Fitoquímicos: una nueva clase de prebióticos / Phytochemicals: a new class of prebiotics

RESUMEN La microbiota intestinal (MI) es considerada como un nuevo blanco para la prevención y manejo nutricional de las alteraciones inflamatorias y metabólicas asociadas a las enfermedades crónicas no-transmisibles. Los prebióticos son principalmente fibras solubles cuyo consumo favorece el crecimiento de poblaciones bacterianas beneficiosas de la MI e impacta favorablemente la salud del consumidor. Esta revisión presenta a los fitoquímicos dietarios, que incluyen a más de 8.000 compuestos, como una nueva clase de prebióticos debido a su capacidad de estimular poblaciones de Lactobacillus, Bifidobacterium, Akkermansia y de bacterias productoras de butirato en el colon, a expensa de bacterias potencialmente dañinas como C. histolyticum. Además, los fitoquímicos son transformados por la MI en múltiples metabolitos que ejercen actividades biológicas a veces más potentes que la molécula inicial de la cual provienen. Individuos con distintos metabotipos han sido descritos de acuerdo a su capacidad de responder al consumo de isoflavonas, lignanos o elagitaninos, dependiendo de la presencia en su MI de bacterias capaces de transformar dichos polifenoles en equol, enterolactona/enterodiol y urolitinas, respectivamente, los cuales exhiben actividades biológicas. Valerolactonas y ácidos aromáticos también son producidos por la MI a través del metabolismo de las proantocianidinas. El efecto prebiótico de los fitoquímicos contribuiría a explicar los efectos saludables del consumo de frutas y verduras ricos en fitoquímicos.

ABSTRACT Intestinal microbiota (IM) is considered as a new target for the prevention and nutritional management of inflammatory and metabolic alterations associated with non-transmissible chronic diseases. Prebiotics are mainly soluble fibers whose consumption favors the growth of beneficial bacterial populations of the IM and positively impacts health. This review discusses dietary phytochemicals, which include more than 8,000 compounds, as a new class of prebiotics due to its ability to stimulate populations of Lactobacillus, Bifidobacterium, Akkermansia and butyrate producing bacteria in the colon at the expense of potentially harmful bacteria, such as C. histolyticum. In addition, phytochemicals are transformed by IM into a great array of metabolites exerting biological activities and are sometimes more potent than the initial molecule from which they are derived. Individuals with different metabotypes have been described according to their ability to respond to the consumption of isoflavones, lignans or ellagitannins, depending on the presence in their IM of bacteria capable of transforming these polyphenols into equol, enterolactone/enterodiol and urolithins, respectively, which exhibit biological activities. Valerolactones and aromatic acids are also produced by the IM through proanthocyanidin metabolism. The prebiotic effect of phytochemicals would help to explain the healthy effects associated with the consumption of fruits and vegetables rich in phytochemicals.

Evaluation of phenolic profile, antioxidant and anticancer potential of two main representants of Zingiberaceae family against B164A5 murine melanoma cells

BACKGROUND: Curcuma longa Linnaeus and Zingiber officinale Roscoe are two main representatives ofZingiberaceae family studied for a wide range of therapeutic properties, including: antioxidant, anti-inflammatory, anti-angiogenic, antibacterial, analgesic, immunomodulatory, proapoptotic, anti-human immunodeficiency virus properties and anticancer effects. This study was aimed to analyse the ethanolic extracts of Curcuma rhizome (Curcuma longa Linnaeus) and Zingiber rhizome (Zingiber officinale Roscoe) in terms of polyphenols, antioxidant activity and anti-melanoma potential employing the B164A5 murine melanoma cell line. RESULTS: In order to evaluate the total content of polyphenols we used Folin-Ciocâlteu method. The antioxidant activity of the two ethanolic extracts was determined by DPPH assay, and for the control of antiproliferative effect it was used MTT proliferation assay, DAPI staining and Annexin-FITC-7AAD double staining test. Results showed increased polyphenols amount and antioxidant activity forCurcuma rhizome ethanolic extract. Moreover, 100 μg/ml of ethanolic plant extract from both vegetal products presented in a different manner an antiproliferative, respectively a proapoptotic effect on the selected cell line. CONCLUSIONS: The study concludes that Curcuma rhizome may be a promising natural source for active compounds against malignant melanoma.

Testes fitoquímicos em extratos foliares de Oeceoclades maculata Lindl. (Orchidaceae) / Phytochemical tests in Oeceoclades maculata Lindl. (Orchidaceae) leaf extracts

O presente trabalho teve por objetivo determinar a capacidade antioxidante de Oeceoclades maculata. A atividade foi determinada de acordo com a capacidade do extrato hidroalcoólico das folhas reduzir o radical DPPH. Os resultados obtidos permitem concluir que os conteúdos de polifenóis e flavonas/flavonóis são maiores no extrato preparado a frio (EBHF) do que no extrato preparado a quente (EBHQ), sugerindo que o aquecimento usado na preparação do extrato altera esses componentes ativos. Portanto, para esta espécie deve ser realizado o método de extração a frio para conservar as substâncias que possuem atividade antioxidante.

This work aimed to determine the antioxidant capacity of Oeceoclades maculata. The antioxidant activity was determined in accordance with the ability of the hydroalcoholic extract of the leaves to reduce the DPPH radical. The results showed that the polyphenol and flavonoid contents are greater in the cold extract (EBHF) than in the hot extract (EBHQ), which suggests that the heating effect in the preparation of the extract modifies these active compounds. Therefore, for this species, the cold extraction method must be carried in order to conserve the substances with antioxidant activity.