Tyrosol improves ovalbumin (OVA)-induced asthma in rat model through prevention of airway inflammation

Abstract Purpose Asthma is an inflammatory disease that affects many people around the world, especially individuals of pediatric age. The effectiveness of tyrosol, a natural phenolic compound, was examined in the asthma model induced by ovalbumin (OVA). Methods For this purpose, 4 groups, each consisting of 8 rats, were formed. Serum physiological was given to the control group for 21 days. OVA was given to OVA, OVA + Dexamethasone (Dexa) and OVA + tyrosol groups intraperitoneally and by inhalation. Additionally, 0.25 mg/kg Dexa was administered to the OVA + Dexa group and 20 mg/kg tyrosol to the OVA + Tyrosol group by oral gavage. Serum, blood, BALF fluid and lung tissues of the rats were examined. Results it was observed that the MDA level decreased, GSH level and GPx activity increased, and there was no change in CAT activity in the tyrosol treatment groups. It was also observed that NF-κB, TNF-α, IL-4, IL-5, IL-13, IFN-𝛾, and IgE levels decreased compared to the OVA group. However, no effect on IL-1 β level was observed. In addition, it was determined that tyrosol treatment increased the IL-10 level. The results of the histopathological investigation of lung tissue showed that tyrosol significantly ameliorated OVA-induced histopathological lesions. Additionally, PAS staining showed that mucus hypersecretion was significantly reduced with the use of tyrosol. In addition, it was determined that the number of eosinophils decreased significantly. Conclusions The obtained results showed that tyrosol presented antioxidant and anti-inflammatory features on OVA-induced rats and preserved tissue architecture.