Quercetin modulates mast cell activation and the IL-33/ST2/NF-κB axis in allergic rhinitis

Area of Science:

• Immunology
• Pharmacology

Background:

• Allergic rhinitis (AR) involves immunoglobulin E (IgE)-mediated mast cell (MC) activation.
• The precise anti-allergic mechanisms of quercetin in AR require further elucidation.
• Interleukin-33 (IL-33) plays a significant role in AR pathogenesis.

Purpose of the Study:

• To investigate the anti-allergic effects and mechanisms of quercetin in a mouse model of AR.
• To assess quercetin's impact on IL-33-stimulated mast cells in vitro.
• To explore quercetin's modulation of the IL-33/ST2/NF-κB signaling pathway.

Main Methods:

• In vitro studies utilized rat basophilic leukemia (RBL-2H3) cells stimulated with IL-33 or IgE.
• Assays included ELISA, Western blotting, and RT-qPCR to measure cytokine secretion, degranulation, apoptosis, and pathway component expression.
• In vivo efficacy was evaluated in an ovalbumin (OVA)-induced mouse model of AR.

Main Results:

• Quercetin suppressed IL-33-induced cytokine production, degranulation, and apoptosis in RBL-2H3 cells.
• In vivo, quercetin alleviated AR symptoms, reduced Th2 cytokines, OVA-specific IgE (OVA-sIgE), and IL-33 levels.
• Quercetin downregulated IL-33/ST2/NF-κB pathway proteins in nasal tissues and improved histopathology.

Conclusions:

• Quercetin exhibits significant anti-allergic effects in a mouse model of AR.
• These effects are attributed to the suppression of mast cell activation.
• Quercetin's mechanism involves the inhibition of the IL-33/ST2/NF-κB signaling cascade.