Alpha-glucosidase and DPP-IV Inhibitory Activities of Ethanol Extract from Caesalpinia sappan, Andrographis paniculata, and Syzygium cumini

Background: Diabetes is one of the fastest-growing global health problems of the 21^st century. Antidiabetic medicine has been widely marketed with various mechanisms of action. However, there are side effects from these drugs. Therefore, most diabetic patients consume herbal as complementary. Plants that have been shown to have potential as an antidiabetic are Caesalpinia Sappan, Andrographis Paniculata and Syzygium Cumini. Objective: This study aims to examine the in vitro antidiabetic activity of single and combined ethanol extract of those three plants by inhibiting alpha-glucosidase and DPP-IV (Dipeptidyl peptidase IV) enzymes. Materials and Methods: The alpha-glucosidase inhibitory activity was determined using the paranitrofenil alfa-D-glukopiranosida (pNPG) reaction at a wavelength of 405 nm. Acarbose was used as the positive control. The DPP-IV inhibitory activity using H-Gly-Pro-AMC substrate and detected by fluorescence at λex = 365 nm and λem=415-445 nm. Sitagliptin was used as the positive control. LC-MS analysis was performed to identify the compounds contained in the combined extract. Results: Caesalpinia sappan showed better activity to inhibit alpha-glucosidase enzyme than acarbose at IC₅₀ of 9,29 μg/mL. The combined extract obtained higher inhibition as DPP-IV inhibitor than single extract at 63, 69%. The highest compound in the combined extract were 5,7-Dihydroxy-3-(4'-hydroxybenzyl) chromone, Protosappanin E-1, Saurufuran B and candidate mass C₃₆H₃₈N4O₅. Conclusion: These results indicate that single extract or combined extract potential as antidiabetic.