Structural characterization of an active fructan from Atractylodes lancea rhizome and evaluation of its hypoglycemic and adjunctive hypoglycemic effects.

Superior biodegradability and biocompatibility have established natural polysaccharides as increasingly prominent materials in biomedical and food applications. A growing number of plant-derived polysaccharides with the ability to regulate glycolipid metabolism or assist in hypoglycemic functions have been identified and studied. In this work, ALP-1 was extracted and purified from the dried rhizomes of Atractylodes lancea (Thunb.) DC. Structural analysis revealed that ALP-1, with a molecular weight of 5072 Da, is primarily a neutral polysaccharide consisting of fructose and glucose at a molar ratio of 94.77 %: 5.23 %. It was characterized as a fructan featuring Glcp- (1→, →1) -Fruf- (2 → and Fruf- (2 → linkages as the backbone. ALP-1 demonstrated favorable regulatory effects on glucolipid metabolism both in vitro and in vivo. In addition, the combination of ALP-1 with a low dose of metformin (LMET, 1.0 mmol/L) effectively promoted glucose consumption and glycogen synthesis in IR-HepG2, achieving comparable efficacy to metformin alone. In diabetic mice, the LMET-ALP-1 combination likewise yielded hypoglycemic outcomes equivalent to metformin monotherapy, as evidenced by enhanced glucose tolerance, improved serum lipid metabolism, attenuated hepatic steatosis, and recovery of pancreatic islet function. These findings indicate that ALP-1 has potential as a functional component for regulating glycolipid metabolism and may serve as an adjunctive therapy to metformin for hypoglycemic applications in the future.