A traditional Japanese medicine mitigates TNBS-induced colitis in rats

Abstract

Objective. Differences in dietary habits may be one of the reasons that the incidence of inflammatory bowel disease has remained lower in Japan than in Western countries. We investigated whether a traditional Japanese medicine (Strong Wakamto®), based on Aspergillus oryzae koji, would exert any effect on experimental colitis in rats. Material and methods. Colitis was induced using an enema of trinitrobenzene sulfnic acid (TNBS) and ethanol. Strong Wakamto was administered for 28 days before induction of colitis and for 7 days thereafter, and the effect of this medicine was evaluated. Results. Treatment with 5% Strong Wakamto improved loss of body-weight, increased colon weight and significantly decreased the histological damage score for colon mucosa. Decreases in faecal Lactobacillus sp., superoxide dismutase activity and zinc concentrations, and the increased IL-1β expression in colonic tissue after TNBS enema were improved when Strong Wakamto was given. The present in vitro studies indicate that administration of Strong Wakamto prevents lipopolysaccharide-induced TNF-α production in human macrophages. Conclusions. Oral administration of Strong Wakamto mitigates experimental inflammatory bowel disease induced by TNBS enema in rats. The beneficial effects seem attributable to a combination of balancing microflora, immunomodulatory effects on gut macrophages, and enhancement of anti-superoxide activity in colonic tissues.

• Anti-superoxide activity
• Aspergillus oryzae koji
• experimental colitis
• inflammatory bowel disease
• microflora