Comparison of Histopathological Effects of Thymoquinone and Local Nasal Corticosteroids in Allergic Rhinitis in a Rabbit Model.

BACKGROUND/AIMS In this study, we aimed to evaluate the histopathological effects of thymoquinone treatment of the nasal mucosa in a rabbit model of allergic rhinitis, and we compared its effects with those of nasal mometasone furoate. METHODS A total of 24 male New Zealand rabbits were used. The animals were randomly assigned to one of four groups. Group 1 received no treatment, while group 2 underwent ovalbumin (OVA) sensitization only. Group 3 was the study group; after OVA sensitization, the rabbits were treated with intranasal thymoquinone. The group 4 rabbits received mometasone furoate for 7 days after OVA sensitization. Mucosal structures were stained with hematoxylin and eosin, while toluidine blue was used to stain mast cells. Apoptosis was evaluated using a TUNEL assay. RESULTS In the positive control groups, including the thymoquinone and intranasal mometasone furoate groups, intraepithelial and submucosal inflammation and goblet cell hypertrophy were significantly decreased compared to group 2 (p < 0.001). The cilial structure was normal, as was the chondrocyte structure in both treatment groups. CONCLUSION This is the first study to evaluate the histopathological effects of thymoquinone in an allergic rhinitis model. Thymoquinone reduced allergic inflammation and may be valuable for treating allergic rhinitis. However, additional studies are needed.