Antioxidant and vasodilatory effects of blackberry and grape wines

Abstract

In contrast to the well-described various biological effects of grape wines, the potential effects of commonly consumed blackberry wine have not been studied. We examined in vitro antioxidant and vasodilatory effects of four blackberry wines and compared them with the effects of two red and two white grape wines. Although some blackberry wines had lower total phenolic content relative to the red grape wines, their antioxidant capacity was stronger, which may be related to a higher content of non-flavonoid compounds (most notably gallic acid) in blackberry wines. Although maximal vasodilation induced by blackberry wines was generally similar to that of red wines, blackberry wines were less potent vasodilators. Vasodilatory activity of all wines, in addition to their flavonoid and total phenolic content, was most significantly associated with their content of anthocyanins. No association of vasodilation with any individual polyphenolic compound was found. Our results indicate the biological potential of blackberry wines, which deserves deeper scientific attention.

FIG. 1.

Relaxation in noradrenaline-precontracted rat aortic rings following exposure to grape red (RW1 and RW2), grape white (WW1 and WW2) and blackberry (BW1, BW2, BW3, and BW4) wines. Results are shown as mean±SEM values (n=15 per wine sample). By two-way analysis of variance, Bonferroni's post hoc test: *P<.05 versus red grape (RW1 and RW2) and blackberry (BW1, BW2, and BW3) wines; ^†P<.05 versus blackberry wines (BW1, BW2, and BW3).

FIG. 2.

Relationships between vasodilatory activity (E_max) and (A) total phenolic, (B) flavonoid, and (C) anthocyanin content of the tested wine samples. Total phenolic and flavonoid contents were expressed in milligrams of GAE per liter, and anthocyanin content was expressed in milligrams of M-3-G per liter.