Hawthorn ( Crataegus species) is a spiny, flowering shrub or small tree of the rose family. The flowers, berries, and leaves of hawthorn are used to make drug. But, most of the finding supporting the cardiac activity of hawthorn are based on evaluation of the dried flowering tops of the plants. Hawthorn were used to treat heart diseases ranging from irregular heartbeat, chest pain, high blood pressure, hardening of the arteries, and congestive heart failure (CHF).
Hawthorn extract is regarded in Europe as a efficacious and safe therapy for the early stages of heart disease and has been used for a number of diseases including arteriosclerosis, angina, myocarditis, nervous conditions like insomnia. Herb extract demonstrated anti-inflammatory, antimicrobial and gastroprotective activity in vitro. The most studied standard hawthorn extracts are LI 132® and WS® 1442. Hawthorn herb, in the form of standard extract (WS 1442 or LI 132), can be used as an adjunct to medical treatment to relieve symptoms of New York Heart Association classes I through III chronic CHF. (WS 1442 and LI 132, are standardized to oligomeric procyanidins and flavonoids, respectively). The German Commission E (an official government agency similar to the FDA) approved the use of extracts of hawthorn in patients suffering from heart failure graded stage II according to the New York Heart Association.
Hawthorn Herb Clinical Trials and Results
Hawthorn extract indicates different effects that may be useful in heart failure includinganti-arrhythmic activities, and the ability to enhance coronary blood flow and cardiac output. These properties may be mediated by inhibition of phosphodiesterase types III and IV, antioxidant activities and anti-inflammatory activities. 9 double-blind, placebo-controlled studies, involving a total of more than 750 patient, have found hawthorn extract efficacious for the therapy of mild to moderate CHF. In an analysis that mathematically combined the findings of ten controlled studies involving 855 participants, hawthorn was found to be significantly better than placebo for improving exercise tolerance, decreasing shortness of breath and enhancing the physiologic function of an ailing heart in mild to moderate congestive heart failure.
A 4 year study on the effects of hawthorn, commissioned by the “German Ministry of Health”, found that it improves contractions in the veins and heart while dilating the heart. The scientists concluded that hawthorn extract is best used for low heart function, congestion, arrhythmia and tightness in the chest and no adverse effects were noted. Hardening of the arteries, is an abnormal thickening and loss of elasticity of the arterial walls. Hawthorn have been shown to reduce the size of atherosclerotic plaques. Hawthorn extract avoids arteries from becoming re-blocked after surgery to remove blockages, according to a research performed at the “Department of Pharmacy, University of Munich“. Researchers explained that rats that were supplemented with hawthorn herb and subsequently applied balloon angioplasty demonstrated 44 % less reproduction of arterial muscle cells than rats that underwent the surgery however did not receive hawthorn extract. This research was reported in the Aug 2010 edition of the medical journal Atherosclerosis.
The main cardiovascular protective effect of the plant is usually attributed to its flavonoid content, especially the oligomeric proanthocyanidins. These flavonoids have very powerful vitamin P activity, working synergistically with vitamin C to promote capillary stability. The bioflavonoid complexes in hawthorn include oligomeric procyanidins vitexin, hyperoside and quercetin. The free radical scavenging activities of an ethanol extract of hawthorn were proven in a research reported in the Journal of Agricultural and Food Chemistry on September 2008.
Hawthorn extract exerts mild blood pressure-lowering effect, which appears to be a result of a number of various pharmacological activities. It dilates coronary vessels, inhibits angiotensin-converting enzyme (ACE), acts as an inotropic agent. Elevated angiotensin-converting enzyme causes an increase in angiotensin II and systemic vasoconstriction. This condition elevates blood pressure. In a study investigated the efficacy of high doses of hawthorn extract (900 mg) in 1476 patients with Stage I and Stage II cardiac insufficiency, with treatment lasting 4 and 8 weeks. The symptom score decreased by a average of 66% at the conclusion of treatment, with the Stage I NYHA patients largely symptom-free. A subgroup of patients with symptoms including borderline hypertension demonstrated reduced in systolic and diastolic pressure.
In 1998, in a double blind placebo-controlled study, Dr NH Mashour demonstrated that hawthorn extract consumption leads to a sharp reduction in cardiac failure symptoms, stage II. In a clinical study 60 patient with angina (chest pain that can occur when blood cannot freely pass through narrowed coronary arteries) were given either 180 mg/day of hawthorn berry leaf flower extract or placebo for three weeks. Those who received hawthorn experienced improved blood flow to the heart and were also able to exercise for longer periods of time without suffering from chest pain.These finding suggests hawthorn may help combat chest pain, which is caused by low blood flow to the heart. In a Chinese clinical study with 46 patients suffering from angina, a Chinese variety of hawthorn reduced the number of angina attacks by 85% compared to 37% on placebo.
Hawthorn extract can help increase the amount of blood pumped out of the heart during contractions , widen the blood vessels, and enhance the transmission of nerve signals.This plant also have a positive inotropic activity on the contraction amplitude of myocytes. Hawthorn extract helps to enhance blood flow, according to an article reported in 2007 in the Journal of Herbal Medicine and Toxicology.
Hawthorn herb has shown promise in both uncontrolled and controlled clinical studies in the therapy of NYHA (New York Heart Association) functional class II congestive heart failure-defined as “fatigue or shortness of breath during heavy exertion and possibly during normal activities.” Over a period of 8 weeks, hawthorn extract resulted in a significant healing in the performance of the heart. Participants reported relief in subjective symptoms, such as reduced performance, shortness of breath, and ankle edema. In a observational study showed 450 mg hawthorn extract WS 1442 given twice daily for 24 weeks significantly improved exercise tolerance and fatigue, blood pressure, ejection fraction, and resting pulse in patients with NYHA-II cardiac insufficiency.
One placebo-controlled, double-blind trial on 30 participant for 8 weeks was conducted with hawthorn extract WS 1442 at a dose of 160 mg per day. The Hawthorn group demonstrated a statistically significant effect over placebo in all parameters. An 8 week placebo-controlled, double-blind study using hawthorn extract (WS 1442) in 136 participant with Stage II NYHA cardiac insufficiency focused on changes in the blood pressure and heart rate output measured at the beginning and end of therapy. A evident healing in the performance of the heart in the hawthorn group was seen, while the placebo group progressively worsened. In a study, 209 participant with relatively advanced CHF were given either 1800 milligrams or 900 milligrams of standardized hawthorn extract or placebo. The findings after 16 weeks of treatment demonstrated important improvements in the hawthorn extract groups as compared to the placebo groups. A review of scientific studies reported in the Cochrane Database of Systematic Reviews in Jan 2008 concluded that hawthorn extract indicates important symptom development when used together with standard drugs to treat chronic heart failure.
One study found that hawthorn extract (900 mg/day) taken for two months was as efficacious as low doses of captopril (is used to treat high blood pressure and heart failure) in improving symptoms of heart failure. In one randomized, placebo-controlled, double-blind trial with hawthorn, 40 participant suffering from class II (NYHA II) CHF were given hawthorn extract or a placebo. Exercise tolerance in the treatment group increased by 10% while it decreased by approximately 17% in the placebo group. A other study provides data that this plant can improve heart function in people with chronic heart disease. This 8-week, double-blind, placebo-controlled study tested the properties of 600 mg/day of LI 132®. 78 patients with Stage II heart disease taking hawthorn had important gains in their stamina, had lower blood pressure and lower heart rates while exercising, and pumped more blood at lower pressure.
The recommended daily dose ranges from 160 to 1800 mg. However some doctors believe there is greater effectiveness with higher dosages (600 to 1,800 mg in 2 or 3 divided doses daily). Researches demonstrate that full effects may take up to six months to develop. The standardization of hawthorn extracts is based on the overall content of flavonoids (2.2%) and proanthocyanidins (18.75%). (Hawthorn extract LI 132 is standardized to 2.2% flavonoids. Hawthorn extract WS 1442 is standardized to 18.75% oligomeric procyanidins).
Hawthorn herb is well tolerated. A dosage of 160 mg to 1600 mg per day taken for 6 to 24 weeks was found to be safe in studies. Reported adverse effects were mild and included nausea, dizziness, increased heart rate, and stomach upset.Theoretic interactions exist with digoxin, antiarrhythmics and antihypertensives drugs. Concomitant use may necessitate a reduction in the dosage of these medications. Consult a doctor before taking hawthorn with any heart drug.