Antioxidant and Alpha Glucosidase Inhibitor Screening of Merremia peltata L. as Potential Traditional Treatment for Diabetes Mellitus

Introduction: Merremia peltata is ethnomedicine plant used as traditional medicine in Sulawesi, Sumatra, Maluku and Papua. M. peltata is used for diabetic. Diabetes mellitus therapy with inhibit activity of alpha glucosidase enzyme could delay absorption of monosaccharides after a meal and interrupt glucose transport into the circulation. Objective: This research purpose is to investigate in vitro antioxidant activity and alpha glucosidase enzyme inhibitor leaves and stem extract of M. peltata. Method: The Stem and leaves of M. peltata were extracted sequentially using the UAE method using hexane, ethyl acetate, and methanol as mobile phase/solvent. The M. peltata extracts were subjected to the antioxidant activity assay by the DPPH radical scavenging and FRAP method. Antidiabetic activity was determined by an enzymatic alpha glucosidase inhibitor. Result: The extract which had best performance in antioxidant activity was stem ME with value of IC₅₀ in DPPH 47.41 μg/mL and total antioxidant power 340.04 μmol/g. This study showed that leaves and stem extract of M .peltata have potential alpha glucosidase inhibitors for diabetic therapy. Stem ME had the best activity with IC₅₀ value 47.44 μg/mL, almost two times better than acarbose as a positive control (IC₅₀ = 98.38 μg/mL). Leaves ME, leaves EA, and stem EA also give better activity of alpha glucosidase inhibitors than acarbose with IC₅₀ value 67.24 μg/mL, 69.38 μg/mL, and 72.85 μg/mL, respectively. Conclusion: M. peltata has potential antioxidant and alpha glucosidase inhibitor activity for diabetic therapy.