Flavonoids in hypertension: a brief review of the underlying mechanisms

Flavonoids are a diverse group of bioactive polyphenolic compounds abundant in dietary plants and herbs. Regular consumption of flavonoids exerts cardio-vasculoprotective effects and may reduce the onset or progression of many cardiovascular diseases, particularly hypertension. Observational studies suggest inverse associations among either of these three combinations: a) anthocyanin intake and risk of myocardial infarction (MI), b) flavanone intake and risk of ischemic stroke and c) flavonol intake and risk of type 2 diabetes mellitus. Human randomized controlled trials (RCTs) show that catechins and quercetin impart significant blood pressure lowering effects. Mechanistically, flavonoids mediate their antihypertensive effects through increasing nitric oxide (NO) bioavailability, reducing endothelial cell oxidative stress or modulating vascular ion channel activity. In this review, we focus on the six main subgroups of flavonoids, namely flavones, flavonols, flavanols, flavanones, anthocyanins, and isoflavones. We further discuss their antihypertensive effects, and their possible mechanisms of regulating blood pressure. We conclude by addressing the safety of these compounds as well as their potential use in hypertension management and treatment.