Histopathological Evaluation of the Effect of Bromelain on Myringosclerosis in Rats

Abstract

BACKGROUND: Myringosclerosis is frequently detected after otitis media with effusion treatment via ventilation tube insertion.The study was performed to investigate the effect of bromelain as an antioxidant and anti-inflammatory on myringotomized rats. METHODS: The myringotomy operations of 15 Wistar Albino rats were performed under an otomicroscope. Three groups were formed by randomly separating these animals. The day after unilateral myringotomy, the control group was injected with 0.9% NaCl (saline) intraperitoneally (i.p.). The rats of the second group were injected 15 mg/kg/day of bromelain i.p. The third group received 30 mg/kg/day of bromelain i.p. On the 22nd day, the myringotomized ears of the animals were investigated via otomicroscope to determine myringosclerosis. After euthanasia of the animals, tympanic membrane (TM) thickness and inflammation of middle ear mucosa were investigated histopathologically. RESULTS: The control group had higher myringosclerosis scores than the bromelain curative groups (P = .048). The median TM thickness of the control group (64.75 mu m) was higher than the bromelain 15 mg/kg group (34.95 mu m) (P = .009) and the bromelain 30 mg/kg group (27.84 mu m) (P = .008).The inflammation scores were higher in the control group compared to the bromelain curative groups (P = .039). There were no statistically significant differences according to myringosclerosis scores (P = .117), TM thickness (P = .079), and inflammation scores (P = .490) between the bromelain low and high dose groups. CONCLUSION: Bromelain treatment prevented the formation of myringosclerosis, reduced TM thickness, and supressed inflammation in myringotomized rats.