St. John’s Wort: A Closer Look

Posted By on August 2, 2008

St. John’s wort (Hypericum perforatum), a perennial with yellow flowers that grows abundantly in North America, Europe and Asia, has gained much publicity for its ability to effectively compete with the leading prescription antidepressants. This knowledge has also raised intense controversy over the safety of the long-term use of St. John’s wort. The research has shown St. John’s Worts abilities reach far beyond its use as an anti-depressant. Out of a necessity to understand its mechanism of action, researchers discovered it works against depression on a much more broad spectrum than they initially thought.

Its Uses
Historically, St. Johns wort was used in the treatment of “nervous conditions,” mental disorders, nerve pain, and in folk medicine to rid the body of “evil spirits.” It has also been used topically for wound healing and burns. Several healing properties of St. John’s wort have been discovered, including anti-bacterial, anti-viral and anti-inflammatory components. This has made St. John’s Wort a candidate for the treatment of many illnesses including depression, seasonal depression disorder (SAD), cancer, premenstrual syndrome, viral infections such as viral encephalitis and HIV, bacterial infections, alcoholism, somatoform disorders, ear pain, burns and wound healing.

Chemical Background
Hypericin is the constituent in St. Johns wort that was originally targeted for its monoamine oxidase (MAO) inhibiting behavior, similar to that of the original pharmaceutical anti-depressants. Upon further examination another constituent named hyperforin exhibited anti-depressant effects by mimicking a class of anti-depressants called SSRI’s (selective serotonin reuptake inhibitors). Low levels of serotonin have been associated with an increase in depression, aggression, obsessive-compulsive disorder (OCD), bipolar and anxiety disorders. SSRI’s boost serotonin levels by increasing the amount of serotonin available to stimulate neuron firing. In addition to serotonin, hyperforin also increases the activity of norephinephrine and dopamine (hormones that can influence mood in addition to increasing heart rate and blood pressure), GABA and L-glutamate. This indirect effect on the central nervous system has stimulated an increase in stress hormones in some patients, a justified cause for concern among patients dealing with bipolar and anxiety disorders. On the contrary, this more complete profile of behavior may be a better compliment for the treatment of depression because research has found important factors and neurotransmitters besides serotonin are altered during depression.

Potential for Cancer Patients?
Both hypericin and hyperforin have shown anti-tumor activity. Hypericin is toxic to cancer cells after direct exposure to sunlight, which accounts for its potential use in photodynamic cancer therapy. Hyperforin has been shown to induce tumor cell death by activating the control center in a cell (mitochondria) that is responsible for self-destruction when abnormal growth occurs.

Drug Interactions & Side Effects

Hypericin and hyperforin act on one of the main detoxifying pathways in the liver, affecting the P450 system of enzymes involved in the breakdown and metabolism of drugs. As a result, interference occurs when St. Johns wort is taken in conjunction with at least 50% of pharmaceutical drugs, dampening the effect of the drug. A list of known contraindications includes cholesterol lowering drugs, oral birth control pills, certain chemotherapy agents, immunosuppressants, anti-depressants, medications used during surgery and various others. Although St. John’s wort has been shown to kill or inhibit the growth of HIV in vitro, it also interferes directly with a popular HIV drugs (indinavir). Most common side effects include an increased sensitivity to sunlight, anxiety, dizziness, stomach upset, fatigue and headache. Due to the many known interactions and side effects caused by St. John’s Wort, we recommend consulting a healthcare provider before supplementation.

Note: These statements have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure or prevent any disease. If you have medical problems seek a professional.

Works Cited
1. University of Maryland Medical Center. 2006. St. John’s wort. Accessed 6/28/07.
2. Thorne Research 2004. Hypericum Perforatum. Alternative Medicine Review Vol. 9 No. 3. 318-325. Accessed 6/28/07.
3. Marilyn Sterling, R.D. St. John’s wort; Effective with Caveats. Spring 2002. Nutition Science News.

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