Researchers recently discovered that the widely used diabetes drug metformin has a rather unexpected — and intriguing — side effect: It encourages the growth of new neurons in the brain.
The study also found that the neural effects of the drug make mice smarter, according to Freda Miller, Ph.D., senior scientist in the Department of Developmental Biology at the Hospital for Sick Children in Toronto and lead author of the study. Another bonus: It may provide cognitive benefits to those suffering with Alzheimer’s.
The discovery is an important step toward therapies that aim to repair the brain not by introducing new stem cells but rather by spurring into action those that are already present, she said. The fact that it’s a drug that is so widely used and so safe makes the news all that much better, she added.
Earlier work by Miller’s research team highlighted a pathway known as aPKC-CBP for its role in telling neural stem cells where and when to differentiate into mature neurons. Other researchers had found the same pathway is important for the metabolic effects of the drug metformin, but in liver cells.
“We put two and two together,” Miller said, noting the researchers thought that if metformin activates the CBP pathway in the liver, it might also do that in neural stem cells of the brain to encourage brain repair.
The new evidence lends support to that idea in both mouse brains and human cells, she said. 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 diabetes drug might already be serving as a brain booster for those who are now taking it, there are already some early hints that it may have cognitive benefits for people with Alzheimer’s disease, according to researchers. It had been thought those improvements were the result of better diabetes control, but it now appears that metformin may improve Alzheimer’s symptoms by enhancing brain repair, Miller said.
She said her team now hopes to test whether metformin might help repair the brains of those who have suffered brain injury due to trauma or radiation therapies for cancer.
Source: Cell Press