Yang Wu, Hou Jia, Lu Yuan, Chen Peng-cheng, Liao Shang-gao, Huang Yong
Zhongguo Zhong Yao Za Zhi. 2015 Nov;40(21):4281-7.
A UPLC-ESI-MS/MS method was used to determinate the main active fractions gallic acid, protocatechuic acid, myricetrin, hyperoside and quercitrin in Polygonum capitatum extracts by in situ intestinal perfusion models; the absorption rate constants and cumulative penetration rate of absorption were calculated. The effect of different drug concentrations, different intestine segments, bile and P-gp inhibitors on the absorption mechanism of Gallic acid and other compositions in P. capitatum extracts. The experimental results showed that gallic acid, protocatechuic acid, myricetrin and quercitrin were observed saturated at high concentration (P < 0.05). Bile had significant inhibition effect on protocatechuic acid absorption and had promotion effect on myricetrin and hyperoside absorption (P < 0.05). P-gp inhibitor verapamil could significantly enhance the absorption of Protocatechuic acid (P < 0.05). The overall trend for absorption of various compositions was that small intestine > colon. This indicated that the absorption mechanism of P. capitatum extracts in rat intestine was in line with fist-order kinetics characteristics. The composition could be absorbed in all of the different intestinal segments, and the absorption was mainly concentrated in small intestine. The protocatechuic acid may be the substrate of P-gp.
采用超高效液相色谱-电喷雾串联质谱法（UPLC-ESI-MS/MS），通过原位肠灌注模型测定头花蓼提取物中的主要活性成分没食子酸、原儿茶酸、杨梅苷、金丝桃苷和槲皮苷；计算其吸收速率常数和吸收累积透过率。考察不同药物浓度、不同肠段、胆汁及P-糖蛋白（P-gp）抑制剂对头花蓼提取物中没食子酸等成分吸收机制的影响。实验结果表明，没食子酸、原儿茶酸、杨梅苷和槲皮苷在高浓度时呈现饱和现象（P<0.05）。胆汁对原儿茶酸的吸收有显著抑制作用，对杨梅苷和金丝桃苷的吸收有促进作用（P<0.05）。P-gp抑制剂维拉帕米可显著增强原儿茶酸的吸收（P<0.05）。各成分的吸收总体趋势为小肠>结肠。这表明头花蓼提取物在大鼠肠道中的吸收机制符合一级动力学特征。该成分在不同肠段均可吸收，且吸收主要集中在小肠。原儿茶酸可能是P-gp的底物。
