title: Protective effects of glycyrrhizic acid by rectal treatment on a TNBS-induced rat colitis model.
abstract: OBJECTIVE
  The research compared rectal and oral treatments with glycyrrhizic acid for trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.
  
  
  METHODS
  Wistar rats were randomly divided into seven groups: one normal and six with colitis, including TNBS, glycyrrhizic acid (2, 10 and 50 mg/kg, rectally treated and 10 mg/kg, orally treated) and sulfasalazine (positive control, 225 mg/kg rectally treated) groups. Colitis was induced by colonic administration of TNBS in 30% ethanol.
  
  
  RESULTS
  There were significant pathological changes in colon in TNBS-treated groups, and rectal glycyrrhizic acid significantly attenuated colitis. Myeloperoxidase, tumour necrosis factor-α and interleukin-1β of colon tissue or serum in the rectal glycyrrhizic acid groups were markedly reduced when compared with the TNBS group, and lower than in the orally treated glycyrrhizic acid group. It was further noted that, in vitro, glycyrrhizic acid (up to 100 µg/ml) inhibited interleukin-6 and elevated interleukin-10 production in lipopolysaccharide-activated macrophages, and significantly inhibited proliferation of spleen lymphocytes, suggesting the immunoregulatory function of glycyrrhizic acid.
  
  
  CONCLUSIONS
  Rectally administered glycyrrhizic acid has significant protective effects against TNBS-induced colitis in rats, and the rectal route may be a complementary treatment for inflammatory bowel disease.
authors.affiliation: College of Pharmacy, Wuhan University, Wuhan, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Jin
authors.initials: J
authors.lastname: Xiang
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Shi
authors.initials: S
authors.lastname: Wang
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lee
authors.forename: Hong
authors.initials: H
authors.lastname: Ding
mesh_terms: D000284:Administration, Oral; D000285:Administration, Rectal; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D003092:Colitis / Q000139:chemically induced / Q000517:prevention & control*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019695:Glycyrrhizic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000187:drug effects; D014302:Trinitrobenzenesulfonic Acid / Q000633:toxicity
chemical_list: D000893:Anti-Inflammatory Agents; D015850:Interleukin-6; D016753:Interleukin-10; D019695:Glycyrrhizic Acid; D014302:Trinitrobenzenesulfonic Acid