School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
Eur J Pharm Sci. 2019 Mar 1;129:99-109. doi: 10.1016/j.ejps.2019.01.002. Epub 2019 Jan 6.
Ferulic acid (FA), a natural antioxidant, has displayed some potential benefits against Alzheimer's disease. However, due to its poor blood-brain barrier (BBB) permeation and low bioavailability, the clinical use of FA for the treatment of Alzheimer's disease has been limited. In the present study, we applied an L-type amino acid transporter (LAT1) - mediated prodrug approach to deliver FA into the mouse brain and synthetized three novel LAT1-utilizing prodrugs of FA. We used a previously proposed methodology for the development of transporter-utilizing prodrugs and investigated their cellular uptake via LAT1 in vitro in ARPE-19 cells, BBB permeation using in situ perfusion in mice and pharmacokinetics after a single i.p. injection in mice; and compared the findings to our previous structure-pharmacokinetics relationship analysis of LAT1-utilizing prodrugs. In addition, we evaluated interspecies differences in the bioconversion rate of the ester-based prodrug in mouse and human plasma and liver S9 subcellular fraction. It was found that amide-based prodrugs with an aromatic ring in the promoiety were effectively bound to LAT1 and utilized the transporter for cellular uptake in vitro and crossed the BBB after in situ perfusion in mice. In addition, the amide prodrug with the promoiety directly conjugated in the meta-position to FA was bioconverted to the parent drug in mouse brain. Importantly, the study showed that the analogous ester-based prodrug did bind to LAT1 but did not utilize the transporter for cellular uptake in ARPE-19 cells. However, the presence of an ester linker between the prodrug and the parent drug promoted favorable bioconversion properties in human in comparison to mouse tissues in vitro i.e. the ester prodrug showed higher stability in human plasma (75% of intact prodrug in 5 h) and liver S9 subcellular fraction (181 min) in comparison to mouse plasma (t 2.6 min) and liver S9 fraction (t 23.3 min), suggesting that ester-based prodrugs may offer potential benefits in humans. In conclusion, switching from an amide to ester linker between the promoiety and the parent drug can affect the bioconversion rate of prodrugs in different species as well as influencing their cellular uptake mechanism. Furthermore, the results demonstrated the effective application of structure-pharmacokinetic relationships and screening methodology for developing LAT1-utilizing prodrugs and highlighted the importance of evaluating the biotransformation of parent drug and prodrugs in different species.
阿魏酸（FA）是一种天然抗氧化剂，具有治疗阿尔茨海默病的潜力。然而，由于其较差的血脑屏障（BBB）通透性和低生物利用度，FA 用于治疗阿尔茨海默病的临床应用受到限制。在本研究中，我们应用 L 型氨基酸转运体（LAT1）介导的前药方法将 FA 递送至小鼠脑内，并合成了 FA 的三种新型 LAT1 利用前药。我们使用了先前提出的用于开发转运体利用前药的方法，并在体外 ARPE-19 细胞中研究了它们通过 LAT1 的细胞摄取，在小鼠原位灌流中研究了 BBB 通透性，并在小鼠单次腹腔注射后研究了它们的药代动力学；并将研究结果与我们以前对 LAT1 利用前药的结构-药代动力学关系分析进行了比较。此外，我们评估了酯基前药在小鼠和人血浆和肝 S9 亚细胞级分中的生物转化率的种间差异。结果发现，具有芳香环的酰胺基前药与 LAT1 有效结合，并在体外通过转运体进行细胞摄取，在小鼠原位灌流后穿过 BBB。此外，与 FA 直接在对位连接的酰胺前药在小鼠脑中被生物转化为母体药物。重要的是，该研究表明，类似的酯基前药虽然与 LAT1 结合，但在 ARPE-19 细胞中不利用转运体进行细胞摄取。然而，前药和母体药物之间存在酯键连接促进了体外人比小鼠组织更好的生物转化特性，即酯前药在人血浆（5 小时内 75%的完整前药）和肝 S9 亚细胞级分（181 分钟）中显示出更高的稳定性，与人相比，小鼠血浆（t 2.6 分钟）和肝 S9 级分（t 23.3 分钟），这表明酯基前药可能在人类中具有潜在益处。总之，在促进子和母体药物之间从酰胺键到酯键的连接的转变可以影响不同物种中前药的生物转化率，并影响其细胞摄取机制。此外，结果证明了结构-药代动力学关系和筛选方法在开发 LAT1 利用前药方面的有效应用，并强调了评估不同物种中母体药物和前药的生物转化的重要性。
