I agree totally. Both in regards of selective consumption of fruit. The immunity of birds to capsaicin was actually an example, before fully seeing the video to its end. You can feed a bird the most virulently potent weapons-grade chili pepper, and it won't tell the least difference from pecking at a corn on the cob (well it might taste different but then again, I am not a bird and I don't eat vegetables with vanishingly few exceptions in just as few circumstances)
Another good example, would be certain tropical or neotropical trees, who's seeds must germinate underground. So rather than producing big, juicy fruit that could, and probably would; end up in the belly either of a ground dwelling or tree-inhabiting animal or that of a peckish human, these plants, which grow in arid locations, they cover their seeds with a nutrient-rich, oily tissue, not large, and this tissue; called an eliasome, is again, not huge.
It need not be, however, for its intended recipient is not a ground dwelling or arboreal mammal or bird, but ants. These fatty, protein rich eliasomes coating every seed are eaten by the ants, but not before the ants have dragged them back from whence they came, caching the seeds underground, wherein they consume the eliasome of these seeds, taking their reward from the plants, for planting the seeds underground, in the caches of the ants, along with plenty fertilizer, by way of the ants' waste.
Other trees, do something perhaps along the same theme lines, although with a different strategy. Acacia species, IIRC, possibly Mimosa, and they are armed with the most formidable thorns, with hollow bulbous bases, which house, together, a colony of vicious ants, armed both beak and backside, and when faced with predation (or vibration), out rush a swarm of furious ants with huge jaws, and any animal small enough is swarmed, killed and probably eaten, the touch of a nearby plant too, signals the tree's private army, and out they come, mauling and mutilating the plant so severely, that if it is anything but established, it dies. In return, aside from the free housing, the trees, also either Acacia or Mimosa, also grow these unique yellow ovoid shaped packages which serve only the purpose of being a protein and calorie-rich portion of food, which the ants take and feed from, and IIRC, even tuck into a pouch under the jaws of their larvae, these energy-costly food-packets are produced specifically for the benefit of the ants, for their protection of their living space, their physical bodies, and the role of the ants as a private army, of swarming, stinging, biting vicious little bastards with a hair trigger of a temper.
As for medicines, of course, the plants do not produce medicine for us, but as they say, the dose, maketh the poison, the same principle can act in reverse. What is poison in excess, can serve as the antithesis of the action of either another poison, or the action of a disease upon the body. An excessively fast, weak heartbeat for example, can be remedied with the use of cardenolide or bufadenolide glycosides, known commonly as cardiac glycosides, for their effect in both slowing the rate of the heart, whilst strengthening its force. Cardenolides, in plants are the more common of the two, both are steroidal in structure, whilst with one exception bufadienolides are produced only by animals, the exception being the squills, the best known being Scilla maritima, the sea squill or maritime squill, a hyascinth-looking plant, with a large bulb, this is used in small amounts as a cough remedy (even now, its a component of Gee's linctus, an over the counter (in the UK) cough mixture based upon tincture of opium, and a little squill tincture, along with something fiery tasting, capsicum extract perhaps, and something treacly, the squill is harmless at the consumption level of a couple of bottles, I've used it before, quite a few times, for while OTC it actually contains enough opium tincture to be quite potent. Its old fashioned, and these days quite hard to find, I only know two pharmacies in the city that stock it, at least of any I have ever been into, one near me and the other in the city center, the nearer one is erratic in stocking it, whilst the other place usually does)
The squill, in larger amounts, surprisingly, contains bufadienolide type cardiac steroidal glycosides, which normally are produced by animals alone, toad venom, most usually, whilst the cardiac steroids of plants are otherwise exclusively those of the cardenolide type. The most well known source of them, are plants of the genus Digitalis, the foxgloves. Others include oleanders (extremely poisonous, a couple of leaves being sufficient if consumed to kill a man, people have even died from both burning the wood and being in the area of the smoke, or from using its wood as a skewer to cook food), pretty, but lethal; and there are many others, often used as arrow poisons, Strophanthus, an african tree, contains a medley of cardenolides, and is used to poison arrows or darts intended for taking down large animals, the dart poison being highly lethal, but because it is a glycoside, it is rendered harmless by cooking, not all glycosides are, but the nature of the glycoside class of chemicals, is that of an alkaloidal backbone, bonded to a sugar moiety of various natures, each according to its kind, and they are thermally unstable, the sugar group cracking off when heated as in cooking, so the hunters just cut out the area the projectile itself penetrated for good measure, and cook their dinner, so too, it is with the infamous Upas tree, Upas antiaris, containing another cardiac glycoside.
In the case of antiarin, the glycosidic toxin, a mere scratch from the wood of the large tree can kill within moments, it is used for both hunting and warfare, applied to darts or arrows, apparently, it used to, at least, be the case that the condemned criminal alone, was to harvest the poison, such was its fearsome reputation that they approached only with the wind blowing away, and that it was believed so frightfully toxic that so much as breathing the air from around the tree would kill, and that no plant would thrive beneath its trunk. The toxic exhalation part at least, is legend, although exclusion of light by virtue of Upas being such a large tree, native to java, possibly sumatra, IIRC, is not surprising if it excludes plants from growing immediately underneath.
IIRC this is the cardiac glycoside-bearing tree that a specific type of highly heat-resistant palm leaf is used to prepare the poison from, the sap being evaporated down with extreme delicacy, for the palm species in question can resist extreme heat, the natives, with similar great care, taste a tiny amount of the poison, and if it tastes sweet, it has been 'overcooked' and quite useless. This is due to its nature as a glycoside, the toxicity is utterly dependent upon the glycosidic bond of its backbone to the sugar rhamnose, and in the heat, if this breaks down, the rhamnose is lost, and freed, and as it is a sugar, it tastes sweet. So the taste-test, albeit something I'd sooner not try doing, is accurate. Not bad organic chemistry for jungle tribesmen without so much as a vacuum pump to their name.
Other examples of poison made medicine (and cosmetic in this case), would be the famed belladonna, Atropa belladonna, a plant favouring calcareous soils, with wide, lanceolate tipped leaves, and which produce a large berry, perhaps 3/4 of an inch around, a little smaller perhaps when mature, starting green, and turning a deep deep purple, almost black and full of juice, the pulp being filled with little seeds, no more than 1.5mm or so in diameter and bearing, when mature at least, small pitted indentations, the seeds of the common variety being of a black color with a quite silvery cast to them, there is a variety, or subspeqies, I know not whether it qualifies as a distinct subspecies, or just a variant, I have seeds for both although I have yet to germinate them, its quite difficult. The variant is white of seed, and creamy colored in their bell-shaped flowers. The commoner variety has purple, drooping, bell shaped flowers.
A very attractive plant. However the entire plant contains a variety of tropane alkaloids (tropane being the name for the chemical N-Methyl-8-azabicyclo[3.2.1]octane although I'll link to the wikipedia on it for those of us who are not great with chemical nomenclature, but roughly put, it is a cyclic (connected in a ring) 8-carbon (nine, if you include the N-methyl group but this isn't part of the octane ring) chain, with an unusual bridged structure, making it a 3D structure when drawn on paper, the carbon bridgehead being a secondary amine, with a carbon from each side of the bridge connected to an amino nitrogen atom.
Tropane derivatives are very common amongst the Solanaceae, the nightshade family, of which belladonna (italian meaning 'beautiful lady', because the alkaloids it contains are potent anticholinergics, of the muscarinic acetylcholine receptors group of ACh receptors, and these, cause massive dilation of the pupils, among other effects; so fashionable italian ladies used to drop the juice of the berries into their eyes, to do this, because it was thought beautiful at the time, although needless to say, fucking with deadly nightshade without knowing exactly what you are doing, is a dangerous affair indeed, although I have used it, most carefully weighed, in the form of the dried leaf or seeds, as a remedy for nausea when no other was to hand, although the amount is small, and I do know what I am doing with herbs and medicinal fungi, which to use, why and how to use them, and which never to so much as contemplate taking internally, and those to take neither internally nor externally.)
Tropanes also, are to be found in coca plants, Erythroxylon coca, E.novogratense and relatives, the plants which, to the delight of many, the misery of some, and the unbridled fury of governments the world over, overtly, whilst their spook clades trade it on the sly, contain cocaine, and its biosynthetic precursors and degradation products. Both the atropine, scopolamine (now better known as hyoscine, as in the IBS remedy buscopan, which is hyoscine butylbromide, hyoscine, derivatized to make it a quaternary ammonium salt, which bears a permanent positive charge, that serves to prevent its being uptaken past the blood-brain-barrier, so its effects are peripheral only, that prevents another side effect of toxic levels of antimuscarinic compounds such as the anticholinergic types of tropane derivative, delirium, a psychotic, nightmarish hallucinatory delirium, which apparently causes near universally a horror trip, and occasionally sends people going completely batshit, including one I read of, who hijacked a cruise liner and went joyriding and shouting tirades of the most abject, hilarious insanity)
The nightshade type tropane alkaloids, block muscarinic acetylcholine receptors, the result of a small dose, is remediation of nausea, less salivation and sweating, as well as dilation of the pupils (they can also be used locally applied to paralyze the cilliary musculature of the eyes, preventing accomodating of the pupil during medical procedures performed upon the eye, I've had such treatment after I got blasted in the face with boiling hot corrosive alkali slops)
A toxic dose, causes pupil dilation, the heart rate is screwed with, drymouth, lack of sweating, all secretions are dried up, urinary retention occurs, and delirium, the patient losing all contact with reality. They cause true hallucinations, unlike the drugs commonly known as hallucinogens, which do not actually cause one to lose contact with reality, the tropane poisons literally cause true hallucinations, where the patient believes what they see to be reality and cannot no matter what, tell any of them from reality.
These plants are sometimes used in initiation rituals in various tribes, some used them as punishment for unruly kids, using Datura species, now and again through history, for offing people other people didn't like very much, and too often, kids without access too proper psychedelics abuse them, although the dividing line between a delirious nightmare trip inducing dose and one that kills, is thin, and the alkaloid content of the different nightshade-type plants also varies, not just from plant to plant, but season to season, the different parts of the plant, the area they grow, so you have a damn fine tightrope to walk if you try that sort of thing.
However, their antimuscarinic effect is put to many medical uses, eye surgery and aftercare, cardiac medicine, and also as part of the autoinjector devices issued to troops at risk of facing chemical warfare, these contain two chemicals as a combi-injector, sort of like an epi-pen, that just has to have the cap taken off and the right end stabbed into a muscle, one half is an oxime compound like obidoxime, or the earlier pralidoxime, which reacts with organophosphorus nerve agents to dephosphorylate the poisoned acetylcholinesterase enzyme (acetylcholinesterase is an enzyme which hydrolyzes acetylcholine, a neurotransmitter. There are two major families of cholinergic receptor for this neurotransmitter, muscarinic, named for muscarine, first found in the fly agaric mushroom (an atypical psychotropic mushroom, and in small quantities, and in either case when subjected to a heat-curing process to break down a neurotoxin, as an excellent condiment for meat, red meat especially, and in particular, beef. I had it on my steak supper last night, mixed in with my custom blend of spices and herbs), although the muscarine levels are so tiny as to be inconsequential in Amanita muscaria, the fly agaric (y'know, the one with the red cap, white gills and stem, white warts on the cap and usually a little gnome with a fishing rod sitting on the top
), which acts as an agonist of muscarinic acetylcholine receptors, the opposite effect to the nightshade tropane toxins.
The other being the nicotinic ACh receptors, acetylcholine is the natural neurotransmitter for both, these two are the major two families, whilst each have subtypes, all bind acetylcholine. Once it binds to the receptors, it is then broken down by acetylcholinesterase. Nerve agents, such as sarin, tabun, soman (G series agents) GV (a hybrid between G and V type agents no surprise there) and V agents such as VX, the most well known of them, and VR, an isomer of VX, of russian design, and again of russian design, the novichok agents (russian, meaning 'newbie' or 'newcomer'), latest generation in nerve agents, and the most toxic, either novichok-5 or novichok-7 being perhaps ten times as lethal as VX on a weight basis (dermal exposure lethal dosage of VX, is perhaps ten milligrams); they block acetylcholinesterase, causing spontaneous, repetitive firing of cholinergic receptors of both types, causing hypersecretion of fluid on the muscarinic side, that fills the airways and causes one to drown in their own fluid, whilst on the nicotinic side, there are both types in the brain, which when overactivated in this way, cause seizures, as well as these caused more directly by the action on muscle, for muscle activation is caused by binding of acetylcholine to nicotinic receptor subtypes specific to the neuromuscular junction, it binds, activates the muscle contraction, and then acetylcholinesterase chews it up and shits it out, deactivating the muscular contraction.
Poisons (and surgical tools) like curare (curare itself, the arrow/dart poison, a paralytic agent acts as a non-depolarizing neuromuscular blocker, the non-depolarizing bit means it does not first act as an agonist at neuromuscular junction nicotinic ACh receptors, causing repetitive firing until the muscles can fire no longer, most neuromuscular blocking agents used medically are of the non-depolarizing type, the main exception being the depolarizing neuromuscular blocker succinylcholine, that mimics acetylcholine but cannot be hydrolyzed, causing first spontaneous repetitive contractions and then muscular exhaustion within moments, and as it cannot be degraded by acetylcholinesterase, stays there, preventing the muscle from 'recharging' and becoming able to fire again)
The nerve agents, on the nicotinic side, are depolarizing type, although without directly binding to receptors, but blocking the enzyme which degrades acetylcholine, causing IT to behave in a manner akin to a depolarizing neuromuscular blocker, as well as powerful muscarinic agonist of all subtypes.
The nerve agent combi-pen combines a physical reversal agent, the oxime compound, with atropine, the poison from the nightshades (or at least, one of them, they have quite the slew of tropane alkaloid poisons in them), the atropine acts to save your life on the short term, preventing you from drowning in your own blood plasma, whilst the oxime goes about its work dephosphorylating the acetylcholinesterase which has been attacked and phosphorylated by the nerve agent (although reportedly, the novichok agents were designed to be immune to oximes, and also, conventional organophosphorus nerve agents 'age', whereby the poisoned enzyme undergoes a rearrangement, IIRC, although its a while since I read up on the transition states of the nerve agent-acetylcholinesterase transition states, phosphorylating a serine residue within the enzyme where it then becomes invulnerable to oximes. They do so at different speeds, unconnected with the lethal acute dose, for example, the V agent VX takes 24-48 hours to become irreversible with oximes, and by weight takes less to kill you than does the G series agent soman, but if you don't get the oxime agent within ten minutes, with soman, its complex with cholinesterase has aged, and cannot be dephosphorylated with the oxime antidotes. Treatment is supportive only, and chances are, one is, in a word, fucked.
While atropine doesn't prevent the paralysis and failure of breathing that the nerve agents cause, it does keep you alive long enough for the oxime to work. And for supportive further treatment.
The nightshades sure didn't intend for their products to cure soldiers or civilians poisoned by nerve agents, they evolved these chemicals to kill predators.
Kill, or cure? for the most part, its a matter of both dose, and intention. Curare is a puzzle to me, since it is active only if it enters the bloodstream. If given orally, it is without effect, assuming there be no lesion, cut etc. within the areas of your insides that it contacts. On the tip of a blowgun dart, its near enough as quick as a bullet, well, sort of, it paralyzes within moments, and then you suffocate to death. Or if you are the monkey in a high tree that happens to find itself on the other end of a hunter's blowpipe, then probably break your neck when you drop like a stone.
If you'd like me to go further into such things, feel free to ask, likewise any specific queries. I am quite well up on toxicology and medicine. If you've heard of it, I can probably explain its MO, if you have never heard the likes, be it from the desert or the ocean, the jungle or anywhere in between, I've probably a good idea. Metals, inorganic and organic natural/synthetic toxins, ants, spiders, scorpions, bacterial toxins, plants, fungi, marine dinoflagellates and toxic fish...I've gotcha.
