Figure 1.

In vitro skin antioxidant effects of tyndallized Lactobacillus acidophilus (AL). (a) Primary human keratinocyte (HaCaT) cells were subjected to ultraviolet-B (UVB) irradiation (30 mJ/cm²) in the absence or presence of AL (50–200 µg/mL), and the resulting reactive oxygen species (ROS) levels were determined with a H2DCFDA staining assay. (b) Cell viability of HaCaT cells treated with the indicated dose of AL (50–200 µg/mL) for 24 h was measured using the tetrazolium colorimetric (MTT) assay. (c) HaCaT cells were subjected to UVB irradiation (30 mJ/cm²) and treated with the indicated dose of AL (50–200 µg/mL) for 24 h. The cytoprotective effects of AL were measured using the MTT assay. (d) The ABTS radical scavenging activity of AL at the indicated concentration (25–400 µg/mL) was measured. +: indicate treatment, −: indicate non-treatment. For all applicable experiments, statistical significance was evaluated using the Mann–Whitney U test. ## p < 0.01 compared with the normal group, ** p < 0.01 compared with the control group.