ANTIBIOTIC MAY STAVE OFF MS

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ANTIBIOTIC MAY STAVE OFF MS

Study finds minocycline fights disease in rats

By Robin

HealthScoutNews Reporter

FRIDAY, Dec. 21 (HealthScoutNews) -- Multiple sclerosis (MS),

a crippling disease of the central nervous system, could one day

be treated with a common antibiotic, a new study suggests.

Researchers at the University of Wisconsin, in collaboration with

German scientists, found that minocycline helped rats fight off a

disease that's the animal equivalent of chronic MS in humans.

The drug could decrease the severity of MS symptoms or even

prevent relapses, they say. The findings appear in today's issue

of the ls of Neurology.

" It would either block the disease or lessen the severity of the

disease. It protects the central nervous system, " says senior

author Ian Duncan. One expert finds the results encouraging and

exciting, but adds a caveat. " I think we always have to temper

our enthusiasm with a certain amount of caution until it's been

tested on humans, " says G. LaRocca, director of

health-care delivery and policy research at the National Multiple

Sclerosis Society. Some treatments that have worked in the rat

model of MS have been successful in humans, but many have

not, he says. Duncan acknowledges that, but he says the rat

model is the best available model for MS, and it's used to test

most MS drugs before human trials. And he says a human

clinical trial already has been scheduled next year at the

University of Calgary.

" We need to do more work to nail this down " to determine more

specifically exactly how minocycline works on the nervous

system, Duncan says.

MS, which affects more than 300,000 Americans, is

characterized by inflammation and the loss of the myelin sheaths

that protect the body's nerve fibers. Symptoms include

numbness and possible paralysis, as the brain's ability to send

signals to the rest of the body is weakened by the progressive

destruction of myelin. The disease has no known cause or cure,

and the triggers for relapses remain unclear. As the disease

moves into its final stages, the sheaths are damaged and nerve

fibers are destroyed. But Duncan says minocycline, a member of

the tetracycline family, seems to protect both.

" In MS, not only could it stop inflammation and protect myelin, it

could also protect neurons themselves. We are exploring further

aspects of the mechanisms of its effects and its neuroprotective

properties, " Duncan says.

In the study, researchers looked at four groups of rats: one group

received a high dose of the protein that causes autoimmune

encephalomyelitis (EAE) and was then treated with minocycline;

a second group received a lower dose of the same protein to

more closely resemble chronic MS; that group was then treated

with minocycline. There were also were control groups for both

the high-dose group and low-dose group. Whether the rats were

treated before or at the onset of the disease, the antibiotic

lessened the severity of symptoms and blocked relapses. Later,

the drug was found to have protected both the myelin sheaths

and the nerve fibers in the rats' brains.

Duncan says his team considered trying minocycline to treat MS

because Finnish studies had shown the antibiotic stopped the

activation of microglial cells, which patrol the brain and respond

to immune events, in stroke patients. Microglial cells are one of

the main culprits in MS and other neurological diseases, Duncan

says. Treating neurological diseases through microglial

deactivation " may have much broader consequences, " Duncan

says. LaRocca says the best answer may eventually come from

a combination treatment, much like the drug cocktails doctors

now give to AIDS patients. " This is the really encouraging thing,

that there's so much going on in this area of research, " he says.

" Perhaps a combination of drugs will work with MS. "

SOURCES:

Interviews with Ian Duncan, Ph.D., BVMS, professor, neurology,

department of medical sciences, School of Veterinary Medicine,

University of Wisconsin, Madison; G. LaRocca,

director, health-care delivery and policy research, National

Multiple Sclerosis Society, New York City; Dec. 21, 2001,

ls of Neurology