paraguariensis , hasta la fecha no se han realizado estudios sobre la producción de estos compuestos in vitro . En este trabajo, mostramos que la concentración de metabolitos secundarios desde callos de I. pa raguariensis es posible y altamente dependiente de la fase de crecimiento del callo. Observamos que la mejor fase para la producción de compuestos secundarios en callos de yerba mate es la fase de crecimiento estacionario en ambos genotipos probados. En es ta fase se observaron niveles más altos de compuestos fenólicos, ácido clorogénico y ácido 3,5 - dicafeoilquínico y una mayor actividad antioxidante. El ácido clorogénico y el ácido 3,5 - dicafeoilquínico presentaron correlación positiva con la actividad antio xidante. Por primera vez, se reportaron compuestos secundarios en callos de yerba mate cultivados in vitro .

Teofilina como agente capacitante do sêmen bovino / Theophylline as a capacitating agent of bovine semen

Objetivou-se avaliar a teofilina como agente capacitante substituto ou associado à heparina sobre a reação acrossômica dos espermatozoides e o desenvolvimento de embriões produzidos in vitro. O experimento foi realizado com quatro touros e três tratamentos, totalizando 12 grupos experimentais. O sêmen dos touros foi avaliado nos tratamentos descritos a seguir: tratamento 1 (HEP): heparina - 10µg/mL; tratamento 2 (TEO): teofilina - 5mM; tratamento 3 (HEP + TEO): heparina (10µg/mL) + teofilina (5mM), por zero, seis, 12 e 18 horas, corados com trypan blue/Giemsa para avaliação da reação acrossômica. Para a produção dos embriões, os agentes capacitantes foram adicionados aos meios de fertilização. Na análise espermática, a taxa de reação acrossômica verdadeira foi maior (P<0,05) no tempo zero hora, enquanto para espermatozoides mortos, as maiores taxas (P<0,05) foram nos tempos de 12h (84,46±5,82) e 18h (86,75±4,19). A taxa de embriões produzidos (37,97±13) e a taxa de eclosão (33,50±14) foram maiores (P<0,05) para o tratamento HEP. Não foi observada diferença (P>0,05) entre touros na análise de reação acrossômica nem na PIVE. A utilização da teofilina foi tão eficiente quanto a da heparina na indução da reação acrossômica, no entanto resultou em menores taxas de produção embrionária.(AU)

The sperm capacitating process should take special attention during in vitro embryo production (IVEP) once that affects the success of embryo production. The study aimed to evaluate theophylline as substitute capacitating agent or in combination with heparin on the sperm acrosome reaction and development of embryos produced in vitro. The experiment was carried out using 4 bulls and 3 treatments, establishing 12 experimental groups. Each bull was evaluated in the following treatments: Treatment 1 (HEP): Heparin - 10mg/mL; Treatment 2 (THEO): Theophylline - 5mM; Treatment 3 (HEP + THEO), Heparin (10mg/mL) + Theophylline (5mM). The semen of bulls was incubated in each treatment for 0, 6, 12 and 18h, stained with Trypan blue / Giemsa and analyzed by electron microscopy for assessment of acrosome reaction. Using sperm of same bulls, capacitating agents were added to the fertilization media, for IVEP. In sperm analysis, the true acrosome reaction rate was higher (P<0.05) in time 0h, while sperm dead rates were highest (P<0.05) at 12h (84.46±5, 82), and 18h (86.75±4.19). The produced embryos rate (37.97±13) and hatching rate (33.50±14) were larger (P<0.05) for HEP treatment. There was no difference (P>0.05) between bulls in acrosome reaction analysis neither for IVEP. The use of theophylline was as effective as heparin in the induction of the acrosome reaction, although it resulted in lower embryo production rates.(AU)

Alcaloides y polifenoles del cacao, mecanismos que regulan su biosíntesis y sus implicaciones en el sabor y aroma / Cacao alkaloids and polyphenols: Mechanisms that regulate their biosynthesis and its implications on the taste and aroma

El sabor y aroma de los granos de cacao (Theobroma cacao L.) fueron las principales razones que promovieron su domesticación y uso alimentario por los pueblos precolombinos de Mesoamérica. Incluso hoy día, la calidad sensorial determina la clasificación entre cacaos finos y a granel. Muchos compuestos químicos de las almendras son responsables de la calidad sensorial, pero sobresalen los polifenoles y los alcaloides, compuestos que de manera directa inciden en el sabor y palatabilidad de las almendras y de manera indirecta sobre los precursores de aroma. Los alcaloides están asociados con el amargor. Su concentración está relacionada con la variedad y se modifica con el procesamiento. Los polifenoles son responsables, junto con otras moléculas de la astringencia (poco deseable en chocolates), pero también de propiedades antioxidantes deseables por los consumidores. En esta revisión se abordan aspectos de la biosíntesis de estas importantes moléculas en las almendras de cacao, de las implicaciones en el sabor y aroma, así como los cambios que ocurren durante el procesamiento de las mismas(AU)

The flavor and aroma of cacao (Theobroma cacao) beans were the main reasons that promoted its domestication and food-use by pre-Columbian peoples of Mesoamerica. Polyphenols and alkaloids are compounds that directly affect the flavor of the cocoa beans and indirectly on the flavor precursors. The alkaloids are associated with bitterness; its concentration is related to the cultivar and its modifying through the processing. Polyphenols molecules are responsible together with other molecules of the astringency (not desirable in chocolate), but also are responsible for antioxidant properties, very desirable by consumers. This review focuses on aspects of the biosynthesis of these important molecules in cocoa beans as well as implications in taste and flavor. The changes of these molecules that occur during processing are also approached(AU)

Acute exercise and caffeine improve insulin-induced hypoglycemia in normal and malnourished rats / Exercício agudo e cafeína melhoram a hipoglicemia induzida por insulina em ratos normais e desnutridos

In food restriction, hypoglycemic episodes can be more severe and persistent. This study assessed the influence of acute exercise and caffeine on the insulin-induced hypoglycemia in freely-fed or malnourished (50% food restriction) young rats. At the age of 60 days, rats under overnight fasting received an insulin injection to cause an episode of hypoglycemia. In some animals, hypoglycemia was preceded by an acute session of exercise, in others, caffeine was orally given 15 minutes after insulin injection; or exercise and caffeine were combined. Blood samples were collected at regular intervals for five hours after insulin injection. A beneficial effect of both exercise or caffeine on the hypoglycemic episode in the malnourished rats was found. In the control rats, the association of exercise+caffeine was more beneficial than either intervention alone. It is discussed that exercise and caffeine, alone or combined, can be used as exogenous anti-hypoglycemic resources, but considering the nutritional status of the subject.

Na restrição alimentar, os episódios de hipoglicemia podem ser mais severos e persistentes. Este trabalho avaliou a influência do exercício agudo e da cafeína sobre a hipoglicemia induzida por insulina em ratos jovens alimentados livremente ou desnutridos (50% de restrição alimentar) desde o nascimento. Aos 60 dias de idade, os ratos em jejum noturno receberam injeção de insulina para causar um episódio de hipoglicemia. Em alguns animais, a hipoglicemia foi precedida por sessão aguda de exercício; em outros foi administrada a cafeína via oral, 15 min. após a injeção de insulina; ou foi associada a exercício e cafeína. Amostras de sangue foram coletadas em intervalos regulares por 5h desde a aplicação da insulina. Registrou-se efeito benéfico do exercício e da cafeína isolados sobre o episódio hipoglicêmico nos ratos desnutridos. Nos ratos controle, a associação de exercício+cafeína teve efeito benéfico mais acentuado do que as intervenções separadas. É discutido que exercício físico e cafeína, isolados ou combinados, podem ser explorados como recursos anti-hipoglicêmicos exógenos, levando-se em consideração porém o estado nutricional do indivíduo.

Efecto de la fermentación sobre la actividad antioxidante de diferentes clones de cacao colombiano / Effect of fermentation on the antioxidant activity of different Colombian cocoa clones

Introducción: el cacao es una de las principales fuentes de polifenoles. Estos compuestos se encuentran relacionados con la actividad antioxidante y las características organolépticas del cacao y sus subproductos. Durante el procesamiento, los granos de cacao son sometidos a diferentes etapas que pueden afectar el contenido de esos metabolitos, pero que son cruciales para el desarrollo de la calidad organoléptica. Una de estas etapas es la fermentación. Objetivo: evaluar el efecto de la fermentación sobre el contenido de metabolitos secundarios y la actividad antioxidante en 5 clones de cacao cultivados en Colombia. Métodos: en los clones estudiados se determinó el contenido de fenoles totales, antocianinas totales y taninos condensados, mediante métodos espectrofotométricos; así como catequina, epicatequina, teobromina y cafeína por cromatografía líquida de alta resolución. La capacidad antioxidante se evaluó mediante las metodologías del DPPH. (1,1-diphenyl-2-picrylhydrazyl), FRAP (ferric reducing antioxidant power), ORAC (oxygen radical antioxidant capacity) y la capacidad atrapadora de radicales superóxido. Resultados: el efecto de la fermentación sobre los clones de cacao no fue uniforme, observándose tanto cambios positivos como negativos en los contenidos de los diversos metabolitos secundarios y la actividad antioxidante, en dependencia de la variedad. Sin embargo, los cambios en la actividad antioxidante expresada como TEAC (trolox equivalent antioxidant capacity) DPPH están correlacionados con los diversos cambios en el contenido de fenoles totales durante el proceso de fermentación y descritos por la expresión siguiente: DDPPH= 6,36099*Dfenoles+5,10923, con r²= 0,982. Conclusiones: la fermentación afecta el potencial antioxidante de los clones de cacao, lo cual es importante para el desarrollo de las propiedades organolépticas de los productos finales.

Introduction: cocoa is one of the main sources of polyphenols. These compounds are related with the antioxidant activity and sensory characteristics of cocoa and its sub-products. During processing, cocoa beans are subjected to different stages, which may affect the content of these metabolites. However, these processes are crucial in the development of organoleptic quality of cocoa beans. One of these stages is the fermentation. Objective: to evaluate the effect of fermentation on the content of secondary metabolites and the antioxidant activity in five Colombian cocoa clones. Methods: the total phenol content, total anthocyanins and condensate tannins were determined for the studied clones by spectrophotometric methods. Additionally, the content of catechin, epicatechin, theobromine and caffeine were determined by high-performance liquid chromatography (HPLC). The antioxidant capacity of cocoa clones was determined by the methods DPPH. (1,1-diphenyl-2-picrylhydrazyl), FRAP (ferric reducing antioxidant power), ORAC (oxygen radical absorbance capacity) and superoxide radical scavenging capacity. Results: the effect of fermentation on cocoa clones was not uniform. Both positive and negative changes in the contents of various secondary metabolites and antioxidant activity were observed depending on the variety. However, changes in antioxidant activity expressed as TEAC (trolox equivalent antioxidant capacity) DPPH were correlated with the changes in the total phenol content during fermentation and described by the following expression: DDPPH= 6.36099* Dphenols + 5.10923, with r² = 0.982. Conclusions: fermentation affects the antioxidant potential of cocoa clones, which is important for the development of organoleptic properties of final products.

Evidencia del uso de metilxantinas en las exacerbaciones de la EPOC / Evidence for the use of methylxantines in exacerbations of COPD

Introducción: A las metilxantinas se les atribuyen efectos broncodilatadores, entre otros. Se recomiendan en la enfermedad pulmonar obstructiva crónica (EPOC) estable, cuando el tratamiento con β2 agonistas y anticolinérgicos no es suficiente para mejorar los síntomas, en los estadios más avanzados de la enfermedad y en las exacerbaciones. Objetivo: Conocer la evidencia que respalda el uso de metilxantinas en las exacerbaciones de la EPOC y otros beneficios, además de su efecto broncodilatador. Métodos: Búsqueda computarízada en Medline y EMBASE de estudios controlados aleatorízados que compararon las metilxantinas (teofilina oral, aminofilina o doxofilina intravenosa) contra placebo para la exacerbación aguda de la EPOC en enfermos atendidos en urgencias y en su hospitalización inmediata. Resultados: De 1,356 estudios de EPOC, sólo cinco cumplieron con los criterios de inclusión para el análisis. La evidencia obtenida fue la siguiente: Con respecto a la función pulmonar (VEF1, la mayoría de los estudios no encontraron mejoría significativa, sólo en uno se obtuvo mejoría al tercer día de tratamiento; otro estudio mostró disminución de la PaCO2 y ligero aumento del pH a las 12 h, en el grupo de aminofilina vs placebo. No hubo diferencias significativas en los días de hospitalización, calidad de vida y escalas de disnea. Las náuseas y el vómito fueron más frecuentes en el grupo de metilxantinas. Conclusiones: El uso basado en evidencias de metilxantinas en las exacerbaciones de la EPOC requiere de protocolos perfectamente estructurados, controlados y aleatorizados que muestren resultados estadísticamente significativos.

Introduction: Methylxantines are used for stable chronic obstructive pulmonary disease (COPD), when there is need for an additional drug besides β2 agonists and anticholinergics, in the more advanced stages of the disease and during acute exacerbations. Among other effects, methylxantines are said to have bronchodilator properties. Objective: To review the evidence supporting the use of methylxantines during acute exacerbations of COPD , and the presence of other beneficial properties besides their bronchodilator effects. Method: Medline and EMBASE computer search for aleatorized controlled studies comparing methylxantines (oral theophylline, intravenous aminophylline or doxophylline) vs placebo. Results: Only five of 1,356 published studies fulfilled the inclusion criteria. The evidence showed no significant improvement in FEV1 only one study showed a 70 vs 40 mL improvement on day 3; there was also decrease in the PCO2 and slight increase in the pH 12 hours after the use of aminophylline. There was no significant improvement in length of stay, quality of life nor dyspnoea scales. Nausea and vomiting were more frequent in the methylxantine group. Conclusions: We need properly structured protocols with statistically significant results, to define the evidence based place for the use of methylxantines in the treatment of acute exacerbations of COPD.