Isolation and purification of polyphenols, hypoglycemic and hypolipidemic and active constituent analysis of walnut septum polyphenols

Walnut septum is rich in polyphenolic substances, but the hypoglycaemic and hypolipidemic effects of walnut septum polyphenols (WSP) and the main active compounds responsible for these effects are still unknown. In the present study, WSP was firstly extracted, and then purified using D101 macroporous resin, and the purity of WSP obtained was 87.36 %. WSP inhibited the activity of α-glucosidase and pancreatic lipase with IC 50 values of 36.2 μg/mL and 155.9 μg/mL, respectively. Furthermore, WSP increased glucose consumption and decreased oxidative stress in insulin-resistant C2C12 cells, as well as inhibited lipid accumulation in 3 T3-L1 adipocytes. Eight naturally active ligands for α-glucosidase and pancreatic lipase were identified from WSP by affinity ultrafiltration combined with liquid chromatography-mass spectrometry analytical methods. Further molecular docking showed strong binding between these eight ligands and the enzyme. The results of the study lay a scientific foundation for the development of walnut septum as a functional food for hypoglycemic and hypolipidemic.