Optimum Parameters for Extraction of Cinnamomum verum Leaves Towards α-Glucosidase Inhibition

Abstract

Cinnamomum verum (kayu manis) is an herb that possesses antidiabetic properties and has been used for the treatment of diabetes traditionally. However, there is insufficient scientific data to provide optimum extraction parameters for C. verum leaves for antidiabetic activities. This research aims to determine the optimum extraction parameters of C. verum leaves towards α-glucosidase inhibition and evaluate the correlation between α-glucosidase inhibition, total phenolic content and DPPH radical scavenging activity. The C. verum was extracted with water through an infusion method under different temperatures (60.0°C, 77.5°C, 95.0°C) and extraction time lengths (10 minutes, 20 minutes, 30 minutes). The optimization process was designed using Design Expert software, which applied the Response Surface Method (RSM) and Central Composite Design (CCD). The analyses conducted were antidiabetic property (α-glucosidase inhibition assay), total phenolic content (TPC) (Folin-Ciocalteu colorimetric method) and antioxidant property (2,2-diphenyl-1-picrylhydrazyl, DPPH radical scavenging activity). Results showed that the obtained optimum extraction parameters for C. verum leaves (81.10°C, 19.54 minutes) exhibited α-glucosidase inhibition (87.30±0.67%), total phenolic content (0.12±0.00 mg GAE/g) and DPPH radical scavenging activity (51.25±0.48%). The α-glucosidase inhibition positively correlates with DPPH radical scavenging activity and total phenolic content. These findings have provided a positive relationship between extraction temperature and extraction time length on antidiabetic properties of C. verum leaf extract.