The Bio-Functional Properties of Pigmented Cereals may Involve Synergies among Different Bioactive Species

This study was aimed at characterizing the anthocyanin profile in different varieties of pigmented corn and wheat and in some of their milling fractions, and at investigating the anti-inflammatory and enzyme-inhibiting activities of these materials. Acid/ethanol extracts were used to assess total anthocyanins, overall antioxidant activity, the overall polyphenol profile, and for evaluating the inhibition of pancreatic alpha-amylase and of intestinal alpha-glucosidase. Dose-dependent inhibition of both enzymes was evident in all extracts within the same range of bioactive concentration, although with a different efficiency of individual extracts towards each enzyme. Anti-inflammatory response was evaluated by using acid-free extracts and a cellular model based on Caco-2 cells transiently transfected with a luciferase reporter gene responding to cytokine stimulation. The immune response of interleukin-stimulated cells decreased significantly in a dose-responsive manner in the presence of 20-50 micromol/liter anthocyanins from all grains extracts, again with a different efficiency. By comparing the different inhibitory ability of extracts from the various sources, it appears that the observed effects are in most cases higher than what observed in similar extracts from other sources, and that the activity in each extract may be related to specific synergies between anthocyanins and other phenolics.