Background: Rhinosinusitis is a common disorder and its treatment includes a variety of topical and systemic drugs. This study was designed to determine the histopathological effect of thymoquinone on experimentally induced rhinosinusitis in rats.
Methods: Sixty rats were randomly allocated into 3 test and 2 control groups, each of which consisted of 12 animals. The rhinosinusitis model was induced using intranasal application of platelet-activating factor. In test groups, the animals were separated into groups: (1) rhinosinusitis-antibiotherapy, (2) rhinosinusitis-thymoquinone, (3) rhinosinusitis-combination therapy. The positive and negative control groups were defined: rhinosinusitis group without any treatment and the group without rhinosinusitis, respectively. The histopathological features (vascular congestion, inflammation, and epithelial injury) in nasal respiratory and olfactory mucosa of animals were examined and graded according to their severity. A quantitative and statistical analysis of histopathological features was performed.
Results: All histopathological features showed statistically significant differences between negative and positive control groups, respectively. Conversely, neither the group with rhinosinusitis-antibiotherapy nor the group with rhinosinusitis-thymoquinone had a statistically significant difference with the negative control group. Moreover, none of the histopathological features showed a statistically significant difference, when the group with rhinosinusitis-antibiotherapy and the group with rhinosinusitis-thymoquinone were compared. A statistically significant difference was not determined when the group with rhinosinusitis-combination therapy was compared with the group with rhinosinusitis-thymoquinone. The histopathological features did not show a statistically significant difference between the group with combination therapy and the negative control Conclusion: Thymoquinone is a promising bioactive agent for the treatment of rhinosinusitis, and its histopathological effect is as equivalent as an antibiotic.