Research advances in preparation methods, structural characteristics, pharmacological activities, structure-activity...

Saposhnikovia divaricata polysaccharides (SDPs) are important bioactive macromolecules derived from the roots of Saposhnikovia divaricata and have attracted sustained attention because of their structural diversity, favorable biocompatibility, and broad pharmacological potential. However, studies on SDPs over the past five years, particularly those concerning extraction techniques, structural characterization, pharmacological activities, and structure-activity relationships, have not yet been systematically summarized. Therefore, this review systematically summarizes the latest progress in this field, with emphasis on the development of green and efficient extraction strategies, such as ultrasound-assisted extraction, enzyme-assisted extraction, and ultrasound-synergistic enzymatic water extraction, while also outlining key structural features including molecular weight, monosaccharide composition, glycosidic linkage types, branching structures, and spatial conformation. Current evidence indicates that SDPs exhibit multiple pharmacological activities, including anti-allergic, anti-inflammatory, immunomodulatory, hepatoprotective, antitumor, and antioxidant effects, and that these activities are closely associated with their structural characteristics. Notably, SDPs show remarkable neuroprotective potential, which may be mediated by alleviating oxidative stress, inhibiting microglial inflammatory activation, ameliorating glutamate-induced neuronal injury, regulating catecholamine neurotransmitter release, and modulating the gut-brain axis. This review aims to provide systematic support for promoting the in-depth development and rational application of SDPs in clinical medicine and health-related products.