Tufts research shows how St. John's Wort prevents certain drugs from being absorbed by the body

Boston [04.13.01] -- While St. John's Wort has been used as an herbal remedy for everything from depression to tumors, scientists have discovered that the herb can actually interfere with a wide variety of drugs.

   New research by graduate student Michael Perloff, from Tufts' Sackler School of Graduate Biomedical Sciences, helps explain why the popular "mood booster" interferes with everything from antibiotics and painkillers to AIDS and cancer drugs.

   "Researchers at Tufts University have found that St. John's Wort appears to boost the activity of a 'drug transporter' in the intestines," reported the New York Times. "This revved up drug transporter may prevent certain drugs from being sufficiently absorbed by the body."

   The Tufts team of scientists -- led by Pharmacology department head, Dr. David Greenblatt -- found that St. John's Wort increased the "drug transporters" by up to 300 percent, reported Reuters, causing the body to "usher away far more of the drugs than it normally would."

   While St. John's Wort has been known to interfere with drugs taken by HIV and transplant patients, the new Tufts findings should allow researchers to screen many more drugs for interactions with the herb.

   In the Times article, Greenblatt said certain painkillers, cancer drugs and antibiotics may be added to the list of medications impacted by the herbal remedy.