Diabetes drug can repair brain damage in mice and make new cells grow – but it may only work in WOMEN because it’s boosted by a female sex hormone
- Metformin is a drug that helps those with type 2 diabetes control blood sugar
- Studies have shown that it encourages the growth of new neurons in the brain and improves learning and memory skills
- Researchers induced strokes in mice and then gave them daily injections of metformin
- The drug activated neural stem cells in the brain but only in adult female mice
- The female sex hormone estradiol boosts the ability of stem cells to respond to metformin while the male sex hormone testosterone impedes this ability
A diabetes drug may be able to repair brain damage – but only in women, a shocking new study finds.
In research conducted on mice, scientists found that metformin, used to treat type 2 diabetes, activates stem cells in the brain, which self-renew and improve cognitive impairment.
Researchers discovered that this only worked in female mice because the sex hormone estradiol boosted the ability of stem cells to respond to metformin.
However, the male sex hormone testosterone inhibited it.
The team, from the University of Toronto in Ontario, Canada, says this could be a game changer in treating brain injuries and damage from strokes, cerebral palsy – and maybe even Alzheimer’s disease.
A new study, from the University of Toronto in Ontario, Canada, has found that the female sex hormone estradiol amplifies the effect that the drug metformin has on brain stem cells (file image)
The new research, published in the journal Science Advances, builds upon a 2012 study that was investigating treatment for childhood brain damage.
It was in that study that researchers found the drug metformin – which is widely used in diabetes treatment to control blood sugar – helped repair the brains of newborn mice that had suffered strokes.
Metformin activates stem cells in the brain, which encourages the growth of new neurons and cells, especially those killed during a brain injury.
Several studies have shown that brain injuries – particularly in childhood – can cause cognitive problems with memory or visual-spatial skills that last years.
‘We wanted to find out if metformin also promoted cognitive recovery,’ said lead author Dr Cindi Morshead, a professor in the department of surgery at the University of Toronto.
‘You can fix a hole in someone’s brain but if they don’t function better it’s irrelevant to them.
For the new study, the team induced strokes in newborn mice and then gave them daily metformin injections.
Afterwards, the rodents were put in a puzzle box to test their learning and memory.
Results showed that metformin was able to activate neural stem cells in the brain – but only in the adult female mice.
‘When we first looked at the data, we did not see the benefit of the metformin treatment,’ said Dr Morshead. ‘Then we noticed that adult females tended to do better than the males.’
The researchers didn’t understand why until they looked at hormones and realized that the female sex hormone estradiol – used most often to treat symptoms caused by menopause – was amplifying the effect metformin had on stem cells.
On the other hand, the male sex hormone testosterone – which regulates fertility and muscle mass – hindered the effect metformin had.
To test this, researchers removed the ovaries of female mice, which meant they were no longer producing estradiol.
Without this hormone, the stem cells did not respond to metformin treatment.
‘To know that there are both age and sex dependent effects – it has such implications for treatment and therapeutics,’ said Dr Morshead.
Future research will focus on how soon after a brain injury does metformin treatment need to begin and how long will treatment be needed before effects are recognized.