Asthma affects millions of adults and children in the United States. Its increasing prevalence, the absence of curative treatments, and concerns about side effects from long-term use of asthma drugs have prompted interest in complementary and alternative therapies such as traditional Chinese medicine (TCM) herbs.
In a recent article, NCCAM-supported scientists from the Mount Sinai School of Medicine reviewed research evidence on TCM herbs for asthma, focusing on studies reported since 2005:
- Preliminary clinical trials of formulas containing Radix glycyrrhizae in combination with various other TCM herbs have had positive results. One study compared an herbal formula called ASHMI (antiasthma herbal medicine intervention) with the drug prednisone in adults; three others looked at herbal formulas as complementary therapies in children. All of the trials reported improvement in lung function with the herbal formulas and found them to be safe and well tolerated. Most of the trials showed significant improvements in asthma symptom scores, although one did not.
- A 3-year followup of 14 patients with asthma taking an extract of Sophora flavescens Ait (a component of ASHMI) reported positive clinical results and no side effects.
- Laboratory findings on TCM herbal remedies suggest several possible mechanisms of action against asthma, including an anti-inflammatory effect, inhibition of smooth-muscle contraction in the airway, and modulation of immune system responses.
The authors noted that clinical trials are under way for ASHMI. They also summarize research on a TCM formula being developed to combat peanut allergy.
Li X-M, Brown LV. Efficacy and mechanisms of action of traditional Chinese medicines for treating asthma and allergy. Journal of Allergy and Clinical Immunology.; 123(2):297–306.2009