Correlation between polyphenolic profile and antioxidant, antiproliferative and cytoprotective activities of old and modern common wheat varieties

Epidemiological studies correlated whole grains intake to a reduced incidence of chronic disease such as cardiovascular disease and cancer. This potentially protective effect could be attributed in part to phenolic compounds present in whole grains and to their strong antioxidant properties. Aim of this study was to characterize the phenolic profile of 6 common wheat genotypes (1 modern and 5 old cultivars) and to evaluate their potential antiproliferative and cytoprotective effect in different cell culture systems. A leukemic cell line, HL60, and cultured rat cardiomyocytes, were supplemented with different phenolic extracts for 24 h and oxidative stress was induced by H2O2-treatment. Antiproliferative and cytoprotective effects were measured in terms of intracellular ROS level decrease and influence on cell viability. Old varieties displayed higher polyphenol and flavonoid content which positively correlated (P<0.05) to antioxidant activity determined by FRAP test. The HPLC-TOF-MS analyses allowed the identification of more than 60 different phenolic compounds, including coumarins, phenolic acids, anthocyanins, flavones, isoflavones, stilbens and lignans. Clustering analysis, based on similarity among phytochemical profiles, highlighted two main divergent groups, one formed by Palesio and Inallettabile varieties and the second one including all other old genotypes. The evaluation of the effect on cell viability and ROS intracellular level in in vitro models confirmed differences in cyotoprotective/antiproliferative properties among cultivars, correlated to peculiar phytochemical profile of the extracts. Data presented support the healthy role of cereals in human nutrition due to the presence of nutraceutical components and their possible synergistic effect and underline the importance of a re-discovery of old varieties for the development of functional food specifically targeted to oxidative stress-related diseases prevention.