Structural analysis and anti‐obesity effect of Polygonatum cyrtonema polysaccharide against obesity induced by high‐fat diet in mice

Abstract This study aimed to analyse the physicochemical properties of Polygonatum cyrtonema polysaccharide (PCP) and evaluated its effects in a high‐fat diet (HFD)‐induced obese mice. Experimentally, PCP was established as a homogeneous heteropolysaccharide with both α‐ and β‐configurations, and its estimated average molecular weight was ˜5.1 kDa. Besides, we discovered its major monosaccharides, including galactose, mannose, rhamnose, galacturonic acid and glucose. PCP markedly decreased obesity‐related parameters, improved serum lipid profile, fasting blood glucose, and leptin levels and reversed insulin resistance. It also reduced the hepatic infiltration of lipid droplets and the size of adipocytes in adipose tissues. Finally, PCP simulation significantly downregulated the mRNA expression of CCAAT/enhancer‐binding protein‐α (C/EBPα), peroxisome proliferator‐activated receptor‐γ (PPARγ), sterol regulatory element‐binding protein‐1c (SREBP‐1c) and fatty acid synthase (FAS). On the contrary, it increased carnitine palmitoyltransferase (CPT1) and uncoupling protein 2 (UCP2) levels closely related to thermogenesis and glucolipid metabolism. Taken together, these findings have provided evidence that PCP could be a potential anti‐obesity ingredient in preventing diet‐induced obesity.