A quick google doesn’t yield a definitive answer. However, THC and other cannabinoids in plants may:
Do you realize how much coca leaf you’d have to eat to ingest 8 grams of cocaine??? According to our friends at the DEA, coca plants usually contain much less than 1% cocaine. The LD50 for cocaine is about 93 mg/kg in mice. For sake of argument, assume that humans have the same LD50 (unless of course you’d like to volunteer for a study to determine one for humans ;)). For a 150 lb (68 kg) human, they would have to ingest a little over 6 grams of pure cocaine. To get the same effect from eating plants, you’d have to ingest 600 grams of leaves.
Another example of people ingesting cocaine, there are several brands of tea popular in South America, particularly Peru because they legitimize the production of cocaine, for example “Coca Mate”. Basically it’s teabags filled with coca leaves. Brew this up and drink it and you get such effects as stimulation of the central nervous system and (from a Peruvian who worked in our lab) headache relief. The Peruvian in question drank the tea on a fairly regular basis (back home, it’s illegal here) but never became addicted to it in the way a cokehead would be.
As for tryptamines: some of them are broken down by enzymes in the stomach (cite). Basically, preparing things like ayahuasca takes advantage of a chemical reaction that protects the active ingredient from breaking down.
As for THC: these guys have references to studies including one that determines an LD50 in lab rats (yes, it’s pretty high).
Incidentally, marihuana typically contains somewhere between 1-5% delta-9-tetrahydrocannabinol. Yes, you’d have to smoke/eat a lot to reach the LD50, but this just further supports the assertion that I previously made (and that Blake so stubbornly opposes despite a lack of ability to back anything up) that the plant CAN’T have a “large, unmeasured dose” in the wild. There are just way too many other compounds present in your typical plant to claim that the concentration of a drug can be higher than the extracted PURIFIED amount.
Once again, to quote Blake: “There is a good reason why hard drug addicts die from overdoses: too much of the stuff kills them. Humans take in very small measured doses. Anything feeding on the plant takes in very large unmeasured doses. It don’t feed on the plant for long.” Read carefully and you see he(she?) is comparing apples to oranges. Humans ingest PURIFIED (relatively speaking) forms of drugs, so of course they’d die from even a small overdose (like heroin addicts dying with the needle still in their arms).
<rant>I don’t normally like starting fights or irrational arguments on these forums, but I’m losing patience with you, Blake. You claim in another thread that you’re a professional biologist. What is your field that you feel qualified to comment on drug physiology but don’t even know about tryptamines? Please start citing your claims instead of just patronizing everyone on here.</rant>
Which would be about half a decent meal for a browser. Leaf eating monkeys eat C20% of their body weight in leaves every day.
So what you are basically saying is that any animal browsing in the plant would get a lethal dose.
And of course that would be a fatal dose, not just a dose sufficient to get you so sick that you can’t evade predators. There is a big difference between LD50 and field lethality…
Well, obviously even the most intelligent animals don’t know how to create drugs, so animals can’t really become addicted to drugs in the wild.
But from time to time, animals in the wild will come upon fermented fruits, consume them, and become drunk. And some of the higher animals (primates and elephants, for instance) who’ve experienced the joys of intoxication attempt to repeat it by seeking out and eating fruits in the same areas where they found the fermented stuff earlier.
So, even in the wild, animals can get high accidentally, and some like the experience enough to try to re-create it.
You betcha they do. One of the most mind-baffling animal addiction situations ocurrs when parrots and members of the parrot family (cockatoos, cockatiels, parakeets, etc.) become addicted to the fluid in their own feathers and pluck them out just to suck the fluid out.
Durned if I can cite it at the moment, but I’ve read about elephants who become addicted to fermented fruit, and will make great journeys, tear down fences, and so forth, to get to where they know the fruit is.