Abstract: The polyphenol composition and antioxidant and anti-starch hydrolase activities in wild blue honeysuckle fruit collected from the Lesser Khingan Mountains in northeast China were analyzed. Anthocyanin and non-anthocyanin fractions were obtained by solid-phase extraction (SPE) and the chemical composition was determined. Total phenolics and total anthocyanins were also determined in the polyphenol crude extracts, and antioxidant activity was measured by determining 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity, ferric reducing antioxidant power (FRAP), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging capacity, and oxygen radical absorbance capacity (ORAC). In addition, the inhibitory activity of α-amylase, α-glucosidase and lipase were determined. The results showed that the fruit contained abundant anthocyanins and non-anthocyanin polyphenols, especially cyanidin-3-glucoside and kaempferol-3-rutinoside. The contents of total phenolics and total anthocyanins in the polyphenol crude extracts were up to 82.7 and 49.8 mg/100 g respectively, indicating strong antioxidant activity. The half-maximum inhibitory concentrations (IC50) for α-amylase, α-glucosidase and lipase were 0.39, 0.933 and 12.31 mg/mL, respectively. This study demonstrates that blue honeysuckle fruit could be used as a promising inhibitor of starch hydrolase.

Key words: wild blue honeysuckle; polyphenols; antioxidant activity; anti-starch hydrolase activity