Research progress on polysaccharides in Medicago sativa L. (alfalfa): Structural characteristics, pharmacological...

Medicago sativa L. (M. sativa) is the most representative member of the Medicago L. genus of the Fabaceae family, widely distributed worldwide. M. sativa polysaccharides are one of the most important bioactive components, which have been proven to have various pharmacological activities, including anti-inflammatory, antioxidant, anti-tumor, immunosuppressive, neuroprotective, hepatoprotective, hypoglycemic, and obesity relieving effects. In terms of extraction, the Hot water extraction method can retain the nutrients in the residue for recycling. Enzyme-assisted extraction and Alkaline extraction methods are more suitable for the chemical structure of cellulose and hemicellulose M. sativa polysaccharides. At present, unclear structure-activity relationships and insufficient understanding of mechanisms hinder the development and utilization of M. sativa polysaccharides. Therefore, this article focuses on three key factors: chemical structures, pharmacological activities, and structure-activity relationships, and systematically reviews their research progress. Clarify the correlation between the structural characterization and pharmacological activities of M. sativa polysaccharides and reveal the key mechanisms by which they exert immunomodulatory and obesity relieving effects. These research results demonstrate the potential of M. sativa polysaccharides in drug development and provide a theoretical basis for their further development and application.