| [ Summary ] |
The ingredients of the herbal medication Rikkunshito were determined five hundred years ago, since that time they have been widely used as a treatment for dyspepsia symptoms. Although, the mechanisms producing the effects of Rikkunshito have not been clarified over hundreds of years, recent studies of the pharmacological actions of Rikkunshito have been performed. Those studies showed a promotion of peristaltic movement between the duodenum and the ileum. Improvements in fasting and postprandial contraction and gastric emptying were also observed. In clinical studies, Rikkunshito has been shown to improve symptoms after gastrectomies and those due to chemotherapy. Rikkunshito has also been reported to improve symptoms associated with reflux esophagitis. Furthermore, in relation to the mechanisms involved, Rikkunshito has been shown to increase plasma ghrelin levels and also to enhance the action of ghrelin through an increase in the binding activity of GHSR-1a to ghrelin. Some of the contents such as 3,3', 4', 5,6,7,8-heptamethoxyflavone, hesperidin and isoliquiritigenin have been shown to be effectors for orexigenic effects through an antagonism to 5-HT2B or 2C receptors. Progress in the study of the mechanisms related to the orexigenic action of Rikkunshito are reviewed. |