IN VITRO ALPHA-GLUCOSIDASE ENZYME INHIBITOR ACTIVITY ON ETHANOL EXTRACT OF EUCALYPTUS LEMON LEAVES (CORYMBIA CITRIODORA (HOOK.) K.D. HILL & L.A.S. JOHNSON), EUCALYTPUS LEAVES (MELALEUCA LEUCADENDRA (L.) L.), CLOVER BUDS (SYZYGIUM AROMATICUM (L.) MERR. & L.M. PERRY), AND SELECTED FRACTIONS

• Main Author: Putri Fauzia, Raina
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/82630
• Institution: Institut Teknologi Bandung

Diabetes mellitus (DM) is a chronic metabolic disease characterized by increased in blood glucose levels beyond normal limits. The ?-glucosidase (EAG) has a role as a catalyst for the process of breaking down polysaccharides into monosaccharides. Inhibitors of EAG activity are one of the treatments for patients suffering from type II DM. Lemon eucalyptus leaves (Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson), eucalyptus leaves (Melaleuca leucadendra (L.) L.), and clove buds (Syzygium aromaticum (L.) Merr. & L.M. Perry) have the potential to be inhibitors of EAG to lower blood glucose levels. This research aims to determine the inhibitory potential of the extracts and fractions of the three samples against EAG. EAG inhibitory activity was tested in vitro using a microplate assay and the absorbance was measured at a wavelength of 405 nm. Sample extraction was carried out by maceration method using 70% ethanol. The selected extract was continued to the fractionation process using the liquid-liquid extraction (LLE) using graded solvents, which were n-hexane and ethyl acetate. Acarbose, as a positive control in this EAG inhibition test had an IC50 of 83.94 ± 7.24 ?g/mL. The IC50 values of the ethanol extracts of lemon eucalyptus leaves, eucalyptus leaves, and clove buds were respectively 4.45 ± 0.24 ?g/mL, 9.20 ± 1.14 ?g/mL, and 9.44 ± 0.48 ?g/mL. Fractionation was carried out on selected extracts, namely lemon eucalyptus leaves, and the IC50 of the ethyl acetate fraction and water fraction were 8.29 ± 0.31 ?g/mL and 4.99 ± 0.37 ?g/mL, respectively. In general, the ethanol extract of lemon eucalyptus leaves, eucalyptus leaves, and clove buds as well as the ethyl acetate fraction and water fraction of the ethanol extract of lemon eucalyptus leaves have strong EAG inhibitory activity, so they have the potential to be developed as antidiabetics. Overall, the best IC50 value is shown by the ethanol extract of lemon eucalyptus leaves and the water fraction of lemon eucalyptus leaves.