Jiaogulan (Gynostemma pentaphyllum) is a vine indigenous to remote mountainous regions of south China. It’s been consumed for centuries as a tea or vegetable and as a medicine for relieving fatigue and cold symptoms.
Scientific studies into the activities of this plant have revealed that it is an extremely potent inducer of nitric-oxide enzyme systems inside blood vessels, eNOS (e for endothelial, NOS = nitric oxide synthetase) that are critical to keeping the vessels dilated and blood moving smoothly.
Nitric oxide also stimulates the release of ”growth factors,” signal molecules that trigger growth of new blood vessels and tissue repair and remodeling. These effects occur at the low levels of nitric oxide that are naturally produced by the cells lining the blood vessels. When tissue is injured in any way, the normally inactive iNOS enzyme system is activated. Nitric oxide is then produced at levels much higher than normal, which shuts down the eNOS system and is part of the cascade that triggers an inflammatory response. Jiaogulan has the unique ability to tone down the iNOS inflammatory response while it supports the eNOS circulatory and healing one.
We first told readers about Jiaogulan in our May 2004 article on its use in horses with laminitis. Several readers have asked about how it is used in horses with lung allergies/reactive airways, since we mentioned that in the summaries of the research presented at the Equine Congress. An article published in the August 2005 issue of the Journal of Pharmacy and Pharmacology showed that Jiaogulan reduced resistance to air flow at baseline, inhibited histamine-induced bronchoconstriction by 68% and inhibited inhaled allergen induced bronchoconstriction by 80%.
We decided to try it in combination with Spirulina (see December 2004) for horses with symptoms of allergic/reactive lung disease that were free of symptoms on Spirulina at rest but still had prolonged respiratory recovery times after work and poor exercise tolerance. A dose of 2000 mg of Jiaogulan was used in combination with 20 grams of Spirulina, twice a day, with the Jiaogulan given 20 minutes before feeding. The response was excellent, with eight of eight test horses showing normal respiratory recovery rates and exercise tolerance on this combination.
Some other research into the effects of Jiaogulan that are of interest include one in the March 2006 issue of the Journal of Biomedical Sciences that found Jiaogulan inhibits release of the inflammatory cytokine (cellular messenger) called NF-Kappa-B. This is the same cytokine suppressed by aspirin and also the one that activates the iNOS enzyme system above. This probably explains how Jiaogulan is able to activate vascular nitric oxide production but suppress inflammatory nitric oxide pathways at the same time. It also shows a direct anti-inflammatory activity for this herb.
Another study published in the May-June 2006 issue of Alternative Therapies in Health and Medicine compared the response of insulin-resistant people to diet therapy alone or diet plus Jiaogulan supplementation. Both groups improved, but the people on diet plus Jiaogulan showed greater improvement. Many insulin-resistant horses are given Jiaogulan to help them with laminitis and encourage good hoof growth, although there are no studies on Jiaogulan and insulin resistance itself.
Finally, Jiaogulan is showing some early promising results as a treatment for DSLD.