Hawthorns active components are mostly flavonoids (luteolin, apigenin, vitexin, rutin, and quercetin as glycosides) and procyanidins. Hawthorn is also a source of tannins or polyphenols (oligomeric cathechins and epicathechins), carboxylic acids (caffeic acid), triterpenes and simple amines (choline, acetylcholine and tyramine). Researchers were unable to find one major active ingredient. It would seem that the therapeutic effect of Hawthorn, like that of many other herbs, rests on the synergy of all of its components.(1) The various in vivo and in vitro studies have identified many of Hawthorns therapeutic effects: Increase of cardiac contractility (positive inotropic effect). As a result, heart efficiency and ejection fraction are increased.(2) Peripheral resistance reduction (post-charge reduction). The lesser the resistance, the lesser the effort needed by the heart. The final effect is a reduction in oxygen consumption. (2) Coronary vasodilator (improves heart irrigation and oxygen supply). A well irrigated heart is better fit for exercise and stresses. (3) Increase of cardiac contraction efficiency. The contraction is quicker and more efficient, which allows for a longer rest period (refractory period). The heart has therefore a better endurance. (4) Slight reduction in hypertension. Incidentally, Hawthorn can also improve hypotension. Its final effect is a normalizing one on mild cases of either low or high blood pressure. (6) Cholesterol reduction. (7) The German Commission E acknowledges its benefits in cases of: decreasing cardiac output as described in functional Stage I and II (NYHA). See table 1.
Table 1: Cardiac failure or cardiac insufficiency can be classified according to its symptoms and impact on the quality of life. The most used classification comes from the New York Heart Association.
Stage I : No limitation in ordinary physical activity. No shortness of breath, undue fatigue or palpitation. Stage II : Slight limitation of physical activity. Patients are comfortable at rest. Ordinary physical activity results in fatigue, shortness of breath, palpitation or angina (chest pain). Stage III : Marked limitation of physical activity. Patients are comfortable at rest but slight activity leads to symptoms. Stage IV: Inability to carry on any physical activity without discomfort. Patients have congestive heart failure symptoms at rest and increased discomfort is experienced with any physical activity.