Antidiabetic activity and phytochemical screening of extracts from indonesian plants by inhibition of alpha amylase, alpha glucosidase and dipeptidyl peptidase IV

Active compounds of plants have potency as antidiabetic that can be used in diabetes mellitus treatment. One of the strategies is maintaining postprandial glucose level through inhibition of α-amylase and α-glucosidase and preventing the hydrolysis of Glucagon Like Peptide-1 (GLP-1) through inhibition of Dipeptidyl peptidase IV. So that pre-prandial and post-prandial glucose levels can be controlled properly. The aim of this study was to determine in vitro inhibitory activity of α-glucosidase, α-amylase and Dipeptidyl peptidase IV from 42 ethanolic extracts of selected Indonesian plants. Inhibitory activity was measured using spectrophotometric method. α-amylase activity was measured at λ = 540 nm, α-glucosidase activity and the DPP-IV activity were measured at λ = 405 nm. Eight extracts inhibit both α-glucosidase and α-amylase better than acarbose as a positive control. These extracts are Camelia sinensis (white, green, fermented), Pometia pinnata, Syzygium polyanthum, Artocarpus heteropyllus, Lagerstroemia speciosa and Persea Americana. The ethanolic extracts have DPP-IV inhibitory activity between 10-20%, lower than Diprotin as positive control, except Camelia sinensis (white) which gave the inhibition more than 30% at 62.5 μg mL^-1. This study showed us that some extracts have inhibition activity of α-glucosidase, α-amylase and DPP-IV.