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?