Table 1.

Antioxidants frequently used in laboratory experiments.

Antioxidant	Structure	Protective Effect	Note
Ascorbic acid		Directly interacts with O2•− and H2O2.	In the presence of iron, it becomes powerful source of ROS.
Ebselen		Directly interacts with H2O2 at low concentrations.	Ebselen becomes powerful source of ROS at high concentrations.
Deferoxamine		As an iron chelator, inhibits Fenton reaction.	Deferoxamine prevents formation of •OH indirectly.
1,4-Dithiothreitol		Directly interacts with •OH and reduces disulphide bonds in protein samples.	At neutral and alkaline pH, it autoxidises rapidly. It is used in cell-free extracts.
Glutathione		Directly interacts with •OH but not with O2•− and H2O2.	In reactions catalysed by GPx, effectively reduces H2O2 and ROOH.
Mercaptoethanol		Directly interacts with •OH and reduces disulphide bonds in protein samples.	Due to its relatively high cytotoxicity, it is used in cell-free extracts.
N-acetylcysteine		Directly interacts with •OH and HOCl but not with O2•− and H2O2.	Although its application scale is limited, it is overused.
Thiourea		Directly interacts with O2•−, H2O2, and •OH.	Although its application scale is very wide, it is used rarely.
Trolox		It is used to “repair” a variety of biomolecules damaged by oxidative stress.	A water-soluble analogue of vitamin E.