Structural characterization and hypoglycemic activity of a novel pectic polysaccharide extracted from Atractylodes...

Type 2 diabetes mellitus (T2DM) ranks first among global non-communicable chronic diseases, with the third highest incidence rate, making dietary intervention an effective strategy. In this study, a pectic polysaccharide named ALP-2 was isolated and characterized from Atractylodes lancea (Thunb.) DC., and its potential hypoglycemic activity both in vitro and in vivo was investigated. Structural studies revealed that ALP-2 (96.33 kDa) was a homogeneous pectic polysaccharide composed of homogalacturonan (HG), rhamnogalacturonan II (RG-II) and rhamnogalacturonan I (RG-I) domains in a 17.5: 1: 1.3 ratio. ALP-2 showed superior effects on enhancing glucose uptake and consumption, promoting glycogen synthesis, and attenuating overproduction of reactive oxygen species (ROS) in insulin resistance HepG2 cells. In vivo, after five weeks of treatment, ALP-2 supplementation improved body weight and indicators related to glucose/lipid metabolism. Meanwhile, it suppressed hepatic oxidative stress, alleviated liver pathological changes such as steatosis, ballooning degeneration, and inflammatory cell infiltration, thereby attenuating liver injury. Furthermore, the anti-diabetic effects of ALP-2 correlated with specific alterations in the gut microbiota, manifested as increased abundances of Dubosiella, Faecalibaculum, and Bifidobacterium alongside a reduction in Escherichia-Shigella, which fostered a healthier gut environment. Collectively, this study highlights the dual potential of ALP-2, making it relevant to both the functional food and pharmaceutical industries.