Chemical analysis and photoprotective effect of an extract of wine from Jacquez grapes

The present study was aimed at evaluating the in vitro antioxidant activity and in vivo photoprotective activity of an extract of wine obtained from Jacquez (Vitis aestivalis-cinerea x V vinifera) grapes (JW-E). The chemical profile of the JW-E was characterised by a significant level of proanthocyanidins, together with lower amounts of anthocyanins and hydroxycinnamic acids. The antioxidant activity of the JW-E was assessed by means of various in vitro tests (bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical; peroxidation, induced by the water-soluble radical initiator 2,2'-azobis(2-amidinopropane) hydrochloride, on mixed dipalmitoylphosphatidylchofine/linoleic acid unilamellar vesicles; UV radiation-induced peroxidation in phosphatidylcholine multilamellar vesicles). In all in vitro tests employed, the JW-E proved to possess strong antioxidant/free radical-scavenging effectiveness. Furthermore, when topically applied, a gel formulation containing the JW-E afforded significant in vivo protection against UVB light-induced skin erythema (monitored by reflectance spectrophotometry) in healthy human volunteers.