ABSTRACT Stellariae Radix, a frequently employed traditional Chinese medicine, originates from the dried roots of Stellaria dichotoma L. var. lanceolata Bge. To elucidate the structural characteristics and anti‐Alzheimer's disease (AD) efficacy of S. dichotoma polysaccharides (SDP), SDP was extracted and comprehensively characterized using ultraviolet–visible spectroscopy (UV–Vis), Fourier‐transform infrared spectroscopy (FT‐IR), nuclear magnetic resonance (NMR) spectroscopy and high‐performance liquid chromatography (HPLC). The results revealed that SDP is composed of galactose, glucose, arabinose, galacturonic acid, mannose, and rhamnose at a molar ratio of 5.561:2.224:0.802:0.616:0.613:0.184. In vitro experiments demonstrated that SDP exhibited potent scavenging activities against ABTS, DPPH, and hydroxyl radicals in a dose‐dependent manner, with the average scavenging rates reaching 99.07%, 89.44% and 56.43% respectively at the concentration of 5 mg/mL. In a C57BL/6J mouse model of AD, administration of SDP (50–200 mg/kg) significantly ameliorated cognitive dysfunction, increased the hippocampal levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px), decreased the malondialdehyde (MDA) content, and regulated the expression of oxidative stress‐related proteins, including Nrf2, Keap1 and NQO1. These findings indicate that SDP possesses antioxidant and neuroprotective properties, suggesting its potential therapeutic value for the treatment of AD.
Sun et al. (Sun,) studied this question.