Effccts Of Rhizoma Curcumae Decoction And β-elemene On Duodenal Contractility Of Rat

Background and purpose: Traditional Chinese medicine Rhizoma curcuma (RC)has a wide range of pharmacological effects. RC is reported to improve gastrointestinalmotility, strengthen the gastrointestinal motor function. β-elemene, a type of volatile oil,is extracted from RC. The aim of this study was to investigate the effects of RC andβ-elemene on rat the contractility of isolated duodenal segment and related mechanismsand compare the effects of RC and β-elemene.Methods:(1) Duodenal segments (DS) were prepared and used in the study. In normalcontractile state, the effects of RC and β-elemene at different concentrations on rat thecontractility of duodenal segment of rat were observed respectively using BL-420biological and functional experimental system.(2) The effects of RC and β-elemene, at different concentrations, on thecontractility of rat DC in different contractile states were determined respectively.(3) Corresponding receptor antagonists were used to investigate the underlyingmechanisms in RC and β-elemene-produced effects on duodenal contraction.Results:(1) RC increased duodenal contraction in a dose dependent manner, which couldbe partially blocked by muscarinic receptor antagonist atropine and L-type calciumchannel blocker verapamil respectively.(2) β-elemene inhibited duodenal contraction in a dose dependent manner and itinhibited the contraction induced by different concentration of CaCl2. β-elemeneinduced inhibition was found similar to verapamil induced inhibition.Discussion:(1) The contractility of isolated rat duodenal segment in normal contractility wassignificantly increased by RC and the possible mechanism is via activation of muscarinic receptor related mechanisms.(2) β-elemene inhibited the increased contractility of isolated rat duodenalsegment induced by Ca2+，suggesting the inhibition is related to Ca2+influx.(3) The effects of RC on the smooth muscle of duodenal segment was stimulatorywhile the effects of β-elemene was inhibitory, implicating that RC rather than volatileoil is the main component in exerting excitatory effects. The exact component of RC inexerting excitatory effects need further study.