Abstract: Objective To investigate the effect of cinnamaldehyde on apoptosis of nasal mucosa cells in rats with allergic rhinitis (AR) and its mechanism. Methods The AR model was established in rats and the rats were randomly divided into AR group, low-, medium-and high-dose cinnamaldehyde groups and loratadine group, another 10 rats were selected as the sham operation group (sham group). The apoptosis of nasal mucosa cells, the level of serum IL-6, and the expression levels of IL-6, JAK2, STAT3 mRNAs and JAK2, p-JAK2, STAT3, p-STAT3, Bcl-2, Bax proteins were detected. Results Compared with the sham group, the level of serum IL-6, the expression levels of IL-6 mRNA and P-JAK2 / JAK2, P-STAT3 / STAT3 and Bcl-2 proteins of nasal mucosa cells were increased in the AR group (P < 0. 05), while the apoptosis index (AI) and Bax protein expression level were decreased (P< 0. 05). Compared with the AR group, the level of serum IL-6, the expression levels of IL-6 mRNA and P-JAK2 / JAK2, P-STAT3 / STAT3 and Bcl-2 proteins in rats nasal mucosa cells in the low-dose, medium-dose and high-dose cinnamaldehyde groups and the loratadine group were decreased (P< 0. 05), while the AI and Bax expression level were increased (P< 0. 05). Conclusion Cinnamaldehyde can promote the apoptosis of nasal mucosal cells in AR rats, and the mechanism may be related to the inhibition of IL-6 / JAK2 / STAT3 signaling pathway. 

Key words: cinnamaldehyde, allergic rhinitis, nasal mucosa, apoptosis, IL-6 / JAK2 / STAT3 signaling pathway