Hawthorn fruit, leaves, berries and blossoms contain many active flavonoid glycosides including rutin and quercetin.
Hawthorn fruit is particularly rich in anthocyanidins, and proanthocyanidins.
These flavonoids are responsible for the red to blue colors of grapes, berries and flowers.
The active constituents isolated from hawthorn are the saponins and the cyanogenic glycosides.
Hawthorne flavonoids promote vasodilatory actions on both peripheral and coronary circulation.
It is believed that hawthorn’s action on the heart is due to the active cyanogenic glycosides that stimulate parasympathetic (vagal) activity.
Parasympathetic activity results in a slower heart rate and an increase in the heart’s stroke volume. Hawthorn improves coronary blood flow by its effect on the vessels supplying cardiac muscle. The coronary arteries increased blood flow is due to the relaxation of smooth muscle in arterial walls caused by active agents (glycosides) in hawthorn.
The paradoxical effects of hawthorn (sympathetic stimulation of the coronary circulation and a parasympathetic effect on cardiac muscle) improve cardiovascular efficiency. The result of hawthorn’s action is an increase in oxygen consumption and energy metabolism by the heart.
Skeletal muscles also benefits from hawthorn’s actions since improved heart activity increases their delivery of blood and nutrients.
Hawthorn extracts have been shown to dilate coronary vessels by a relaxation of smooth muscle, thereby improving cardiac circulation. Consequently, hawthorn produces an accelerated metabolism and improved energy production within cardiac muscle with a resulting increase in stroke volume and a more efficient delivery of oxygen and nutrients to skeletal muscle.
Hawthorn flavonoids are believed to stabilize vitamin C (ascorbic acid) by protecting vitamin C from oxidation. The sparring effect on vitamin C causes an increase in vitamin C concentrations. High concentrations of vitamin C are required in metabolically active cells (skeletal muscle) to quench the free radicals produced during energy production. Furthermore, hawthorn flavonoids enhance collagen formation by aiding its cross-linkage and preventing free radical destruction.
Free radicals have been linked to the aging process, inflammation and atherosclerosis. Hawthorn extracts are believed to enhance the action of superoxide dismutase (SOD), an enzyme responsible for scavenging free radicals.
Hawthorn extracts have demonstrated the ability to inhibit lipid peroxidation, which is caused by highly reactive free radicals. Lipid peroxidation is believed responsible for the oxidation of fats that initiates atherosclerosis.
Medical and Preventive Use
Hawthorn extracts produced a demonstrable drop in blood pressure in animal studies and improved cardiac function in small human studies. Hawthorn extracts have become a valuable drug in the treatment of heart and circulatory disorders.
Hawthorn extracts have been shown to be clinically effective in reducing blood pressure and cholesterol levels. Hawthorn is theorized to inhibit the inflammatory response to injury. Hawthorne extracts, like other extracts containing proanthocyanidins (grape seed, etc.) may prevent atherosclerosis through its antioxidant activity.