The Role of Topical Thymoquinone in the Treatment of Acute Otitis Externa; an Experimental Study in Rats

The aim of this experimental study was to compare the dose-related effect of topical thymoquinone (TQ) with other topical agents used in the management of acute otitis externa (AOE) in a rat model.

Forty-eight male Wistar albino rats were divided into six groups each with eight rats per group. Group I was the control group with no external otitis, whereas external otitis were created in the other five groups (study groups). Dexamethasone, 0.1% TQ, 0.4% TQ, ciprofloxacin, and 0.9% saline (NaCl) drops was applied once daily in Groups II-VI, respectively. The treatment was administered regularly for 10 days. Pathologic and microbiologic evaluation were performed. Pathologically, the thicknesses of the stroma and the epithelium in the external auditory canal (EAC) were measured using an occulometer. Edema in the stroma, density of inflammatory cells and blood vessels, presence of fibroblasts, and changes in collagen fibers in the EAC were evaluated in five different areas to obtain the area of highest concentration and classified into four grades (0=no change, 1=mild, 2=moderate, 3=severe).

The higher concentration of TQ (0.4%) was more effective than dexamethasone and 0.1% TQ with respect to antibacterial and the anti-inflammatory properties.

TQ, particularly at a concentration of 0.4%, may be considered for topical application alone in the treatment of AOE, without any requirement for a combined treatment.