Effects of Thymus quinquecostatus Celakovski on Allergic Responses in OVA-Induced Allergic Rhinitis Mice

Abstract

Allergic rhinitis (AR) is defined allergic disease that is mediated by Th2 cells. Its incidence rate is showing a growing tendency worldwide. Research on traditional medicine for AR is also being increasingly conducted. Thymus quinquecostatus Celakovski (TQ) has been used as an important medicinal and aromatic plant in the world. The purpose of this study was to assess whether TQ can alleviate AR. BALB/c mice were sensitized and challenged with ovalbumin (OVA) to provoke AR. Mice were treated with ethanol extract of TQ at 10 or 100 mg/kg after the intranasal OVA challenge. Their clinical symptoms such as nasal rubbing and sneezing were significantly reduced in the ethanol extract group (10 or 100 mg/kg) compared to the OVA group. Serum levels of Th1 (TNF-α) and Th2 (IL-4, IL-5, and IL-6) cytokines and IgE levels (both total and OVA-specific) were significantly reduced by administration of ethanol extract of TQ at 100 mg/kg. The thicknesses of the nasal septum and epithelium were significantly reduced by the administration of ethanol extract of TQ. These results suggest that TQ may inhibit early and late phases of AR reactions.