Effect of 18 beta-glycyrrhetinic Acid on Aquaporin 1, 5 Expression in the Nasal Mucosa of Rats with Allergic Rhinitis

Objective To investigate the influence and its significance of 18 beta-glycyrrhetinic acid on the expression of aquaqporin 1,5 (AQP1,5) in rat nasal mucosa with allergic rhinitis (AR). Methods Sixty Wistar rats were randomly divided into four groups : model control group, loratadine group, 18 beta-glycyrrhetinic acid group and normal control group. Rats in model control group, loratadine group and 18 beta-glycyrrhetinic acid group were first induced for allergic rhinitis by dripping ovalbumin, and then were treated respectively. After 2 weeks, 4 weeks, 6 weeks, 8 weeks and 10 weeks, the expression of AQP1,5 in the nasal mucosa of each group was investigated and compared by immunohisto chemical technique. Results The distribution of AQP1,5 was consistent in all groups. AQP1 expressed mainly in capillary and blood sinus endothelial cells, and fibrocytes. AQP5 expressed intensively in the membrane and cytoplasm of the epithelium in the glands, cilia, and ductal epithelial area. The statistical analysis of immunohistochemical staining showed that the quantity of AQP1,5 in model group was significantly higher than that in normal group (P < 0.05), and with the extension of drug intervention time, the expression of AQP1, 5 in loratadine group and 18 beta-glycyrrhetinic acid group were gradually decreased and almost equivalent to normal group. Conclusion 18 beta-glycyrrhetinic may relieve symptoms of AR by down-regulating the expression of AQP1,5.