Extraction, purification, structural characteristics and biological properties of the polysaccharides from Radix Saposhnikoviae: A review

Radix Saposhnikoviae (R. Saposhnikoviae), commonly known as FangFeng, is a renowned medicinal herb in China extensively utilized in traditional Chinese medicine. It expels pathogenic wind from the body surface, alleviates pain by removing dampness, and relieves convulsion. Therefore, it is mainly used for treating exterior syndrome, itchy wind papules, rheumatic arthralgia, and splenic asthenia-induced dampness. R. saposhnikoviae has important medicinal value, and the polysaccharide component is one of its important active ingredients.This review summarizes the factors influencing the content of polysaccharides in R. Saposhnikoviae (PRSs), the techniques employed for their extraction, separation, and purification, their structural characterization, and their biological activities.Relevant research reports on PRSs were collected from the Chinese National Knowledge Infrastructure, Web of Science, PubMed, Wanfang Data Knowledge Service Platform, China Master Theses Full-text Database, and China Doctoral Dissertations Full-text Database.The content of PRSs can vary depending on cultivation methods and harvesting time. PRSs were extracted using various extraction techniques such as hot water, ultrasonic-assisted, microwave-assisted, and enzymatic extractions, as well as water extraction and alcohol precipitation. Effective purification methods involve protein removal using trifluoro-trichloroethane and the decolorization of the polysaccharide using column chromatography with D280 anion exchange resins. Current research highlights the significant pharmacological activities of PRSs in R. Saposhnikoviae, including immunomodulatory, antioxidant, anti-allergic, anti-cancer, and anti-osteoporotic effects as well as prevention of calcium loss and maintenance of mucosal function.PRSs play a crucial role as bioactive constituents of R. Saposhnikoviae, exhibiting diverse biological activities and promising applications. A deeper understanding of PRSs will contribute to the improved utilization of R. Saposhnikoviae and the development of related derivatives of the active ingredients.