Therapeutic effect and mechanism of Daikenchuto in a model of methotrexate-induced acute small intestinal mucositis

Abstract

Abstract Daikenchuto (DKT) has positive therapeutic effects on improving various gastrointestinal disorders. The present study investigated whether or not DKT has a potential therapeutic effect on chemotherapy-induced acute small intestinal mucositis (CIM) in a rat model. Intraperitoneal injection of 10 mg/kg methotrexate (MTX) every 3 days for a total of 3 doses was used for induction of CIM in a rat model. The MTX and DKT-MTX groups were injected with MTX as above from the first day, and the DKT-MTX and DKT groups were administered 2.7% DKT via the diet at the same time. The Control and DKT groups were given the same volume of placebo. The body weights, food intake and plasma diamine oxidase (DAO) levels were measured every three days. The rats were euthanized on day 15, and small intestinal samples were collected for histological, histochemical, and mRNA analyses. The DKT-MTX group showed an improvement in the body weight and conditions of gastrointestinal disorders as well as increased levels of DAO in plasma and in the small intestinal villi. The pathology results showed that small intestinal mucosal injury in the DKT-MTX group was less severe than that in the MTX group. Immunohistochemistry for myeloperoxidase and malondialdehyde and quantitative real-time polymerase chain reaction (RT-qPCR) for TGF-β1 and HIF-1α showed that DKT attenuated peroxidative damage and inflammatory responses. The crypts in the DKT-MTX group contained more Ki-67-positive cells than MTX group. The ZO-1 immunofluorescence results showed that DKT promoted repair of the small intestinal mucosal barrier. RT-qPCR for the amino acid transporters EAAT3 and BO+AT also confirmed that DKT promoted mucosal repair and thus promoted nutrient absorption in the small intestine. DKT protected against MTX-induced CIM in a rat model by reducing inflammation, stimulating cell proliferation, and stabilizing the mucosal barrier.