The potential application and molecular mechanisms of natural products in the treatment of allergic rhinitis: A review

Allergic rhinitis (AR) is a non-infectious chronic inflammation of the nasal mucosa mainly mediated by immunoglobulin E (IgE) in atopic individuals after exposure to allergens. The application of AR guideline-recommended pharmacotherapies alone or in combination can rapidly relieve symptoms of AR but with poor long-term efficacy, and many of these therapies have reported side effects. Many natural products and their derivatives have shown potential therapeutic effects on AR with fewer side effects. This review arms to expand understanding of the roles and mechanisms of natural compounds in the treatment of AR and to highlight the importance of utilizing natural products in the treatment of AR. We conducted a systematic literature search using PubMed, Web of Science, Google Scholar, and Clinical Trials. The search was performed using keywords including natural products, natural compounds, bioproducts, plant extracts, naturally derived products, natural resources, allergic rhinitis, hay fever, pollinosis, nasal allergy. Comprehensive research and compilation of existing literature were conducted. This article provides a comprehensive review of the potential therapeutic effects and mechanisms of natural compounds in the treatment of AR. We emphasize that natural products primarily exert their effects by modulating signalling pathways such as NF-κB, MAPKs, STAT3/ROR-γt/Foxp3, and GATA3/T-bet, thereby inhibiting the activation and expansion of allergic inflammation. We also discussed their toxicity and clinical applications in AR therapy. Taken together, natural products exhibit a great potential in the treatment of AR. This review also expected to facilitate the application of natural products as candidates for treating AR. Furthermore, drug discovery based on natural products has promising prospect to break barriers in AR treatment.