Antioxidant Activity of Averrhoa bilimbi Linn. Leaves Extract Using Two Different Types of Solvents

Abstract

Exposed to the pollution has led to generation of reactive oxygen species (ROS) in human skin. ROS generated cause many skin diseases such as skin-aging, inflammation, melanogenesis and skin cancer. ROS is a family of oxygen-based free radicals that contains or capable of producing an unpaired electron. Antioxidant is a molecule that can inhibit the reaction of free radical from ROS by donating its electron. Averrhoa bilimbi Linn. (AVBL) is one of the potent natural antioxidant belongs to the group of Oxalidaceae which can be widely found in Asia including Malaysia. Traditionally, this plant has been used to treat many diseases such as cough, itchiness, pimple, fever and inflammation. As a result, much attention has been directed towards the studies regarding the potential of this plant in treating disease. The present study was undertaken to assess the antioxidant activity of AVBL leaves extract. The AVBL leaves were extracted using sonicator with ethanol and distilled water as two different types of solvent. The total phenolic content (TPC) and flavonoid content (TFC) of this study were determined by using Folin-Ciocalteu reagent and aluminium chloride colometric assay. Antioxidant activity of the plant extract was tested using 2,2- diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing power (FRAP). From the analyses, water extract of AVBL possessed greater extraction yield (11.231%) as compared to ethanolic extract (5.358 %). However, ethanolic extract of AVBL leaves revealed higher result of TPC (126.4±0.35 mg/g gallic acid equivalent), TFC (32.80±0.37 mg/g quercetin equivalent), DPPH (0.0019±0.0003) and FRAP (41.81±0.45 mg/g gallic acid equivalent). The results of TPC and TFC have strongly positive correlation with antioxidant capacity (r = 1). Thus, it can be concluded that this plant is a potent source of natural antioxidant.