DPPH radical scavenging activity
Experiments were carried out as described previously (Yıldırım et al., 2001). Briefly, 0.5 mM DPPH (Fluka) radical solution in methanol was prepared, and then 1 ml of this solution was mixed with 3 ml of the sample solution. Final concentrations of extracts were 100 and 300 μg/ml. BHT was used as a positive control at the same concentrations. After incubation for 30 min in the dark, the absorbance was measured at 517 nm. Decreasing the absorbance of the DPPH solution indicates an increase in DPPH radical scavenging activity. This activity is given as percent DPPH radical scavenging, which is calculated with the equation