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

Abstract

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

Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba

“…On the one hand, the results showed that agathisflavone, avicularin, cyanidin, and pelargonidin exhibited significant inhibitory activity in digestive enzymes ( α -glucosidase and/or α -amylase), and agathisflavone, avicularin inhibited α -glucosidase with IC 50 values of 11.4 ± 0.9 µmol/L, 69.8 mg/L, respectively. In addition, delphinidin-3-arabinoside has the potential to modulate dipeptidyl peptidase-IV and its substrate GLP-1, to increase insulin secretion [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. On the other hand, previous research suggested that 3,5,7,2′,6′-pentahydroxyflavone with a hydroxyl group in the B ring possessed a potent activity against lipid peroxidation [ 25 ].…”

Dual Regulation of Sulfonated Lignin to Prevent and Treat Type 2 Diabetes Mellitus

“…However, the inhibition capacity (IC 50 , 32.4 μg/mL) of SL 2 to α-amylase was close to that of acarbose to α-amylase (IC 50 , 27.3 μg/mL). This may be because SL 2 has a variety of polyphenol structures and the primary mechanism of the effect of polyphenol inhibition may be attributed to the interactions of noncovalent bonds (hydrogen bonds) between enzymes and polyphenols . Likewise, the importance of hydroxyl groups of polyphenols in the interaction between the active site of α-amylase (Glu233) and amino acid residues has also been reported .…”

“…This may be because SL 2 has a variety of polyphenol structures and the primary mechanism of the effect of polyphenol inhibition may be attributed to the interactions of noncovalent bonds (hydrogen bonds) between enzymes and polyphenols. 31 Likewise, the importance of hydroxyl groups of polyphenols in the interaction between the active site of α-amylase (Glu233) and amino acid residues has also been reported. 32 Sun et al had shown through molecular docking analysis that the hydroxyl groups of polyphenols make a contribution to the inhibition effect.…”

Dihydrochalcone glycoside biosynthesis in Malus is regulated by two MYB‐like transcription factors and is required for seed development

“…DHCs have biological activities that can benefit human health, especially in the treatment of type 2 diabetes. Phlorizin and clinical drugs, such as empagliflozin and ertugliflozin developed from it, prevent the reabsorption of glucose in the kidney by inhibiting sodium glucose co‐transporter 2 activity (Dong et al., 2012; Ehrenkranz et al., 2005; Niu et al., 2022; Xiao et al., 2021). Trilobatin is a natural, non‐calorific sweetener, being ~35–100× sweeter than sucrose (Jia et al., 2008; Wang et al., 2020).…”