Ingredient May Fight Cystic Fibrosis
Apr. 22, 2004
UPDATED AT 3:48 PM EDT
Washington — A
substance in a common spice that helps turn curry and mustard
yellow may also help treat deadly cystic fibrosis, a study by Yale
University scientists indicates. Eating large doses of the
substance found in turmeric — a key
ingredient of curry — significantly cut deaths among mice with the
genetic disease. The discovery prompted the Cystic Fibrosis Foundation
to fund a study on its effects in patients this summer.
The substance, called curcumin,
is sold as a dietary supplement,
but CF specialists stressed that patients should not self-medicate. No
one yet knows if large amounts of curcumin could interact dangerously
with the other medicines they take. Still, “it's very promising,”
said Dr. Peter Mogayzel Jr., director
of the Cystic Fibrosis Center at Baltimore's Johns Hopkins Hospital.
“This is research that really has the potential, I think, to benefit
patients down the road.”
Cystic fibrosis afflicts about 30,000 children and
young adults in
the United States. It is estimated to affect one in every 2,500
children in Canada.
CF attacks patients' lungs with a thick mucus, trapping
Most eventually die from lung damage or infection. CF also harms
digestion and vitamin absorption as the mucus clogs other organs.
Treatments to fight lung infections and improve nutrition have
dramatically improved care and lengthened survival into the 30s. But
they treat only symptoms.
The curcumin research, published in Friday's edition of the journal
Science, shows a possible way to attack the disease's underlying cause.
In most patients, CF's damage stems from a single genetic defect.
It skews a protein called CFTR that is responsible for balancing the
salt content of cells lining the lungs and certain other organs.
CFTR is supposed to travel to a cell's surface to create channels
for chloride ions to exit that cell. But cells police protein quality,
trapping mutated CFTR and shuttling it to a holding bin for later
destruction. Thus, chloride cannot escape, and an eventual salt buildup
inside cells leads to the dangerous mucus formation. So-called
protein trafficking might fix that: Block the cellular
police long enough for CFTR to reach the surface, and even a mutated
version could open some chloride channels. Scientists for several years
have experimented with two chemicals, phenylbutyrate and a relative of
caffeine, that promise to do that.
Yale's Dr. Michael Caplan tried a slightly different
route. That cellular holding bin also stores calcium, which many of the
cell's protein policemen need to function. Would inhibiting the bin's
release of calcium in turn allow mutated CFTR time to escape?
Experiments with a calcium-inhibiting chemical showed
worked. But that chemical spurs cancer, so Dr. Caplan needed a safer
Enter curcumin. Derived from turmeric, the
East Indian yellow spice
used to flavour curries and colour mustard, it has long been used in
Asian folk remedies as an antiseptic, a digestive aid or a cold
Still, unproved attempts to find a medical use do show that people can
tolerate fairly high doses, and it seems to inhibit calcium the way Dr.
In a series of elegant experiments, Dr. Caplan and Yale
CF specialist Dr. Marie Egan showed:
— Daily curcumin
slashed the death rates of CF-stricken mice.
The mice had the same genetic defect that causes the
but they quickly die of a mucus-blocked digestive tract instead of lung
damage. Only 10 per cent of curcumin-treated mice died within 10 weeks,
compared with 60 per cent of untreated mice — and the survivors gained
— Electrical measurements of how well nasal tissue
ions also showed “a dramatic effect,” Dr, Caplan said. Curcumin-treated
mice improved from very poor levels to almost normal.
— Additional test-tube studies, performed with the
Toronto, showed that CFTR got to the cell surface and functioned after
addition of curcumin.
The next step: The CF Foundation and SEER
Pharmaceuticals will hunt
for an appropriate dose and check for side effects in a first-stage
study of two dozen CF patients this summer.
Meanwhile, both Dr. Caplan
and the CF Foundation's Dr. Preston
Campbell stress that people should realize that treatments that help
mice do not always help people.
Aside from possibly
wasting money, large curcumin doses could
interact with prescription drugs, and because dietary supplements are
largely unregulated, there is no proof that today's supplies are pure,