Botox - is it really the most toxic?

Everyone wants to stay young forever - who wouldn't? But some people are willing to go further than others and inject botulinum toxins - the most toxic chemical known to man - into themselves in order to achieve this. The botox procedure has become the world's most popular procedure with one million procedures alone in the UK with a market now worth £18 million.


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The injection

The botulinum toxins come from bacteria called Clostridium botulinum, which belong to the group of of non-pathogenic gram positive bacteria. There are various toxins produced from these bacteria. The botox injection contains botulinum toxin A (C₆₇₆₀H₁₀₄₄₇N₁₇₄₃O₂₀₁₀S₃₂ ). When it is injected it inhibits the release of acetylcholine (a neurotransmitter), which prevents signals being transmitted from nerve cells to muscle cells. The inhibition of the release of acetylcholine at presynaptic motor neurones. The toxins chemically bind to receptors on cholinergic neurones (nerves which use acetylcholine) allowing the receptor-botulinum complex which is formed to be engulfed by the neurone by endocytosis. The toxin is then able to move in the cytoplasm of the cell and prevent the release of acetylcholine from the nerve cells in the form of exocytosis of vesicles containing acetylcholine. This prevents the nerve endings from degenerating however new nerve terminals form over a time period of several months.

However, it is also believed that botulinum toxin is capable of inducing muscular overactivity as an effect of inhibiting transmission of alpha motor neurones. 

Botulinum toxin:

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Further, the inhibition of the release of acetylcholine caused by botulinum toxin means that it has interesting medicinal uses and can be used to manage head aches, hemifacial spasm and focal destinies.

Generally scientists measure toxicity on LD50 values which is the amount of a substance needed to kill half of a specified population. Mice are a particular favourite to use for discovering the LD50 values. The Botulinum toxins value is 5 ng/kg (nanogram per kilogram), to put this into perspective - the toxicity of mercury is about 1 mg/kg - 100 mg/kg.  When you inject a mouse with a dose that is not large enough to kill it, it will paralyse it for up to a month. It is for this reason that botulinum is classified as one of the most poisonous substances. 

Image from: psychiatricdrugs

Image from: YouTube

References: 

• IFL Science
• Illumin