DPPH free radical scavenging assay

DPPH° scavenging activity of plant extract was calculated by recording the potential of extracted sample to reduce DPPH° into DPPH-H (a colorless compound). The antioxidant potential of plant extract was measured by DPPH° scavenging assay with mild modification.²¹ Briefly, 0.1 mL of plant extract (62.5-500 mg/mL) was added in 2 mL of DPPH° solution (0.1 mM) in methanol and the mixture was allowed to stand for 1 h in dark at room temperature. The absorbance was measured at 517 nm. Free radical scavenging activity of plant extract was calculated by using following formula:

where the initial and final absorbance are the absorbance values of DPPH° at zero time and after 1 h of plant extract addition.