Anti-inflammatory effects of H 2 S during acute bacterial infection: a review.

Hydrogen sulfide (H2 S), previously only considered a toxic environmental air pollutant, is now increasingly recognized as an important signaling molecule able to modulate several cellular pathways in many human tissues. As demonstrated in recent studies, H2 S is produced endogenously in response to different cellular stimuli and plays different roles in controlling a number of physiological responses. The precise role of H2 S in inflammation is still largely unknown. In particular, the role of H2 S in the regulation of the inflammatory response in acute and chronic infections is being actively investigated because of its potential therapeutic use. To study the effect of H2 S as an anti-inflammatory mediator during bacterial infections, we developed an ex vivo model of primary cells and cell lines infected with Mycoplasma. Our data demonstrate a dichotomic effect of H2 S on the NF-kB and Nrf-2 molecular pathways, which were inhibited and stimulated, respectively.