单向灌流法研究姜黄素的大鼠在体肠吸收

Research on Intestinal Absorption Characteristics of Curcumin in Rats

目的研究姜黄素在大鼠肠内的吸收特性。方法采用大鼠在体肠段单向灌流模型,HPLC法对药物的质量浓度进行检测,分别研究药物不同质量浓度、不同时间点以及吸收部位姜黄素吸收的情况。结果姜黄素质量浓度对ka有显著性影响(P<0.05),而对Kapp无显著性影响;姜黄素的肠吸收速率随时间出现周期性的波动,且在灌肠达到稳态后1 h,ka的大小顺序为:40、20、80μg/ml;姜黄素在各肠段的ka和Kapp比较均无明显差异(P>0.05),各肠段的ka(h-1)为十二指肠>回肠>空肠>结肠;Kapp为十二指肠>空肠>回肠>结肠。结论姜黄素在吸收过程中存在高浓度饱和现象,初步判断姜黄素的吸收为主动转运。但姜黄素的浓度对其吸收的量影响不大;同时,姜黄素存在明显的肝肠循环;且在全肠道吸收较完全,无特定吸收窗也无明显吸收部位。

Objective To investigate the intestinal absorption characteristics of curcumin in rats. Methods The intestine in rat was cannulated for in situ perfusion to study the absorption mechanism of curcumin. HPLC was used to determine the concentration of curcumin. The effect of drug concentration, time points and absorption site on the absorption had been studied. Results The concentration of curcumin had distinctive effect on the absorption kinetics of intestine but no distinctive effect on Kapp. Rate of intestinal absorption of curcumin showed cyclical fluctuations over time. And 1 h after the perfusion within the steady-state, the order of absorption rate constant （ka） was ： 40 〉 20 〉 80 I^g/ml. Ka and Kapp of curcumin in the intestines showed no significant differences （P 〉 0.05 ）. The order of Ka was ： duodenum 〉 ileum 〉 jejunum 〉 colon, and that of Kapp was ： duodenum 〉 jejunum 〉 ileum 〉 colon. Conclusion The saturation phenomenon of absorption of curcumin appears when in high concentrations. It is initially determined that absorption of curcumin is the active transport. And there exists obvious enterohepatic circulation in absorption of curcumin. And curcumin is completely absorbed at all segments of intestine in rats. There are no Lspecific absorption window and no obvious absorption site.