Thus, the aim of the present study was firstly to examine
the antioxidant effects of stem extracts from three Greek
grape (Vitis vinifera) varieties (i.e., Mandilaria, Mavrotragano
and Moshomavro) at a cellular level, particularly in human
umbilical vein endothelial EA.hy926 and C2C12 muscle
cells. Moreover, since the polyphenolic composition has been
shown to affect the antioxidant activity of wine and grape seed
extracts (26,27), we also investigated whether the polyphenolic
composition of grape stem extracts affects their antioxidant
capacity. Grape stem extracts may be used as antioxidant food
supplements for reducing the oxidative stress-induced detrimental
effects on human health, and thus the understanding of
the mechanisms through which they exert their bioactivities is
of particular importance.