Fluorescence was measured at wavelengths of 325/440 nm (AGEs), 330/415 nm (dityrosine), 325/434nm (N-formylkynurenine), 365/480 nm (kynurenine), and 295/340 nm (tryptophan) [14, 15].
As a result of OS, the level of tryptophan fluorescence decreases and the levels of products of oxidative destruction of tryptophan such as kynurenine and N-formylkynurenine, easily detectable by fluorescence, increased.
The content of N-formylkynurenine in blood serum proteins of nontreated MS patients was significantly increased with respect to control (p <0.001).
Combined treatment with INF-beta and melatonin was more effective in attenuating oxidative stress, being effective in diminishing the increase in the levels of N-formylkynurenine, kynurenine, carbonyl, and AGE content where treatment with INF-beta alone was ineffective.
reported an impairment in the immunomodulatory and antimicrobial actions of the hepatic enzyme tryptophan 2,3-dioxygenase, which converts tryptophan, the essential amino acid for hosts and pathogens, to N-formylkynurenine
, the precursor of the immune-relevant kynurenines, upon hypoxic conditions mimicking those occurring in vivo during infection and cancer, for example.