Functional dyspepsia (FD) is a highly prevalent chronic gastrointestinal (GI) disorder that causes a considerable burden to both the patient and society. Although the etiology and pathogenesis of FD are poorly understood, FD is associated with pathophysiologic abnormalities including delayed gastric emptying (GE), impaired gastric accommodation, and visceral hypersensitivity.1,2) Delayed GE has been reported in 30-40% of FD patients, 3) and a number of studies have demonstrated impaired gastric accommodation after meals in approximately 40% of patients. 4) Given these results, we hypothesized that GE of a semi-solid meal, GI transit, and gastric accommodation would be suitable markers for evaluating motor effects in animal models.Corydalis tubers, the roots of Corydalis yahusuo W.T. WANG (Papaveraceae), have long been used as herbal medicine for their analgesic and anti-ulcer effects. It has been reported that Corydalis tuber extracts exhibit several biological activities, acting as both an anti-spasmodic agent in the GI tract and as an analgesic. [5][6][7][8] Previous phytochemical studies reported that Corydalis tubers are made up primarily of alkaloid compounds including corydaline, berberine, protopine, and palmatine. [8][9][10][11][12] These alkaloid compounds are reported to provide the analgesic, anti-spasmodic, and anti-acetylcholinesterase activities associated with Corydalis tubers. Of these compounds, corydaline is considered the marker compound for quality control of Corydalis extract; however, the pharmacological effects of corydaline on GI motor function have not yet been studied.We previously investigated the prokinetic activities of corydaline to determine its potential bioactivity in FD and elucidated the basis of the selection of corydaline as the principal marker compound for quality control. 13) In the present study, we evaluated the effects of corydaline on GE and GI transit in rats and gastric accommodation in conscious dogs.
MATERIALS AND METHODS
Plant MaterialPlant material was commercially purchased at Kyungdong herbal market (Seoul, Korea) and identified by Dr. S. Choi at the Research Center of Dong-A Pharm. Co., Ltd. (Yongin-si, Korea). A voucher specimen has been deposited in our laboratory at Kyung Hee University.Extraction and Isolation Dried Corydalis tuber (30 kg) was extracted with 50% aqueous ethanol three times at room temperature. Upon removal of the solvent under vacuum, the ethanolic extract yielded 2.85 kg of material (Corydalis tuber extract, CTE; 7.6% by dry weight). We found that the CTE contained corydaline, palmatine, berberine, and other isoquinoline alkaloids. Based on HPLC analysis, the prescribed range of index components including corydaline and palmatine was detected in the CTE. The CTE was suspended in H 2 O and partitioned successively with n-hexane, ethyl acetate (EtOAc), and n-butanol. The EtOAc-soluble fraction (15 g) of the extract was subjected to a silica gel column using mixtures of n-hexane-EtOAc of increasing polarity as eluents to give 12 sub-fraction...