The next cure for Alzheimer’s disease may come from an unexpected place. In a new study published this week, scientists have found evidence in mice that xenon gas could help treat the neurodegenerative disease.
Researchers from Brigham and Women’s Hospital and the University of Washington led the study, published Wednesday in the journal Science Translational Medicine. In mice with Alzheimer’s disease, xenon gas reduced inflammation and brain shrinkage. Researchers are now starting the first human trials to further test the potential of the therapy.
Xenon gas is already used in medicine as an anesthetic and medical imaging agent. Research also suggests that xenon can help protect the brain, and some researchers have experimented with using it to treat depression and other brain-related disorders (unfortunately, studies on depression have not yet yielded conclusive results). Because xenon easily passes through the blood-brain barrier, a shield that protects the brain from infections but also prevents most drugs from entering it, scientists wondered if xenon could also protect the brains of people with Alzheimer’s disease.
The researchers tested xenon inhalation on two types of mice engineered to develop the brain damage seen in Alzheimer’s disease. In these mice, the gas activated the protective response of unique immune cells in the brain called microglia, and this activation in turn helped their brains resist the destructive changes associated with Alzheimer’s disease. For example, the mice had reduced levels of inflammation and brain atrophy. The researchers also noticed promising signs of a reduction in amyloid plaques, one of the biomarkers closely associated with the development of Alzheimer’s disease.
“This is a very novel discovery that shows that simply inhaling an inert gas can have such a profound neuroprotective effect,” said senior researcher Oleg Butovsky, a neurologist at Brigham and Women’s Hospital and Harvard Medical School, in a statement from Mass General Brigham. “One of the main limitations in Alzheimer’s research and treatment is that it is extremely difficult to develop drugs that can cross the blood-brain barrier, but xenon gas can do so.”
Although these findings are based only on studies in mice, they are convincing enough for the researchers to take it one step further. In the next few months, the team plans to launch a first phase of trials that will test the safety and immune effects of xenon gas on healthy humans. In the long run, this discovery could pave the way for new opportunities to utilize xenon’s potential for brain treatment.
“If the clinical trials are successful, the possibilities for using xenon will be enormous,” said study co-author Howard Weiner, co-director of the Ann Romney Center for Neurological Diseases at Brigham and Women’s Hospital and lead investigator of the new study. “This could open the door to new treatments for patients with neurological diseases.”
Although significant advances have been made in the treatment of Alzheimer’s disease in recent years, the best drugs to date still only have a modest effect in slowing the progression of the disorder. Therefore, new therapies that can affect Alzheimer’s disease from a different angle would be highly desirable. Currently, about 7 million Americans are believed to be living with Alzheimer’s disease, and this number could almost double by 2050.
