Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Herbal dietary supplement alters metabolism of chemotherapy drug

21.08.2002


Researchers in the Netherlands have found that the herbal dietary supplement St. John’s wort interferes with the metabolism--and potentially the effectiveness of--the chemotherapy drug irinotecan. Their findings appear in the August 21 issue of the Journal of the National Cancer Institute.



St. John’s wort (Hypericum perforatum L.) is widely used to treat mild to moderate forms of depression. Past studies have suggested that the compound increases levels of CYP3A4, an enzyme involved in drug metabolism. The enzyme inactivates the colorectal cancer chemotherapy drug irinotecan.

To examine the interaction between St. John’s wort’s and irinotecan, Ron H. J. Mathijssen, M.D., and Alex Sparreboom, Ph.D., of the Department of Medical Oncology at the Erasmus MC-Daniel den Hoed Cancer Center, and their colleagues treated five patients with irinotecan alone or in combination with St. John’s wort.


At the end of the study, blood levels of SN-38 (the active metabolite of irinotecan) were 42% lower in patients receiving irinotecan and St. John’s wort than when the patients received irinotecan alone. Detoxification of the drug to other known metabolites also decreased with St. John’s wort.

"Our findings suggest that irinotecan metabolism and toxicity are altered by [St. John’s wort] and that the two agents cannot be given safely in combination without compromising overall antitumor activity," the authors write.

They note that their results may have implications for other anticancer drugs metabolized by CYP3A4, such as the taxanes (paclitaxel). Combining these drugs with St. John’s wort may make it necessary to increase drug dosage to achieve the optimal pharmacologic effect. "Until specific dosing guidelines are available, it is strongly recommended that patients receiving chemotherapeutic treatments with such agents refrain from taking [St. John’s wort," they conclude.

In a related editorial, Patrick J. Mansky, M.D., and Stephen E. Straus, M.D., of the National Center for Complementary and Alternative Medicine at the National Institutes of Health, point out that cancer patients are among the most likely to seek complementary and alternative medical remedies to reduce the side effects of treatments. They say that, in addition to St. John’s wort, a number of herbal remedies have been identified that affect synthetic drug metabolism and, potentially, drug efficacy.

The National Institutes of Health is funding studies of complementary and alternative medicine practices in cancer patients. While waiting for these results, "it would be prudent for patients and their oncologists to appreciate that, no matter how beneficial some approaches may appear to be, they are not all safe," the editorialists conclude.


Contact: David Drexhage, Erasmus MC-Daniel den Hoed Cancer Center, +31 10 463 5525, d.a.drexhage@azr.nl (8:30 a.m. to 5:30 p.m. GMT)

Editorial: NCCAM press office, (301) 451-8876

Mathijssen R, Verweij J, Bruijn P, Loos W, Sparreboom A. Effects of St. John’s wort on irinotecan metabolism. J Natl Cancer Inst 2002;94:1247–9.

Editorial: Mansky P, Straus S. St John’s Wort: more implications for cancer patients. J Natl Cancer Inst 2002;94:1187–8.

Attribution to the Journal of the National Cancer Institute is requested in all news coverage.

Linda Wang | EurekAlert!
Further information:
http://jncicancerspectrum.oupjournals.org/

More articles from Health and Medicine:

nachricht Research offers clues for improved influenza vaccine design
09.04.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Injecting gene cocktail into mouse pancreas leads to humanlike tumors
06.04.2018 | University of Texas Health Science Center at San Antonio

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>