Bioactivities and mechanisms of dietary proanthocyanidins on blood pressure lowering: A critical review of in vivo and clinical studies.

Proanthocyanidins, widespread in natural plant sources, are bioactive substances that exhibit broad benefits to human health. Of note, proanthocyanidins have been reported to lower blood pressure and prevent hypertension, but a critical review of this is lacking. In this review, information on the basic structures and absorption of dietary proanthocyanidins as well as their bioactivities and related mechanisms on the lowering of blood pressure derived via in vivo and clinical studies are summarized. Clinical studies have shown that proanthocyanidins have a pronounced blood pressure-lowering effect, effectively preventing hypertension and reducing the occurrence of cardiovascular and cerebrovascular diseases. The potential mechanisms, which are herein reviewed in detail, involve the improvement of vascular function, reduction of oxidative stress and inflammation, and modulation of lipid metabolism. Taken together, this work provides information for a better understanding of the antihypertensive effects of proanthocyanidins, which may promote their use to reduce the risk of developing hypertension.