Arginase inhibitory and antioxidant activities in syzygium cumini (L.) skeels leaves extracts collected from three different locations of java

Arginase inhibition and antioxidant activities may improve endothelial dysfunction. Previous studies demonstrated that Syzygium cumini leaves had pharmacological effects in diseases related to endothelial dysfunction, but there was no source linking the effect with arginase inhibitory activity. The aim of this study was to investigate arginase inhibitory and antioxidant activity of S. cumini leaves extract from different sources of simplisia, also determine its total phenolic content and gallic acid concentration. The leaves of S. cumini collected from Tangerang, Bogor and Sukoharjo city in Java, Indonesia. Arginase inhibition assay was done in vitro using colorimetric determination of urea which generated from L-arginine and arginase reaction. Antioxidant activity was evaluated using DPPH and FRAP methods. Total phenolic content of extract determined using Folin-Ciocalteu method. Gallic acid concentration was estimates using HPTLC. At a concentration of 50 μg/mL, all extracts exhibited arginase inhibition above 80%. However, the most active extract was sample collected from Bogor > Tangerang > Sukoharjo. Antioxidant activity of extract also came in that order. Determination of total phenolic content and gallic acid concentration of extracts revealed that S. cumini leaves collected from Bogor had the highest phenolic content (476.18 mgGAE/g) and gallic acid concentration (4.4 mg/g of extract). S. cumini leaves from different sources possessed different activity value on arginase inhibition, but not significant statistically. The leaves extract from Bogor, with the highest phenolic content and gallic acid concentration, showed the highest arginase inhibitory and antioxidant activity.