Investigation of cytotoxic effects of oxymetazoline on lung in a rat model of rhinitis medicamentosa

BACKGROUND Rhinitis medicamentosa, also known as 'rebound congestion,' is inflammation of the nasal mucosa caused by the overuse of topical nasal decongestants. Although local decongestants resolve the initial nasal obstruction, the overuse causes rebound obstruction. However, how the overuse of the decongestant causes rhinitis medicamentosa is not known. OBJECTIVES Here, we show the intracellular effects of oxymetazoline, commonly used a local decongestant, on the cell death pathways. We also investigated the antioxidative effects of erdosteine suspension (175 mg/5mL), an antioxidative agent. METHODS Thirty Wistar-albino rats were used to form the rhinitis medicamentosa model. After rhinitis medicamentosa was clinically detected, we removed the whole lungs of animals to perform the molecular analyses of cell death pathways. RESULTS We found a statistically significant decrease in the expression levels of Atg5 (p=0.021), Atg7 (p=0.013) and Ulk1 (p=0.036) in the oxymetazoline group compared to the control group (p<0.05); however, Caspase 3 expression level was recorded to be significantly increased in the oxymetazoline group, and the expression level of Beclin1 recorded to be substantially increased in erdosteine group (p=0.001). CONCLUSION Based on these grounds, we suggest that vasoconstriction in capillary vessels caused by oxymetazoline could lead to a decrease in the blood supply, which triggers autophagy to ensure cellular homeostasis.