* Generic drug protected mice from MS
* Drug reversed paralysis in some mice
By Julie Steenhuysen
CHICAGO, Aug 17 A widely used blood pressure
drug may hold promise as a treatment for multiple sclerosis,
U.S. researchers said on Monday.
Lab tests found the generic drug lisinopril, developed by
Merck (MRK.N) and sold as Prinivil or Tensopril, prevented
paralysis in mice with a form of MS.
"Lisinopril was quite powerful, and could even reverse
paralytic disease (in mice)," said Dr Lawrence Steinman of
Stanford University School of Medicine in California, whose
study appears in the Proceedings of the National Academy of
Lisinopril, also sold by AstraZeneca (AZN.L) as Zestril, is
an angiotensin-converting enzyme, or ACE inhibitor. It acts by
blocking angiotensin, a hormone that makes blood vessels
contract, increasing blood pressure.
"The angiotensin system is critical for maintaining blood
pressure, but it may play other roles," Steinman said in an
e-mail. He said angiotensin is directly related to a
biochemical mechanism called nuclear factor kappa B, or NF-kB,
which underlies inflammation.
MS occurs when the immune system mistakenly attacks the
myelin sheath protecting nerve cells, disrupting communication
between the brain and other parts of the body. It affects about
2.5 million people globally, producing symptoms that range from
mild illness to permanent disability.
Since both MS and high blood pressure are diseases caused
in part by inflammation, Steinman and colleagues wanted to see
if angiotensin was involved in the autoimmune disease.
Steinman's earlier work on inflammation in MS helped lay
the groundwork for the blockbuster drug natalizumab or Tysabri,
sold by Biogen Idec (BIIB.O) and Elan Corp ELN.I.
For the latest research, Steinman's team studied brain
tissue from patients with MS. They found elevated levels of
receptors -- molecular doorways in cells -- for angiotensin.
They also found more receptors for the enzyme that is blocked
by the drug lisinopril.
"The receptors were on blood vessels but also on neurons
and surrounding brain cells," Steinman said.
The researchers studied the effects of the drug using mice
injected with a chemical that causes them to develop MS-like
The team gave lisinopril to healthy mice, then gave the
injection that triggers the MS-like disease. Mice that got
lisinopril first did not develop MS.
Mice that had been injected with lisinopril had an
abundance of immune system cells known as regulatory T cells
that are capable of damping down the immune system.
When they transferred regulatory T cells from mice exposed
to lisinopril into a paralyzed mouse, "they quickly reversed
paralysis," Steinman said.
Steinman said the finding suggests the same effect might
occur in people with MS, and possibly other autoimmune
"It will be important to test whether lisinopril and other
angiotensin blockers can do this in MS patients," he said. "We
are trying to secure funds to run such trials beginning next
(Editing by Maggie Fox and Paul Simao)