芒果苷大鼠肠吸收特性研究

目的研究芒果苷在大鼠肠道的吸收动力学特征。方法采用大鼠在体肠循环实验,用超高效液相色谱法和紫外分光光度法分别测定芒果苷和酚红的浓度,考察药物浓度、pH值和不同肠段对芒果苷吸收的影响,并与知母水煎液比较芒果苷在大鼠肠道吸收的差异。结果芒果苷浓度为2.0,5.0,10.0,20.0μg.mL-1时,吸收速率常数(ka)分别是0.0541,0.0467,0.0491,0.0220 h-1,吸收百分率(Fa)分别是14.05%,13.14%,12.43%和5.82%;随肠液pH升高,ka和Fa依次增加;芒果苷在肠段内吸收存在差异,各肠段的吸收速率常数按结肠、十二指肠、回肠和空肠依次下降;知母水煎液组中,肠循环液中芒果苷含量的上升和新芒果苷含量的下降呈同步变化。结论芒果苷在大鼠小肠段的吸收存在高浓度饱和现象,并且受到药物浓度、肠循环液pH值、肠段等因素的影响。

Intestinal absorption properties of mangiferin in rats

Objective To study the intestinal absorption characteristics of mangiferin of rats.Methods The intestine of rats was cannulated for in situ recirculation.UPLC and UV methods were respectively applied to measure the concentrations of mangiferin and phenolsulfonphthalein in intestine perfusate.The effects on the absorption of mangiferin were observed at different drug concentrations,pH values and intestinal segments.The absorption of mangiferin in Anemarrhena rhizoma had been studied in rat intestines.Results At different mangiferin concentrations of 2.0,5.0,10.0,20.0 μg·mL-1,the absorption rate constant(ka) and absorption percentage(Fa) were 0.0541,0.0467,0.0491,0.0220 h-1 and 14.05%,13.14%,12.43%,5.82%,respectively.The absorption of mangiferin increased with the increasing of pH value.It was different in the absorption of mangiferin at different intestinal segments,ka and Fa decreased from colon,duodenum,ileum to jejunum in order.In the groups of Anemarrhena rhizoma,the mangiferin content increased along with the decrease of neomangiferin content.Conclusions The intestinal absorption of mangiferin was saturated when the concentration increased to a certain level,and could be affected by the drug concentration,pH value and intestinal segments.