The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity assay
followed the method of Lim et al. (2023) with slight modifications.31 (link) The positive control used is ascorbic acid (AA)
with a concentration ranging from 0 to 25 μg. In 1.5 mL microcentrifuge
tubes, 50 μL of the positive control or the extracts was allowed
to react with 1 mL of 0.1 mM DPPH in the dark for 30 min. The blank
set (negative control) is prepared by adding 1 mL of methanol instead
of DPPH into the 50 μL extract samples and positive control.
Absorbance of the reaction and blank sets was measured at 518 nm using
a UV–vis spectrophotometer microplate reader (TECAN, infinite
M200 PRO). The half-maximal effective concentration (EC50) is calculated from the linear regression equation of the DPPH scavenging
activity scatter plot against the sample concentration.
followed the method of Lim et al. (2023) with slight modifications.31 (link) The positive control used is ascorbic acid (AA)
with a concentration ranging from 0 to 25 μg. In 1.5 mL microcentrifuge
tubes, 50 μL of the positive control or the extracts was allowed
to react with 1 mL of 0.1 mM DPPH in the dark for 30 min. The blank
set (negative control) is prepared by adding 1 mL of methanol instead
of DPPH into the 50 μL extract samples and positive control.
Absorbance of the reaction and blank sets was measured at 518 nm using
a UV–vis spectrophotometer microplate reader (TECAN, infinite
M200 PRO). The half-maximal effective concentration (EC50) is calculated from the linear regression equation of the DPPH scavenging
activity scatter plot against the sample concentration.
