The main active component of Polygonatum sibiricum (P. sibiricum) rhizome is Polygonatum sibiricum Polysaccharide (PsP) with antioxidant function. At present, only the mature rhizome of P. sibiricum is used to extract PsP, while the young rhizome of by-product is discarded directly as waste, resulting in significant wastage of P. sibiricum resources. We used ultrasound-assisted extraction-deep eutectic solvents (UAE-DESs) method to extract PsP of young and mature rhizomes, respectively. The extraction rate, structure composition and antioxidant ability of PsP between young and mature rhizomes were compared, so as to provide references for comprehensive utilization of P. sibiricum resources. The PsP extraction rate (33.88 ± 1.95%) of young rhizome was close to that (45.08 ± 1.92%) of mature rhizomes. The main component (PsP-2) of the PsP in young rhizome contained six kinds of monosaccharides, which belonged to acidic polysaccharides. The above characteristics of the PsP of young rhizome were similar to those of mature rhizome. The PsP of young rhizome also exhibited similar biological activity to that of the mature rhizome, which indicated even more advantages in DPPH free radical scavenging ability. The results of this study support the utility of the young rhizome, consequently helping to avoid unnecessary waste and provide reference for comprehensive utilization of P. sibiricum.

Oxidative stress is closely associated with sarcopenia obesity (SO). As the primary active component of Polygonatum sibiricum, Polygonatum sibiricum polysaccharide (PsP) is recognized as a potent antioxidant and has become a focus of research for potential therapeutic strategies against SO. Our previous study demonstrated that ultrasound-assisted deep eutectic solvents (UAE-DESs) significantly improve the extraction efficiency of PsP; however, the antioxidant effect of PsP extracted using UAE-DESs was unexplored. This study investigated the effects of PsP extracted by UAE-DESs on an oxidative stress model in L6 cells induced by palmitic acid (PA). The results revealed that PsP enhanced the ability of L6 cells to resist PA-induced effects, including ectopic lipid deposition, changes in reactive oxygen species (ROS) levels, malondialdehyde (MDA) contents, and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT). Additionally, PsP upregulated the expression of myosin heavy chain (MHC) and myoblast differentiation (MyoD) protein, while increasing myotube cell diameter. These findings suggested that PsP extracted by UAE-DESs can enhance the antioxidant capacity of L6 cells against PA-induced oxidative stress in a simulated SO model, providing a potential therapeutic agent for the prevention and treatment of SO.