Protective effects of antimicrobial peptide S-thanatin against endotoxic shock in mice introduced by LPS.
Sepsis continues to be a major unresolved medical challenge of the present. Severe sepsis and septic shock are the leading causes of multiple organ failure and mortality in noncoronary intensive care units (ICUs). The primary reason of septic shock is the activation of host effecter cells by endotoxin and lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the key point of treatment is removing LPS. S-thanatin (Ts), an analog of thanatin, was synthesized by substituting the 15th amino acid of threonine with serine, which showed a broad antimicrobial activity against gram-negative and gram-positive bacteria. We have reported its LPS-binding and -neutralizing activity in vitro. The aim of this study is to examine the LPS-neutralizing activities and the protective effects of S-thanatin in vivo. Every mice was injected intraperitoneally with LPS (from Escherichia coli O111:B4) 150μg before injected intraperitoneally or vena caudalis with 3mg/kg, 6mg/kg and 12mg/kg, and measured endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, as well as lethality. The results showed that S-thanatin can significantly reduce endotoxin and TNF-α level in plasma, at the same time resulting in the highest survival rates.
Southeast University, Nanjing, People's Republic of China. guoqiu wu@hotmail.com
Guoqiu
G
Wu
Xiaofang
X
Li
Xuepeng
X
Deng
Xiaobo
X
Fan
Shenglan
S
Wang
Zilong
Z
Shen
Tao
T
Xi
D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D004731:Endotoxins / Q000097:blood; D004926:Escherichia coli / Q000187:drug effects; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008826:Microbial Sensitivity Tests; D012772:Shock, Septic / Q000097:blood / Q000517:prevention & control*; D016019:Survival Analysis; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D023181:Antimicrobial Cationic Peptides; D004731:Endotoxins; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; C440499:lipopolysaccharide, Escherichia coli O111 B4; C098076:thanatin