Oxymetazoline as an anti-inflammatory drug in nose sprays: Mode of action now clear

The GSF experts have now elucidated the exact mechanism of an anti-inflammatory effect. This is an important contribution by the GSF to the transfer of knowledge from fundamental research to practical application.

When a patient has a cold (rhinitis), the body reacts to a viral infection by showing inflammatory reactions. Oxymetazoline interferes with this process in different ways: on the one hand it inhibits the enzyme 5-lipoxygenase, which is involved in the production of proinflammatory substances – so-called leukotrienes. The scientists from the GSF Institute of Inhalation Biology have shown this in vitro, i.e. in cell-free systems, and in body cells from lung tissue (alveolar macrophages). On the other hand oxymetazoline reduces the oxidative stress due to inflammatory reactions accompanying a cold, which damages the cells. This was shown by the scientists using stress marker substances in the alveolar macrophages.

The effects mentioned occurred even with relatively low concentrations, which – as the scientists think – are achieved by nose sprays. Preliminary studies had shown that high doses of oxymetazoline can inhibit inflammation. The exact mechanisms, however, were not yet known.

“The special feature of the mode of action is that proinflammatory processes are inhibited, but anti-inflammatory processes are not influenced,” says Dr. Ingrid Beck-Speier from the Institute of Inhalation Biology of the GSF. Thus, laboratory experiments have shown that 15-lipoxygenase is not inhibited. This is an enzyme involved in the production of anti-inflammatory substances.

The GSF – Research Center for Environment and Health investigates the foundations of a medicine of the future for the development of new approaches in prevention, diagnosis and therapy. The aim is to closely link research and application. This is also what this research project, cofunded by Merck Selbstmedikation, stands for. Merck uses oxymetazoline in nose sprays.