黄葵醇提物中黄酮类成分在体肠吸收研究

Absorption of flavonoids from Abelmoschus manihot extract by in situ intestinal perfusion

为了研究黄葵黄酮类成分的肠吸收机制,进行了黄葵醇提物不同浓度、不同肠段大鼠在体肠吸收研究。采用HPLC法测定循环液中药物浓度,分析了黄葵6种黄酮类成分的肠吸收,开展了P-gp抑制剂对黄葵黄酮类成分吸收影响的研究。结果显示:黄葵各黄酮成分在不同浓度下,Ka值没有明显差异(P>0.05),吸收呈一级动力学过程,提示为被动扩散吸收;各黄酮成分之间的吸收有差异性,苷类成分的Ka值小于苷元类成分;各成分在不同肠段均有吸收,金丝桃苷和杨梅素的最佳吸收部位分别为空肠和十二指肠;P-gp抑制剂维拉帕米可促进异槲皮苷、金丝桃苷、杨梅素和槲皮素3'-O-葡萄糖苷的吸收。

To explore the mechanism of the absorption of flavonoids from Abelmoschus manihot flowers,in situ intestinal recirculation was performed to study the effect of the absorption at different concentrations and different intestinal regions.To evaluate the conditions of the absorption of six flavonoids from Abelmoschus manihot flowers,the concentrations of Abelmoschus manihot in the perfusion solution were determined by HPLC at predesigned time.And we have investigated the inhibitory effect of six flavonoids from Abelmoschus manihot flowers on P-glycoprotein（P-gp） drug efflux pump.The results demonstrated that the absorption rates of flavonoids from Abelmoschus manihot flowers are not significantly different（P0.05） at various drug concentrations,the absorption of flavonoids from Abelmoschus manihot flowers is a first-order process with the passive diffusion mechanism.The absorption rates of each of flavonoids are significantly different.The absorption rate of flavonoid glycoside was lower than that of aglycone;the flavonoids from Abelmoschus manihot flowers could be absorbed in all of the intestinal segments.The best parts of intestine to absorb hyperoside and myricetin are jejunum and duodenum,separately.Verapamil could enhance the absorption of isoquercitrin,hyperoside,myricetin and quercetin-3＇-O-glucoside by inhibiting P-glycoprotein（P-gp） drug efflux pump.