Unraveling the Extraction, Structure, Bioactivities, and Structure–Activity Relationship of <i>Salvia miltiorrhiza</i> Polysaccharides: A Review

<i>Salvia miltiorrhiza</i>, a widely recognized traditional medicinal plant, is not only extensively used in clinical settings but also increasingly valued for its potential as a functional food ingredient. <i>S. miltiorrhiza</i> polysaccharides (SMPs), as the primary active components of <i>S. miltiorrhiza</i>, demonstrate excellent performance in antioxidant, hepatoprotective, and immunomodulatory effects. These attributes facilitate their advancement in nutritional health products, dietary supplements, and health-enhancing functional foods. Combining therapeutic and nutritional value, SMPs serve as a vital bridge connecting traditional medicine with modern functional food applications. This work offers a systematic assessment of the procedures for the extraction and purification of SMP, along with its structural features, biological activities, uses, and structure-activity connections. This framework is anticipated to establish a theoretical basis for subsequent research, applications, and progress in human health and product development.