A 75 μl DPPH solution was added to 3 ml methanol and the absorbance was taken immediately at 516 nm for con¬trol reading.
Different concentrations of standard and test samples were diluted with methanol up to 3 ml and 75 μl of DPPH was added.
The absorbance was taken immediately after addition of DPPH solution at 516 nm using Shimadzu 1800 spectrophotometer.
Methanol was used as a blank. Decrease in absorbance in presence of test samples at dif¬ferent concentration was noted after 10, 20 and 30 min.
The % reduction and IC50 were calculated as follows