Tanshinone IIA exerts immune modulatory effect and might be a useful strategy to ameliorate immunosuppression in polymicrobial sepsis. - GreenMedInfo Summary

BACKGROUND: The importance of sepsis-induced immunosuppression and its contribution to mortality has recently emerged. In this study we examined the effects of Tanshinone II-A (TSN), a widely used traditional Chinese medicine, on immunosuppression in experimental peritonitis induced septic mice.

MATERIALS AND METHODS: Sepsis was achieved by means of cecal ligation and puncture (CLP). TSN at different doses (5, 15 and 45 mg/kg, i.p.) were used at different time-points (0, 3, 6 and 12 h) after CLP to evaluate its effect on the survival of septic mice. In parallel experiments, mice given TSN at optimal dose and time-point were euthanized to collect peritoneal macrophages, blood and tissue samples at 24 h afterthe CLP.

RESULTS: TSN improved the survival of septic mice in a dose- and time-dependent manner. TSN reduced CLP-induced serum biochemical parameters and protected organs from histopathological injuries. CLP-induced apoptosis and decreased percentages of splenic CD4and CD8T cells were reversed in TSN-treated mice. Moreover, CLP-induced formation of regulatory T cells (Treg) in the spleen was abolished in TSN-treated mice. CLP greatly decreased the levels of interferon-γ and interleukin (IL)-2 in the spleen, while the levels of IL-4 and IL-10 increased after CLP. TSN completely reversed these alterations and elicited a more-balanced Th1/Th2 response. Moreover, TSN promoted macrophage phagocytotic activity and improved bacterial clearance of septic mice. Lastly, TSN abolished CLP-triggered increase in serum HMBG1 level. And HMGB1 neutralization could increase the percentages of splenic CD3+CD4+/CD3+CD8+ lymphocytes and decreased the Treg population.

CONCLUSIONS: Overall, our data suggest that TSN exerts immune modulatory effect and might be a useful strategy to ameliorate immunosuppression in polymicrobial sepsis.