Colonic vascular conductance increased by Daikenchuto via calcitonin gene-related peptide and receptor-activity modifying protein 1

The effect of traditional Japanese medicine (Kampo) on gastrointestinal function

Traditional Japanese medicine (Kampo) is used to treat various disorders of the gastrointestinal tract in Japan, where it is fully integrated into the modern healthcare system. Recently, scientific research on herbal medicine in Japan has been reported in English journals. The objective of the current review is to introduce two traditional Japanese medicines and to provide evidenced-based information regarding their use. Daikenchuto, which consists of three different herbs, is the most frequently prescribed traditional Japanese medicine in Japan. Daikenchuto stimulates gastrointestinal motility though a neural reflex involving presynaptic cholinergic and 5-HT3 receptors. Daikenchuto improves postoperative bowel motility and postoperative ileus. Furthermore, it is reported to cause an increase in gastrointestinal hormones (motilin, vasoactive intestinal peptide, and calcitonin gene-related peptide) and intestinal blood flow. Rikkunshito, a traditional Japanese medicine consisting of eight herbs, is thought to stimulate gastrointestinal motility and ghrelin secretion. Rikkunshito is effective for improving the symptoms of functional dyspepsia, gastroesophageal reflux disease, and cisplatin-induced anorexia and vomiting. Traditional Japanese medicine has the potential to be used successfully in the treatment of gastrointestinal disorders. Details regarding the physiological and clinical effects of traditional Japanese medicine must be further examined in order to become more widely accepted in other countries.

Profiling of the compounds absorbed in human plasma and urine after oral administration of a traditional Japanese (kampo) medicine, daikenchuto

Daikenchuto (DKT), a pharmaceutical-grade traditional Japanese (Kampo) medicine, has been widely used for the treatment of various gastrointestinal disorders including postoperative ileus and has been integrated into the modern medical care system in Japan as a prescription drug. DKT is a multiherbal medicine consisting of Japanese pepper (zanthoxylum fruit), processed ginger, and ginseng with maltose as an additive. Despite substantial research on the pharmacological activities of DKT and its ingredients, the lack of studies on absorption, distribution, metabolism, and excretion of DKT has made it difficult to obtain a consistent picture of its mechanism of action. In the present study, we constructed an analysis procedure consisting of seven conditions of liquid chromatography and mass spectrometric analysis, which enabled the identification of 44 ingredients of DKT component herbs. We investigated the plasma and urine profiles of these ingredients 0.5 to 8 h after oral administration of 15.0 g of DKT in four healthy volunteers. The results indicated that 1) hydroxy-α-sanshool and [6]-shogaol, the prominent peaks in plasma derived from Japanese pepper and ginger, respectively, were detected at 0.5 h and thereafter decreased throughout the sampling period; 2) ginsenoside Rb(1), a prominent peak derived from ginseng, increased gradually during the sampling period; 3) glucuronide conjugates of hydroxy-sanshools, shogaols, and gingerols were detected in plasma and urine; and 4) no obvious differences between samples from the two male and the two female individuals were observed. These results provide a strong basis for future studies on pharmacokinetics and pharmacology of DKT.

Anti-colitis and -adhesion effects of daikenchuto via endogenous adrenomedullin enhancement in Crohn's disease mouse model

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.

The herbal medicine Daikenchuto increases blood flow in the superior mesenteric artery

Daikenchuto is a traditional herbal medicine that is used for the treatment of cold feeling in the abdomen, while Orengedokuto, also a traditional herbal medicine, is used for treating inflammatory and ulcerative diseases affecting internal organs. However, the effects of these herbal medicines on cardiac output (CO) and intestinal blood flow have never been investigated. This examiner-blinded randomized crossover study intended to clarify the influence of Daikenchuto and Orengedokuto on CO and blood flow volume in the superior mesenteric artery (SMA). Fourteen healthy men (35 +/- 7 years old) were randomly assigned to two groups: group A and group B. Initially, all subjects were given 50 ml of water orally. After 7 days, subjects in group A were given 5.0 g of Daikenchuto, and 7 days later they were given 2.5 g of Orengedokuto. These herbal medicines were given to group B subjects in the reverse order. CO and SMA blood flow volume were measured from rest to 90 min after the administration of water or each medicine. There was a significant increase in SMA blood flow volume after the administration of Daikenchuto, compared to water alone (p < 0.05) and Orengedokuto (p < 0.05). SMA blood flow volume was significantly increased between 5 and 90 min after administration of Daikenchuto (p < 0.01) compared to the resting state. However, there was no significant change in CO after the administration of either agent. The present study indicates that Daikenchuto increases SMA blood flow volume without increasing CO.