Table 3.

Oxidative stress biomarkers of multiple sclerosis. The redox status can be monitored by the activities of oxidative and antioxidative enzymes and the presence of degradation products derived from cellular components. ↑: increase, ↓: decrease, -: unknown.

Classes		Types	Human Samples		Reference
			Blood	CSF
Reactive Species		Reactive Nitrogen Species	↑	↑	[47]
Oxidative Enzymes		Xanthine Dehydrogenase (XDH)	↓	-	[46]
		Nicotinamide Adenine Dinucleotide Phosphate (NADPH) Oxidase	mixed	-	[48]
		Superoxide Dismutase (SOD)	↑	↓	[49,50,51,52]
		Inducible Nitric Oxide Synthase (iNOS)	↑	↑	[18,53,54,55]
		Myeloperoxidase (MPO)	mixed	-	[48]
Antioxidative Enzymes and Transcriptional Factors		Glutathione Peroxidase (GPx)	↑(relapse) ↓(remission)	↓	[56,57,58,59,60,61]
		Glutathione Reductase (GSR)	-	↑	[61,62]
		Catalase	↓	-	[61,62]
		Xanthine oxidase (XO)-Uric Acid	↓	-	[46]
		Nuclear Factor Erythroid 2-Related Factor (Nrf2)	↑	-	[52]
		Peroxisome proliferator-activated receptors (PPARs)	-	↑	[63]
		Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)	↓	-	[64]
Degradation Products and End Products	Protein	Protein carbonyls	↑	-	[65,66,67,68,69,70,71]
		3-nitrotyrosin (3-NO-Tyr)	↑	-	[68,69,70,72]
		Protein glutathionylation	-	↑	[73]
		Dityrosine	↑	-	[74]
		Advanced oxidation protein products (AOPPs)	↑	-	[49,74,75]
		Advanced glycation end products (AGEs)	↑	↑	[74,75]
	Amino acids	Asymmetric dimethylarginine (ADMA)	↓	-	[76]
	Lipid	F2-isoprostane (F2-isoP)	↑	↑	[77,78,79,80,81]
		Malondialdehyde (MDA)	mixed	↑	[61,82,83,84,85]
		4-hydroxynonenal (4-HNE)	-	↑	[86]
		Hydroxyoctadecadienoic acid (HODE)	↑	↑	[87]
		Oxysterol	mixed	↑	[88]
	DNA	8-dihydro-2′deoxyguanosine (8-oxodG)	↑	-	[56]