Protective effect of comaruman, a pectin of cinquefoil Comarum palustre L., on acetic acid-induced colitis in mice.

The efficacy of comaruman CP, a pectin of marsh cinquefoil Comarum palustre L., was investigated using a model of acetic acid-induced colitis in mice. Mice were administered comaruman CP orally 2 days prior to rectal injection of 5% acetic acid and examined for colonic damage 24 hr later. Colonic inflammation was characterized by macroscopical injury, higher levels of myeloperoxidase activity, enhanced vascular permeability, and diminution of colonic mucus. Oral administration of comaruman CP was found to prevent progression of colitis. Colonic macroscopic scores and the total square of damage were significantly reduced in mice treated with CP compared with the vehicle-treated colitis group. Peroral pretreatment of mice with comaruman CP was shown to decrease tissue myeloperoxidase activity in colons compared with the colitis group. Comaruman CP was found to stimulate production of mucus by colons of normal and colitis mice. Comaruman CP decreased the inflammatory status of normal mice as elicited by reduction of vascular permeability and adhesion of peritoneal neutrophils and macrophages. Thus, a preventive effect of comaruman on acetic acid-induced colitis in mice was detected. Reduction of neutrophil infiltration and enhancement of colon-bound mucus may be implicated in the protective effect of comaruman.