Fig 2: Schematic diagram of gallic acid treating dry eye through its anti-inflammatory and antioxidant effects. LPS, lipopolysaccharide; CD-14, clusterdifferentiation-14; MD-2, myeloid differentiation protein-2; TLR4, toll like receptor 4; IκB, inhibitor of NF-κB; P, phosphorylated; NF-κB P65, nuclear factor kappa-B P65; IL-6, interleukin 6; TNF-α, tumor necrosis factor alpha; NO, nitric oxide; ROS, reactive oxygen species; Keap1, Kelch-like ECH-associated protein 1; Nrf2, nuclear factor E2-relate factor-2; ARE, antioxidant response elements; HO-1, heme oxygenase-1; NQO-1, NADPH quinineoxidoreductase-1

Fig 3: Antioxidant effect of gallic acid (GA) on lipopolysaccharide (LPS)-activated oxidative stress. a Western blot analysis of p-Nrf2, HO-1, and NADPH quinone oxidoreductase-1 (NQO-1) proteins in RAW264.7 macrophages. b Confocal microscopy images of RAW264.7 macrophages. Cell nuclei are shown in blue (DAPI) and nuclear factor E2-related factor 2 (Nrf2) is shown in green. RAW264.7 macrophages were pre-treated with GA (100 µM) for 16 h followed by the stimulation of LPS (1 µg/mL) for another 8 h. Data are presented as mean ± SD (n = 3). *P < 0.05, **P < 0.01, ****P < 0.001 compared to the LPS group