Old dog Aspirin knows new tricks

[img_inline align=”right” src=”http://padnws01.mcmaster.ca/images/steinbergfullerton.jpg” caption=”Greg Steinberg, associate professor of medicine and Canada Research Chair in Metabolism, Obesity and Type 2 Diabetes (left), and postdoctoral fellow Morgan Fullerton. Steinberg is co-principal investigator of a new study that shows Aspirin may have more uses than previously thought. Photo by Mike Lalich.”]Researchers have discovered some new things about one of the world's oldest drugs.

Researchers in Canada, Scotland and Australia have discovered that salicylate, the active
ingredient in Aspirin, directly increases the activity of the protein AMPK (AMP-activated
protein kinase), a key player in regulating cell growth and metabolism. AMPK, which is
considered a cellular fuel-gauge, is switched on by exercise as well as the commonly
used anti-diabetic medication metformin.

The research from scientists at McMaster, the University of Dundee and the University of
Melbourne has been published in the journal Science.

“We're finding this old dog of Aspirin already knows new tricks,” said Dr. Greg Steinberg,
a co-principal investigator of the study. “In the current paper we show that, in contrast
to exercise or metformin, which increase AMPK activity by altering the cells energy
balance, the effects of salicylate is totally reliant on a single Ser108 amino acid of the
beta 1 subunit.

“We show that salicylate increases fat burning and reduces liver fat in obese mice and
that this does not occur in genetically modified mice lacking the beta1 subunit of
AMPK,” he said.

Steinberg is an associate professor of medicine in the Michael G. DeGroote School of
Medicine at McMaster University and the Canada Research Chair in Metabolism, Obesity
and Type 2 Diabetes. The study also involved Morgan Fullerton, who
holds a Banting Postdoctoral Fellowship.

These findings are important as a large clinical trial is currently underway testing
whether salsalate (a well-tolerated aspirin derivative), can prevent Type 2 diabetes.

Salicylate, which is derived from willow bark, and is the active ingredient in Aspirin, is
believed to be one of the oldest drugs in the world with first reports of its use dating
back to an Egyptian papyrus in 1543 BC.

An anti-inflammatory drug first used as a painkiller more than a century ago, Aspirin is
now given to people at risk of heart attacks and strokes as well as patients with vascular
disease.

Three studies published last month in the medical journal The Lancet reported that
taking an Aspirin every day may significantly reduce the risk of many cancers and
prevent tumors from spreading. The unanswered question was how this anti-cancer
benefit occurs.

With many recent studies showing that metformin may be important for cancer
prevention, the authors' study raises the possibility that Aspirin may also be working in
a similar manner.

Further studies are needed as the concentrations of salicylate used in the current study
were higher than the cancer trials.