Hawthorn extract

Hawthorn

by JP Saleeby, MD

The genus Crataegus sp. better known as Hawthorn is a spiny shrub native to the Northern Hemispheres of North America, Asia and Europe. Know for centuries for its medicinal properties, it is the single oldest known herb used in western (or European) medicine. While many of the plant parts such as the flowers, leaves and fruit are used medicinally, those of the dried flowering tops have, at least in the west, stood the test of time and utilization for therapy related to the heart. Chinese medicine (TCM) has used predominantly the berry for its medical uses mostly as a digestive aid.

Extracts of the flower of the Hawthorn plant (specifically C. monogyna and C. laevigata species) have been intensly studies and the extracts show active ingredients in the oligomeric procyanidine (OPC), flavonoid family of compounds. OPCs are responsible for the free-radical scavenging properties probably best seen in reducing damage due to myocardium injury/insult following ischemia or infarct, as they lessen the effects of neutrophil elastase that is the causative agent in scar tissue formed after myocardial injury (heart attack). Research has shown Hawthorn extracts to have positive inotropic effects that increase cardiac output and the force-frequency ratio in a failing human heart. The Flavonoids found in this herb are active against and inhibit phosphodiesterase and also activate the cardiac endothelium-derived relaxing factor making for increased vasodilation, something that is beneficial in cardiac patients. The flavonoids are further effective in reducing platelet aggregation and adhesion. This is beneficial for prevention of thrombosis and occlusion of coronary vessels (arteries) related to coronary artery disease. Much the same action that aspirin (ASA) and Plavix (clopidogrel) have on platelets we see with Hawthorn.

By and large the greatest impact Hawthorn extracts have on the cardiac system is with the myocardium and its positive effects in cases of congestive heart failure (CHF). Some researchers state that this herb also stabilized the myocardium and reduces dysrhythmias or abnormal heart rhythms. There was review and analysis of studies reported in the 2008 Cochrane review that showed "alternative" treatments with Hawthorn stood up nicely to more conventional therapies for CHF. When used against placebo in double blinded studies on CHF patients Hawthorn substantially increased maximal work load tolerance, improved symptoms of fatigue and dyspnea (shortness of breath) and increased exercise tolerance in patients with failure. In a separate study by Tauchert M., et al, published in 1994 in a German peer reviewed journal, Hawthorn was compared to the ACE-inhibitor drug Capoten (captopril) head on and the results were favorable for Hawthorn. Standardized doses of Hawthorn provided equal, statistically significant positive results no different than the pharmaceutical agent Capoten. Capoten is a main stay drug of traditional therapy for CHF. In a trial published in 2008 under the acronym SPICE, Dr. Holubarsch, et. al., showed the protective effects of Hawthorn against cardiac death and sudden death in those entered into the trial.

There are no absolute contraindications for taking Hawthorn extracts aside from allergic sensitivity to the plant. Side effects are minimal and those most common are vertigo and dizziness. It is not recommended during pregnancy and/or breastfeeding as it has the potential for uterine stimulation. It is estimated by Dr. Zick, et. al., in a 2005 study that as many as a third of patients with CHF are taking Complimentary and Alternative Medical (CAM) supplements and that these may have untoward effects in combination with standard drug therapy. Care must be taken with the use of Hawthorn root and such medications as digoxin, vasodilators, ACE-inhibitors, calcium channel blockers. There is the theoretical concern of the potentiation effect of the combination of Hawthorn extract with these other cardiac drugs. However no data exists of problems with concomitant use of digoxin, another drug commonly used in CHF. The dose can range depending on the patient and practitioner, but standard doses are 600 to 1800 mg divided into two or three doses.

The German Commission E (to Germany what the Physician Desk Reference (PDR) is to the USA) specifically recommends hawthorn leaf and flower as a therapeutic herb for CHF in its monographs. The German Commission E monographs are some 380 monographs detailing herbs, their uses, dosages, adverse effect and drug interactions along with pharmacological effects that comprise a respected therapeutic guide to herbal medicine practitioners.



Ref:

1. Dahmer S , Scott E Health Effects of Hawthorn, J. AFP, February 15 2010 Vol. 81 No. 4:465-468.
2. Tauchert M, et. al, Effectiveness of hawthorn extract L1 132 compared with the ACE-inh. Capopril. Much Med. Wochenschr. 1994;136:S27-33.
3. Holubarsch CJ, et. al., Investigation of Crataegus extract WS 1442 in CHF (SPICE) trial study group. Eur J. Heart Fail. 2008;10(12):1255-1263.
4. Zick, SM, et. al., The prevalence and pattern of complementary and alternative supplement use in individuals with chronic heart failure. J Card Fail. 2005;11(8):586-589.
5. The Complete German Commission E Monographs, Therapeutic Guide to Herbal Medicines, 1st ed. 1998.

(c) 2010