Brief Article
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World J Gastroenterol. May 7, 2011; 17(17): 2223-2228
Published online May 7, 2011. doi: 10.3748/wjg.v17.i17.2223
Topical application of glycyrrhizin preparation ameliorates experimentally induced colitis in rats
Tomohiro Kudo, Shinichi Okamura, Yajing Zhang, Takashige Masuo, Masatomo Mori
Tomohiro Kudo, Yajing Zhang, Takashige Masuo, Masatomo Mori, Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan
Shinichi Okamura, Department of Medical Informatics and Decision Sciences, Gunma University School of Medicine, Gunma 371-8511, Japan
Author contributions: Kudo T, Zhang Y and Masuo T performed the majority of experiments; Mori M gave vital suggestion; Okamura S and Kudo T designed the research and wrote the manuscript.
Correspondence to: Dr. Shinichi Okamura, Department of Medical Informatics and Decision Sciences, Gunma University School of Medicine, 3-39-15 Maebashi, Gunma 371-8511, Japan. sokamura@showa.gunma-u.ac.jp
Telephone: +81-27-2208773 Fax: +81-27-2208773
Received: August 5, 2010
Revised: September 18, 2010
Accepted: September 25, 2010
Published online: May 7, 2011
Abstract

AIM: To examine the efficacy of glycyrrhizin preparation (GL-p) in the treatment of a rat model of ulcerative colitis (UC).

METHODS: Experimental colitis was induced by oral administration of dextran sodium sulfate. Rats with colitis were intrarectally administered GL-p or saline. The extent of colitis was evaluated based on body weight gain, colon wet weight, and macroscopic damage score. The expression levels of pro-inflammatory cytokines and chemokines in the inflamed mucosa were measured by cytokine antibody array analysis. The effect of GL-p on myeloperoxidase (MPO) activity in the inflamed mucosa and purified enzyme was assayed.

RESULTS: GL-p treatment significantly ameliorated the extent of colitis compared to sham treatment with saline. Cytokine antibody array analysis showed that GL-p treatment significantly decreased the expression levels of pro-inflammatory cytokines and chemokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, cytokine-induced neutrophil chemoattractant-2, and monocyte chemoattractant protein-1 in the inflamed mucosa. Furthermore, GL-p inhibited the oxidative activity of mucosal and purified MPO.

CONCLUSION: GL-p enema has a therapeutic effect on experimental colitis in rats and may be useful in the treatment of UC.

Keywords: Glycyrrhizin, Colitis, Dextran sodium sulfate, Ulcerative colitis, Cytokine, Chemokine, Protein array, Myeloperoxidase, Enema, Carboxymethylcellulose