Abstract
Allergic rhinitis (AR) is one of the most common chronic inflammatory diseases and its main feature is nasal mucositis. It has been recently revealed that lidocaine demonstrates optimal effects in the treatment of various diseases. However, a limited number of studies have examined the association between lidocaine and AR. In the present study, the AR mouse model was established to explore the effects of lidocaine in AR and to further analyze its molecular mechanism. Subsequently, different concentrations of lidocaine were provided to the animals by intranasal administration and a series of indices were assessed. The data indicated that the frequencies of mouse sneezing and nose rubbing were suppressed following an increase in lidocaine concentration. Subsequently, the number of inflammatory cells was measured. Wright's-Giemsa staining results indicated that lidocaine significantly decreased the numbers of leukocytes, eosinophils, neutrophils and lymphocytes in the nasal lavage fluid (NLF) of AR mice. In addition, the expression levels of ovalbumin (OVA)-specific immunoglobulin E (IgE), leukotriene C4 (LTC4) and certain inflammatory factors were assessed by ELISA. Lidocaine reduced OVA-specific IgE and LTC4 expression in NLF and plasma derived from AR mice. It also decreased the expression levels of IL-4, IL-5, IL-13, IL-17 and TNF-α. Lidocaine caused upregulation of IFN-γ and IL-2 expression levels. Subsequently, western blot analysis indicated that lidocaine suppressed phosphorylated (p)-p38 and p-p65 expression levels in AR mice. Collectively, the results indicated that the NF-κB and p38 MAPK signaling pathways were involved in the lidocaine-mediated relief of AR in mice. In order to further verify the association between the NF-κB and p38 MAPK signaling pathways and AR in mice, the effects of the NF-κB inhibitor IMD-0354 and the p38 MAPK inhibitor SB 203580 were assessed on AR mice. The results indicated that these two compounds exhibited similar inhibitory effects on AR mice as those noted with the use of lidocaine. These findings suggested that lidocaine represented a novel therapeutic agent for AR.