Abstract: In this study,the content of polyphenol in the extract A from seabuckthorn leaf was extracted by solvent extraction,and the extract B was prepared by macroporous resin.On the basis of the research in antioxidant capacity and radical scavenging ability of the extract,porcine pancreatic α-amylase and 3,5Dinitrosalicylic acid (DNS) methods were used to evaluate the in vitro hypoglycemic activity of extracts.The results showed that polyphenol content from extract A and B were 18.59% and 30.25%,respectively;With VC equivalent,total antioxidant capacity of per gram were 6.15 mg and 9.79 mg,respectively;corresponding to IC₅₀ of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical clearance were 20.19 μg/mL and 8.6 μg/mL;When the concentration of porcine pancreatic αamylase was below 0.5 mg/mL and the reaction time was less than 1 min,the enzymatic reaction system had a good linear trend.Under these conditions,the content of polyphenol in the extract B had a certain inhibitory effect on porcine pancreatic α-amylase,the semi-inhibitory concentration of 0.25 mg/mL,were reversible anti-competitive inhibition.This study can provide data support for the development and utilization of seabuckthorn leaves.

Key words: seabuckthorn leaves, polyphenol, antioxidant, hypoglycemic activity