Nitric oxide (NO), produced by endothelial nitric-oxide synthase (eNOS), is recognized as a central anti-inflammatory and anti-atherogenic principle in the vasculature. Decreased availability of NO in the vasculature promotes the progression of cardiovascular diseases. Epidemiological and clinical studies have demonstrated that natural products, in daily diet or phytomedical preparations, may improve vascular function by enhancing NO production and bioavailability. Phyto-ingredients in tea, cocoa, pomegranate and soy are known to positively influence eNOS activity and/or endothelial function, in vitro and in vivo. In this review, we discuss the common pathways modulating endothelial NO production to provide a basis for subsequent mechanistic discussions. We herein also discuss about the mechanism and clinical efficacy of the mentioned dietary ingredients. In summary, there is increasing evidence that several single natural products and plant extracts influence endothelial NO production. Identification of such compounds and characterization of their cellular actions may increase our knowledge of the regulation of endothelial NO production and could provide valuable clues for the prevention or treatment of cardiovascular diseases.
Key words: Cocoa; Flow-mediated dilation (FMD); Nitric oxide synthase; Phytochemical; Pomegranate; Tea