Anti-inflammatory Potential of Some 4-aminopyridine's Peptide Derivatives – in Vivo and in Vitro Evaluation

Abstract

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized by inflammatory demyelination and neurodegeneration. Fampyridine (4-aminopyridine, 4-AP) is a drug used for MS treatment as it readily passes through the blood-brain barrier exhibiting anti-inflammatory effects. Its high toxicity, however, limits its wider application. To reduce 4-AP high toxicity, we have designed new peptides-containing 4-AP derivatives showing about 150 times lower toxicity than 4-AP. This work aims to investigate the cytotoxicity and in vivo anti-inflammatory effects of three newly synthesized peptide derivatives of 4-AP, defined as substances A, B, and C. In addition, their inhibitory potential against MMP-2 and -9 proteolytic activity was evaluated as well. To study the anti-inflammatory effect of the 4-AP-derivatives we used a rat model for immune complex-induced inflammation. In vitro cytotoxicity test was performed on WEHI-164 cells. Inhibition of matrix metalloproteinase (MMP-9 and -2) proteolytic activity was assessed by gelatinase zymography and densitometric analysis. Our results showed that treatment with the 4-AP derivatives kept cells viable and metabolically active showing no cytotoxicity. Substances A and C inhibited the proteolytic activity of both isoforms of MMP-2 and -9 even when applied in the lowest concentration, whereas substance B had no inhibitory effect on the MMP-9 activity and inhibited MMP-2 activity only applied at higher concentrations. Along with its inhibitory effect on the MMP-2 and -9 proteolytic activity, substance A demonstrated a clear anti-inflammatory effect either preventing or inhibiting the production of antibodies in the blood circulation of rats. Substance A might be very promising as a drug molecule.