Dr.Steve's BOTTOM LINE: The endothelium (or inner lining) of blood vessels uses nitric oxide (NO) to signal the surrounding blood vessel smooth muscles to relax. This results in vasodilation (opening up of the relaxed blood vessels) and increased blood flow. NO also inhibits platelet aggregation, and white blood cell adhesion to the endothelium, which reduces atherosclerotic plaque formation. This helps prevent, retard and possibly treat cardio-vascular disease. People with atherosclerosis (hardening of the arteries) and hypertension often have problems with available NO in their body. So what do herbs have to do with this?

This study shows that many TCM herbals have very high NO bioactivity by several biochemical mechanisms and thus provide this important molecule to blood vessels and other tissues for better cardiovascular performance. So, this has implications for those with high blood pressure, angina or just a desire for better cardiovascular support. The science for plausibility is there, but additional clinical trials are needed to determine optimal use and safety.

Nitric oxide bioactivity of traditional Chinese medicines used for cardiovascular indications.

Free Radic Biol Med. 2009 Sep 15;47(6):835-40

Authors: Tang Y, Garg H, Geng YJ, Bryan NS

Traditional Chinese medicine (TCM) has been used for centuries to treat and prevent certain ailments and diseases. Although TCM has served as mainstream medical care throughout Asia for many generations, it is considered an alternative medical system in much of the Western world. Because many TCMs are used primarily for cardiovascular indications characterized by a nitric oxide (NO) insufficiency, we hypothesized that some, if not all, of these TCMs have a robust NO bioactivity that may act to restore NO homeostasis. We tested a group of convenience samples of TCMs obtained in the United States for endogenous nitrite, nitrate, nitroso, and nitrite reductase activity as well as their ability to relax isolated aortic rings. The results from this study reveal that all of the TCMs tested reveal NO bioactivity through their inherent nitrite and nitrate content and their ability to reduce nitrite to NO. Many of the TCM extracts contain a nitrite reductase activity greater by 1000 times that of biological tissues. Repletion of biological nitrite and nitrate by these extracts and providing a natural system for NO generation in both endothelium-dependent and -independent mechanisms may account for some of the therapeutic effects of TCMs.