In vitro Antioxidant Activity in DPPH Assay

The in vitro free radical scavenging activities of the crude extract, solvent fractions, and ascorbic acid were determined by using diphenyl-2-picrylhydrazyl (DPPH; Sigma Aldrich) assays according to the methods described by Blois³⁷ and Desmarchelier et al.³⁸ Different concentrations of 100 mL of a methanolic solution ranging from 50–1,000 mg/mL were added to 3.9 mL of a 0.004% methanolic solution of DPPH. The absorbance was measured at 517 nm after 30 minutes, and the percentage inhibition of DPPH was calculated. The percentage of the scavenging of the DPPH free radical was calculated by the formula: (A0-A1)/A0*100, where A0 is the absorbance of the control and A1 is the absorbance of the extract/standard. All experiments were performed in triplicate measurements.