On ethnography, hallucinogens, improvised knife, etc.

[migueldiaz]

Originally Posted by fearn

Speaking as one of those scientists (I'm a trained botanist), there's this one little problem with that statement. It's incomplete.

Yes, few plants have been tested. There's a reason. Some plant families are rich in drug-type chemicals. The tomato family is a good example of this, and has given us atropine, scopalamine, nicotine, etc. Some families are not rich.

Basically, the are ~800 species of figs in the tropics, and there are hundreds of species of oaks. The chemistry of both groups is known fairly well, they're pretty consistent among species and they're not good sources for new drugs. I could go on at length, but the reason no one is checking the plants that we know about is because there's a very low probability that we'll find anything new in them ...

Bioprospecting goes in and out as a fad among drug companies. Right now, they're bioprospecting in the ocean and in animals, because they're finding new classes of pain killers (cone snails) and antibiotics (frogs, alligators, etc) to study. I'm sure that they will eventually go back to the rainforests, but even then, they're probably going to be looking at things like fungi, bacteria, and animals, as much as the plants.

Thanks for those comments.

Can I just request for your comments please on my two back-of-the-envelope calculations?

Here's quick-and-dirty calculation no. 1 --

[a] there are currently about 13,000 drugs per US Food & Drug Admin., if I understood correctly this webpage;

[b] if the stat we picked up was correct in that 25% of Western drugs came from rainforest ingredients, then that would be 3,250 out of the 13,000;

[c] again if it's true that only 1% of rainforest flora has been tested, then shouldn't that mean that the 99% untested plants ought to give us thousands of more new drugs?

On the one hand, I myself like anybody else will find it ridiculous if someone will say that we expect to see 321,750 new drugs (i.e., 99 x 3,250) once the remaining 99% have been tested.

On the other hand, if we are to say that no significant new drugs are to be expected from the 99%, wouldn't that be swinging to the opposite extreme?

After all, the 1% tested did yield 3,000+ drugs.

Could it be that the most likely scenario will be somewhere in between? (though perhaps skewed towards the scenario you just described, in that the success rate will be much lower this time, on account of the similar traits of many species, etc.).

Just thinking out loud ...

I'll post next that second rough calcs

[fearn]

Originally Posted by migueldiaz

Thanks for those comments.

Can I just request for your comments please on my two back-of-the-envelope calculations?

Here's quick-and-dirty calculation no. 1 --

[a] there are currently about 13,000 drugs per US Food & Drug Admin., if I understood correctly this webpage;

[b] if the stat we picked up was correct in that 25% of Western drugs came from rainforest ingredients, then that would be 3,250 out of the 13,000;

[c] again if it's true that only 1% of rainforest flora has been tested, then shouldn't that mean that the 99% untested plants ought to give us thousands of more new drugs?

On the one hand, I myself like anybody else will find it ridiculous if someone will say that we expect to see 321,750 new drugs (i.e., 99 x 3,250) once the remaining 99% have been tested.

On the other hand, if we are to say that no significant new drugs are to be expected from the 99%, wouldn't that be swinging to the opposite extreme?

After all, the 1% tested did yield 3,000+ drugs.

Could it be that the most likely scenario will be somewhere in between? (though perhaps skewed towards the scenario you just described, in that the success rate will be much lower this time, on account of the similar traits of many species, etc.).

Just thinking out loud ...

I'll post next that second rough calcs

Hi Miguel,

As I noted above, it isn't a linear calculation, because diversity isn't evenly distributed among plant families, and because some groups of plants are far more likely to have potential drug properties than others.

For example, the three most common plant families worldwide are the asters, orchids, and grasses. Of these, we're alive as a civilization because of the grasses (they're our main food source), and we get some interesting herbals (echinacea, wormwood, etc) from the Asters. Orchids? Pretty flowers and vanilla, yet they're the most diverse family in the tropical forests. It isn't that people don't use orchids for various things (like fiber or pretty flowers) but they aren't a drug source.

Figs are another great example. I suspect there are some herbal uses that might even be useful for medicine. There are 800+ species of figs, and they're a keystone of life for tropical forests, because they fruit all year. Yet as far as I know, they all have much the same biochemistry, so no one is looking at figs as a source of medicine. That's another 800 species.

I can keep on going until I run out of space, but the point is that, while most plants have some basic herbal use, often those uses are things we already know about. Finding a genuinely new drug is like finding a needle in a haystack.

Those 1% that were already tested belonged to families that we knew contained drug compounds (like the nightshade family) or were used by indigenous people to do amazing things (like the curare plants or Davis' hallucinogens). Effectively, we've high-graded the forests for their easily accessible drug plants. While I'm sure that there's new undiscovered drugs out there, I don't think it's going to be easy to find, and the cost of finding those unknowns is what's keeping people from testing them.

Hope this helps. It's nothing like a linear calculation. It's more like gold-mining.

Best,

F