The ability of the extract to scavenge DPPH radical was determined
according to the method described by Mensor et al. (2001). One ml
of a 0.3 mM DPPH methanol solution was added to a solution of the
extract or standard (250 µg/ml, 2.5 ml) and allowed to react at room
temperature for 30 min. The absorbance of the resulting mixture
was measured at 518 nm and converted to percentage antioxidant
activity (AA %). Methanol (1.0 ml) plus extract solution (2.5 ml) was
used as a blank. 1 ml of 0.3 mM DPPH plus methanol (2.5 ml) was
used as a negative control. Solution of gallic acid served as positive
control.