[Effects of 18ß-sodium glycyrrhetinic acid on TNF-α expression in rats with allergic rhinitis].

Objective:To observe the effect of 18ß-sodium glycyrrhetinic acid(18ß-SGA) on the expression of TNF-α in nasal mucosa of rats with allergic rhinitis（AR）, and explore the intervention mechanism of 18ß-SGA on AR. Method:One hundred and six SPF-level Wistar rats were randomly divided into control group, AR group, budesonide group, 18ß-SGA low dose group and high dose group. After the AR rat model was constructed by ovalbumin, the rats were given drug intervention and sacrificed after 2 and 4 weeks of intervention. The nasal mucosa of the rats was taken for immunohistochemical staining, RT-qPCR and Western-blotting to localize and quantify the expression of TNF-α. Result:By immunohistochemistry, Western-blotting and RT-PCR, TNF-α was mainly found in the columnar epithelium, vascular endothelium, glandular and some inflammatory cytoplasm of nasal mucosa. And the expression of TNF-α in the nasal mucosa of AR rats was significantly increased than the normal group at the protein and mRNA levels (P<0.01). After intervention with different doses of 18ß-SGA, the expression of TNF-α was significantly decreased (P<0.01), especially after 4 weeks of 18ß-SGA low dose group(P<0.01). Conclusion:Different doses of 18ß-SGA have therapeutic effects on AR, and its mechanism of action may be related to the inhibition of TNF-α expression.