目的 研究红参水提物中人参三萜在人小肠上皮细胞的吸收特性。方法 利用人源结肠腺癌细胞系Caco-2细胞单层模型测试红参水提物中人参三萜从顶端（apical，AP）侧到底端（basolateral，BL）侧、BL侧到AP侧2个方向的转运过程。应用色谱-质谱技术对人参三萜进行定量分析，计算转运参数和表观渗透系数（P_app）。结果 在Caco-2细胞单层模型中，发现大多数人参三萜皂苷吸收程度中等或不良，但是，唯有2个苷元20（S）-原人参三醇（protopanaxatriol，PPT）和20（R）-PPT吸收程度良好（P_app值接近1×10^-5 cm/s）；此外，还发现人参三萜皂苷20（S）-G-Rh₁、20（R）-G-Rh₁、G-Rk₃、G-Rh₄、PG-RT₅这5个单糖苷的P_app值皆在1×10^-6 cm/s数量级，提示它们吸收程度中等。所考察的42个人参三萜其中包括8对R、S差向异构体，结果显示R/S异构体的吸收情况并没有显著性差异。结论 随着人参三萜皂苷苷元上糖取代基数目的增多，其P_app值越来越小，提示多糖基的人参三萜皂苷在体内很难被吸收，可能是前药。

Objective To study the absorption and transport characteristics of ginseng triterpenoids from the Hongshen (Ginseng Radix et Rhizoma Rubra) water extract in human intestinal epithelial. Methods Caco-2 (the human colon adenocarcinoma cell lines) cell monolayer was used as an intestinal epithelial cell model. The permeability of the ginseng triterpenoids in the Ginseng Radix et Rhizoma Rubra water extract from apical side (AP side) to basolateral side (BL side) or from BL side to AP side was evaluated. The concentration of the ginseng triterpenoids was measured by LC-MS technological method. Transport parameters and permeability coefficients (P_app) were then calculated. Results In human Caco-2 cell monolayer model, it was revealed that most ginsenosides were moderately or poorly absorbed compounds, whereas only two aglycone, 20(S)-protopanaxatriol (PPT) and 20(R)-PPT, exhibited as well absorbed compounds (P_app values were near 1×10^–5 cm/s). In addition, the P_app values of five monoglycosides including 20(S)-G-Rh₁, 20(R)-G-Rh₁, G-Rk₃, G-Rh₄, and PG-RT₅ in the bi-directional transport were quantitative degree of 1×10^–6 cm/s, which were defined as moderately absorbed compounds. Among them, there were eight pairs of R and S isomers, whereas there was no significant difference on their trends in the bi-directional transport between these R and S isomers. Conclusion With the increase of glycosyl substitution group at ginsenoside aglycone, the P_app value of ginsenoside becomes smaller and smaller, which indicated that ginsenosides with polyglycosyl group are difficult to be absorbed in vivo. These ginsenosides could be prodrugs.

R285

国家自然科学基金（81973446）