Radical scavenging activity (RSA) of the extracts was determined
by the method of Singh et al. (2002). Briefly, 0.1 ml of
100-fold diluted extracts was taken in different test tubes. Five
millilitres of a 0.1 mM methanolic solution of DPPH was added to
the test tubes and vortexed for 10 s. The tubes were kept in a water
bath at 27 C for 20 min. The control was prepared as above using
0.1 ml of water instead of the extract. Absorbance of the resulting
violet coloured mixture was read at 517 nm after baseline correction
with methanol. Radical scavenging activity was expressed as
the inhibition percentage and was calculated using the following
formula: