Antioxidant/cytoprotective effects of L. gasseri OLL2809 or L13-Ia on LPS-pulsed DCs. Intracellular and extracellular (upper inserts) thiol concentrations (A, D, G), GST (B, E, H) and NQO1 activities (C, F, I) were measured in DCs challenged with irradiated strains (black bars), DCs exposed to conditioned media from MODE-K cells (SupMODE, dashed bars) or DCs incubated with supernatant from irradiated bacteria (SupOLL2809 and SupL13-Ia, empty bars). LPS-pulsed DC culture was used as control. Extracellular thiols are expressed as nmoles/min. Intracellular GSH levels are expressed as nmoles/mg prot/min. GST and NQO1 activities were measured in cytoplasmic extracts and the obtained values, upon normalization to the protein content, were expressed as nmoles 1-chloro-2,4-dinitrobenzene (CDNB)/mg/min and nmoles NAD/mg/min, respectively; columns represent the mean ± SD and are representative of three independent experiments. *, P < 0.05 **, P < 0.01; ***, P < 0.001.