Inhibitory properties of polyphenols in Malus Winter Red crabapple fruit on α-glucosidase and α-amylase using improved methods

To explore the inhibitory activity of polyphenols on alpha-glucosidase and alpha-amylase, 16 polyphenols were isolated, identified, and quantified in an edible Matus Winter Red crabapple fruit. The limitations of two traditional methods for alpha-glucosidase and alpha-amylase activity assay in vitro were assayed. An improved method based on an HPLC assay for alpha-glucosidase and a colorimetric method coupled with a custom-made minicolumn for alpha-amylase were established. Compared with positive controls, acarbose and miglito, most polyphenols, especially the four aglycones (cyanidin, quercetin, phloretin, and 3-hydroxyphloretin) showed higher inhibition rates on alpha-glucosidase. None of the polyphenols showed higher inhibition rates on alpha-amylase than acarbose, but most, especially the four aglycones, showed higher inhibition rates on alpha-amylase than miglito. The MMus Winter Red fruit has great potential for postprandial blood glucose management as a potential diet therapy for diabetic patients.

Automated summary

This study investigated the inhibitory activity of polyphenols on alpha-glucosidase and alpha-amylase in Matus Winter Red crabapple fruit, showing promising potential for postprandial blood glucose management and dietary therapy for diabetic patients.