Antidiabetic properties of dietary phenolic compounds: Inhibition effects on α-amylase, aldose reductase, and α-glycosidase.

Aldose reductase (AR), α-amylase, and α-glycosidase are vital enzymes to prevent diabetic complications. Here, AR was purified from sheep kidney using elementary methods with 111.11-purification fold and with 0.85% purification yield. The interactions between some phenolic compounds and the AR, α-glycosidase, and α-amylase enzyme were determined. It was found that phenolic compounds exhibit potential inhibitor properties for these enzymes. For α-amylase, studied phenolic compounds showed IC50 values in the range of 601.56-2,067.78 nM. For α-glycosidase, Ki values were found in the range of 169.25 ± 27.22-572.88 ± 106.76 nM. For AR, Ki values in the range of 8.48 ± 0.56-43.26 ± 7.63 µM. However, genistein showed the best inhibition effect toward AR and α-glycosidase, but delphinidin chloride exhibited the best inhibition effect against α-amylase enzyme. We determined that all compounds showed noncompetitive inhibition effect against AR and α-glycosidase. Also, studied phenolic compounds may be useful in the prevention or treatment of diabetic complications.