Botox may reach nervous system: study

Botox, a potent toxin used for cosmetic surgery, can escape into the central nervous system, a new study has found.
Researchers at The University of Queensland found that Botox - also known as Botulinum neurotoxin serotype A - is transported via our nerves back to the central nervous system.
UQ Queensland Brain Institute laboratory leader Professor Frederic Meunier said people had used the deadliest known neurotoxin, Botox, for decades to treat various conditions and for cosmetic purposes.
"The discovery that some of the injected toxin can travel through our nerves is worrying, considering the extreme potency of the toxin," Meunier said.

"However, to this day no unwanted effect attributed to such transport has been reported, suggesting that Botox is safe to use," he said.
"While no side-effects of using Botox medically have been found yet, finding out how this highly active toxin travels to the central nervous system is vital because this pathway is also hijacked by other pathogens such as West Nile or Rabies viruses.

"A detailed understanding of this pathway is likely to lead to new treatments for some of these diseases," Meunier said.
Dr Tong Wang, a Postdoctoral Research Fellow in Meunier's laboratory, discovered that most of the toxin is transported to a cellular dump where it is meant to be degraded upon reaching the central nervous system.

"For the first time, we've been able to visualise single molecules of Botulinum toxin travelling at high speed through our nerves," Wang said.
"We found that some of the active toxins manage to escape this route and intoxicate neighbouring cells, so we need to investigate this further and find out how," Wang said.
The research is published in the Journal of Neuroscience.