Caco-2细胞单层模型研究葛根提取物中葛根素转运机制及白芷提取物对其转运的影响

 目的 利用人源结肠腺癌细胞系 Caco-2 细胞单层模型,研究了葛根提取物中葛根素的吸收转运机制,以及白芷提取物对其吸收转运的影响。方法 建立人源结肠腺癌细胞系 Caco-2细胞模型,利用此模型研究葛根提取物中葛根素的双向转运特征,并考察时间、药物浓度、pH值对其转运的影响;研究葛根中葛根素在P-糖蛋白（P-gp）、人多药耐药蛋白（MRP）蛋白专属抑制剂存在或缺失条件下,葛根素在Caco-2细胞模型的转运情况;并考察白芷提取物对葛根中葛根素吸收转运的影响。结果 在pH 5.5弱酸条件下,葛根素吸收较好;随着葛根提取物浓度的增大,K_a值逐渐增大,P_app值逐渐增加并趋于平衡,在加入P-糖蛋白和人多药耐药蛋白蛋白抑制剂后,葛根的P_{app AP-BL}增大,P_{app BL-AP}/P_{app AP-BL}降低;白芷提取物中香豆素能够促进葛根素的转运。结论 葛根提取物中葛根素在Caco-2 细胞模型的吸收机制以被动转运为主,同时存在着载体转运,P-糖蛋白和人多药耐药蛋白蛋白可能为其主要载体并参与载体转运的过程,白芷提取物对葛根素有一定促吸收作用。

Transport Mechanism of Puerarin and the Influence of Angelica dahurica Extracts on Absorption of Puerarin in Caco-2 Cell Model

OBJECTIVE To study the transport properties of puerarin across Caco-2 cell membrane and determine the influence of Radix Angelicae Dahuricae extract on the transport of puerarin using the well-characterized, human-based intestinal Caco-2 cell model as a platform. METHODS The characteristics of the bidirectional transport of puerarin was investigated. The effects of time, drug concentration, pH, P-gp inhibitor and MRP inhibitor on the absorption of puerarin were observed. Then the influence of the extract of Radix Angelicae Dahuricae on the transport of puerarin was studied. Drug concentration was measured by HPLC and the apparent permeability coefficients (P_app) and apparent permeability ratio (PDR) were calculated. RESULTS Puerarin was better absorbed in weak acid of pH5.5. The K_a and P_app of puerarin was of concentration-dependent,and the transport showed saturation with increasing time and concentration.When P-gp/MRP inhibitors were added to the model, the P_{app AP-BL}of puerarin in Caco-2 cell increased and the P_{app BL-AP}/P_{app AP-BL} of puerarin reduced. The absorption of puerarin was improved when combined with Radix Angelicae Dahuricae. CONCLUSION The intestinal absorption of puerarin in Caco-2 cell monolayer model is mainly a passive diffusion process, and active transportation mediated by P-gp and MRP transporter is also involved. Radix Angelicae Dahuricae can enhance the intestinal absorption of puerarin.