Protective effects and mechanism of Dachengqi decoction on intestinal septic mice / 中国药房

ABSTRACT

OBJECTIVE To study the protective effects of Dachengqi decoction （DCQD） on intestinal septic mice， and to explore the possible mechanisms from the Toll-like receptor 4（TLR4）/myeloid differentiation factor 88（MyD88） signaling pathway. METHODS The SPF male C57BL/6J mice were randomly divided into Sham group， Sham+DCQD-H group， model （CLP） group， DCQD-L group， DCQD-H group and Positive group. The model of intestinal sepsis was established by cecal ligation and puncture in CLP group， DCQD-L group， DCQD-H group and Positive group. Three days before the operation and seven days after the operation， DCQD-L group and DCQD-H group were given DCQD intragastrically at 4， 8 g/kg （calculated by crude drug）， respectively. Positive group was given ulinastatin intraperitoneally 2 h before operation and 7 d after the operation （at 50 000 U/kg）. In Sham group and Sham+DCQD-H group， only cecum of mice was exposed without ligation and puncture. Sham+DCQD- H group was given DCQD intragastrically （8 g/kg，calculated by crude drug） 3 days before the operation and 7 days after the operation. Both the Sham group and CLP group were given normal saline 0.2 mL intragstrically and intraperitoneally each day， for 10 consecutive days. After the operation， the severity of sepsis was assessed， and the 7 d survival rate of mice was assessed. One hour after the last medication， the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in serum and ileum of mice were determined； the pathological and morphological changes of mice’s liver， lung， kidney and ileum were observed； mRNA expressions of the TLR4 and MyD88 in ileum were tested. RESULTS Compared with CLP group， sepsis score， the levels of TNF-α and IL-6 in serum and ileum （except for IL-6 in ileum of DCQD-L group）， damage score of the liver， lung， kidney and ileum， mRNA expressions of TLR4 and MyD88 in ileum were all decreased significantly in DCQD-L group and DCQD-H group （P＜0.05 or P＜0.01）， while 7 d survival rate （except for DCQD-L group） was increased significantly （P＜0.05）. The damage to liver tissue in mice was significantly improved， and inflammation infiltration and apoptosis were reduced； lung tissue damage had been alleviated， with varying degrees of improvement in alveolar atrophy， bleeding and edema； the renal tissue damage was improved and weakened dilation of renal tubular lumen was weakened； the damage and edema of ileal tissue were significantly improved. CONCLUSIONS DCQD may exert a protective role on intestinal septic model mice. The mechanism may be related to the inhibition of systemic inflammation， the reduction of multiple organ damage， and down-regulation of TLR4/MyD88 signaling pathway.