2.4.3. Hydroxyl radical scavenging activity
Hydroxyl radical was generated by Fenton system to test the
hydroxyl radical scavenging activity of the inclusion complex
(Valentão et al., 2002). 1.5 mL phenanthroline (5 mM) was mixed
with 4.0 mL phosphate buffer (0.75 M, pH 7.4), 1.0 mL ferrous sulfate
(7.5 mM) and 2.5 mL sample solution was added and shaken,
then, 1.0 mL hydrogen peroxide (1.0%, w/v) was added to the
mixtures. After incubation at 37 ◦C for 1 h, the absorbance of the
resulting solution (Ax) was measured at 536 nm. According to the
above procedure, the sample solution was replaced by deionized
water, the absorbance (As) was measured, finally, both the sample
solution and hydrogen peroxide were replaced by the same volume
of deionized water, and the absorbance (A0) was obtained.
The hydroxyl radical scavenging effect (KH) was calculated using
the following equation: