Biochemistry: Botulinum Toxin

Botulinum Toxin: Why It Is So Deadly and Why People Are Using It

All throughout history, there has been a need to improve our appearance and our health. With new discoveries as well as advancements in technology, there are now more options for cosmetic and medical procedures. Botulinum toxin, more commonly known by the commercial name “Botox” or “Dysport,” is one of the most deadly toxins on earth, yet it commonly used for beauty purposes and is even used to treat certain health problems.

The History of Botulinum Toxin

The botulism bacterium, clostridium botulinum, was discovered by Emile Pierre van Ermengem after there was an outbreak of botulism from smoked ham in a Belgian village. In the early twentieth century, the toxin released by the clostridium botulinum bacteria was isolated. The various strains of botulinum toxin are large peptides, which are chains of amino acids that are held together by a disulfide bridge. One amino acid chain has a molecular weight of 100 kDaltons, and the second chain has a molecular weight of 50k Daltons.

How Botulinum Toxin Works

        The heavier amino acid chain is used to detect and bind to nerve fibers and absorb into the cell. In the lighter amino acid chain, an enzyme called protease breaks up the proteins that release neurotransmitters. One of these neurotransmitters is acetylcholine which is a chemical messenger that tells muscles to contract and is located where nerve endings meet the cells. When the acetylcholine is broken down and prevented from releasing, this leads to flaccid paralysis, which means the muscle is unable to contract. The reason for most botulism related deaths is due to the fact that the botulinum toxin reaches the respiratory system and causes respiratory failure. An estimated that one gram of botulinum toxin could kill as many as one million people and several kilos of the toxin could kill every human on earth.

Uses for Botulinum Toxin

          Despite the numerous dangers associated with botulinum toxin, a very small concentration of the toxin can be injected into humans to paralyze muscles. Botulinum toxin is administered by plastic surgeons to address cosmetic concerns such as:

• Glabellar lines (frown lines between the eyebrows)
• Canthal lines (crow's feet)
• Forehead furrows
• Skin bands on the neck

Botulinum toxin is also administered by doctors to treat:

• Blepharospasm (spasm of the eyelids)
• Idiopathic rotational cervical dystonia (severe neck and shoulder muscle spasms)       
• Chronic migraine
• Severe primary axillary hyperhidrosis (excessive sweating)
• Strabismus (crossed eyes)
• Post-stroke upper limb spasticity
• Detrusor overactivity urinary incontinence
• Overactive bladder
• Hemifacial spasm
  
  

          The different types of botulinum toxin have been categorized into type, A, B, C, D, E, F. Fairly recently however, a new type of botulinum toxin, type H, has been discovered and is now known as one of the most deadly neurotoxins on the planet.

Resources:

https://www.chemistryworld.com/podcasts/botox/6392.article

http://www.medicalnewstoday.com/articles/158647.php

https://www.plasticsurgery.org/cosmetic-procedures/botulinum-toxin