Posts Tagged ‘poison’

Christmas chemistry, the science of holly

// December 21st, 2011 // 5 Comments » // Poisons

pudding with holly

Chocolate orange icecream pudding with side of holly. Image by webmink

Green and red, classic Christmas colours, adorn the spiky holly shrub. A sprig may garnish puddings, but garnish nibblers like me must hold back on holly for it is poisonous in large doses – though some leaves can make a tasty beverage!

Holly includes about 400 species in the genus Ilex. The cultivated species is Ilex aquifolium, and about 20 or 30 of those bright berries can kill an adult. Poisonings are more likely in pets or children, and about five berries will make a kid feel sick.

It’s the usual suspects in symptoms – sleepiness, sore tummy, vomiting, diarrhoea. Larger doses cause paralysis, kidney damage and death.

Chemically, they contain a cocktail of active ingredients. Among them are the triterpenes, precursors to steroids which are cytotoxic (kill cells), steroids and a nitrile called menisdaurin.

Traditional medicines use holly for fever, gout and chronic bronchitis.

Holly, image by 4nitsirk, flickr

A couple of species native to North America, I. vomitoria aka yaupon and I. cassine, make caffeine and were used to make “black drink”, a stimulating brew also used as a vomit-causing emetic.

South American species I. paraguariensis contains as much as 1.6% caffeine (five times more than the above species) and some of the cocoa chemical theobromine in their leaves, and tasty tannins.

Also called yerba mate, I. paraguariensis is brewed to make mate tea, which is delicious. It’s pronounced MAH-tay, but be careful not to put the emphasis on the second syllable. Wikipedia says that makaes mah-TAY, which means “I killed” in Spanish.

So it’s fine to have a sprig of holly in the house for Christmas, just don’t make a holly pie out of it!

Platypus. Poisonous, egg laying mammal with ten sex chromosomes

// October 13th, 2010 // 7 Comments » // Recent Research, Science Communication, Sex and Reproduction, The Realm of Bizzare

Platypus

Image by Urville Djasim

Ah, the elusive platypus. The water dwelling animal with fur, webbed feet and a beak. It may just be the strangest animal on the planet. Not only does it look weird, it’s poisonous, can sense electricity, lays eggs and secrete milk through their skin, and have an excessive number of sex chromosomes.

It’s poisonous.
It is SERIOUSLY poisonous. The males have poison barbs under their front feet which they mainly use during the spring breeding season. One scratch from these babies and you will be in terrible agony.

My friend studied platypuses (yes, that’s the plural I checked) in honours and her colleague injected himself with platypus venom in the name of science. For months he had excruciating pain for months which did not respond to any painkillers, including morphine. Because of this quality, platypus venom could help scientists develop drugs which work differently to our current repertoire.

Research into platypus venom is lacking because it is hard to come across samples. But just last month researchers identified 83 possible venom genes using DNA extracted from an active venom gland. Some of the genes are similar to those in snakes, pufferfish and starfish. Now the platypus hardly evolved from a starfish. Instead, it’s an example of convergent evolution, traits that arise separately in different species and give a selective advantage. Illustrious journal Nature says platypus venom confirms the convergent evolution theory for venom. (Research paper Whittington CM, & et al (2010). Novel venom gene discovery in the platypus. Genome biology, 11 (9) PMID: 20920228)

Electroreceptor bill
Sharks use electroreception to find prey by sensing the electricity animals have in their body. Monotromes (mammals that lay eggs) including platypuses and echidnas, are the only mammals with the same ability, and the platypus is the strongest. Closing its eyes and nose when it dives, the platypus relies almost entirely on electrolocation and touch to find the tasty crustaceans it snacks on. Sharks and platypuses are hardly related, making this another yet another example of convergent evolution.

Electroreceptors are located in rows on the bill, which might help it find prey by noticing which receptors pick up the electricity first. We do the same thing with our ears, hearing noises at slightly different times tells us which direction the sound is coming from. When the platypus hunts, it moves its bill side to side, which might reveal how far away the prey is. It’s similar to how pigeons bob their head for depth perception.

Image by TwoWings

Laying eggs
A female platypus has two ovaries, but only the left one is functional. Why? We don’t know.

Eggs spend 28 days developing inside their mother’s body and 10 days outside. The babies (often called puggles) are born with teeth, which drop out as they mature.

The mother produces milk, but she doesn’t have teats or nipples. Instead puggles lick or nibble on her skin to drink, gaining nutrients and probably an immune system. Living in mud, platypuses are born with no immune system, making them worse off than human babies which have immature immune systems at birth and rely on colostrum to boost their protection.

Sex chromosomes
Since the platypus genome was sequenced in 2008, we know a bit about these strange sex chromosomes. We know that they are more similar to birds than mammals, suggesting that our own mammal-like reptile ancestors might have had sex chromosomes like the birds of today. But there’s one big difference that makes the platypus unique.

They have ten sex chromosomes. Males have five X and five Y. Females have ten X. Humans, in fact, almost all mammals have only two. During platypus sperm production, the sex chromosomes pair up as X1Y1, X2Y2, X3Y3, X4,Y4, X5,Y5, so they can split evenly to make sperm that have 5X or 5Y. Phew. After all that, I’m surprised the males have any energy left for mating.

Did the CIA spike a bakery in France with hallucinogens?

// August 27th, 2010 // 6 Comments » // Drugs, Poisons, Sex and Reproduction, The Realm of Bizzare, Unethics

On August 15, 1951 a small town in southern France called Pont-Saint-Esprit briefly entered the twilight zone. Hundreds of people reported acute psychotic episodes and physical symptoms such as nausea. They experienced traumatic hallucinations, and 50 of those affected were put in asylums. Five died. The event was later traced back to pain maudit – cursed bread.

In 2009 American journalist Hank Albarelli cited evidence that it was actually caused by CIA experiments into LSD. His book A Terrible Mistakesuggests the mass hallucinations experienced that day was a government funded field experiment into the newly found drug.

There would be potential for LSD to be used as chemical warfare – sprayed onto an army it would turn soldiers into… well… I don’t know but with guns involved I think it would be bad. I’m not sure if his conclusion is correct, but his article makes a compelling argument.

I have to say, conspiracy theories really do it for me. I think they’re great. Nothing like a little paranoia to keep you on your toes. There are, however, other opinions on what caused the Pont-Saint-Esprit madness.

One explanation is ergotism. Ergot is a group of fungi (most prominently Claviceps purpurea) which grow on rye, wheat and related grain-producing when-I-grow-up-I-want-to-be-bread plants. The fungus produces a neat little cocktail of alkaloid drugs which cause spasms, diarrhea, nausea and hallucinations – similar to those experienced at Pont-Saint-Esprit that fateful day.

In fact, the psychosis could have been caused by ergot or LSD, both have similar symptoms. LSD was first derived from the ergot alkaloid ergotamine. Controlled doses of ergot poisons have been used to treat migraine headaches and control bleeding after childbirth. Accidental, and dangerous, ingestion of ergot was known as Saint Anthony’s Fire (not to be confused with Saint Elmo’s Fire) for the monks of Saint Anthony who were really good at treating it. Ergotism was also blamed for Agent Scully’s hallucinations in the episode Never Again, where she gets a badass tattoo with some red ink that could have been coloured with ergot.

Greek myth time! In Ancient Greece annual initiation ceremonies were held for the cult of Persephone and Demeter. Demeter was the goddess of grain, farming and plenty, a bit of an Earth mother goddess with rich wheat coloured hair and a flowing dress. She guaranteed a good harvest. She had a daughter called Persephone, who loved the flowers. One day when Persephone was looking at some flowers in a field, Hades the god of the underworld noticed her, opened up the ground and abducted her. When Demeter noticed her daughter was gone, she was stricken with grief and refused to bring the harvest.

Persephone was trapped in the underworld for months on end. Desperate for her hand in marriage, Hades would offer her food, but Persephone know not to eat the food of the dead or she would never be able to leave. However one day Hades offered her a pomegranate, her favourite dish, and she ate six seeds.

Up in the mortal world, the land was dying. People were starving, having never experienced such famine. No matter how they prayed to the goddess she would not bring the harvest. Seeing the despair of the people, Zeus the king of the gods went down to his brother Hades and asked if he could bring Persephone back to her mother. Awkward conversation ensued.

Hades finally agreed, but oh noes! Persephone had eaten the food of the dead! The six pomegranate seeds meant that she had to spend six months of the year in the underworld as Hades wife. The other six months she would live with Demeter her mother. That’s why we have the seasons – autumn and winter when Demeter mourns, spring and summer when Demeter is reunited with her daughter.

Anyhoo, to be initiated into the Demeter and Persephone cult was called the Eleusinian Mysteries, some mysteries including this myth with added details. I think some of the mysteries included the use of pomegranate as a contraceptive (the link between fertility and death, perhaps.) You also had to fast during the initiation, and afterwards you would drink a barley drink called Kykeon and great revelations would be revealed.

Kykeon, made of barley, quite possibly tainted with ergot. Revelation or hallucination, you tell me.

Rhododendron Poison – Truth behind the science of Sherlock Holmes

// December 27th, 2009 // 11 Comments » // How Things Work, Poisons, Science in the Movies

I saw Sherlock Holmes last night with SexyMan, the cinema was packed and we sat in the second row from the front. I watched the movie like a fan watches a tennis match, but surprisingly it was still good!

It might have helped that any great expectations had been dashed by a friend on facebook, but nonetheless I thought it was an enjoyable, action-packed, fast-paced fast-talking very sexy flick.

But then I’m not a film critic. I am, however, a science geek. This post has been carefully written to avoid spoilers, but if you want to play it safe go and see the movie and come back in 3 hours. K?

At one point in the movie they talk about rhododendron poison, but don’t explain at all what it is.

Rhododendrons (and azaleas, the dwarf (midget) version) are a moderately toxic group of plants. If you’re out strolling the mountains near the eastern side of the Black Sea in Turkey, or generally in the USA or UK, then don’t eat this plant:

Rhododendron ponticum.

Not all members of the genus are poisonous, but play it on the safe side and don’t eat random plants.

It’s not HUGELY poisonous, about 100 grams need to be ingested by a 25 kg child to seriously poison them, but it is a problem for livestock – particularly sheep, goats and cows – who munch on the flowers and get seriously sick.

Of course, if you boiled it down and concentrated the liquid… well that’s a different story. The toxin is water soluble, so it can be extracted from the leaves and flowers.

The toxin is called grayanotoxin. It binds to specific sodium ion channels in cell membranes (which I’ve talked about before) and prevents inactivation, causing persistent activation of muscle and nerve cells. This causes a range of symptoms based on where the activated cells are located, such as muscle weakness, vomiting, sweating, salivation, seizures, and either dangerously slow or dangerously fast heartbeat, depending on the dose. In the end, it can cause death.

Don’t think you’re safe just because you don’t make a habit of eating plants – the toxin is also found in the nectar of flowers, and bees that feast on them can make “mad honey.” It took out an army in 401 BC lead by Xenophon of Athens against Persia – hundreds of soldiers vomiting and unable to walk for a day. No-one died, unlike in 67 BC, where the army of Mithradates IV killed Pompey the Great’s soldiers while they were incapacitated. It’s biological warfare, victory has never tasted sweeter.

Mad honey is still a problem today – not so much the stuff in a grocery store (which is diluted and problem tested and stuff) but organic honey direct from the beehive can be risky. Plus some men use it as an aphrodisiac. Idiots.

That’s the rhododendron poison, making a comeback after 2400 years on a big screen near you! What did you think of the movie? There were lots of sciencey deductions made that weren’t very well explained, so if you have any questions, post a comment and I’ll do me best!






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