## 3 Results
### FBCC-EP858, FBCC-EP920, and FBCC-EP1014 Exhibit Strong DPPH Radical Scavenging Activity
Treatment with H\({}_{2}\)O\({}_{2}\) increased DCFDA fluorescence (green) in zebrafish larvae, and FBCC-EP858, FBCC-EP920, and FBCC-EP1014 gradually diminished the fluorescence intensity in a concentration-dependent manner (Figure 3C,D). The results indicate that FBCC-EP858, FBCC-EP920, and FBCC-EP1014 can attenuate H\({}_{2}\)O\({}_{2}\)-induced ROS production both in vitro and in vivo. Figure 3: ROS production in vitro and in vivo. (**A**,**B**) RAW 264.7 macrophages were seeded at a density of 5 \(\times\) 10\({}^{4}\) cells/mL and treated with the indicated concentrations of FBCC-EP858 (0–100 \(\upmu\)g/mL), FBCC-EP920 (0–50 \(\upmu\)g/mL), and FBCC-EP1014 (0–100 \(\upmu\)g/mL) for 24 h, and 200 \(\upmu\)M hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)) was treated for 4 h. (**A**) The cells were stained using a Muse Oxidative Stress Kit, and (**B**) ROS\({}^{+}\) cell population was analyzed using a Muse Cell Analyzer. (**C**,**D**) The indicated concentrations of FBCC-EP858, FBCC-EP920, and FBCC-EP1014 were applied to 3 dpf zebrafish larvae 2 h before the addition of 1 mM H\({}_{2}\)O\({}_{2}\) for 22 h. (**C**) The larvae were stained using 20 \(\upmu\)M DCFDA for 30 min and visualized using a CELENA S Digital Imaging System. (**D**) The DCFDA fluorescence intensity was calculated using ImagJ 1.50i. Each value represents the mean \(\pm\) SEM from three independent experiments. Significant difference: *** \(p<0.001\) vs. untreated group (Student’s \(t\)-test) and *** \(p<0.001\) vs. H\({}_{2}\)O\({}_{2}\)-treated group (one-way ANOVA). FBCC-EP858, FBCC-EP920, and FBCC-EP1014 Maintain Mitochondrial Membrane Potential in H\({}_{2}\)O\({}_{2}\)-Treated RAW 264.7 Macrophages  
As oxidative stress is responsible for ROS-mediated cellular damage and depolarization of mitochondrial membrane potential [36], we investigated whether the reduction of ROS by FBCC-EP858, FBCC-EP920, and FBCC-EP1014 could preserve mitochondrial membrane potential in H\({}_{2}\)O\({}_{2}\)-treated RAW 264.7 cells. As illustrated in Figure 4A,B, H\({}_{2}\)O\({}_{2}\) caused a significant increase in the total cell population with depolarized mitochondria membrane potential. However, treatment with FBCC-EP858, FBCC-EP920, and FBCC-EP1014 decreased the population and maintained mitochondrial membrane potential. These results suggest that FBCC-EP858, FBCC-EP920, and FBCC-EP1014 are able to prevent oxidative stress-induced depolarization of mitochondrial membrane potential. FBCC-EP858, FBCC-EP920, and FBCC-EP1014 Hypegulate the Expression of Nrf and HO-1 in RAW 264.7 Macrophages  
To confirm whether FBCC-EP858, FBCC-EP920, and FBCC-EP1014 can increase the expression of Nrf2 and HO-1, we performed RT-PCR and western blotting. Our results showed that treatment with FBCC-EP858 (Figure 5A), FBCC-EP920 (Figure 5B), and FBCC-EP1014 (Figure 5C) led to a concentration-dependent upregulation of _Nrf2_ and _HO-1_ expression in RAW 264.7 macrophages. Furthermore, consistent with gene expression data, FBCC-EP858 (Figure 6A), FBCC-EP920 (Figure 6B), and FBCC-EP1014 (Figure 6C) were  
Figure 4: Mitochondrial membrane potential. RAW 264.7 macrophages were seeded at a density of 5 \(\times\) 10\({}^{4}\) cells/mL and treated with the indicated concentrations of FBCC-EP858 (0–100 \(\upmu\)g/mL), FBCC-EP920 (0–50 \(\upmu\)g/mL), and FBCC-EP1014 (0–100 \(\upmu\)g/mL) for 2 h followed by treatment with 200 \(\upmu\)M H\({}_{2}\)O\({}_{2}\) for 22 h. (**A**) The cells were stained using a Muse MitoPotential Kit, and (**B**) mitochondrial membrane depolarized cell population was analyzed using a Muse Cell Analyzer. Each value indicates the mean \(\pm\) SEM from three independent experiments. Significant difference: *** \(p<\) 0.001 vs. untreated cells (Student’s \(t\)-test), and *** \(p<\) 0.001, *** \(p<\) 0.01 and * \(p<\) 0.05 vs. H\({}_{2}\)O\({}_{2}\)-treated group (one-way ANOVA). found to increase Nrf2 and HO-1 expression. These findings suggest that FBCC-EP858, FBCC-EP920, and FBCC-EP1014 can enhance Nrf2 and HO-1 expression. Figure 5: _Nrf2_ and _HO-1_ expression.