Abstract.
Bungur (Lagerstroemia loudonii Teijsm. & Binn.) belongs to the Lytrhaceae that traditionally was used as antidiabetic, antiinflammatory, antihypertensive and diuretic. Other bungur plants such as Lagerstroemia speciosa have been known for the activity as alpha-glucosidase inhibitor. Based on chemotaxonomy, the distribution of compounds in one family or genus and its activity has similarities, then tested for the activity of alpha-glucosidase of Lagerstroemia loudonii Teijsm. & Binn. The leaves and fruits was extracted by reflux using 96% ethanol. The process of fractionation by liquid-liquid extraction. Testing of alphaglucosidase inhibitor activity was performed in vitro using colorimetric method at 400.4 nm, acarbose used as standard inhibitor. The results of alpha-glucosidase inhibitory activity of leaves with IC50 showed the ethanol extracts, n-hexane, ethyl acetate and water fractions respectively 262.20 pg/ml; 97.16 pg/ml; 62.73 pg/ml; 145.30 pg/ml; and fruits with IC50 showed the ethanol extracts, n-hexane, ethyl acetate and water fractions respectively 1.50 pg/ml; 3.69 pg/ml; 37.38 pg/ml; 22.59 pg/ml. IC50 standard acarbose was 10.95 pg/ml. The results of this research from Lagerstroemia loudonii Teijsm. & Binn. leaves and fruits can be developed into herbal preparations to lower blood glucose levels.