芒果苷大鼠在体肠道吸收机制研究

目的:研究芒果苷大鼠在体肠道吸收机制。方法:采用大鼠在体肠段灌流模型,建立高效液相色谱/紫外分光光度法测定肠循环液中芒果苷的浓度,研究不同芒果苷浓度、胆汁及吸收部位对芒果苷吸收参数的影响。结果:芒果苷在5.0~25.0μg.mL-1浓度范围内对小肠吸收速率常数(Ka)无影响;在12.5μg.mL-1浓度下对结扎胆管大鼠的小肠Ka有影响;各肠段的Ka回肠>空肠>结肠>十二指肠,分别为0.164、0.132、0.125、0.107h-1。结论:芒果苷的吸收符合一级动力学特征,吸收机制为被动扩散;芒果苷在各肠段均有较好的吸收,胆汁使芒果苷在小肠的透过系数增大。

Mechanism of in Situ Intestinal Absorption of Mangiferin in Rats

OBJECTIVE： To investigate the mechanism of in situ intestinal absorption of mangiferin in rats. METHODS： The in situ intestinal perfusion model was employed. HPLC/UV was developed to determine the concentration of mangiferin in intestinal circulated fluid. The effects of mangiferin concentration, bile and absorption site on the absorption parameters were studied. RESULTS： The mangiferin at a concentration from 5.0 to 25.0μg · mL ^-1 had no influence on the intestinal absorption kinetics （Ka） but it did at a concentration below 12.5 μg · mL ^-1 in biliary duct- ligated rats. The absorption rate constants（Ka） in descending order were 0.164 h ^-l（i^1.eum）,0.132 h ^-1（jejunum）, 0.125 h ^-1（colon） and 0.107 h^-1 （duodenum）, respectively. CONCLUSION： The absorption of mangiferin is in line with firstorder kinetics with passive diffusion absorption mechanism. Mangiferin is well absorbed at all segments of intestine in rats, and bile is conducive to the increase of the permeability coefficient of Mangiferin in intestine.