In vitro antioxidant activity of meniran (Phyllantus urinaria) functional drink in human low density lipoprotein (LDL)

Abstract

Preparation process for meniran (Phillantus urinaria) functional drink (MFD) influences its antioxidant activity. This research aims to understand the phenolic content, DPPH Radical Scavenging Activity (RSA), and LDL oxidation of MFD through various preparation processes. Those preparation processes included soaking fresh meniran (SFM), boiling fresh meniran for 5 minutes (BFM5’), boiling fresh meniran for 10 minutes (BFM10’), and soaking dried meniran (DM). The phenolic content was determined with Folin–Ciocalteu, antioxidant activity was assessed using DPPH and TBARS assay with LDL as the oxidation substrate. An antioxidant references in this research used ascorbic acid. The phenolic content in methods of SFM, BFM5’, BFM10’ and DM were 122±0.022, 182±0.043, 192 ±0.03, and 117 ±0.019 mg GAE/g of meniran respectively. Meanwhile, the DPPH RSA of SFM, BFM5’, BFM10’ and DM accounted for 82.18±0.35, 86.19±0.53, 86.75±0.64 and 69.96% respectively. As comparison, the DPPH RSA of ascorbic acid 50 ppm is 75.65±0.82%. At the same time the optimum inhibition of TBARS formation from BFM5’ and BFM10’ methods were 45.83 % and 48.66%, with MDA concentration in human LDL accounted for 38.30±2.39 and 36.30±1.82 nmol MDA/mg protein, respectively. As comparison, MDA concentration in human LDL added with ascorbic acid 25 ppm accounted for 41.35±2.41 nmol MDA/mg protein. In contrast, the control human LDL was 70.70±2.35 nmol MDA/mg protein. This study concludes that the BFM5’ and BFM10’ methods showed the highest antioxidant properties compared to other methods. All methods showed that MFD extract in concentration more than 25 ppm increased the concentration of MDA in human LDL. Therefore, to produce meniran functional drink in optimum antioxidant properties is best by using BFM5’ and BFM10’ preparation methods in meniran concentration of not more than 25 ppm.