The alkaloids isolated from RC may have beneficial effects on diabetic complications and DM due to the inhibitory activities against α-glucosidase or aldose reductase [49]. RC extract had the α-glucosidase inhibitory activity with the half maximal inhibitory (IC50) value at 3.528 mg mL(-1), which could be effective for treating DM, and the alkaloids were main components that inhibited α-glucosidase activity in RC extract [50]. This evidence concerns the gene AKR1B1 and diabetes mellitus.