Diabetes Drugs May Help
Multiple Sclerosis Sufferers
Source: AScribe Newswire
by: University of Illinois at Chicago
06/12/2002
CHICAGO -- Drugs currently used to treat Type 2
diabetes may
also prove useful for treatment of multiple sclerosis, according to
studies at the University of
Illinois at Chicago and the West Side Veterans Administration Hospital.
The results are published in the June issue of the journal Annals of
Neurology.
Douglas Feinstein, a research associate professor of anesthesiology at UIC,
says two antidiabetic drugs called thiazolidinediones, or TZDs, already
approved by the Food and Drug Administration for treatment of Type 2
diabetes, prevented the development of an animal model of MS in the
studies.
Other tests, already under way, are designed to test if the drugs could
also be effective in other neurological diseases, including Alzheimer's,
Parkinson's and
stroke, he says.
The drugs prevented the MS-like disease known as experimental autoimmune
encephalomyelitis from occurring in healthy mice and reduced symptoms when
given to mice that were already ill. Moreover, the drugs were effective in
two different models of the disease, a chronic form in which the mice
became ill and remained sick and a model in which the mice developed a
relapsing form of the disease, which is similar to the more prevalent form
of MS.
The antidiabetic TZDs used in the study were originally developed to
increase the body's sensitivity to the low levels of insulin present in
Type 2 diabetes. Rather than influencing the amount of insulin in the
body, these insulin sensitizing drugs increase the ability of cells and
tissue to take up the correct amount of glucose, Feinstein explains.
However, more recent studies demonstrate that the drugs carry out other
actions, he says. The drugs prevent the activation and growth of
lymphocytes and reduce the production of inflammatory substances by
activated brain cells. He and his colleagues believe this may be the
primary way the drugs act to reduce the symptoms of MS in mice.
MS is believed to result from increased production of inflammatory immune
proteins. This immune activity causes damage to myelin, the substance that
insulates nerve fibers, along with nerve fibers themselves.
"The causes of MS are not completely understood," Feinstein says.
"However, it is known that activated lymphocytes in the bloodstream enter
the brain, where they produce toxic substances that eventually cause
damage to the myelin-forming cells of the brain ((the oligodendrocytes))
and to neurons as well. In addition, once in the brain, the lymphocytes
activate resident brain cells that further increase the production of
toxic substances."
Feinstein is now designing a clinical trial to test the safety and proper
dosage of the drugs in MS patients. He hopes to start that trial within a
year.
Even if the drugs are only as good as those currently in use, they still
offer an advantage for patients because they can be taken orally.
"The minimum we're hoping for is that they will be as good as any of the
existing drugs," Feinstein says. "But there's a possibility they could
prove to be better because this is a different class of drugs with
different targets and effects."
The study involved collaborations with researchers at several other
universities and hospitals, including Dr. Michael Heneka of the University
of Bonn in Germany, and was supported by a grant from the National
Multiple Sclerosis Society.
