The stuffy noses and sinus pressure of head colds are uncomfortable, but for most people, they go away within days. For those with chronic sinusitis, however, those symptoms and others drag on for weeks. Now scientists are onto a potential new therapy that could address one of the underlying factors associated with the condition. They describe their work in the ACS journal Molecular Pharmaceutics.

In the body, nitric oxide (NO) plays a critical role in immunity. Researchers have found that this simple molecule is an important antimicrobial agent that helps prevent sinus infections. Low levels of NO in nasal passages have been linked to chronic sinusitis, a condition in which the sinuses become inflamed, making breathing through the nose difficult. It can also lead to facial pain and headaches. One therapeutic approach could involve boosting NO levels. Mark E. Meyerhoff and colleagues wanted to test out this idea.

The researchers developed a simple method to make molecules called low-molecular-weight, arginine-rich peptides from an already-approved drug compound protamine. In lab tests, the peptides increased nitric oxide production in mouse immune cells and cells that line airways, making them a good candidate for further development.