3.5.4. Fe2<sup>+</sup> Chelating Activity

It has been reported that Fe2<sup>+</sup> is a powerful pro-oxidant among various metal ions and Fe2<sup>+</sup> chelation may prevent oxidative damage through retarding metal-catalyzed oxidation and inhibiting ROS production [42]. In this work, the Fe2<sup>+</sup> chelating activity of the *P. cretica* extract was determined and compared with a chelating standard (EDTA-2Na). As shown in Figure 7, at different test doses of 50, 100, 200, 400, 800, and 1600 <sup>μ</sup>g/mL, the Fe2<sup>+</sup> chelating activity of the *P. cretica* extract was 4.74 <sup>±</sup> 1.77, 9.98 ± 1.89, 18.65 ± 1.86, 31.56 ± 2.48, 51.87 ± 2.17, and 74.21 ± 1.83%, respectively, with an IC50 value of 713.41 μg/mL. According to these results, it could be concluded that the *P. cretica* extract had certain Fe2<sup>+</sup> chelating activity.

**Figure 7.** Fe2<sup>+</sup> chelating activity of the *P. cretica* extract obtained by optimized ultrasound-assisted compared with EDTA-2Na.
