Characterization ofVicia(Fabaceae) seed water extracts with potential immunomodulatory and cell antiproliferative activities

Abstract

Vicia seeds represent an underutilized source of nutritional and functional components. Besides being rich in proteins, they are also rich in polyphenols, free amino acids, and lectins. These components are enriched in a by-product of the production of protein isolates, a pH 4 soluble extract. Extracts from six Vicia have been analyzed, and NO radical scavenging and antiproliferative activities have been determined. Canavanine was the main free amino acid, while gallic acid derivatives were the most abundant of polyphenols. Fractionation of the extracts by ultrafiltration rendered a lectin-free fraction that exhibited nitric oxide radical scavenging activity. Based on this activity, and in the presence of high levels of polyphenols and canavanine that are inhibitors of inducible nitric oxide synthase, it is proposed that these extracts may have an immunomodulatory effect. In addition, some extracts inhibited proliferation of cancerous Caco-2 cells, further supporting the potential of Vicia extracts as functional components. Practical applications During the production of Vicia protein isolates an aqueous soluble fraction, considered a by-product, is generated which is rich in polar polyphenols, free amino acids, and water soluble proteins that are of interest from a functional point of view. In six Vicia species this aqueous fraction showed NO radical scavenging and cell antiproliferative activity. Hence, these fractions usually considered as a by-product, could be exploited as a source of functional compounds with potential health promoting properties. This could result in the revalorization of Vicia seeds and decrease in the generation of by-products from the process of Vicia protein isolate productions.