Anti-colitis and -adhesion effects of daikenchuto via endogenous adrenomedullin enhancement in Crohn's disease mouse model☆
Received 10 July 2009; received in revised form 28 August 2009; accepted 19 September 2009. published online 30 November 2009.
Abstract
Background and aims
Adrenomedullin (ADM) is a member of the calcitonin family of regulatory peptides, and is reported to have anti-inflammatory effects in animal models of Crohn's disease (CD). We investigated the therapeutic effects of daikenchuto (DKT), an extracted Japanese herbal medicine, on the regulation of endogenous ADM in the gastrointestinal tract in a CD mouse model.
Methods
Colitis was induced in mice by intrarectal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS); afterwards, DKT was given orally. Colonic damage was assessed on day 3 by macroscopic and microscopic observation, enzyme immunoassays of proinflammatory cytokines in the colonic mucosa, and serum amyloid A (SAA), a hepatic acute-phase protein. To determine the involvement of ADM, an ADM antagonist was instilled intrarectally before DKT administration. The effect of DKT on ADM production by intestinal epithelial cells was evaluated by enzyme immunoassay and real-time PCR.
Results
DKT significantly attenuated mucosal damage and colonic inflammatory adhesions, and inhibited elevations of SAA in plasma and the proinflammatory cytokines TNFα and IFNγ in the colon. Small and large intestinal epithelial cells produced higher levels of ADM after DKT stimulation. A DKT-treated IEC-6 cell line also showed enhanced ADM production at protein and mRNA levels. Abolition of this effect by pretreatment with an ADM antagonist shows that DKT appears to exert its anti-colitis effect via up-regulation of endogenous ADM in the intestinal tract.
Conclusion
DKT exerts beneficial effects in a CD mouse model through endogenous release and production of ADM. Endogenous ADM may be a therapeutic target for CD.
aDivision of Gastroenterologic and General Surgery, Department of Surgery, Asahikawa Medical College, Hokkaido 078-8510, Japan
bTsumura Research Laboratories, Tsumura & Co., 3586 Yoshiwara, Ami-machi, Inashiki-gun, Ibaraki 300-1192, Japan
cDepartment of Anatomy, Asahikawa Medical College, Hokkaido 078-8510, Japan
Corresponding author. Division of Gastroenterologic and General Surgery, Department of Surgery, Asahikawa Medical College, 2-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510, Japan. Tel.: +81 166 68 2503; fax: +81 166 68 2193.
☆ Part of this work was presented at Digestive Disease Week 2009, American Gastroenterologic Association (AGA), Chicago, USA.
ABSTRACT