2.1. Hydroxyl radical-scavenging activity:
Hydroxyl radical scavenging activity of extract was measured according to the method of
Halliwell et al. (1987) [11]. One milliliter of the final reaction solution consisted of aliquots
(500 µL) of various concentrations of the extract, 1 mM FeCl3, 1 mM EDTA, 20 mM H2O2,
1 mM L-ascorbic acid, and 30 mM deoxyribose in potassium phosphate buffer (pH 7.4). The
reaction mixture was incubated for 1 h at 37 °C, and further heated in a boiling water bath for
15 min after addition of 1 mL of 2.8% (w/v) trichloroacetic acid and 1 mL of 1% (w/w) 2-
thiobarbituric acid. The color development was measured of 532 nm against a blank
containing phosphate buffer