The therapeutic efficacy of α-pinene in an experimental mouse model of allergic rhinitis

In the present study, the therapeutic effect and underlying mechanism of alpha-pinene (alpha-PN) in the ovalbumin (OVA)-sensitized allergic rhinitis (AR) model were investigated. Our results showed that pretreatment with alpha-PN caused a decrease in clinical symptoms, including a decrease in the number of nasal, eye, and ear rubs, and spleen weight in the OVA-sensitized mice. The level of interleukin (IL)-4 was decreased on the spleen tissue of alpha-PN treated mice. Pretreatment with alpha-PN significantly decreased levels of nasal immunoglobulin E. Protein levels of tumor necrosis factor-a, intercellular adhesion molecule-1, and macrophage inflammatory protein-2 were decreased by the administration of alpha-PN in the nasal mucosa of the OVA-sensitized mice. The increased numbers of eosinophils and mast cells infiltrating the nasal mucosal tissue of mice with AR were decreased following oral administration of alpha-PN. Post-treatment with alpha-PN 1 h after OVA challenge also resulted in a significant reduction of clinical symptoms and IgE levels. In addition, the expression and phosphorylation of receptor-interacting protein 2 (RIP2) and I kappa B kinase (IKK)-beta and activation of nuclear factor-kappa B (NF-kappa B), and caspase-1 were all increased in the activated human mast cell line, HMC-1 cells, however, increased activations of RIP2, IKK-beta, NF-kappa B, and caspase-1 were inhibited by treatment with alpha-PN. Taken together, we suggest that alpha-PN is a promising anti-allergic agent and may be useful in the clinical management of AR. 2014 Elsevier B.V. All rights reserved.