The use of a ‘new nasal solution’ may improve motor recovery and reduce brain damage following an ischaemic stroke. This is one of the conclusions of an international study led by RISE-Health and the University of Beira Interior (UBI), focusing on one of the leading causes of disability worldwide.

The scientific study, carried out on animal models, demonstrated that the nasal administration, shortly after a stroke, of a single low dose of Nestorona® — a laboratory-created substance that mimics one of the body’s protective hormones — significantly reduces the extent of brain tissue damage caused by the stroke and improves the recovery of motor function.

According to Sara Meirinho, a researcher at RISE-Health, the conventional oral route compromises the efficacy of Nestorona®, a drug currently used for contraceptive purposes.

“When administered orally, Nestorona® loses much of its potential, with less than 10 per cent of the substance reaching the bloodstream due to degradation in the liver. The nasal route emerges as the ideal alternative to overcome this obstacle. It bypasses first-pass hepatic metabolism and enables part of the drug to reach the brain directly via the olfactory and trigeminal nerves, making this anatomical region highly promising for treating neurological disorders,” explains the specialist.

According to researchers at RISE-Health, administering this drug nasally enabled it to reach the brain extremely quickly. Just five minutes after nasal administration, Nestorona® reached its peak concentration in the brain, thereby achieving cerebral exposure to the drug approximately twice that obtained via other conventional routes, such as subcutaneous injection.

Discovery may have an impact on various conditions

The potential of this discovery, however, extends beyond stroke. The team led by the country’s largest research unit anticipates that this approach could be adapted for other conditions.

“As well as reducing brain damage following a stroke, there are indications that Nestorona® may have enormous therapeutic significance in the treatment of other central nervous system disorders, such as multiple sclerosis,” points out the RISE-Health specialist.

The researchers emphasise that these findings are based exclusively on studies in animal models, and it is now necessary to move on to clinical trials to confirm the safety and efficacy of this approach in humans.

The study “Low dose intranasal nestorone self-emulsifying drug delivery system promotes neuroprotection in experimental stroke through modulation of glial cells”, published in Drug Delivery and Translational Research, is led by Sara Meirinho and lists Adriana Santos, Susana Alves Ferreira, Catarina Diniz, Gilberto Alves and Graça Baltazar, researchers from the RISE-Health Research Unit and UBI, as authors. The initiative also involves the participation of specialists from Spain and the United States of America.