Evaluation of antioxidant activity of plant
extract
1,1-Diphenyl-2-picrylhydrazyl (DPPH) was
prepared by taking 1 mg of DPPH in 25 ml
methanol to make 100 µl solution. The stable
DPPH radical was used for the determination of
antioxidant activity. Different concentrations of
extract in respective solvents were added at an
equal volume of 10 µl to 90 µl of 100 µM
methanolic DPPH solution in a total volume of
100 µl in 96 well plates. The contents were
mixed and incubated at 37 °C for 30 min.
Ascorbic acid was used as standard antioxidant.
The reduction in absorbance was measured at
517 nm by using microplate reader; in
comparison with the control solution (maximum
absorption). The decrease in absorbance
indicates increased scavenging activity. The
DPPH radical scavenging activity is mentioned
as percentage [7].