The researchers reported that rats receiving the diabetes drug Actos before, during and after radiation treatments did not experience cognitive impairment.
The scientists compared whether treatment with Actos for four weeks or for 54 weeks after radiation would be more effective, and found there was not a significant difference.
The study involved young adult rats that received either radiation treatment equal to levels received by humans. Animals in both groups received either a normal diet or a diet containing the diabetes drug.
Cognitive function was assessed a year after the completion of radiation therapy using an object recognition test. Rats receiving radiation exhibited a significant decrease in cognitive function, unless they received the diabetes drug for either four or 54 weeks after radiation.
Currently there are no known treatments to prevent cognitive impairments. Radiation causes the cognitive problems because it speeds up the brain's aging process.
“The drug is already prescribed for diabetes and we know the doses that patients can safely take,” said Mike Robbins, senior researcher.
Robbins said because the drug shows promise for preventing cognitive impairment, it may allow doctors to give higher doses of radiation. Currently, while higher doses of radiation have been associated with longer survival, dose is limited because of potential damage to surrounding healthy tissue.