Multi-target antiviral mechanisms of traditional Chinese medicine polysaccharides against respiratory viruses: A review from structure-activity relationships to modern applications.

Respiratory viruses are major pathogens that pose a serious threat to human health, and the global pressure for their prevention and control has continued to intensify since 2019. Constrained by factors such as high viral variability and complex pathogenic mechanisms, existing prevention and control measures still have obvious limitations, making the development of safe and effective novel antiviral drugs an urgent need. Natural products serve as an important source for innovative drug discovery, and among them, traditional Chinese medicine(TCM) polysaccharides have emerged as a frontier in antiviral research against respiratory viruses owing to their multi-target actions, high safety profiles, and favorable immunomodulatory activities. This paper systematically reviews the mechanisms of action and structure-activity relationships of TCM polysaccharides against respiratory viruses, summarizes the current status and progress of their investigation as novel vaccine adjuvants, dissects key scientific issues and research bottlenecks in the field, and provides a perspective on future directions. This review aims to provide a scientific basis and theoretical reference for the exploration of anti-respiratory virus activities of TCM polysaccharides, the elucidation of their mechanisms of action, and the advancement of preclinical research and application.