Researchers from at Wake Forest University Baptist Medical Centre have found that a compound used in blood pressure medication may help prevent cognitive loss after radiation therapy in brain tumor patients.
In the study conducted using a rat model, the researchers assumed that that a compound similar to the anti-hypertensive drug losartan can prevent the cognition loss that has been closely-associated with radiation therapy for brain tumor treatment.
The researchers hope that the same theory could easily be applied in a human clinical trial setting because the drug used has a long-established safety profile in patients who have taken it to treat high blood pressure.
"We need to kill cancer cells but also prevent or reduce treatment-related side effects," said Mike E. Robbins, Ph.D., a professor in the department of radiation oncology at the Brain Tumor Centre of Excellence, part of Wake Forest University School of Medicine.
"One very interesting feature of this compound is that it has never shown any pro-tumor effects. If anything, it appears to have anti-tumor properties.
"We're very close to having a compound that will protect the normal brain from cognitive injury as a result of radiation and, at the same time, we may very well increase the likelihood of one day curing brain cancer patients of their tumors," he added.
Previous studies had shown that radiation may lead to the overproduction of angiotensin II (Ang II), a peptide that has been associated with decline of brain function.
Blocking the binding of Ang II to the Ang type I receptor in patients receiving radiation, researchers suggest that they could prevent or hinder cognitive decline.
In the study involving 80 rats, each group was divided in half to either receive radiation or no treatment.
Then, each of those halves was divided into two more groups: one that received L-158,809, the compound similar to losartan, in its drinking water, and one group that received plain drinking water. The rats that received the drug received it before, during and for different time intervals - 14, 28 or 54 weeks - post-radiation.
In addition, a small group of rats continued to receive the drug for only five weeks after radiation.
They found that administering L-158,809 before, during and for as little as five weeks after radiation either prevents or lessens the severity of radiation-induced cognitive impairment.
"This study provides hope that we may be able to take a drug that has been prescribed to millions of individuals with essentially very little morbidity and give it to cancer patients and stop them from experiencing cognitive impairment as a result of brain radiation," said Robbins.
The findings appear in the International Journal of Radiation, Biology, Physics.