Hypericum
Scientific
Name: St. John's Wort Other Names: Amber
Touch-and-Heal, Hardhay, Hypericum perforatum, Klamath Weed,
Millepertuis, Rosin Rose, SJW, Tipton Weed
Who is this for?
Uses
Used sporadically since ancient times to treat a number of
various conditions, St. John’s wort has become popular again as an
antidepressant. It contains several chemicals, including hypericin,
hyperforin, and pseudohypericin, which are thought to be the major
sources of antidepressant activity. In several studies of laboratory
animals and humans, one or more of the chemicals in St. John’s wort
appeared to delay or decrease re-absorption of the neurotransmitters
dopamine, norepinephrine, and serotonin by nerve cells.
Neurotransmitters are chemicals that carry messages from nerve cells
to other cells. Ordinarily, once the message has been delivered,
neurotransmitters are re-absorbed and inactivated by the cells that
released them. Chemicals in St. John’s wort may keep more of these
antidepressant neurotransmitters available for the body to utilize.
Multiple studies have shown that St. John’s wort may be effective in
relieving mild to moderate depression, although maximum
antidepressant effects may take several weeks to develop.
However, recent studies have challenged the antidepressant
effects of St. John’s wort. At least two large, well-controlled
clinical studies found no difference in relief of major depression
among individuals who received St. John’s wort and those taking
placebo (sugar pills). In one of the studies, a prescription
antidepressant medication also showed no significant effect on major
depression. Whether the studies lasted long enough and whether the
doses of antidepressants and St. John’s wort were high enough to
produce significant effects may be questionable. Early in 2003, the
U. S. National Institute of Mental Health began a 4-year clinical
study to compare the effectiveness of St. John’s wort with both a
prescription antidepressant and placebo (sugar pill) for treating
mild depression.
In addition to its potential for depression, St. John’s wort has
also been studied for the treatment of other emotional disorders
such as anxiety, obsessive-compulsive disorder (OCD), menopausal
mood swings, and premenstrual syndrome. In laboratory studies, it
has shown some effectiveness for lessening the symptoms of nicotine
withdrawal and for reducing the craving for alcohol in addicted
animals. It is believed that chemicals in St. John’s wort may act
like other chemicals that are associated with relieving emotional
conditions. These effects are poorly understood, however. Currently,
studies sponsored by the National Center for Complementary and
Alternative Medicine, a part of the U.S. National Institutes of
Health, are underway to test the effectiveness of St. John’s wort
for OCD and social phobia as compared to placebo (sugar pills). More
studies are planned for use of St. John’s wort in these mental
conditions.
Possible antiviral effects of St. John’s wort are being
investigated for the treatment of HIV/AIDS, hepatitis C, and other
viral illnesses. It is thought that hypericin, pseudohypericin, and
other chemicals in St. John’s wort may stick to the surfaces of
viruses and keep them from binding to host cells. Another theory is
that St. John’s wort may contain chemicals that interfere with the
production or release of viral cells. This antiviral activity is
enhanced greatly by exposure to light. However, the doses needed for
active antiviral effect from St. John’s wort may be so high that
unbearable side effects may limit its usefulness as an antiviral.
More research is needed to prove or disprove the effectiveness and
to determine effective dose levels of St. John’s wort for viral
illnesses.
St. John’s wort may be applied topically. It has mild antibiotic
effects, which are thought to be attributed mainly to its hypericin
content, although a cream containing 1.5% hyperforin has been found
useful in studies for treating dermatitis. Hypericin also seems to
have an additional anti-inflammatory effect caused by interrupting
the body’s production of natural chemicals that promote
inflammation. Additionally, St. John’s wort contains between 3% and
15% of a chemical group known as tannins, which act as astringents.
An astringent shrinks and tightens the top layers of skin or mucous
membranes, thereby reducing secretions, relieving irritation, and
improving tissue firmness. All these properties may make St. John’s
wort moderately useful for minor skin irritations such as cuts,
razor burn, and scrapes. Studies comparing long-term use of topical
St. John’s wort against prescription treatments for skin conditions
are needed.
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