Natural Products Targeting Airway Inflammation and Mucus Hypersecretion: Molecular Mechanisms and Therapeutic Potential for Respiratory Health

Chronic respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis, and chronic bronchitis, are characterized by persistent airway inflammation and mucus hypersecretion, leading to airway remodeling and progressive pulmonary dysfunction. Although current therapies improve disease control, they often fail to adequately target the complex molecular mechanisms underlying chronic airway diseases and may cause adverse effects during long-term use. Natural products have therefore emerged as promising multitarget therapeutic agents because they simultaneously regulate oxidative stress, inflammatory signaling, epithelial dysfunction, and mucus production. Recent evidence demonstrates that marine-derived bioactive compounds and plant-derived phytochemicals modulate key signaling pathways, including nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), Janus kinase/signal transducer and activator of transcription (JAK/STAT), the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, and nuclear factor erythroid 2-related factor 2 (Nrf2), thereby suppressing airway inflammation, oxidative stress, goblet cell differentiation, and MUC5AC overexpression. Advances in nanoformulation, pulmonary drug delivery, multi-omics, artificial intelligence-assisted drug discovery, and network pharmacology are expected to accelerate clinical translation. Collectively, natural products represent promising candidates for the development of evidence-based functional foods, nutraceuticals, and novel therapeutic strategies for chronic respiratory diseases.