Evaluation of antioxidant properties from different parts of Phaleria macrocarpa (Mahkota Dewa) and optimization studies of selected plant part

Abstract

Phaleria macrocarpa is a medicinal plant originates from Papua Island, Indonesia. It shows potential application in ethno-pharmacological properties due to the presence of large amounts of bioactive compounds. In this study, there different parts such as stem, leaves and fruits were selected for its antioxidant activity evaluation. Firstly, Folin-Ciocalteu assay was used for the total phenolic content (TPC) analysis while aluminiumchloride assay was employed for the determination of total flavonoids content (TFC). Moreover, the antioxidant activity was done by using 1,1-diphenyl-2-picryhydrazyl (DPPH) assay. The extraction of phenolic compounds from P. macrocarpa was done by Ultrasound Assisted Extraction (UAE). Additionally, the stem, leaves and fruits of this plants were examined to contain 8.833±1.3915 mg GAE/g dw, 15.851±1.2343 mg GAE/g dw and 23.210±0.0468 mg GAE/g dw respectively for TPC analysis while it consists of 2.281±0.1804 mg QE/g dw, 12.057±0.1503 mg QE/g dw and 25.2517± 0.0868 mg QE/g dw in TFC analysis. Based on the two analysis conducted, it was deduced that fruits achieved the highest value in both Folin-Ciocalteu and aluminium chloride assays. Nevertheless, the fruits also exhibited the highest antioxidant activity of 92.41% which was in correlation with the TPC and TFC findings and hence it was chosen for the optimization studies. Response Surface Methodology under the Design of Expert software was employed to analyze the optimum parameters required for the antioxidant activity. The result showed that the optimum conditions for the highest antioxidant activity were 96.91% with the extraction temperature of 500C, extraction time of 40 minutes and 1 g: 30 ml solid to solvent ratio.