Choleretic Activity of Turmeric and its Active Ingredients

Turmeric, a rhizome of Curcumin longa L. is widely used as both a spice and an herbal medicine. The traditional use of turmeric in gastroenterology is mainly based on its choleretic activity. The aim of this study is to determine the effects of turmeric on bile flow (BF) and total bile acids (TBAs) excretion in a bile fistula rat model after acute duodenal administration. A significant dose-dependent enhancement in both BF and TBAs was detected after treatment with the turmeric decoctions which suggested the choleretic activity was bile acid-dependent secretion. In order to direct the active group of compounds, aqueous (AE), ethyl acetate (EtOAc), and petroleum ether (PE) extracts were investigated. The EtOAc and PE extracts showing high effects were purified to locate the active ingredients. Three curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) and 2 sesquiterpenes (bisacurone B and ar-turmerone) were isolated. It was found Bisacurone B was the most potent choleretic ingredient followed by ar-turmerone, bisdemethoxycurcumin demethoxycurcumin, and then curcumin. The amounts of the active ingredients were quantitatively analyzed by high-performance liquid chromatography. The EtOAc and PE extracts had high sesquiterpenes and curcuminoids content, while the AE extract had poor content of sesquiterpenes and curcuminoids which affected neither BF nor TBAs. Based on the results of multiple linear regression analysis, the content of BIS and TUR were dominant factors (P < 0.01) of controlling BL and TBAs in EtOAC and PE extracts.