Antioxidant activity and intracellular ROS levels in response to HGSL DHLs (DH005, DH014, and DH026). (a) DPPH and ABTS radical scavenging activity of DH005, DH014, and DH026 compared to pak choi and ascorbic acid (AA, 100 µM) as a positive control. (b) RAW264.7 cells were preincubated with L-NMMA (200 μM), HGSL DHLs, or the pak choi extract for 1 h, followed by stimulating with LPS (10 ng/mL) for 16 h. Intracellular ROS production was determined with 2,7-dichlorofluorescein diacetate (DCF-DA) staining. Data are presented as the mean ± SEM with statistical significance indicated as * p < 0.05, ** p < 0.01, and *** p < 0.001 compared to the control, LPS-only, or pak choi-treated group.