DPPH Radical Scavenging Assay: The
antioxidant activity of the extracts was measured
on the basis of the scavenging activity of the
stable 1, 1- diphenyl 2-picrylhyorazyl (DPPH)
free radical according to the method described by
Brand-Williams et al[22]
with slight
modifications. 1ml of 0.1mM DPPH solution in
methanol was mixed with 1ml of plant extract
solution of varying concentrations ( 50, 100, 150,
200 and 250 µg/ml). Corresponding blank sample
were prepared and L-Ascorbic acid (1-100 µg/ml)
was used as reference standard. Mixer of 1ml
methanol and 1ml DPPH solution was used as
control. The reaction was carried out in triplicate
and the decrease in absorbance was measured at
517nm after 30 minutes in dark using UV-Vis
spectrophotometer. The inhibition % was
calculated using the following formula.
Inhibition % = Ac-As/Ac×100