Total Phenolic and Flavonoid Content and In Vitro Antioxidant Activity of Methanol Extract and Solvent Fractions of Desmodium ramosissimum G. Don

Abstract

Oxidative stress has been linked to the pathogenicity of many diseases. This study investigated the total phenolic content (TPC) and total flavonoid content (TFC) of the methanolic extract and solvent fractions (n-hexane, ethyl acetate, n-butanol, and aqueous) of Desmodium ramosissimum using Folin–Ciocalteu and aluminum chloride assays, respectively. The extract and solvent fractions were further appraised for their in vitro antioxidant capacity using total antioxidant capacity (TAC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and ferric reducing antioxidant power (FRAP) methods at varying concentrations of 25–300 µg/mL. Results revealed that ethyl acetate and n-butanol fractions possessed elevated levels of TPC and TFC when compared to other solvent fractions and extracts in a concentration-dependent manner. The ethyl acetate fraction had the highest TPC (532.36 mg GAE/g), TFC (2843.33 mg QE/g), and ferric reducing potential (56.70 mg GAE/g) at 300 µg/mL. In addition, at 300 µg/mL, the TAC (77.33 mg AAE/g) of the n-butanol fraction and its DPPH radical scavenging ability (86.04%) were higher. As shown in this study, organic solvents with different chemical natures are capable of extracting chemical constituents with antioxidant components of different polarities, and D. ramosissimum may also be considered a rich source of natural antioxidants, justifying its pharmacological use in traditional medicine.