Astragalus Polysaccharides Attenuate Ovalbumin-Induced Allergic Rhinitis in Rats by Inhibiting NLRP3 Inflammasome Activation and NOD2-Mediated NF-κB Activation

Allergic rhinitis (AR) is an IgE-mediated chronic inflammatory disease of the allergic nasal mucosa. It has a significant effect on quality life; most patients with AR also suffer from sleep disorders, mood disorders, and deterioration in social relationships. As increasing numbers of medicinal plants show productive anti-inflammatory activity against inflammatory diseases, there is growing interest in natural medicinal plant ingredients. To this end, we selected Astragalus polysaccharides (APS) to evaluate its anti-inflammatory effect on ovalbumin-induced AR rats, and we further explored its impact on NLRP3 inflammasome activation and NOD2-mediated NF-κB activation. We found that APS can alleviate the nasal symptom of AR rats and attenuate pathological alterations. APS also reduced the inflammatory cytokine levels. APS not only inhibited the NLRP3 inflammasome activation but also inhibited NF-κB activation by decreasing NOD2 expression and blocking the phosphorylation of NF-κB (p65). In conclusion, APS can effectively improve the inflammatory symptoms of nasal mucosa in AR rats, which may be mediated by the inhibition of NLRP3 inflammasome activation and NOD2-mediated NF-κB activation. These findings indicate that APS has the potential to be used as a therapeutic agent for AR.