DPPH• scavenging activity was measured according to a previously
published method with some modifications
One half milliliter of each extract
solution was added to 1 ml of a freshly prepared 0.1 mM DPPH
solution dissolved in methanol.
The mixture was shaken and
left to stand at room temperature for 30 min in the dark.
The
absorbance was detected at 517 nm using a spectrophotometer
against a control.
The results were expressed as an IC50
value, which is the concentration of the extract that scavenges
50% of the DPPH•.