Comparison of treatment efficacy of omega-3 fish oil and montelukast in ovalbumin-protease-induced allergic rhinitis model in rats

•Omega-3 fatty acid is known as an antiallergic and immunomodulator molecule.•Allergic rhinitis models can be created on experimental animals.•The efficacy of fish oil in the allergic rhinitis model can be evaluated. Montelukast is a well-known leukotriene receptor antagonist commonly used in treating allergic rhinitis and asthma. Omega-3 fatty acid is also known as an antiallergic and immunomodulator molecule. This study aimed to elucidate the efficacy of systemic montelukast and omega-3 fatty acid treatment in allergic rhinitis models in Wistar Hannover rats. This research was conducted on 28 healthy Wistar Hannover rats weighing 250–350 g. After establishing the allergic rhinitis model, nasal symptoms were observed and scored, and the nasal mucosa of all rats was investigated histologically. Light microscopy was utilized to evaluate the degree of ciliary loss, goblet cell hyperplasia, vascular congestion, vascular proliferation, inflammatory cell infiltration, eosinophil infiltration, and hypertrophy in chondrocytes. As a result of the analysis of the data obtained from the study, it was determined that typical allergic rhinitis symptoms such as nasal scratching and sneezing were significantly reduced in the rats in the montelukast and omega-3 treated group, and these symptoms did not increase after repeated intranasal OVA-protease applications. Histological examinations after fish oil treatment did not reveal typical inflammatory changes in allergic rhinitis. None of the rats in the montelukast and omega-3 groups had any increase in goblet cells, whereas 14.3% of the rats in the control group and 28.6% of the rats in the allergic rhinitis group had mild increase. Last but not least, 71.4% of rats in the allergic rhinitis group had a moderate increase. The difference between the groups was statistically significant (p