March 26th, 2011 by David Kroll, Ph.D. in News, Research
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Thunder god vine may not be a useful herbal medicine but the compounds isolated from it are fascinating – if not as medicines, then most certainly as laboratory tools. Nature Chemical Biology recently published an article where a research team from Johns Hopkins, the University of Colorado at Boulder, and Drew University in New Jersey, has determined the molecular mechanism of action of triptolide, an unusual triepoxide compound from the plant.
Tripterygium wilfordii Hook F, or thunder god vine, is known as lei gong teng in Chinese traditional medicine and has a history of use as an anti-inflammatory herb. As with many traditional medicines, usage patterns do not necessarily indicate scientific validity. In fact, a Cochrane review published just last month on herbal therapies for rheumatoid arthritis indicated that the efficacy of thunder god vine was mixed. More concerning is that the herb had significant adverse effects in some trials, from hair loss to one case of aplastic anemia.
Nevertheless, the herb’s components have been studied since the 1970s for since they also appears to kill tumor cells in culture with nanomolar potency and have immunosuppresant activity in animal models. The group of the late natural products chemist at the University of Virginia, S. Morris Kupchan, first identified the unusual structures of triptolide and tripdiolide from Tripterygium wilfordii as described in this 1972 paper from the Journal of the American Chemical Society. Cytotoxic activity toward tumor cells in culture was used to guide the chemical fractionation of extracts. The unusual presence of three consecutive epoxides in the structures of both compounds led Kupchan to hypothesize later in Science that they target leukemia cells by covalent binding to cellular targets involved in cellular growth. Read more »
*This blog post was originally published at Science-Based Medicine*
September 13th, 2010 by David Kroll, Ph.D. in Better Health Network, Health Policy, News, Opinion, Research
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I’m only a monthly contributor here, but between being a Science Based Medicine (SBM) reader and having my own blogs, I often grow weary of the blind criticism that researchers and drug companies couldn’t care less about traditional folk medicines as drug products. My laboratory spends every single day working on natural product extracts in the search for compounds that may have selective effectiveness against cancer. So this is a bit of a sore spot for me.
Two [recent] papers from Cancer Prevention Research on the potential anticancer effects of a diabetes drug (see Nathan Seppa’s story here) remind me to tell the story of a Middle Ages European herbal medicine used to treat polyuria that gave rise to one of the most widely prescribed drugs in the world, metformin (Glucophage in the U.S.). Metformin, known chemically as a biguanide, dimethylguanide to be precise, traces its roots to the plant Galega officinalis. Known as goat’s rue, French lilac, or professor weed, this plant was shown to be a rich source of guanidine and a less toxic compound later called galegin or galegine (isoamyline guanidine). Read more »
*This blog post was originally published at Science-Based Medicine*
August 12th, 2010 by David Kroll, Ph.D. in Better Health Network, Health Policy, Health Tips, News, Opinion, Quackery Exposed, Research
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On the heels of Scott Gavura’s superb post on dietary supplement regulation in the U.S. and Canada, I bring you one of the most egregious and obscene product cases I have seen in 15 years of teaching on botanical and non-botanical products: Miracle Mineral Solution. Please accept my apologies in advance for not having a scholarly post for you — this is just too unbelievable not to share with science-based medicine readers. Read more »
*This blog post was originally published at Science-Based Medicine*
August 5th, 2010 by David Kroll, Ph.D. in Better Health Network, Humor, Opinion, Research
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This post follows a lengthy conversation I had with my wife, a physician-scientist, about this very topic.
Many of you who attended the ScienceOnline2010 conference here last January probably met Carmen Drahl, the Princeton-trained chemist who now writes for Chemical & Engineering News and their appropriately-named drug discovery blog, The Haystack, as well as their Newscripts feature.
For the latter, Dr. Drahl pointed us toward a recent “Crosstalks” paper in Chemistry & Biology by Thomas U. Mayer and Andreas Marx of the University of Konstanz (and her interview with the authors) who mused as follows from their abstract:
Which five molecules would you take to a remote island? If you imagine yourself as a castaway on an island you might pick water, glucose, penicillin, and ethanol in combination with aspirin. However, as a scientist, you may ask yourself which molecules impressed you most by their chemical or biological property, their impact on science, or the ingenuity and/or serendipity behind their discovery. Here, we present our personal short list comprising FK506, colchicine, imatinib, Quimi-Hib, and cidofovir. Obviously, our selection is highly subjective and, therefore, we apologize up front to our colleagues for not mentioning their favorite compounds.
The authors pose two different questions: a) Which molecules, drug or not, would you take as the sole occupant of a desert island? and b) Which drugs most impress you with their chemistry, biology, or impact on science? Read more »
*This blog post was originally published at Terra Sigillata*
July 26th, 2010 by David Kroll, Ph.D. in Better Health Network, Health Policy, News, Opinion, Research
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This is not good. Not good at all.
Recently Paul Goldberg of The Cancer Letter reported on an investigation into Duke cancer researcher Anil Potti, M.D., and claims made that he was a Rhodes Scholar in Australia. The misrepresentation was made on grant applications to National Institutes of Health (NIH) and the American Cancer Society (ACS).
The Cancer Letter, a $375 per year go-to newsletter on cancer research, funding, and drug development, has made this issue free at this PDF link.
News & Observer higher education reporter Eric Ferreri has a nice overview of the situation. Potti has been placed on administrative leave by Duke, and the ACS has suspended payments on his grant and initiated their own investigation. Read more »
*This blog post was originally published at Terra Sigillata*
