穿山龙提取物中薯蓣皂苷的大鼠在体肠吸收

摘要

目的 考察穿山龙提取物中薯蓣皂苷的在体肠吸收特性.方法 运用大鼠在体单向灌流模型,采用高效液相色谱法测定灌流液中薯蓣皂苷含量,分别考察不同肠段、药物浓度和P-糖蛋白(P-gp)抑制剂对薯蓣皂苷吸收的影响.结果 穿山龙提取物中薯蓣皂苷在大鼠全肠段均有吸收,其在不同肠段的吸收速率常数(Ka)和表观吸收系数(Papp)从大到小依次为回肠>十二指肠=空肠>结肠;不同质量浓度的薯蓣皂苷(40,80,120 mg·L-1),其Ka和Papp无显著性影响(P>0.05);含P-gp抑制剂组和不含P-gp抑制剂组比较,薯蓣皂苷的Ka和Papp差异有统计学意义(P<0.05).结论 在实验浓度范围内,穿山龙提取物中薯蓣皂苷的吸收没有浓度依赖性,吸收机制可能为被动扩散;穿山龙提取物中薯蓣皂苷可能是P-gp 底物.%Objective To study absorption characteristic of dioscin from Dioscorea nipponica Makino extract in rat intestine.Methods Single-pass intestinal perfusion (SPIP) model was used for rat in situ and HPLC was used to determine the concentrations of dioscin.The effects of different intestinal segments,drug concentration and P-glycoprotein (P-gp) inhibitor on intestinal absorption were investigated.Results Dioscin could be absorbed in the whole intestine,the absorption rate constant (Ka) and the apparent coefficient (Papp) of dioscin decreased following the sequence of ileum > duodenum =jejunum > colon.Absorption parameters of dioscin had no significant difference at different concentrations (40,80,120 mg·L-1).There were significant differences in Ka and Papp values between P-gp inhibitor group and no P-gp inhibitor group(P<0.05).Conclusion The saturate phenomena was not observed under the test range of drug concentration,and the absorption mechanism may be passive diffusion transport.Dioscin in Dioscorea nipponica Makino extract may be the substrate of P-gp.