SPINAL CORD INJURY
A cholesterol-lowering medicine belonging to the
statin-drug group, Lipitor (tradename for atorvastatin) is
one of society’s most widely used and profitable drugs. By inhibiting
the liver’s enzymatic production of a cholesterol precursor, it lowers
cholesterol levels. Animal and clinical studies suggest that Lipitor
(or related statins) exerts a neuroprotective and anti-inflammatory
influence for various neurological disorders, including MS, AD, stroke,
and SCI.
Drs. Avtar and Inderjit Singh and colleagues at the
Medical University of South Carolina have carried out several studies
indicating that Lipitor minimizes neurological damage in rats with an
experimental contusion injury (i.e., comparable to the sort of injury
observed in most humans). In the first, rats treated before and
after injury with Lipitor recovered more hind-limb function than
control animals (J Neurosci Res. 79(3), 2005).
A more recent study showed that this
neuroprotective effect was also observed when the rats were given
Lipitor only after injury, a finding, of course, needed if the drug is
to have any real-world applicability (J Neurochem; 101, 2007).
Specifically, rats were given oral doses of Lipitor two, four, or six
hours after injury followed thereafter by a once daily dose. Compared to
controls, Lipitor-treated rats regained considerable recovery in
hind-limb function, with the earlier treated rats regaining the most.
Apparently, Lipitor preserves the blood-spinal-cord
barrier after injury, which, in turn, limits the infusion into the
injury site of inflammatory molecules that cause function-compromising
secondary damage. Overall, there was more tissue sparing in
Lipitor-treated rats, including 1) less degeneration of neuronal axons,
2) degradation of the conduction-promoting, axon-insulating myelin
sheath, 3) scar-forming gliosis (the production of a dense complex of
neuronal support cells called glia in the injury area), and 4) apoptotic
cell death.
Lipitor also suppresses the injury-induced
expression of Rho, a molecule that inhibits axonal growth and
regeneration, and initiates a physiological cascade that results in the
death of nearby neuronal cells.
MULTIPLE SCLEROSIS