Free radical scavenging (DPPH.) assay Free radical scavenging was determined by using
the free radical generator DPPH (2,2-diphenyl-1- picrylhydrazyl) assay based on slight modification (Yen and Hsieh, 1997). An aliquot (1 ml) of the serially diluted extract samples was thoroughly mixed to which 1 ml of 500 μM DPPH solution was added.