Effect of gastrointestinal function regulatory Kampo medicine, Dai-kenchu-to on human plasma calcitonine gene-related peptide, substance P and somatostatin levels

Abstract

Background Traditional Chinese herbal (Kampo) medicines, Dai-kenchu-to (DKCT) have been frequently used in the empirical treatment of gastrointestinal obstructions. Although it has been already reported that DKCT increases in the plasma levels of gastrointestinal peptides {vasoactive intestinal polypeptides (VIP) and motilin}, which improves feelings of abdominal coldness and gastrointestinal motility, the mechanism is not yet well understood. In this study, we examined effects of DKCT on the plasma calcitonine gene-related peptide (CGRP), substance P (SP) and somatostatin (SS) levels. Methods DKCT or placebo was orally administered to five healthy male volunteers aged 25–30 years. Venous blood samples were taken before and 20, 40, 60, 90, 120, 180 and 240 min after administration of DKCT. Peptide levels in plasma were measured using a sensitive enzyme immunoassay. Results DKCT (7.5 g) significantly increased in CGRP-like immunoreactive substances (IS) at 40 min, SP-IS at 20–60 min and SS-IS at 180–240 min compared with the each response of placebo. Conclusions In this study, DKCT raised plasma CGRP-, SP- and SS-IS levels. CGRP and SP participate in the control of mucosal blood flow in the gastrointestinal tract. Also, SS participates in the regulation of gastrointestinal motility. DKCT might regulate to the mucosal blood flow by increasing in plasma CGRP- and SP-IS levels. Besides, DKCT might improve the gastrointestinal motility by increasing in plasma SS-IS levels. Clinical Pharmacology & Therapeutics (2005) 77, P13–P13; doi: 10.1016/j.clpt.2004.11.052