Insights Into Effects of Natural Bioactive Components on Inflammatory Diseases in Respiratory Tract.

The increasing prevalence of inflammatory diseases in the respiratory tract worldwide has raised concerns, and due to its high prevalence and poor prognosis, it remains a clinical focus and research hotspot. These inflammatory diseases include airway inflammation, asthma, bacterial antigens-induced tonsil epithelial inflammation, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), COVID-19, acute lung injury, and lung cancer. This review summarizes the relevant molecular mechanisms of inflammatory diseases in the respiratory tract and the progress of natural bioactive components in inflammatory diseases in the respiratory tract. The natural bioactive components have good therapeutic or intervention effects on inflammatory airway diseases in vitro, in vivo, and in clinical trials. The information on inflammatory diseases in the respiratory tract and natural bioactive ingredients in anti-inflammatory diseases were collected from famous literature databases such as Web of Science, PubMed, and Google Scholar, with keywords including bioactive components, inflammatory diseases, respiratory tract, and so forth. The bioactive phytochemicals, such as curcumin, ginsenoside, safranal, melatonin, could improve inflammatory diseases through the regulation of PI3K/Akt, NF-κB, NRF2/HO-1, MAPK, cAMP-PKA, and MEK/ERK Signaling pathways. Further high-quality studies are still needed to firmly establish the clinical efficacy of bioactive ingredients. This review provides new insight for future research on functional food or drug-lead compound development on natural products improving inflammatory diseases in the respiratory tract.