Hemagglutinating activity of polyphenols extracts from six grain legumes

The erythrocyte agglutinating activity of polyphenol extracts from six grain legumes was investigated. Polyphenols are amphipathic molecules that can bind to proteins and lipids through hydrophobic and polar interactions, leading to agglutination of liposomes and bacteria. The extracts from four of the six legumes that were studied caused erythrocyte agglutination at concentrations in the μM range. Soybean extracts had the highest activity, followed by the extracts from lentils, broad bean, and chickpea. As a good representative of these legumes, binding of the polyphenols extracted from lentils to erythrocytes was investigated in more detail, showing that agglutination was mediated by binding of 84% of the polyphenols present in the incubation, which corresponds to 2.42 μg bound polyphenols/mg erythrocytes, and a maximum polyphenol binding of 96% according to Lineweaver–Burk plots. The relatively high concentrations that are required for agglutination justify that polyphenols more probably do not agglutinate erythrocytes in vivo, but the possibility still exists that in vivo binding without agglutination could occur, which could have some effects on the metabolism and health-promoting properties of polyphenols.