From: Brian Symonds   <[log in to unmask]>
 
A person with PD asked me about using St. John's Wort for depression, so I
dug up some info on it that I believe is accurate.
 
Hypericum perforatum is an aromatic perennial herb, producing yellow flowers
in June, and since June 24th is the day traditionally celebrated as the
birthday of John the Baptist, the plant is commonly known as St. John's Wort
(wort is a suffix meaning plant). St. John's Wort was known to ancient
authorities of medicinal plants such as Hippocrates, and is described and
recommended as a useful remedy in herbal books since that time. Recently,
Europeans have "discovered"  that a tea prepared from the herb (leaves and
flowers are harvested) is an effective "nerve tonic", and its use is promoted
for anxiety and depression. It has also been promoted as a diuretic (water
pill type medication), and in the treatment of various conditions ranging
from insomnia to gastritis. An olive oil extract of the fresh flowers
acquires a reddish colour after standing in sunlight for several weeks, and
is promoted for internal use for the same conditions as the tea, but is also
promoted to be applied externally to relieve inflammation and promote
healing, one such use being the treatment of hemorrhoids.
There have been chemical investigations of St. John's Wort. It is 10% tannin,
a compound that has astringent and protein-precipitation actions, and
accounts for its anti-inflammatory effect. Its antidepressant effects are due
to various contained xanthones and flavonoids that act as "monoamine oxidase
inhibitors" or MAOIs. In medicine, MAOIs have generally not been used as the
first choice for antidepressant medications because of their many and
potentially fatal side effects, especially because of their potential
interaction with many over the counter medications (such as cough and cold
preparations), and chemicals found in a variety of foods (such as red wines,
beer including non-alcoholic beer, some cheeses, some fruits, some processed
meats, etc).
The antidepressant activity of St. John's Wort was initially thought to be
due to the presence of hypericin, a reddish dianthrone pigment, but it is now
known that this is not the case. Unfortunately, this compound can induce a
"photosensitivity" of the skin characterised by dermatitis of the skin and
inflammation of the mucous membranes (especially the mouth) on exposure to
direct sunlight (the reaction apparently looks like a poison ivy type
allergic reaction or a shingles type of rash, and is quite uncomfortable).
This does not usually happen with normal doses of St. John's Wort when taken
over short periods of time. Those who take the herb for extended periods are
more at risk.
A newer pure MAOI is called Manerix (Moclobemide), and it is free of many of
the potential interactions and is safer to use than the older types of MAO
inhibitors. It is a monoamineoxidase-A inhibitor, and inhibits the
deamination of serotonin (Prozac by the way also acts by increaseing
serotonin levels in the brain although through a different mechanism),
norepinephrine, and dopamine, thus increaseing their levels in the brain, all
of which are neurotransmitters, and all of which are involved in depression
and anxiety states.
St. John's Wort is generally safe when taken in small amounts, for relatively
short times, if you are not taking any other medications (prescription or
over the counter), and if you do not suffer from heart disease, high blood
pressure, have risk of stroke, liver disease, seizure disorders, Parkinson's
Disease, Diabetes, kidney disease, or thyroid diseases. It should not be
taken in pregnancy, especially the first 14 weeks. You should remember that
it is a mixture of chemicals, and can have potentially serious and even fatal
side effects. If you are using this (or any other herbal or over the counter
medication), you should always inform your doctor.