Complementary Alternative Cardiovascular Medicine

30 Alternative Cardiovascular Medicine
Khellin exerts lipid-lowering effects in animal studies (13). A study of
khellin in 20 nonobese men with normal lipid levels found a significant
increase in HDL cholesterol levels, although total cholesterol and triglyceride
concentrations were unchanged. Unfortunately, nausea and vomiting
caused four volunteers to withdraw, and elevation of liver enzymes
caused an additional two participants to withdraw (14). These side effects
are not generally noted with standardized preparations of the whole fruit.
Generally, recommended standardized extracts provide an equivalent
of 20 mg khellin/d. Prolonged use or overdose of the herb may lead to
nausea, vertigo, constipation, anorexia, headache, pruritus, and sleeplessness
(15). Elevated liver enzymes and vomiting have been noted when the
isolated constituents were administered alone.
CARDIAC GLYCOSIDES
Class I for Congestive Heart Failure
The role of botanical medicine in the treatment of congestive heart
failure (CHF) is a long and interesting one. Plants containing cardiac
glycosides have been used for centuries for the treatment of “dropsy,” the
old term for CHF. The primary plants used for this purpose include foxglove,
squill, strophanthus, and lily of the valley. The ancient Egyptians
used squill as a cardiac medicine, whereas the Romans employed the herb
as a diuretic, heart tonic, emetic, and rat poison. Foxglove was mentioned
in 1250 in the writings of Welsh physicians.
William Withering (1741–1799) first learned the value of foxglove
(Digitalis purpurea) from an old woman in Shropshire, England, “who
had sometimes made cures after the more regular practitioners had failed.
. . . This medicine was composed of 20 or more different herbs; but it was
not very difficult to perceive that the active herb could be no other than the
foxglove.” Withering, an observant physician, not only accurately described
the efficacy of foxglove but also its toxicity, more than 200 yr ago. When
given in large and quickly repeated doses, foxglove causes sickness, vomiting,
purging giddiness, confused vision, objects appearing green or yellow,
increased secretion of urine, slow pulses (as low as 35 beats in a
minute), cold sweats, convulsions, syncope, and death.”
Digitalis glycosides exert a positive inotropic effect via two mechanisms:
direct inhibition of membrane-bound Na + , K + -activated adenosine
triphosphatase (Na + , K + -ATPase), which leads to an increase in the intracellular
concentration of Ca2+ , and an associated increase in a slow inward
Ca2+ current during the action potential (AP).
Digitalis also lowers the heart rate (negative chronotrope), impedes
stimulus conduction (negative dromotrope), and promotes myocardial