Insulin, it turns out, may have big benefits to patients other than diabetics.
At least, that’s the finding of a University of Alberta research team looking at the hormone’s potential to improve brain function in people with HIV.
According to a new study completed by the group, insulin delivered intranasally has three highly positive effects. Not only does it provide a protective shield for brain cells, insulin also impedes the HIV virus from replicating and suppresses inflammation, senior author Christopher Power said Wednesday.
“We always think of insulin as reducing blood sugar, but it has a myriad of other effects,” said Power, the Canada research chair in neurological infection. “We are excited about the possibility because our next step is to translate our experimental findings into clinical applications.”
Of the 35 million people living with HIV or AIDS around the world, it is estimated around 25 per cent experience some form of cognitive impairment. This can include difficulty with memory and concentration, motor control issues and even behavioural problems such as apathy and irritability.
Even those taking antiretroviral medication are at risk of brain dysfunction, because the drugs have trouble finding their way into the brain. The HIV virus remains at work in the brains of such patients, replicating itself and causing inflammation that damages neurons.
Power said his team’s work continues a “made in Canada” run of research success around insulin.
That started, of course, with the discovery of the hormone itself in 1921 by Frederick Banting and Charles Best. Then, about 20 years ago, McGill University scientist Mark Wainberg was the first to prove that insulin can control HIV replication.
Other scholars are now building on that finding to explore insulin’s ability to improve memory and function in Alzheimer’s patients, but Power’s team is the first to direct the research into HIV-related impairment.
Manmeet Mamik, a post-doctoral fellow who served as the study’s lead author, said the intranasal delivery of insulin is key because it is safe and allows the hormone to cross into the brain.
The research was conducted using cultured brain cells and then animal models. The models treated with insulin showed improved memory, speed of function and decision making — largely reversing the effects of the HIV virus.
Mamik said it is not yet clear exactly how insulin achieves these results, but the research has shown that a host’s immune responses are somehow changed when insulin is introduced and interacts with cell receptors.
Power said a randomized control trial involving patients with HIV-associated neurocognitive disorders is set to begin within a few months. Eventually, if the work progresses, intranasal insulin treatments could be an effective tool against HIV-AIDS, which continues to be an epidemic in many developing countries.
“It will be a reasonable therapy because its inexpensive, it’s easily delivered and you don’t need needles,” Power said. “So this is potentially exciting in that sense because you can implement it globally.”
Author: Keith Gerein