Figure 4.

Intracellular reactive oxygen species (ROS) level in Caco-2 cells, measured as the fluorescence intensity (FI) of 20,70-dichlorofluorescin diacetate (DCFH-DA). Caco-2 cells were pretreated for 18 h with raw Portulaca oleracea L. juice (Raw-PJ), chemically acidified PJ (CA-PJ), and PJs fermented (30 °C for 36 h) by Lactobacillus plantarum POM1, T1.3, and EnFIII3, Lactobacillus brevis POM4, Lactobacillus rossiae 2MR8, Pediococcus pentosaceus CILSWE5, Leuconostoc mesenteroides OP9, and Lactobacillus kunkeei B7. Two hours before the end of the treatment, Caco-2 cells were treated with 10 µM H₂O₂ to induce oxidative stress. Bars with different superscript letters differ significantly (p < 0.05).