Amino Acid Derivatives as Palmitoylethanolamide Prodrugs: Synthesis, In Vitro Metabolism and In Vivo Plasma Profile in Rats
作者:Federica Vacondio、Michele Bassi、Claudia Silva、Riccardo Castelli、Caterina Carmi、Laura Scalvini、Alessio Lodola、Valentina Vivo、Lisa Flammini、Elisabetta Barocelli、Marco Mor、Silvia Rivara
DOI:10.1371/journal.pone.0128699
日期:——
Palmitoylethanolamide (PEA) has antinflammatory and antinociceptive properties widely exploited in veterinary and human medicine, despite its poor pharmacokinetics. Looking for prodrugs that could progressively release PEA to maintain effective plasma concentrations, we prepared carbonates, esters and carbamates at the hydroxyl group of PEA. Chemical stability (pH 7.4) and stability in rat plasma and liver homogenate were evaluated by in vitro assays. Carbonates and carbamates resulted too labile and too resistant in plasma, respectively. Ester derivatives, prepared by conjugating PEA with various amino acids, allowed to modulate the kinetics of PEA release in plasma and stability in liver homogenate. L-Val-PEA, with suitable PEA release in plasma, and D-Val-PEA, with high resistance to hepatic degradation, were orally administered to rats and plasma levels of prodrugs and PEA were measured at different time points. Both prodrugs showed significant release of PEA, but provided lower plasma concentrations than those obtained with equimolar doses of PEA. Amino-acid esters of PEA are a promising class to develop prodrugs, even if they need further chemical optimization.
棕榈酰乙醇胺(PEA)具有抗炎和镇痛特性,在兽医和人类医学中得到广泛应用,尽管其药代动力学特性不佳。为了寻找能够逐步释放PEA以维持有效血浆浓度的前药,我们制备了在PEA的羟基上的碳酸盐、酯和氨基甲酸酯。通过体外试验评估了这些化合物的化学稳定性(pH 7.4)以及在鼠血浆和肝匀浆中的稳定性。碳酸盐和氨基甲酸酯在血浆中分别表现出过于不稳定和过于稳定。通过将PEA与各种氨基酸结合制备的酯衍生物,能够在血浆中调节PEA的释放动力学并在肝匀浆中稳定存在。L-Val-PEA在血浆中具有适当的PEA释放,而D-Val-PEA对肝脏降解具有较高的抵抗性,两者均通过口服给予大鼠,并在不同时间点测量了血浆中前药和PEA的水平。两种前药均显示了显著的PEA释放,但提供的血浆浓度低于等摩尔剂量的PEA。PEA的氨基酸酯类是一类有前景的前药开发类别,尽管它们需要进一步的化学优化。