title: Anti-inflammative effect of glycyrrhizin on rat thermal injury via inhibition of high-mobility group box 1 protein.
abstract: OBJECTIVE
  Glycyrrhizin (Gly) has been reported as an inhibitor of extracellular HMGB1 (high-mobility group box 1 protein) cytokine's activity, and protects spinal cord, liver, heart and brain against ischemia-reperfusion-induced injury in rats. The purpose of this study was to investigate the protective effect of Gly in rat skin thermal injury model and to elucidate the underlying mechanisms.
  
  
  METHODS
  Twenty-four male Sprague-Dawley rats (200-250g) were randomly divided into control group, vehicle-treated and Gly-treated burn groups, each group contained eight animals. In the latter two groups, rats were subjected to 30% TBSA (Total Body Surface Area) full-thickness scald injury. In Gly-treated burn group, glycyrrhizin (60mg/kg) was administered intraperitoneally immediately after and at 24th hour burn; in vehicle-treated burn group, Ringer's solution (4ml/kg, as a vehicle) was administered intraperitoneally immediately after and at 24th hour burn. The animals were sacrificed at 48h after injury. Aortic blood samples were obtained to detect tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) with ELISA (Enzyme-Linked Immuno Sorbent Assay) kits. Lung, liver and kidney tissue samples were collected to determine the expression of HMGB1 mRNA and protein. HMGB1 mRNA level was semiquantitatively measured by Real-Time PCR using β-actin as an internal standard, and protein expression of HMGBI was determined by Western blot.
  
  
  RESULTS
  Severe skin scald injury caused a significant increase in plasma TNF-α and IL-1β versus the control group (P<0.001) in 48h after burns. Intraperitoneal administration of Gly (60mg/kg) significantly reduced the levels of serum TNF-α and IL-1β (P<0.01). Gly treatment reduced these biochemical indices accompanied by lower level of HMGB1 protein (P<0.05) and mRNA expression (P<0.01).
  
  
  CONCLUSIONS
  These results demonstrate that Gly possesses an anti-inflammation effect to protect the remote organs from burn-induced injury.
authors.affiliation: Department of Burns and Plastic Surgery, The Drum Tower Clinical Medical College, Nanjing Medical University, Nanjing 210008, China.
authors.forename: Liangyun
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Burns and Plastic Surgery, The Drum Tower Clinical Medical College, Nanjing Medical University, Nanjing 210008, China.
authors.forename: Ziwei
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Department of Burns and Plastic Surgery, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Burns and Plastic Surgery, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Shuqin
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Burns and Plastic Surgery, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Burns and Plastic Surgery, The Drum Tower Clinical Medical College, Nanjing Medical University, Nanjing 210008, China; Department of Burns and Plastic Surgery, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China. Electronic address: smmutanqian@sina.com.
authors.forename: Qian
authors.initials: Q
authors.lastname: Tan
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002056:Burns / Q000188:drug therapy* / Q000378:metabolism; D004195:Disease Models, Animal; D019695:Glycyrrhizic Acid / Q000494:pharmacology*; D024243:HMGB1 Protein / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism; D007274:Injections, Intraperitoneal; D053583:Interleukin-1beta / Q000097:blood; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D000199:Actins; D000893:Anti-Inflammatory Agents; D024243:HMGB1 Protein; D053583:Interleukin-1beta; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019695:Glycyrrhizic Acid
keywords: Burn; Glycyrrhizin; HMGB1; Inflammation