Polygonum cuspidatum polysaccharide: A review of its extraction and purification, structure analysis, and biological activity

Ethnopharmacological relevance: Polygonum cuspidatum Sieb. et Zucc. is mainly distributed in Shanxi, Gansu, and Sichuan province of China. It is also found in Korea and Japan. Its dried roots and rhizomes are used as medicinal herbs and have been used to treat hyperglycemia and various inflammatory disorders.

Aim of the review: This paper aims to provide an up-to-date review of the developments in the studies involving the extraction and purification, structure analysis, pharmacological effects, and potential applications of polysaccharides obtained from Polygonum cuspidatum. Additionally, the possible future research directions of this plant are discussed.

Materials and methods: This article used "Polygonum cuspidatum polysaccharide (PCP)" and "Polygonum cuspidatum" as the keywords and gathered relevant data on Polygonum cuspidatum using electronic databases (Elsevier, PubMed, ACS, CNKI, Google Scholar, Baidu Scholar, Web of Science), relevant books, and classic literature about Chinese herb.

Results: Excluding irrelevant and repetitive documents, 278 documents were finally included, of which 88 were in Chinese and 190 were in English. The CiteSpace software was used to visualize the trends and keywords in this research field. We concluded that the main extraction methods for Polygonum cuspidatum polysaccharide are water extraction and alcohol precipitation, microwave-assisted extraction, ultrasound-assisted extraction, and microjet extraction. High-performance liquid chromatography and column chromatography are also commonly used in the separation and purification of PCP. PCP has antitumor, immunomodulatory, hypoglycemic, and antioxidant effects. This paper provides an updated and deeper understanding of PCP, serving as a theoretical foundation for the further optimization of polysaccharide structures and the development of PCP as a novel functional material for clinical application.