Immunopharmacology and inflammationDetermination of oxidative stress and effect of erdosteine on rhinitis medicamentosa in a rat model

We aimed to determine the presence of oxidative stress in rhinitis medicamentosa (RM) and to evaluate the effect of erdosteine (ED) on mucosal changes in a rat model. Twenty-four male rats were used in this experimental study. Three groups were created. Group 1 (n=8) was the control group. Two puffs of 0.05% oxymetazolin were sprayed into the nasal cavities of the remaining rats (n=16) three times daily for eight weeks. One of these 16 rats was scarified at the end of the eight weeks and examined to confirm the presence of RM. Seven of the remaining 16 rats were killed, and venous blood samples were taken (Group 2). Group 3 (n=8) received 10 mg/kg of an ED suspension orally for seven days. All rats were put on formalin for light microscopy. The total antioxidant status (TAS) was similar in all groups (p=0.073). The total oxidative status (TOS) of the RM group was significantly higher than that of the control group and RM+ED group (Group 3) (p=0.003 and p=0.011, respectively). The pathological recovery of the nasal mucosa of the rats was similar in the RM+ED and control groups. The TOS was high in this RM rat model, and oxidative stress was associated with RM. ED significantly ameliorated nasal mucosal changes induced by RM, suggesting that oxidative stress may play an important role in the pathophysiology of this condition.