2.4.3. Superoxide anion radical-scavenging activity
Superoxide anion radical-scavenging activity was measured
using a non-enzymatic method (Kuda & Ikemori, 2009). The sample
solution (0.1 mL) was treated with 0.05 mL of 250 mmol/l
phosphate buffer (pH 7.2), 2 mmol/l NADH (0.025 mL), and
0.5 mmol/l NBT (0.025 mL), while absorbance at 560 nm was measured
as a blank value. After a 5-min incubation at ambient temperature
with 0.025 mL of 0.03 mmol/l PMS, the absorbance was
measured again. The radical-scavenging capacity was calculated
using the above formula.