Synthesis and evaluation of brain-targeted chemical delivery systems for the neurotrophomodulator 4-methylcatechol.

Since various 4-alkylcatechols stimulate nerve growth factor (NGF) biosynthesis both in-vitro and in-vivo, delivery of these agents to the brain may provide beneficial effect for the treatment of neurodegenerative diseases such as Alzheimer's. Several dihydropyridine-pyridinium salt type redox chemical delivery systems (CDS) of 4-methylcatechol (4-methylcatechol) were prepared as potential brain selective targetry forms for 4-methylcatechol. After preliminary evaluation by in-vitro stability studies in various buffer solutions and biological media, a selected CDS was further investigated in the rat to determine its in-vivo distribution. Selective and sustained delivery of the compound of interest to the rat brain was achieved. Furthermore, the NGF stimulatory activity in the rat brain after peripheral administration of the selected CDS was evaluated by measuring the levels of pre-pro-NGF mRNA in the rat hippocampus and frontal cortex, by dot blot hybridization and analysis. Results showed the peripheral administration of the CDS to achieve a 1.7-fold increase in NGF mRNA compared to control in the rat hippocampus, and an approximately 1.4-fold increase in the frontal cortex.