From field to health : a simple way to increase the nutraceutical content of grape ss shown by NO-Dependent vascular relaxation

Polyphenolic grapevine components involved in plant resistance against pathogens possess various pharmacol. properties that include NO-dependent vasodilation and anti-inflammatory and free radical scavenging activities, which may explain the protective effect of moderate red wine consumption against cardiovascular disease. The aim of this work was (a) to verify the possibility that preharvest treatments of grapevine with a plant activator, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-Me ester (BTH), could lead to an enriched nutraceutical potential of wine and (b) to characterize the profile of metabolites responsible for pharmacol. activity. Plant spraying at the end of veraison, with a water suspension of BTH (0.3 mM), led to increased whole anthocyanin content as confirmed by HPLC comparative anal. Exts. from berry skins of BTH-treated grapevines caused NO-dependent vasorelaxation, with a concn.-response curve that was significantly shifted to the left of the control non-BTH-treated curve. Moreover, 1:1000 dilns. of berry exts. from BTH-treated plants significantly increased basal prodn. of guanosine 3',5'-cyclic monophosphate (cGMP) in human vascular endothelial cells when compared to the corresponding exts. of untreated plants. These results show that BTH treatment increases anthocyanin content of grape exts., as well as their ability to induce NO-mediated vasoprotection. No increase of anthocyanin content was obsd. in the wine exts. from BTH-treated vines. It is concluded that BTH treatment could be exploited to increase the nutraceutical potential of grapes. [on SciFinder (R)]