1995 Volume 68 Issue 3 Pages 263-269
Neopterin is an 2-amino-4-hydroxypteridine derivative and a precursor of biopterin, which is derived from guanosine triphosphate. Previously, we have reported that 5, 6, 7, 8-tetrahydroneopterin (NPH4), a reduced form of neopterin, possesses an antioxidant activity in various systems. In this study, we investigated the activity in more detailed manner and discussed the possible applications of this antioxidant. Analysis by electron spin resonance spectrometry indicated that NPH4 scavenged superoxide anion radicals and hydroxyl radicals as well. Moreover, NPH4 protected the rat brain homogenate from autoxidation. Next, we examined the effect of NPH4 on the cell injury induced by cumene hydroperoxide (CHP) in cultured bovine artery endothelial cells. The activity of lactate dehydrogenase, a marker enzyme of cell injury, was elevated by CHP in a dose-dependent manner, and this elevation was dose-dependently suppressed by NPH4. The elevation of lipid peroxide content was also inhibited by NPH4 in the same fashion. These data suggest that NPH4 would be effective against various diseases whose pathogenesis is active oxygenrelated.
