Friday, January 20, 2006

Can we use this herb to treat my husband's cancer?

That was the question awaiting me Tuesday morning when I first checked e-mail and my telephone messages. Odd, I thought, because my institution is very protective of our e-mail addresses and direct telephone numbers. Ah-ha, the woman must have read our most recent paper where all of my contact info is in black-and-white in the corresponding author section.

This inquiry highlighted for me the chasm that exists for the general public between in vitro cell culture results and the outcomes of clinical trials. All too often, though, herbal manufacturers report in vitro results as "scientific research proves that our product does X, Y, and Z," when, in fact, the remedy would have no effect in a real person. Or, you'd have to take three bottles of the remedy per day just to achieve plasma concentrations of the active components consistent with the observed in vitro effects. (It kills me to give you this link, but I want you to see an example).

My laboratory works on an herbal medicine that others have shown to shrink human prostate tumors in nude mice and prolong their survival. I don't want to mention the herb by name for fear of misleading cancer patients and/or being quote-mined by companies that sell this herb. But just do a PubMed search for "herbal" and "cancer" and you'll see some candidates that have been publicized in the press far more than our little project.

Anyhoo, my chemistry colleagues have now isolated the individual compounds present in this herb, some for the first time. We recently published a paper showing that most of the compounds inhibit human prostate cancer cells from growing in culture, but one was particularly potent and caused the cells to die rather than simply differentiate and just sit there.

So, we're gearing up with a collaborator to test the pure herbal compounds in human tumor xenografts (the nude mouse thing above - I personally no longer work with lab animals). But even if we were a drug company, we'd be at least 5 years away from getting the pure compound approved as a drug...and only if the pure compound had a clear patent position.

If I were a weasel and were selling this compound as an herbal medicine under the US dietary supplement laws, I suspect I could promote my peer-reviewed and published in vitro results as having direct application to humans and sell tons of this dietary supplement to unsuspecting cancer patients. Instead, I closed my e-mail response as follows:

"I apologize that I have no other concrete recommendations, but please recognize that we are still in the early stages of cell culture and mouse experiments. [These] products have both been shown effective in animals that harbor human prostate cancer implants and we are currently testing each extract to see which compounds are most effective. Your last question may refer to our paper showing that a component of [this herbal extract] is the most effective at suppressing prostate cancer cell growth in culture, but it is only about 3-fold more active than other compounds in the mixture. However, we can't make any real recommendations until the extracts and pure compounds are tested in people.

Please feel free to follow-up with any other questions you may have, but recognize that I am not a physician. Since you are in [her hometown], I would encourage you to also look at the integrative oncology programs at Thomas Jefferson Univ Hospital in Philadelphia and Memorial Sloan-Kettering in New York."

I'm certain that the woman wanted me to tell her the doses and products to recommend to her husband, but I'm not in the legal and authoritative position to do so. And, frankly, we really don't yet know how much of this compound gets into the blood stream of people who take X dose of even the best herbal product off the shelf.

What would you have done?


At Thu Jan 26, 09:14:00 PM EST, Anonymous Anonymous said...

Just stumbled on this site and appreciate the responsible way you're addressing these issues.

At Tue Jan 31, 02:54:00 PM EST, Blogger Kim said...

You were absolutely right in what you did...great blog on a topic I am not very familiar with....I'm bookmarking your blog now...

At Tue Jan 31, 07:45:00 PM EST, Anonymous Anonymous said...

Excellent answer. Honest, yet left room for the writer to make her own choices. Well done.

At Thu Feb 02, 11:34:00 AM EST, Blogger define_me said...

I am familiar with herbal treatments as well. My honours thesis was on the effects of herbal treatments (also obliged not to mention which ones I used) on apoptosis. During my defense I had to answer questions dealing with similar issues and I'm the farthest thing from being a doctor! I had to remind them of that.

At Fri Feb 03, 07:03:00 AM EST, Blogger Abel PharmBoy said...

Kim and Mama Mia: thanks for your vote of approval and thanks for coming by. Turns out that PharmMom went back to nursing school when I was 9 to 11 and is now recently-retired. She was the inspiration for me choosing a career in biomedical research, although she is still disappointed that I didn't choose to be a *real* doc. I'll be sure to blogroll Emergiblog and Dust in the Wind.

define_me: thanks also - the biggest issue I see is that herbal advocates don't consider the oral bioavailability of active principles and target plasma concentrations when trying to extrapolate in vitro data in cell culture.

P.S. to you fine Canadian ladies - I apologise for the embarrassing slights of Mr Bush the other evening. We are grateful that you are the #1 provider of oil to the US and most of us don't consider your government to be volatile or unstable!


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