Paraprobiotic Levilactobacillus brevis KU15151 exhibits antioxidative and anti-inflammatory activities in LPS-induced A549 cells.

Levilactobacillus brevis KU15151, isolated from kimchi, has been reported in previous studies to possess probiotic properties. Here, we sought to explore the potential of heat-killed L. brevis KU15151 in improving respiratory health by identifying its antioxidant and anti-inflammatory effects in LPS-induced A549 cells. Inactivated L. brevis KU15151 exhibited strong DPPH and ABTS radical-scavenging abilities (48.78 ± 3.95 % and 69.08 ± 1.09 %) and effectively reduced the production of reactive oxygen species (25.32 %). In addition, it was found to have anti-inflammatory effects by inhibiting phosphorylation of ERK 1/2 (0.556), JNK (0.476), p38 MAPK (0.580), p65 (0.579), and IκB-α (1.170), which are involved in MAPK and NF-κB signaling. It also suppressed the mRNA expression of pro-inflammatory cytokines (0.173-0.617), which are important factors in respiratory diseases. IL-6 (19.47 %) and eotaxin (50.19 %) levels were reduced as measured by ELISA. Therefore, heat-killed L. brevis KU15151 is expected to improve respiratory health.