You’ve heard of fire being a good servant and a bad master, there is the good side and bad side. This is the same with some plants. On one hand, they are poisonous, on the other hand, they heal. How does that work?
If you work in the medicine industry, you would be familiar with the famous quote from Paracelsus, the Swiss physician and alchemist : The dose makes the poison. For all these plants, it’s all about the amounts in the body. There is a therapeutic window where they cure, and above that, they became toxic.
Here are a few examples.
Snowdrops and daffodils
These popular flowers signify the arrival of spring. You’ve probably come across cut daffodil buds with long stems in the supermarket. They are usually at the entrance, by the cut flowers, and not far from the vegetable aisles. If bought and eaten by mistake, they will give you diarrhoea and vomiting.
Both plants contain a chemical called galantamine. Galantamine interferes with the nerve pathway responsible for muscle contraction. When a key enzyme is this pathway is blocked, it affects various muscle pathways, resulting in convulsions, vomiting and breathing difficulties.
It is this very feature that is exploited in chemical warfare like the organophosphate nerve agent poisoning in Salisbury. Both galantamine and those organophosphates compete for the same enzyme. The difference is that the former is temporary, whilst the latter binds to the enzyme permanently. Galantamine, by competing for the same enzyme, prevents organophosphates from taking out all that enzyme in the body.
Galantamine can also be used to treat Alzheimer’s disease. If you want more details @compoundchem gives very good explanation.
Taxol (Paclitaxel) from the yew tree gained a lot of interest among organic chemists owing to its complicated structure. In the body, it blocks cell division. Today Taxol is a chemotherapy drug for several cancer types including breast and ovarian.
This is actually a poisonous plant. It was in the news recently for killing cattle in a field and even people. The poison remains even when the plant is destroyed. In humans, 50 needles of the yew tree will result in a fatal heart attack. The chemical causing this is not paclitaxel itself, but it is in the same family of molecules present in the tree. They affect the muscle contractions in the heart.
Like the yew tree, they contain a chemical that affect the muscle contractions in the heart. Ingestion of these compounds cause nausea, vomiting, diarrhoea and irregular heartbeat.
Another poisonous plant is the infamous Belladonna, aka Deathly Nightshade. Contact or ingestion causes a range of symptoms ranging from dry mouth to hallucinations and death. This website gives a very description of its properties. Similar to galantamine, it works on the nervous system, on the smooth (involuntary) muscles. Literally translated, belladonna means beautiful lady. Ladies used to use this to dilate their pupils to look attractive. Today, this property is utilised, in the correct dose, in ophthalmology (atropine). Belladonna’s other chemical Scopolamine is used for motion sickness and nausea .
My middle-grade book, Secrets of the Great Fire Tree, describes the search of a cure for a disease from a little known tree. It is inspired by two tropical trees, the cannonball tree and the buah keluak tree. One is known for its healing properties, and the other, its poisonous fruit. Secrets of the Great Fire Tree is published by Aurelia Leo
Are there any poisonous plants or healing plants you know? Drop it in the comments below!
First published 1 May 2019. Updated 16 May 2020