Anti-Aging Effects of Polygonatum spp. Polysaccharides: Pharmacological Evidence, Molecular Mechanisms, and Structure–Activity Relationships

Polygonatum species are medicinal and edible plants whose polysaccharides (PSPs) have attracted interest for their potential anti-aging effects. This review synthesizes evidence on the structural characteristics, pharmacological activities, molecular mechanisms, and translational prospects of PSPs. Relevant literature was retrieved from Web of Science and the China National Knowledge Infrastructure using terms related to Polygonatum polysaccharides, aging, structural characterization, and bioactivity. PSPs vary in molecular weight, monosaccharide composition, glycosidic linkages, and branching patterns. Studies using cells, Caenorhabditis elegans, and mammals report aging-related benefits associated with reduced oxidative stress and inflammation, modulation of gut microbiota and immune homeostasis, improved mitochondrial function, and metabolic regulation. Reported molecular changes were associated with Nrf2/HO-1, SIRT1/SIRT3, AMPK/PGC-1α, ERK/NF-κB, and DAF-16-related signaling. Although comparisons among PSP fractions suggest associations between structural features and biological activity, causal structure–activity relationships remain unconfirmed. Moreover, most evidence is preclinical, and differences in botanical sources, extraction methods, and polysaccharide characterization limit cross-study comparisons. Future research should prioritize standardized, structurally defined preparations, direct structure–activity testing, pharmacokinetics, long-term safety, and clinical validation to clarify the potential of PSPs for healthy aging.