Galactosyl prodrug of palmitoylethanolamide: Synthesis, stability, cell permeation and cytoprotective activity

N-Palmitoylethanolamide (PEA) is emerging as a novel therapeutic agent in the treatment of neuropathic pain and neurodegenerative diseases. Unfortunately, PEA poorly reaches the central nervous system (CNS), after peripheral administration, since it is inactivated through intracellular hydrolysis by lipid amidases. Since prodrug approach is one of the most popular methods used to increase cell permeability, the aim of this paper consists in the synthesis of a new galactosyl prodrug of PEA, the palmitoylethanolamide-succinamyl-D-galactos-6'-yl ester (PEAGAL). Biological experiments both in neuroblastoma and in C6 glioma cells, together with quantitative analyses performed through a LC-MS-MS technique, demonstrate the better efficacy of PEAGAL compared to PEA and its higher cell permeation. Our results encourage further experiments in animal models of neuropathic pain and of neurological disorders and/or neurodegenerative diseases, in order to promote a more effective peripherally administrated derivative of PEA.