The antioxidant activity of the essential oil and extracts was assessed
by their ability to scavenging 2,2-diphenyl-1-picrylhydrazyl
stable radicals (DPPH) by using the method
described previously (Shimada et al., 1992). Briefly, 1 mL of
methanolic extract and 5 mL of freshly prepared 0.1 mM
DPPH methanolic solution were thoroughly mixed and kept
in the dark for 60 min. The absorbance of the reaction mixture
at 517 nm was measured with a spectrophotometer. The blank
was prepared by replacing the extract with methanol (1 mL).
The percentage of free radical scavenging activity was calculated
as follows: