Pharmacology in Action – Botulinum Toxin – Deadly Poison, Therapeutic Remedy and Cosmetic Aid
The bacterium Clostridium botulinum, which is responsible for botulism poisoning, produces what is perhaps the most potent toxin known to pharmacologists.The estimated lethal dose of botulinum toxin in humans is 0.3 jag; in other words, 1 gram (equivalent to the weight of three aspirin tablets) is enough to kill over 3 million individuals. Clostridium botulinum does not grow in the presence of oxygen; how-ever, it can thrive in an anaerobic (oxygen-free) environment such as a sealed food can that has not been properly heated to kill the bacteria.
Botulinum toxin actually consists of a mixture of seven related proteins known as botulinum toxins A through G.These proteins are taken up selectively by the cholinergic neurons that innervate our skeletal muscles.The toxin molecules interfere with the process of ACh release at neuromuscular junctions, thereby causing muscle weakness and even paralysis.The symptoms of botulism poisoning include blurred vision,difficulty speaking and swallowing, muscle weakness,and gastrointestinal distress. Most victims recover, although a small percentage die due to severe muscle paralysis and eventual asphyxiation.
Once the mechanism of action of botulinum toxin became known, Once the mechanism of action of botulinum toxin became known, eyelid), and hemifacial spasm (muscle spasms on just one side of the face). Since that time, this substance has also been administered for a variety of other disorders, including spastic cerebral palsy, dystonias (prolonged muscle contractions, sometimes seen as repeated jerking movements), and achalasia (failure of sphincter muscles to relax when appropriate).
Most remarkably,dermatologists have begun to use botulinum toxin (trade name Botox) for cosmetic purposes in patients with excessive frown lines, worry lines, or crow’s-feet around the eyes. Such “dynamic wrinkles,” as they are called, result from chronic contraction of specific facial muscles.When injected locally into a particular muscle or surrounding area, Botox causes a paralysis of that muscle due to a blockade of ACh release from the incoming motor nerve fibers.This leads to a reduction in the offending lines or wrinkles, although each treatment remains effective for only a few months, after which it must be repeated.
According to recent surveys, increasing numbers of people are turning to Botox treatments for purely cosmetic purposes. Depending on one’s perspective,this trend might be considered either horrifying or liberating. Nevertheless, until true antiaging techniques are developed, it is safe to say that some folks will use whatever methods are available to appear younger than they really are.