Fig. 2
The radical-scavenging activity of the non-polar and polar microalgae extracts. (a) Hydrogen peroxide (H2O2) scavenging activity. The microalgae extracts were incubated with 2′,7′-dichlorofluorescein diacetate (DCHF-DA) and H2O2 for 10 min. (b) Hydroxyl radical-scavenging activity. The microalgae extracts were incubated with DCHF-DA, H2O2, and FeCl2 for 10 min.; n = 12/group. Absorbance ratios were calculated by comparing the fluorescence of the microalgae extract-treated group to that of the control group, which was not treated with microalgae extracts. (c) Oxidation of HaCaT cells that were treated with H2O2 for 18 h after overnight pretreatment with the polar microalgae extracts. In the control group, the HaCaT cells were cultured for 18 h in the absence of H2O2 and polar microalgae extracts. Data are representative of two independent experiments and presented as the mean ± SD. p-values are determined by one-way ANOVA with Tukey’s multiple comparisons. *p < 0.05, *** p < 0.001, and **** p < 0.0001 vs. control