Research progress in the extraction, purification, structural features, biological activities, and structure-activity relationships from Prunella vulgaris polysaccharides

Prunella vulgaris L., a globally recognized medicinal and edible plant, has been extensively used in China for over 2000 years, possessing the efficacy of clearing liver-fire, brightening the eyes, dispersing the knot, and reducing swelling. Phytochemical studies have shown that Prunella vulgaris contains various biologically active compounds, including flavonoids, triterpenes, polysaccharides, and phenolic acids. Increasing evidence has demonstrated that Prunella vulgaris polysaccharides (PVPs) are one of representative macromolecular components with various bioactivities that are beneficial to health, such as immunomodulatory, antiviral, antitumor, antioxidant, anti-inflammatory, and hepatoprotective effects, and others. However, the current lack of an understanding of PVPs has restricted their development and utilization. This review emphatically summarized recent progress in the extraction and purification, structural characterization, biological functions, structure- activity relationship, toxicity, and potential applications of PVPs. Additionally, this article also provides a comprehensive understanding, update information and new valuable insights for further research and development of PVPs as therapeutic agents and functional foods.