Exogenous hydrogen sulfide protects against global cerebral ischemia/reperfusion injury via its anti-oxidative, anti-inflammatory and anti-apoptotic effects in rats.

The present study was undertaken to study the effects of exogenous hydrogen sulfide (H(2)S) on global cerebral ischemia-reperfusion(I/R) and the underlying mechanisms. After a 24h I/R, administration of NaHS, an exogenous donor for H(2)S, at the dose of 0.2 or 0.4 μmol/kg significantly decreased the apoplexy index, neurological symptom scoring, and brain infarcted area as compared to the I/R group in a dose dependent manner. At the same time, NaHS-treated rats displayed significant reduction of MDA content, and striking increase of SOD activity in the brain tissues compared with I/R group. The up-regulated mRNA levels of p47(phox) and gp91(phox) subunits of NADPH oxidase were also suppressed by NaHS treatment. In this study, the pro-inflammatory markers TNF-α and MCP-1 in I/R group were markedly increased by 24h I/R, which were significantly attenuated by NaHS in a dose-dependent manner. In contrast, the anti-inflammatory factor IL-10 was markedly induced by NaHS administration. In addition, the expression of the anti-apoptotic protein Bcl-2 was significantly decreased in I/R group compared with the sham-operated group. This reduction was significantly blunted in NaHS-treated group. On the contrary, the pro-apoptotic protein Bax content in brain tissues of I/R group was markedly elevated compared with sham-operated animals. And such an induction of Bax content was significantly ameliorated by NaHS. Taken together, our results suggest that hydrogen sulfide has potent protective effect against a severe cerebral injury induced by a global I/R possibly through the inhibition of oxidative stress, inflammation and apoptosis.