*3.4. Oxidative Stress Assays*

The control of solvent evidenced no significant changes when cells were exposed to 0.3% of DMSO. However, HepG2 cells experienced a significant decrease in ROS levels when they were exposed to all the concentrations of the extract tested after 24 and 48 h, showing a greater decrease after the exposure to 20.6 μg/mL (Figure 5A). Moreover, GSH content underwent concentration-dependent enhancements in comparison to the negative control group after both times of exposure (Figure 5B).

**Figure 5.** ROS content (**A**) and GSH content (**B**) in HepG2 cells exposed to 0–31.18 μg/mL or 0–20.56 μg/mL stilbene extract (45%) during 24 h or 48 h, respectively. All values are expressed as mean ± SD. Differences were considered significant compared to the control group from *p* < 0.05 (\*), *p* < 0.01 (\*\*) and *p* < 0.001 (\*\*\*).

When Caco-2 cells were exposed to increasing concentrations of the extract, ROS content was significantly reduced (Figure 6A). GSH activity was increased significantly at the highest concentrations assayed, 55.77 μg/mL and 39.02 μg/mL for 24 and 48 h, respectively, with enhancements of 1.6 folds compared to the control negative group (Figure 6B).

**Figure 6.** ROS content (**A**) and GSH content (**B**) in Caco-2 cells exposed to 0–55.77 μg/mL or 0–39.02 μg/mL stilbene extract (45%) during 24 h or 48 h, respectively. All values are expressed as mean ± SD. Differences were considered significant compared to the control group from *p* < 0.05 (\*), *p* < 0.01 (\*\*) and *p* < 0.001 (\*\*\*).
