Estudios científicos
Phenolic profiles and anti-inflammatory activities of sixteen table grape (Vitis vinifera L.) varieties
Abstract:
Several studies have shown that fresh grape and its derivatives contain phenolic compounds exhibiting antioxidant and health promoting effects, particularly in relation to the cardiovascular system. In this study, two methods were developed to characterize sixteen varieties of table and wine grapes: (1) a LC-MS method to identify major and minor phenolic compounds; and (2) a HPLC-DAD method to quantify the most representative compounds. Sixty-seven molecules belonging to different classes of phenolic compounds were identified: anthocyanins, flavan-3-ols, flavonols, stilbenes and organic acids. In parallel, the free radical scavenging activity and anti-inflammatory activities of the 16 grape varieties were evaluated. The results showed a good correlation between the total phenolic content and the biological activity. Extracts from Exalta and Albarossa grape varieties were the most active in reducing IL-8 release by gastric epithelial cells (IC50 = 8.48 μg mL-1 and 6.68 μg mL-1, respectively), a biomarker of inflammatory processes. The observed biological activities were mainly associated with skin and seed extracts/portions. The interest in studying table grapes and their non-fermented derivatives as sources of healthy compounds has increased in the last few years and our findings suggest that table grapes and their fresh derivatives, in addition to wine, could be involved in the health promoting effects of the Mediterranean diet.
Comentarios divulgativos:
Los compuestos fenólicos se han relacionado con propiedades antioxidantes y efectos beneficiosos sobre la salud. En este estudio los autores utilizan dos métodos para caracterizar 16 variedades de uvas de mesa: uno con el objetivo de identificar los compuestos fenólicos mayoritarios y minoritarios (cromatografía líquida y espectrometría de masas) y el otro para cuantificar los compuestos más característicos (cromatografía líquida con detector de diodos).
El análisis permitió identificar 67 compuestos fenólicos (antocianinas, flavan-3-oles, flavonoles, estilbenos, ácidos orgánicos). El contenido en compuestos fenólicos totales se correlacionaba con la capacidad antioxidante y antiinflamatoria. Y en los ensayos con células del epitelio gastrointestinal se observó que los extractos de uva Exalta y Albarossa se asociaban a una mayor reducción de los niveles de interleuquina-8 (IL-
8), una citoquina proinflamatoria, con propiedades quimiotácticas y asociada al inicio de la angiogénesis. Estos compuestos bioactivos estaban presentes principalmente en la piel y las semillas. De modo que las uvas, también antes de la fermentación, parecen ser una fuente de compuestos bioactivos beneficiosos.
