Diabetes drug spurs growth of brain cells

Toronto, July 6 (IANS) Popular diabetes drug metformin offers an unexpected yet alluring side effect - it encourages the growth of new brain cells.

The discovery is an important step toward therapies that aim to repair the brain not by introducing new stem cells but rather by spurring those that are already present into action, says the leader of the study team, Freda Miller, from the University of Toronto-affiliated Hospital for Sick Children.

The fact that it is a drug that is so widely used and safe makes the news all that much better.

Earlier work by Miller's team highlighted a pathway known as PKC-CBP for its essential role in telling neural (brain related) stem cells where and when to differentiate into mature neurons (brain cells).

As it happened, others had found before them that the same pathway is important for the metabolic effects of the drug metformin, but in liver cells, reports the journal Cell Stem Cell.

"We put two and two together," Miller says. According to a Toronto statement, it was felt that if metformin activates the CBP pathway in the liver, it could perhaps also do the same in neural stem cells of the brain to encourage brain repair.

The new evidence lends support to that promising idea in both mouse brain and human cells. Mice taking metformin not only showed an increase in the birth of new neurons, but they were also better able to learn the location of a hidden platform in a standard maze test of spatial learning.

While it remains to be seen whether the very popular diabetes drug might already be serving as a brain booster for those who are taking it, there are already some early hints that it may have cognitive benefits for people with Alzheimer's disease.

It now appears that metformin may improve Alzheimer's symptoms by enhancing brain repair.