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Apr 29, 2006 17:03 PDT
Hawthorne Berry for Fluid Arteries
By Michael T. Murray
Key uses of Hawthorn:
Angina
Atherosclerosis
Congestive heart failure
High Blood pressure
General Description
Hawthorn (Crataegus oxyacantha) is a spiny tree or shrub that is
native to Europe. The fruit and blossoms are used medicinally.
Hawthorn leaves, berries, and blossoms contain many biological
active flavonoid components, particularly anthocyanidins and
proanthocyanidains.
These flavonoids are responsible for the red-to-blue colors not only
of Hawthorne berries but also of blackberries, cherries and
blueberries, grapes and many flowers as well.
These compounds are highly concentrated in hawthorn berry and flower
extracts.
High-performance liquid chromatography and thin-layer chromatography
demonstrated that extracts of the flowers are particularly rich in
flavonoids (quercetin, quercetin-3-galactoisde, vitexin,
vitexin-4'-rhamnoside, etc.) and proanthocyanidins.
In addition to flavonoids, hawthorn extracts also contain
cardiotonic amines. (e.g.,phenylethylamine, 0-
methoxyphenylethylamine, tyramine, and
isobutylamine), choline and acetylcholine, purine derivatives (e.g.
adenosine, adenine, guanine, and caffeic acid, amygdalin , pectins,
and triterpene acids 9urolic, oleanolic, and crataegolic acids.
History and Folk use
Hawthorn flowers and berries have been used primarily as heart
tonics and mild diuretics in organic and functional heart disorders
including
congestive heart failure, angina, and high blood pressure.
Hawthorn's astringent qualities were also utilized to relieve the
discomfort of sore throats.
Pharmacology
The pharmacology of hawthorn centers on its flavonoid components,
The proanthocyanidins in hawthorn are largely responsible for its
cardiovascular activities.
Synergism with Vitamin C
Hawthorn flavonoids have very strong "vitamin P" activity. Included
in their effects are ability to increase intercellular vitamin C
levels, stabilize vitamin C (by protecting it from destruction or
oxidation),
and decrease capillary permeability and fragility.
Collagen-stabilizing action
Hawthorns flavonoid components possess significant collagen-
stabilizing action.
Collagen is the most abundant protein in the body and is responsible
for maintaining the integrity of ground substance, tendons,
ligaments, and cartilage.
Collagen is destroyed during inflammatory processes that occur in
rheumatoid arthritis, periodontal disease, and other inflammatory
conditions involving bones, joints, cartilage and other connective
tissue.
Anthocyanidins, proanthocyanidins, and other flavonoids are
remarkable in their ability to prevent collagen destruction.
They affect collagen metabolism in many ways, including:
The unique ability to cross-link collagen fibers, resulting in
reinforcement of the natural cross-linking of collagen that forms
the collagen matrix of connective tissue (ground substance,
cartilage, tendons,etc.
The prevention of free radical damage, due to potent and free
radicals scavenging action.
The inhibition of enzymatic cleavage by enzymes secreted by white
blood cells during inflammation.
The prevention of the release and synthesis of compounds that
promote inflammation, such as prostaglandins serine proteases,
histamine, and leukotrines.
Cardiovascular effects
Hawthorn extracts are clinically effective in reducing blood
pressure,
angina attacks, and serum cholesterol levels and in preventing the
deposition of cholesterol in arterial walls.
The beneficial pharmacological effects of hawthorn in the treatment
of these conditions appear to be a result of the following actions:
Improvement of the blood supply to the heart by "dilating" the
coronary vessels.
Improvement of the metabolic processes in the heart, which results
in an increase in the force of contraction of the heart muscle and
elimination of some types of rhythm disturbances.
Inhibition of angiotensin-converting enzyme
Hawthorns ability to dilate coronary blood vessels,
the vessels supplying the heart with vital oxygen and nutrients, has
been repeatedly demonstrated in experimental studies.
This effect appears to be due to relaxation of the smooth muscle
components of the vessel.
Various flavonoid components in hawthorn have
been shown to inhibit constriction of vessels by a variety of
substances.
When blood vessels constrict, blood pressure goes up.
In addition,
procyanidins have been shown to inhibit angiotensin-converting
enzyme.
This enzyme is responsible for converting angiotensin l to
angiotensin
II, which is potent constrictor of blood vessels.
Recently, several proanthocyanidins have demonstrated a specific
inhibition of angiotensin-converting enzyme similar to that of
captopril.
Captropril is a synthetic angiotensin-converting enzyme inhibitor
widely used in the treatment of high blood pressure.
The proanthocyanidins that appear to have the highest activity are
found in relatively high concentrations in Hawthorne berries,
flowers and their extracts.
Improvement in energy production within the heart has been
demonstrated
in humans and animals to whom Hawthorne extracts have been
administered.
The improvement is a result not only of increased blood and oxygen
supply to the myocardium (muscle of the heart), but also a result of
flavonoid-enzyme interactions.
In particular, hawthorn extracts and various flavonoid components in
hawthorn have been shown to inhibit several key enzymes within the
myocardium (e.g. cyclic AMP phosphodiesterase).
The net result is an increase in the force of contraction.
This is
particularly beneficial in cases of congestive heart failure
(discussed below).
A recent study has shed additional light on how Hawthorne extracts
enhance heart function.
A hawthorn extract standardized for proanthocyanidin content (3.3
percent) was studied utilizing an experimental model to determine
the
effects of a substance on heart function during ischemia.
Although it's effectiveness in this model was less than that of
beta-blockers and calcium channel blockers, two classes of drugs
often used in treating angina, there are two distinctions to be made
(1) the
mechanism by which the drugs work in this model is by improving
coronary blood flow and actually reducing the hearts need for oxygen
by reducing its mechanical function.
In contrast Hawthorne actually "improves" the 'mechanical function'
of the
heart without increasing coronary blood flow.
Evidence that Hawthorne improves energy metabolism and the
utilization of oxygen by the heart was demonstrated by a decrease in
accumulated lactic acid.
Without oxygen, the heart muscle will shift to the breakdown of
sugar
for energy, but this can only go so far without oxygen.
As a result,
pyruvic acid is shunted to lactic acid.
Recovery of heart function in inversely related to the level of
lactic acid in the heart. The beneficial effects of hawthorn in
angina appears
to be related more to its ability to improve "oxygen utilization",
as
noted by the reduction in heart tissue lactic acid levels, rather
than
to its ability to dilate coronary vessels.
Atherosclerosis
Hawthorn extract, like other extracts containing proanthocy |