Abstract: OBJECTIVE:To evaluate the effects of Xuebijing(XBJ) injection in heat stroke(HS) rats and to investigate the mechanisms underlying these effects.METHODS:Sixty anesthetized rats were randomized into three groups and intravenously injected twice daily for 3 days with 4 mL XBJ(XBJ group) or phosphate buffered saline(HS and Sham groups) per kg body weight.HS was initiated in the HS and XBJ groups by placing rats in a simulated climate chamber(ambient temperature 40 ℃,humidity 60%).Rectal temperature,aterial pressure,and heart rate were monitored and recorded.Time to HS onset and survival were determined,and serum concentrations of tumor necrosis factor(TNF)-α,inRESULTS:Time to HS onset and survival were significantly longer in the XBJ than in the HS group.Moreover,the concentrations of TNF-α,IL-1β,IL-6,ALT and AST were lower and liver injury was milder in the XBJ than in the HS group.Heat-stress induced structural changes in KCs and hepatic cells were more severe in the HS than in the XBJ group and the concentrations of TNF-α,IL-β and IL-6 secreted by KCs were lower in the XBJ than in the HS group.CONCLUSION:XBJ can alleviate HS-induced systemic inflammatory response syndrome and liver injury in rats,and improve outcomes.These protective effects may be due to the ability of XBJ to inhibit cytokine secretion by KCs.

Key words: Heat stroke, Kupffer cells, Systemic inflammatory response syndrome, Xuebijing, Liver injury, Inflammatory cytokines