Abstract: To study the effects of Polygonatum kingianum polysaccharides (PKP) on lipid metabolism disorders and brain function impairments in obese mice, the obese mice were treated with PKP, prepared by enzyme-assisted extraction, for 12 weeks. Changes in body mass and blood lipids, as well as pathological changes in liver and adipose tissue were observed. Behavioral changes were detected to assess the autonomic activity and anxiety-like behavior of mice, and inflammation levels in liver, adipose tissue, serum, and brain as well as pathomorphological changes in brain were detected. The results showed that PKP (1 500 mg/kg) reduced body mass gain by 29.6% in obese mice, significantly alleviated dyslipidemia and pathological changes in liver and adipose tissue, and promoted the expression of peroxisome proliferator-activated receptors α (PPARα) in liver (46.0%) and the expression of uncoupling protein 1 in adipose tissue (59.0%). PKP significantly increased autonomic activity and suppressed anxiety-like behavior in obese mice. Furthermore, PKP reduced the expression of F4/80 in liver and adipose tissue by 55.0% and 67.2%, respectively, and the serum levels of pro-inflammatory cytokines in including interleukin 1β by 22.9%, interleukin 6 by 44.6%, and tumor necrosis factor α by 7.8%, but increased the serum level of anti-inflammatory cytokine interleukin 10 by 27.1%. Furthermore, PKP reduced the expression levels of ionized calcium binding adaptor molecule 1 in the hippocampus and cerebral cortex by 16.0% and 28.6%, respectively, and inhibited structural damages of the hippocampus and cerebral cortex. PKP mitigate obesity-induced lipid disorders and brain damages, indicating their potential as a functional food ingredient for obesity and suppressing obesity-induced brain damage.

Key words: Polygonatum kingianum polysaccharides; obesity; anxiety-like behavior; brain damage