ANGIOTENSIN CONVERTING ENZYME INHIBITORY ACTIVITY OF MELINJO (GNETUM GNEMON L.) SEED EXTRACTS AND MOLECULAR DOCKING OF ITS STILBENE CONSTITUENTS

Abstract

ABSTRACTObjectives: To evaluate the angiotensin converting enzyme (ACE) inhibitory activity of melinjo (Gnetum gnemon) seed extract and to study moleculardocking of stilbene contained in melinjo seeds.Methods: Melinjo seed powders were extracted with n-hexane, dichloromethane, ethyl acetate, methanol, and water successively. The extracts wereevaluated ACE inhibitory activities using ACE kit-Wist and the phenolic content using Folin–Ciocalteu method. The extract demonstrated the highestACE inhibitory activity was subjected to liquid chromatography-mass spectrometry (LC-MS) to know its stilbene constituent. The stilbene constituentsin melinjo seed were performed molecular docking using AutoDock Vina, and ligand-receptor Interactions were processed using Ligand Scout.Results: The ethyl acetate extract demonstrated the highest ACE inhibition activity with inhibitory concentration 50% value of 9.77 × 10−8 μg/mLand the highest total phenolic content (575.9 mg gallic acid equivalent/g). Ultra-performance LC-MS analysis of ethyl acetate extract has detected theexistency of resveratrol, gnetin C, ε-viniferin, and gnemonoside A/B. These compounds displayed similar physiochemical properties to lisinopril (ACEinhibitor), as in silico molecular docking studies demonstrated that they fit into the lisinopril receptors.Conclusion: In vitro analysis ethyl acetate extract from melinjo seeds demonstrated the highest ACE inhibitory activity. Molecular docking analysisindicated that resveratrol dimers, gnetin C and gnemonoside A can be considered ACE inhibitor.Keywords: Angiotensin converting enzyme inhibitor, Gnetum gnemon, Melinjo, Total phenolic, Antihypertension, Molecular docking.