Here’s an ironic botanical twist: The more stress placed on wild populations of St. John’s Wort, the more effective the plant might be in warding off human depression.
Plant pathologists from Cornell University and the U.S. Department of Agriculture (USDA) have found that hypericin (pronounced hi-PARIS-in), an active ingredient in St. John’s Wort (Hypericum perforatum), might be increased when predators such as insects attack the plant. Hypericin is concentrated in little black nodules that adorn the floral edges and the plant’s leaves.
St. John’s Wort tablets are standardized by the amount of hypericin contained. Researchers believe that the more hypericin that ends up in the final product, the better it will be at treating depression.
Donna M. Gibson, an USDA plant physiologist and Cornell adjunct professor of plant pathology, and Tara M. Sirvent, a Cornell plant pathology graduate student from Casper, Wyoming, have developed a way to analyze the active chemical and other related compounds in the plant.
The researchers dissolved the chemical components of the plant in a solution and separated them using a technique called high-performance liquid chromatography. This enabled the detection of individual compounds in the plant. Sirvent and Gibson examined wild populations and found plants that had been exposed to stress – particularly attacks from insects – had increased amounts of hypericin.
Now researchers are faced with the problem of finding an economic method for extracting the hypericin from the plant.
Normally, hypericin is extracted by chopping the plant up and extracting it with ethanol. But plant physiologist Stephen O. Duke, head of the Agricultural Research Service at Oxford, Mississippi, may have found a better way.
“The plant has other enzymes that can destroy hypericin when the cells containing the toxin are breached,” he says. “Crushing the plant releases these hypericin-destroying proteins, defeating your purpose. We are looking at chemical extraction methods that may work better – like soaking the leaves in a solution that gently removes the hypericin without having to cut them.”
In addition, Sirvent and Gibson are trying to determine how much of a role pre-harvest factor plays in chemical differences. They are examining factors such as light, moisture, altitude and latitude; the plant parts; the plant’s development stage; and the harvesting and handling practices that might affect the quality of the final product.
All of which is good news for CFS/FM sufferers, where depression is a major side effect of their illness.
Currently, St John’s wort is only available as a dietary supplement. It has yet to receive FDA approval for use as a treatment for depression in the United States. But several companies are doing phase I and II clinical trials, a step toward gaining FDA approval.