Elsevier

Free Radical Biology and Medicine

Volume 47, Issue 6, 15 September 2009, Pages 835-840
Free Radical Biology and Medicine

Original Contribution
Nitric oxide bioactivity of traditional Chinese medicines used for cardiovascular indications

https://doi.org/10.1016/j.freeradbiomed.2009.06.024Get rights and content

Abstract

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.

Section snippets

NO products/metabolite determination

All TCMs were obtained from a local oriental herb and acupuncture shop in Houston, Texas, USA. The TCMs were in their native natural and unrefined form (Fig. 1). Using a mortar and pestle, we ground the herbs into a powder and then placed them in a blender for 10 min at high speed. One gram of powder was then dissolved in 5 ml of PBS, pH 7.4, and mixed vigorously for several minutes. Some of the powders were soluble in buffer, others were suspensions. For nitrite and nitrate analysis,

Results

A wealth of the literature has revealed several TCMs used primarily for cardiovascular indications, from coronary artery disease to acute myocardial infarction and hypertension. The names and indications of the TCMs used in the study are reported in Table 1 and pictures of their native forms used in this study are provided in Fig. 1. This is not meant as a comprehensive assessment of all the TCMs, but was a convenience sample of common TCMs used for cardiovascular indications available over the

Discussion

The results from this study reveal that traditional Chinese medicines that have been used for thousands of years have profound NO bioactivity primarily through enhancement of endothelium-derived NO but also due to the nitrate–nitrite reduction pathways to NO. Many contain nitrite and particularly high concentrations of nitrate in the extracts given to patients. Many of the described benefits of these ancient medications are likely to be a result of their inherent nitrite and/or nitrate content

Acknowledgment

N.S.B. serves on the Scientific Advisory Board of Trivita, Inc.

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