RESUMO
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.
Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Vitis/química , Antocianinas/química , Antocianinas/farmacologia , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Flavonoides/química , Flavonoides/farmacologia , Flavonóis/química , Flavonóis/farmacologia , Frutas/química , Frutas/classificação , Humanos , Interleucina-8/imunologia , Extratos Vegetais/farmacologia , Espectrometria de Massas em Tandem , Vitis/classificaçãoRESUMO
Raisins (Vitis vinifera L.) are dried grapes largely consumed as important source of nutrients and polyphenols. Several studies report health benefits of raisins, including anti-inflammatory and antioxidant properties, whereas the anti-inflammatory activity at gastric level of the hydro-alcoholic extracts, which are mostly used for food supplements preparation, was not reported until now. The aim of this study was to compare the anti-inflammatory activity of five raisin extracts focusing on Interleukin (IL)-8 and Nuclear Factor (NF)-κB pathway. Raisin extracts were characterized by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) analysis and screened for their ability to inhibit Tumor necrosis factor (TNF)α-induced IL-8 release and promoter activity in human gastric epithelial cells. Turkish variety significantly inhibited TNFα-induced IL-8 release, and the effect was due to the impairment of the corresponding promoter activity. Macroscopic evaluation showed the presence of seeds, absent in the other varieties; thus, hydro-alcoholic extracts from fruits and seeds were individually tested on IL-8 and NF-κB pathway. Seed extract inhibited IL-8 and NF-κB pathway, showing higher potency with respect to the fruit. Although the main effect was due to the presence of seeds, the fruit showed significant activity as well. Our data suggest that consumption of selected varieties of raisins could confer a beneficial effect against gastric inflammatory diseases.