Combined Effects of Caffeine and Prostaglandin E2 on the Proliferation of Osteoblast-Like Cells (UMR 106-01).

Background: The general public widely consumes caffeine 1,3,7-trimethylxanthine), which is contained in various foods, beverages and over-the-counter medications. We have shown previously that caffeine intake could affect bone metabolism in vivo. Methods: Because prostaglandin E₂ (PGE₂) is shown to be elevated in the periodontally diseased site, the possible interaction between caffeine and PGE₂ was investigated in the present study using UMR106-01 rat osteoblast-like cells in vitro. Results: Although neither 0.1 mM caffeine nor 0.1 µg/ml of PGE₂ alone showed any inhibitory effects on cell proliferation, the combination of caffeine and PGE₂ showed significant inhibition. However, in order to have inhibitory effects, both caffeine and PGE₂ had to be present at least 72 or 96 hours in the medium. Addition of the endogenous PGE₂ synthesis inhibitor, indomethacin, showed no effects on cell proliferation. Neither cAMP-inducing agent IBMX (0.01 mM and 0.1 mM) nor forskolin (0.001 mM) inhibited cell proliferation, but combined with PGE₂ these agents strongly inhibited proliferation ns was observed with the combination of caffeine and PGE₂, suggesting possibly that the increase of intracellular cAMP concentration plays an important role in the inhibitory effects of cell proliferation. Conclusions: The present data for the first time demonstrate the possible implication of routine caffeine intake in the acceleration of pathological conditions of periodontitis. Thus, we propose that chronic caffeine intake is one of the possible risk factors in the advancement of pathology in the periodontitis patient Further research in this area is warranted. [ABSTRACT FROM AUTHOR]