Myricetin alleviates ovalbumin-induced allergic rhinitis in mice by regulating Th1/Th2 balance

Objective: To evaluate the effect of myricetin on ovalbumin (OVA)-induced allergic rhinitis in mice. Methods: Mice were sensitized and challenged using OVA (5%, 500 mL) intraperitoneally and intranasally, respectively, on an alternative day for 14 days, followed by administration of myricetin (50, 100, and 200 mg/kg) till day 21. Nasal symptoms, biochemical parameters, protein expressions, and histopathology were observed. Results: OVA-induced increased nasal symptoms including rubbing, sneezing, and discharge were significantly reduced by myricetin (100 and 200 mg/kg) (P<0.05). Myricetin also protected against histamine challenge and attenuated elevated serum immunoglobulin E (IgE; total and OVA-specific), total IgG1, and β-hexosaminidase levels, as well as leukotriene C4 and interleukins levels in nasal lavage fluid (P<0.05). Western blot analysis showed that myricetin significantly upregulated the protein expression of T-box expressed in T cells, while downregulating the protein expression of GATA binding protein 3, NF-κB, and 1κВ-α (P<0.05). Additionally, OVA-induced histopathological abberations in the nasal mucosa was markedly ameliorated by myricetin treatment (P<0.05). Conclusions: Myricetin exerts anti-allergic effects against OVA-induced allergic rhinitis via regulating Th1/Th2 balance.