Aims: Lactobacillus rhamnosus GG (L. rhamnosus GG) possess immunomodulatory effects in the host. In the present study, the effect of L. rhamnosus GG on cyclooxygenase 2 (COX2) expression and its pharmacological control was investigated in human T84 colon epithelial cells.
Methods and results: T84 cells were exposed to freeze-dried L. rhamnosus GG in vitro, and the expression of COX2 was detected by Western blot.
Conclusions: L. rhamnosus GG induced COX2 expression in a time- and concentration-dependent manner in T84 cells. COX2 expression was inhibited by tyrosine kinase inhibitor genistein (100 micromol l(-1)), p38 mitogen-activated protein kinase (MAP kinase) inhibitor (SB203580; 1 micromol l(-1)) and dexamethasone (10 micromol l(-1)), whereas inhibitors of p42/44 MAP kinase (PD98095; 10 micromol l(-1)), protein kinase C (Ro 31-8220; 1 micromol l(-1)) and transcription factor nuclear factor kappa B (NF-kappaB) [pyrrolidinedithiocarbamate (PDTC) 100 micromol l(-1)] had practically no effect.
Significance and impact of the study: The results provide novel information on the cellular mechanisms involved in the interaction between L. rhamnosus GG and colon epithelial cells.