2.4 DPPH- Scavenging Activity of Extracts
The DPPH radical-scavenging activity of sample
extracts was determined through free radical scavenging
effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical
(22). Briefly, 900 μl of 0.1 mM DPPH in methanolic solution
was mixed with 100 ตl of samples in methanol. The mixture
was left to stand in the dark, for 15 min at room temperature.
Meanwhile, ascorbic acid (0.01-0.05 mg/ml) was used as
reference under the same conditions. An equal amount of
DPPH (900 ตl) and methanol (100 ตl) served as control.The
decrease in DPPH absorbance (Abs) was measured at
517 nm. The DPPH radical-scavenging activity was
calculated using the following formula: