Bifidobacterium longum HY8004 attenuates TNBS-induced colitis by inhibiting lipid peroxidation in mice

To investigate the mechanisms of the preventive activity of lactic acid bacteria in colitis, the inhibitory effect of Bifidobacterium longum HY8004, which potently inhibited lipid peroxidation in vitro, was examined in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitic mice. We measured the ability of lactic acid bacteria (LAB) to inhibit lipid peroxidation in vitro and to inhibit colitis outcomes, colon shortening, and myeloperoxidase activity in TNBS-induced colitis in C3H/HeN and C3H/HeJ mice. We also measured levels of the inflammatory markers interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha and their transcription factor, NF-kappa B, in the colon by enzyme-linked immunosorbent assay and immunoblot analysis. Among the LAB tested, B. logum HY8004 most potently inhibited lipid peroxidation in vitro but did not inhibit TLR-4-linked NF-kappa B activation in HEK cells. Oral administration of HY8004 inhibited TNBS-induced colon shortening and myeloperoxidase activity in the colon of C3H/HeN and C3H/HeJ mice as well as IL-1 beta and TNF-alpha expression. B. longum HY8004 also inhibited TNBS-induced lipid peroxidation, TLR-4 expression, and NF-kappa B activation in the colon of C3H/HeN and C3H/HeJ mice. B. longum HY8004 can improve colitis via the inhibition of lipid peroxidation as well as NF-kappa B activation.