Scientists for the first time managed to reverse brain aging using a nasal spray

Researchers from the University of Texas have developed an experimental nasal spray that in trials helped reverse age-related brain changes. After two doses, the animals showed improved memory, reduced chronic inflammation, and restored brain cell function. The study was published in the Journal of Extracellular Vesicles (JEV).

With age, chronic low-grade inflammation develops in the brain - so-called neuroinflammatory aging. It is associated with memory deterioration, decreased learning ability, and increased risk of dementia and Alzheimer's disease. The authors of the new study believe that this process may be reversible.

The basis of the therapy was extracellular vesicles - microscopic particles that cells use to transfer molecules to one another. The researchers loaded them with microRNA - short molecules that regulate gene activity and brain cell function. The spray was administered through the nose, which allowed the drug to be delivered directly to the brain, bypassing the blood-brain barrier.

"Intranasal delivery is one of the most exciting parts of our approach. It allows us to target the brain without invasive procedures," noted study co-author Mahidhar Kodali.

After reaching the brain, the therapy suppressed the activity of inflammatory systems, including the NLRP3 inflammasome and the cGAS-STING signaling pathway, which are considered key mechanisms of age-related brain inflammation.

In addition, the treatment improved the function of mitochondria - cellular structures responsible for energy production. With age, their function deteriorates, making neurons less resistant to damage.

"We are essentially restoring the spark to neurons by reducing oxidative stress and restoring mitochondrial function," explained researcher Madhu Lilavati Narayana.

In memory tests, the treated animals were better at recognizing familiar objects, noticing changes in their environment, and performed more successfully on tasks compared to the control group. The scientists were particularly surprised that the effect appeared quickly and persisted for several months after just two doses of the drug.

The authors believe that in the future, the technology could be used to slow age-related cognitive decline, treat dementia, or aid recovery after stroke.