Some American physicians still prescribed the extract in the 1940s to treat high blood pressure. Herbalists long considered the berries the medicinal part of the plant, but the flowers and leaves also contain active ingredients. As with most herbs, hawthorn probably has several active ingredients that work in harmony. Some of the more important ingredients include a mixture of pigment chemicals known as flavonoids . These compounds give the hawthorn berry its distinctive reddish blue color.
Flavonoids scavenge free radicals and lessen the bad effects of inflammation.
They also seem to reduce cholesterol in the bloodstream. Proanthocyanidins, another large group of chemicals, seem to be largely responsible for its beneficial actions on the heart. When ancient physicians used hawthorn as a heart herb, they usually were treating congestive heart failure, which they loosely termed dropsy. Dropsy actually describes the symptoms of edema , an accumulation of fluid in the tissues. When the heart is weak and can t pump enough blood, fluid often accumulates around the ankles.