Saponin fraction from Astragalus membranaceus roots protects mice against polymicrobial sepsis induced by cecal ligation and puncture by inhibiting inflammation and upregulating protein C pathway.
Sepsis remains the leading cause of death in intensive care units. Uncontrolled systemic inflammation and an impaired protein C pathway are two important contributors to sepsis pathophysiology. Based on the beneficial effects of the saponin fraction from Astragalus membranaceus roots (SAM) against inflammation, liver dysfunction, and endothelium injury, we investigated the potential protective roles and underlying mechanisms of SAM on polymicrobial sepsis induced by cecal ligation and puncture (CLP) in mice. SAM, orally administered 1 h before and after CLP, significantly elevated the survival rate of mice. At 96 h after CLP operation, all mice in the model group died, whereas 33.3% of mice in the SAM (400 mg/kg)-treated group survived. SAM attenuated both inflammatory factors and their abilities to induce tissue dysfunction, which was mainly evidenced by decreased infiltration of polymorphonuclear leukocytes, tissue edema, and lung wet-to-dry weight ratio, lowered levels of myeloperoxidase (MPO), nitric oxide (NO), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in serum, as well as downregulated expressions of iNOS and IL-1beta mRNA in livers. Furthermore, we addressed the effects of SAM on the protein C (PC) pathway, closely linked with sepsis. In CLP-induced septic mice, SAM elevated the impaired expression of PC mRNA in livers. In vitro, SAM reversed the decreased expressions of thrombomodulin (TM) and endothelial PC receptor (EPCR) mRNA induced by lipopolysaccharide (LPS) in endothelial cells. These findings suggest that SAM is able to restore the impaired protein C pathway. Taken together, the current study demonstrates that SAM has protective effects on polymicrobial sepsis in mice. The mechanisms of action involve anti-inflammation and upregulation of the PC pathway.
Gao
Xing-hua
XH
Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 1 Shennong Road, 210038 Nanjing, China.
Xu
Xian-xiang
XX
Pan
Rong
R
Li
Ying
Y
Luo
Yu-bin
YB
Xia
Yu-feng
YF
Murata
Kazuya
K
Matsuda
Hideaki
H
Dai
Yue
Y
D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D027885:Astragalus propinquus / Q000737:chemistry*; D002432:Cecum / Q000293:injuries; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D000074283:Endothelial Protein C Receptor; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*; D011486:Protein C / Q000235:genetics / Q000378:metabolism*; D011677:Punctures; D011956:Receptors, Cell Surface / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*; D018805:Sepsis / Q000382:microbiology / Q000401:mortality / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects; D018180:Thrombomodulin / Q000235:genetics
D015703:Antigens, CD; D000074283:Endothelial Protein C Receptor; D008070:Lipopolysaccharides; C478370:PROCR protein, human; D010936:Plant Extracts; D011486:Protein C; D011956:Receptors, Cell Surface; D012503:Saponins; D018180:Thrombomodulin