Hi David,
Check out Vincristine or vinblastine (
link). We already have leukemia drugs from tropical plants.
Anyway, I know more about shamanism than I'm willing to talk about here, but that's only half my point. A bigger point is that we're assuming that, because they're hallucinogens, the people must have been hallucinating to hear the song. I don't know that Davis went out to check, but for all I know, you can hear the difference around the different cultivars of that vine. Maybe it has to do with the mosquitos that were buzzing around it, or something. Miguel's comment was right on: most shamans aren't stupid, and the ones I've met are pretty darn observant. Instead of wallowing in the mysticism of the comment, it's good to ask them whether they can teach you to hear that song, so that you can evaluate their evidence for yourself. It might be that all you have to do is stand under a vine and listen, simple as that.
As for the cost of finding a new drug.... That's a complex question. I'll approach it by telling some anecdotes.
1. A lot of the initial scientific research on Echinacea is incorrect, because the researchers were bad taxonomists and chose the wrong species for their sample. Moral: Correct identification is CRITICAL. This week, the New York times ran an article, one of many noting how taxonomy is a disappearing science. Think about the connection for a second.
2. Drug companies can only make money off of novel products. There's a huge number of drug plants out there, but as one herbalist noted, "how many cures for an upset stomach do you need to know, anyway?" A lot of plants have similar chemicals and work in similar ways. Good for the herbalists, but useless for the drug prospectors. If they can't patent it in some form, they're not interested.
2b. How much does it cost to screen plants? Depends on the method. Davis and his cohorts try to short-circuit the screening process by checking out known herbal medicines. Still, it costs around a billion $US to bring a drug to market in the US, and that includes finding something that might work, clearing all regulatory hurdles and safety tests, plus that wonderful 30% of the budget to marketing (When the time is right...Cialis). This raises the question of how much it is worth to go prospecting, considering how big the strike has to be to pay off for the financiers.
2c. Who owns the knowledge? A company in Texas patented bismati rice, and someone attempted to patent yoga, both in the US. The Indian government has been creating a multi-lingual database of ayurvedic healing preparations, so that anyone who tries to patent a traditional Indian drug in another country can have their patent rejected out-of-hand. Nevertheless, people will use the patent process, especially in the US, to take advantage of tradtional knowledge and even to lock out the people who gave them that knowledge as a gift. I think Davis is a strong advocate for traditional knowledge, but there still is the question about whether the healers and shamans should be talking to him at all, if someone else is going to exploit their knowledge without recompensing them.
2d. Similarly, one can look at the drug molecules as a form of knowledge, and talk about whether the drug prospectors are willing to pay to conserve the forest they're prospecting in. In many cases, they are not, because the economics are messy. You only have to find the drug until you can synthesize it in a lab. Once it's synthesized, the forest is irrelevant to the drug company. Whether this is fair and reasonable is an ethical question.
As I noted before, bioprospecting is a fad among drug companies with about a ten-year return interval. What happens is that they send out a bunch of drug prospectors, test whatever they find, and if they're lucky, bring something to market. If not, they get discouraged, and turn to some other field (like combinatorial chemistry or metagenomics, or whatever) to find new sources for potential drugs. When those fields don't pan out, they hear about some new, neat research about a class of novel biologicals, say the antibiotics found in the skins of frogs, and off they go to the jungle again.
And so it goes. Long answer to a short question, David, but bioprospecting really is like any other form of prospecting. It's risky, and as a result, it tends to be faddish. Is it worth it? You tell me. I'm too busy panning for gold, given the current inflated market
(oh wait, that was last year
).
Best,
F