巴戟多糖在体肠吸收机制的研究

In-vivo Intestinal Absorption Mechanism Study for Polysaccharides of Morindae ficinalis

目的研究巴戟多糖的小肠吸收动力学及吸收促进剂、pH值对其在小肠吸收速率的影响,探讨巴戟多糖小肠吸收机制。方法以紫外分光光度法测定酚红的质量浓度;苯酚-硫酸显色后紫外分光光度法测定巴戟多糖的质量浓度;采用大鼠在体小肠灌注实验考察吸收过程。结果不同浓度的巴戟多糖在大鼠全小肠段的吸收速率常数Ka无显著性差异;pH值对巴戟多糖的吸收有显著影响:pH7.4时,吸收率为(57.25±1.28)%;pH6.8时,吸收率为(44.40±2.01)%;pH5.0时,吸收率为(42.94±2.15)%,三者差异有显著性(P<0.01);0.5%十二烷基磺酸钠或0.5%吐温加入后吸收率分别为(59.21±1.49)%和(53.18±2.59)%,两者作用差异有显著性(P<0.01)。结论巴戟多糖在大鼠小肠吸收为被动扩散,pH为7.4时,其吸收效果较好;吸收促进剂十二烷基磺酸钠和吐温-80均能促进巴戟多糖在大鼠小肠内的吸收,十二烷基磺酸钠的效果较优。

Objective To investigate the absorption kinetics of polysaccharides of Morindae ficinalis in rat small intestines,to observe the effects of absorption enhancers and pH value on the absorptive kinetics,and to explore the intestinal absorption mechanism of the polysaccharides.Methods Ultra-violet（UV）spectrophotometry was used to determine the content of phenol red.After coloration with developing reagents of phenol and vitriol,the polysaccharides were determined with UV spectrophotometry.An in-situ intestinal absorptive model was employed to investigate the absorption of polysaccharides in rat small intestines.Results There was no difference between the Ka of various concentrations of the polysaccharides.But the absorption percentage was effected by pH value and absorption enhancers.The absorption percentage was 57.25 ±1.28% when pH value was at 7.4,44.40±2.01% when pH at 6.8,and 42.94±2.15% when pH at 5.0,the difference being significant between them（P 0.01）.With 0.5% sodium dodecyl sulfate added,the absorption was 59.21±1.49%,and with 0.5%Tween-80 added,the percentage was 53.18±2.59%,the difference being significant（P 0.01）.Conclusion The polysaccharides are absorbed by passive diffusion mechanism.The absorption percentage is higher at pH 7.4 and enhanced by both of sodium dodecyl sulfate and Tween-80,and the effect of the sodium dodecyl sulfate is better.