Jewish World Review August 30, 2002 / 22 Elul, 5762




St. John's Wort & chemotherapy

By Robert A. Wascher, M.D., F.A.C.S.

http://www.NewsAndOpinion.com | St. John's wort (Hypericum perforatum L.) is a commonly used non-prescription herbal supplement that has been touted as a treatment for mild depression. St. John's wort is very commonly taken by patients with cancer, and by cancer patients who are undergoing chemotherapy in particular. Previous studies have shown that St. John's wort increases the levels of a liver enzyme (P450) that metabolizes many different types of drugs. A new study from the Netherlands has looked at the effects of St. John's wort on the blood levels of the chemotherapy drug irinotecan. Irinotecan, or CPT-11, is a relatively new chemotherapeutic drug that inhibits DNA repair enzymes called topoisomerases.

Irinotecan has been used for colorectal and other gastrointestinal cancers, as well as for advanced ovarian cancer. Published in the current issue of the Journal of the National Cancer Institute, this study evaluated 5 cancer patients who were receiving irinotecan. The 5 patients had blood levels of the active form of irinotecan measured while taking St. John's wort, and again while not taking the herbal supplement. While taking 900 mg of St. John's wort in addition to irinotecan, the 5 cancer patients experienced a 42% reduction in the blood levels of irinotecan. This dramatic reduction in the blood levels of irinotecan are worrisome, as this suggests that cancer patients taking St. John's wort may not be deriving the full benefit of chemotherapy with those drugs that are metabolized by the P450 liver enzymes. One such class of chemotherapy drugs includes the taxanes, which are also broken down by the P450 liver enzymes, and may therefore be adversely affected by St. John's wort.

Cancer patients are among the most likely group of patients to seek complementary or alternative therapies. If you are taking St. John's wort, you should check with your doctor or pharmacist to see if any of your medications might be affected by this supplement. If you are receiving chemotherapy for cancer, then you should discontinue St. John's wort until you have completed your cancer treatments.

HOMOCYSTEINE LEVELS, VITAMINS & CORONARY ARTERY DISEASE

Elevated levels of homocysteine (an amino acid) in the blood have been linked with an increased risk of coronary artery disease. The vitamins folate, vitamin B-12 and vitamin B-6 can help to reduce the levels of homocysteine in the blood. The current issue of the Journal of the American Medical Association features a study that looked at the effects of these three vitamins on patients undergoing coronary artery angioplasty. A total of 553 patients in Switzerland were randomized into two groups. The first group received daily supplements of the three vitamins for 6 months, and the second group received placebo pills instead of the vitamins. After an average follow-up of nearly one year, the vitamin group experienced a 32% reduction in the risk of having to undergo repeat angioplasty. Therefore, this study provides further evidence that reducing blood homocysteine levels may have a favorable impact on overall heart health.

BABBLING BABIES & BRAIN FUNCTION

All babies babble before they are able to speak their native language. It has been unclear, to date, whether such "baby talk" is, indeed, talk at all. One school of thought is that babbling is a baby's way of exercising his or her speech muscles in preparation for the later acquisition of the ability to speak their native language. Others have argued that babbling arises from the immature language centers of a baby's brain and, as such, represents the early rudiments of spoken language in babies. An interesting study in the current journal Science sheds further light on this debate. In adults, subtle asymmetries in the position of the lips during speech indicate that the language centers of the left brain are being utilized. Using a sophisticated video camera system, 10 babies were studied from 5 months of age until 12 months of age. The study determined that all of the babies exhibited the characteristic mouth asymmetry that signifies activation of the language centers in the left brain. The authors, therefore, concluded that when babies babble, they are actually utilizing the language centers of their brain. These findings also suggest that the acquisition of language skills begins to appear much earlier than was previously thought. So, when your baby begins to babble and coo at you, consider the possibility that he or she really is trying to tell you something in their own baby language!

JWR contributor Dr. Robert A. Wascher is a senior research fellow in molecular & surgical oncology at the John Wayne Cancer Institute in Santa Monica, CA. Comment by clicking here.

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© 2002, Dr. Robert A. Wascher