Cruciferous Sprouts as Healthy Foods: Elicitation os Phytochemicals and Functionality

Cruciferous sprouts are fresh plant foods very interesting because of their higher levels of nutrients and bioactive compounds compared to adult plants. Germinating seeds for 8 days has been established as optimum for harvest and consumption, allowing manipulation while the content of phytochemicals remains higher than in other vegetables, even though, the bioactive compounds contents decrease during germination. Determining the bioactive compounds (phenolics, glucosinolates and isothiocyanates/indoles) in cruciferous sprouts, as well as selecting the suitable species and the germination time, have been found to be of great importance to maximize the health-promoting properties of sprouts for consumption. Elicitation practices with phytohormones (MeJA, JA and SA), sugars (sucrose and glucose) and amino acids (methionine), by priming seeds and using exogenous spray applications enhanced the contents of glucosinolates, precursors of the bioactive isothiocyanates and indoles, which have been widely studied because of their anticarcinogenic, antioxidant and anti-inflammatory activities. Once broccoli and radish sprouts were selected due to their high content in glucoraphanin and glucoraphenin, respectively, among other health-promoting glucosinolates and phenolic compounds, certain biological activities were evaluated. The metabolism and antiproliferative effect of broccoli sprouts was studied in vitro using cell cultures. The effects of radish sprouts cv. Rambo modulating the energy metabolism was determined in the Drosophila melanogaster model, and the antinociceptive effect of broccoli sprouts was evaluated using rodent models. Finally, shelf-life quality and safety of these sprouts was studied for 7 and 14 days under refrigerated storage. This multidisciplinary work open views to design studies of cruciferous foods for human nutrition, since their incorporation to diet and regular consumption will likely provide positive effects for health and disease prevention.Los brotes de crucíferas son alimentos de origen vegetal de gran interés debido a su mayor contenido en nutrientes y compuestos bioactivos en comparación con el vegetal adulto. No obstante, un objetivo en nuestra investigación es maximizar sus propiedades beneficiosas relacionadas con el contenido en compuestos bioactivos (glucosinolatos y compuestos fenólicos), para ello los estudios de la selección de la especie y el tiempo óptimo de germinación para su recolección y consumo, son factores fundamentales que nos permiten una adecuada manipulación y mantener un contenido en fitoquímicos más alto que el que encontramos en otros vegetales, a pesar de que el contenido en compuestos bioactivos disminuye con la germinación. Para incrementar el contenido en glucosinolatos (precursores de los isotiocianatos e índoles), se empleó la elicitación con fitohormonas (MeJA, JA and SA), azúcares (sacarosa y glucosa), y amino ácidos (metionina) como inductores de semillas y aplicados en spray sobre los brotes. Con todo ello, se seleccionaron los brotes de brócoli y rábano por su alto contenido en glucorafanina y glucorafenina, respectivamente, así como en otros glucosinolatos y compuestos fenólicos, y se evaluaron algunas de sus actividades biológicas. Concretamente se estudió el efecto antiproliferativo de los brotes de brócoli así como la absorción y metabolismo de sus compuestos utilizando cultivos celulares. Por otro lado, se demostró el efecto de los brotes de rábano cv. Rambo sobre el metabolismo energético con el modelo Drosophila melanogaster y, por último, se evaluó el efecto antinociceptivo de los brotes de brócoli utilizando modelos de roedores. Finalmente, y con el objetivo de estudiar la vida útil de los brotes, se analizó su contenido microbiológico y de compuestos bioactivos durante 7 y 14 días de almacenamiento, estableciendo que los brotes bajo condiciones de refrigeración son alimentos seguros para los consumidores. Este trabajo multidisciplinar abre diferente

Estudio de la bioactividad in vitro e in vivo de brotes de brócoli ricos en glucosinolatos/isotiocianatos

Broccoli sprouts are very interesting plant foods due to their potential source of nutrients and bioactive compounds. These sprouts have a higher content in glucosinolates than adult plants, being glucoraphanin the one presented in higher amount. Its hydrolysis product, the isothiocyanate sulforaphane, has shown different biological activities in previous studies, such as antiinflamatory, antioxidant and antiproliferative effect. The aim of this work was to explore the antiproliferative effect of pure glucoraphanin and pure sulforaphane against cell lines of human cancer in vitro, compared to the complete broccoli sprouts. Results showed that the whole plant is more active. On the other hand, also the antinociceptive effect of broccoli sprouts was studied in rodent models in vivo, providing an interesting research line for the study of the action pathways of these natural products as phytotherapeutics.Los brotes de brócoli son alimentos de gran interés debido a su mayor contenido en nutrientes y compuestos bioactivos en comparación con el vegetal adulto. Poseen alto contenido en glucosinolatos, destacando la glucorafanina, que se encuentra en mayor concentración, cuyo producto de hidrólisis, el isotiocianato sulforafano, ha demostrado poseer distintas actividades biológicas, como son la antiinflamatoria, antioxidante y un efecto antiproliferativo. El objetivo de este trabajo fue estudiar el efecto antiproliferativo de estos brotes como matriz vegetal, así como sus compuestos bioactivos puros, la glucorafanina y el sulforafano, demostrando una mayor bioactividad del vegetal como alimento completo. Por otro lado, se demostró el efecto antinociceptivo (analgésico) de estos brotes en modelos de roedores in vivo, abriendo una línea de investigación interesante para el estudio de los mecanismos de acción de estos compuestos naturales como fitoterapéuticos

Seasonal Variation of Health-Promoting Bioactives in Broccoli and Methyl-Jasmonate Pre-Harvest Treatments to Enhance Their Contents

Broccoli is a source of bioactive compounds that provide an important nutritional value. The content of these compounds can vary depending on agronomic and environmental conditions, as well as on elicitation. In this study, three crop trials were carried out to evaluate the effects of the cultivation season, the application of different dosages of methyl-jasmonate (MeJA) on the overall quality and on the total content of bioactive compounds of ‘Parthenon’ broccoli cultivated under the field conditions of southeastern Spain. Color parameters, chlorophyll content, total phenolic compounds, total flavonoids and antioxidant activity were measured to evaluate the overall quality. Moreover, individual carotenoids, phenolic compounds and glucosinolates were evaluated by high performance liquid chromatography with diode array detection (HPLC-DAD) and high performance liquid chromatography equipped with diode array detector coupled to mass spectrometer using electro spray ionization (HPLC-DAD-ESI/MSn). The content of total carotenoids, phenolic compounds and glucosinolates were higher in autumn compared with spring, showing increases of 2.8-fold, 2-fold and 1.2-fold, respectively. Moreover, a double application of MeJA increased the contents of total carotenoids, phenolic compounds and glucosinolates by 22%, 32% and 39%, respectively, relative to the untreated samples. Considering our results, the controlled and timely application of 250 µM MeJA to the aerial parts of the plants four days before harvest, on two consecutive days, seems to be a valid agronomic strategy to improve the health-promoting capacity of Parthenon broccoli, without compromising its overall quality