Botox scare as scientists say the toxin may spread in the body

Scientists are warning that the anti-wrinkle treatment Botox used by millions of women every year can spread from the face to the brain.

The scientists at the Italian National Research Council's Institute of Neuroscience in Pisa injected the toxin into the whisker muscles of rats and found traces of it were evident in the rodents' brain stems three days later and was still present six months later.

Botox is based on the bacteria Clostridium botulinumbotulinum toxin and very small amounts of the drug are used for beauty treatments; it is nevertheless a potentially deadly poison.

It works by weakening or paralysing muscles or blocking nerves to smooth out the skin and the effects last for up to four months.

Botox can cause side-effects such as headaches, an upset stomach or flu-like symptoms and there have been a significant number of reports of dangerous botulism symptoms in some users.

Last month the Food and Drug Administration (FDA) in the U.S. warned that Botox and Myobloc caused severe muscle spasms in children with cerebral palsy, a use not approved by the FDA and some children had died.

Prior to this the group Public Citizen also called on the FDA to warn strongly against the use of Botox and competitor Myobloc, after 180 reports were received of patients suffering fluid in the lungs, difficulty swallowing or pneumonia, which resulted in 16 deaths.

The study's author, Dr. Matteo Caleo, says the toxin also moved from one hippocampus, which controls long-term memory and spatial navigation, to the hippocampus on the other side of the rat's brain.

The researchers say the toxin also moved to the part of the brain associated with eye-head coordination and to the eye.

Experts say the implication that there could be some transmission of the toxin to the central nervous system needs investigation.

Botox was first approved for commercial use in 1989 and made more than £600 million in sales just last year.

The FDA is currently investigating reports of illnesses linked to Botox.

The scientists say although rats and humans have a different physiology and their responses may vary, the results are a concern and more research needs to be carried out.

The research is published in the current issue of the Journal of Neuroscience.