Background: Black carrot is known to be effective against Type 2 diabetes. The phenolic
compounds present in black carrot are responsible for this property, but limited information was
available about the mechanism of action and target enzymes.
Objective: The present study aims at understanding molecular interactions of phenolic compounds
of black carrot with enzymes involved in glucose metabolism in human to identify the potential
inhibitor that can be used as candidate drug molecule to control diabetes.
Method: In vitro assay for inhibition of α-amylase, α-glucosidase and DPP-IV was carried out using
black carrot purified extract and the standard inhibitor acarbose and vildagliptin, recpectively.
The inhibition activity of selected phenolic compounds was also studied by in silico docking with
all these three enzymes for the proper understanding of interactions. Encapsulation of purified
black carrot extract was also carried out.
Results: In vitro IC50 value of purified extract was found to be better than the standard inhibitor
acarbose for α-amylase and α-glucosidase, and vildagliptin for DPP-IV. Similarly, docking scores
of few anthocyanin molecules were found to be higher than their respective inhibitors, suggesting
more effective inhibition. Among anthocyanin molecules of black carrot, cyanidin 3-xylosyl galactoside
was found to be the potential drug to inhibit these enzymes, whereas dipeptidyl peptidase IV
was identified as the best target to control diabetes with anthocyanins of black carrot.
Conclusion: Anthocyanins from black carrot were found to be effective to control diabetes and
very first time we propose that cyanidin 3-xylosyl galactoside is the best potential molecule for inhibiting
enzymes involved in glucose metabolism. The study also shows the encapsulation of anthocyanin
compounds using β-cyclodextrin.