The effect of rosmarinic acid on the prevention of myringosclerosis

Abstract

Objectives: Myringosclerosis commonly occurs as a long-term complication of ventilation during the treatment of otitis media. We aimed to determine the effects of rosmarinic acid as an antioxidant on experimentally induced myringosclerosis. Methods: Twenty-four male Sprague-Dawley rats, weighing 250-300 g, were unilaterally myringotomized and randomly separated into three groups. Group 1 received no treatment (control group) (n = 8); Group 2 received topical rosmarinic acid (n = 8); Group 3 received oral rosmarinic acid (n = 8). On the twenty-first day, the right ears were examined by otomicroscope and findings of myringosclerosis were recorded. Finally, all of the rats were euthanized and the tympanic membrane (TM) thickness and the severity of middle ear mucosal inflammation were evaluated histopathologically. Results: The myringosclerosis severity, TM thickness, and inflammation scores were found to be significantly higher in the control group than in the topical and systemic treatment groups (p < 0.05). There were no statistically significant differences in terms of TM thickness and inflammation scores between the topical and systemic treatment groups (p > 0.05). While moderate and severe myringosclerosis were higher in the control group, mild myringosclerosis was found to be higher in both treatment groups. Conclusion: The local and oral administration of rosmarinic acid suppressed inflammation, reduced TM thickness, and prevented the development of myringosclerosis in myringotomized rats.