Polysaccharides from Scutellaria baicalensis Georgi: Extraction, purification strategies, structural...

Scutellaria baicalensis, a perennial herb belonging to the genus Scutellaria (Lamiaceae), has dried roots that are widely used as a traditional Chinese medicinal herb known as "Huangqin". As one of the major chemical constituents of S. baicalensis, its polysaccharides exhibit diverse biological activities, including immunomodulatory effects, regulation of gut microbiota, antioxidant activity, hypoglycemic effects, anti-inflammatory activity, and antimicrobial properties. Modern pharmacological studies have further confirmed the intrinsic relationship between these activities and traditional therapeutic uses at the molecular level, while also revealing their potential applications in functional foods, dietary supplements, and food additives, thereby providing scientific support for the modernization and application of traditional medicine.

To systematically summarize the latest research progress on the extraction, isolation, purification, structural characterization, and biological activities of Scutellaria baicalensis polysaccharides (SBP), and to explore their structure-activity relationships and potential research directions, with the aim of supporting their further development and application in the pharmaceutical and functional food industries.

Following the PRISMA guidelines, relevant studies were systematically retrieved from PubMed, Web of Science, and CNKI databases, and the latest advances in the extraction, purification, structural characterization, and biological activities of SBP were comprehensively reviewed.

Various extraction methods have been established, including hot water extraction, ultrasound-assisted extraction, and microwave-assisted extraction, among which the Sevag method is commonly employed for deproteinization during purification. Structural studies have primarily focused on monosaccharide composition, molecular weight, and glycosidic linkage patterns. Pharmacological studies have demonstrated that these polysaccharides possess multiple biological activities, including immunomodulatory, antioxidant, hypoglycemic, anti-inflammatory, antimicrobial, and gut microbiota-regulating effects. Structure-activity relationship studies indicate that the biological activities of SBP are collectively determined by their multi-level fine structures, including molecular weight, monosaccharide composition, types and patterns of glycosidic linkages, and higher-order spatial conformations, all of which play critical roles in their biological functions.

Considerable progress has been achieved in the extraction, purification, structural characterization, and biological evaluation of SBP, demonstrating promising pharmacological potential in immunomodulation, anti-inflammatory activity, and metabolic regulation. However, their higher-order structural characteristics, the structure-activity relationships between specific structural motifs and biological activities, as well as in vivo processes such as bioavailability and metabolic fate, still require further investigation.