Table 2.

Melatonin indirectly enhances the antioxidant defense system of cells.

Test subjects	Antioxidant methods	Mechanism	References
ECV304 cell line	Increases antioxidant GSH	Increases the expression of gamma-glutamylcysteine synthetase	[161]
Brain homogenates from rats	Suppresses pro-oxidant enzymes	Reduces the activity of pro-oxidant enzymes such as XO and MPO	[162]
Cells from mice	Anti-inflammatory	Exerts anti-inflammatory effect via the ERK/Nrf2/HO-1 signaling	[163]
Oocytes from mice	Increases antioxidant enzyme	Increase the expression of GPx1/SOD1	[164]
Mice	Increases antioxidant enzyme	Enhances the SIRT3 activity; increases the binding affinity of FoxO3a to the promoters of both SOD2 and CAT	[165]
Mice	Increases antioxidant enzyme	Increases in total antioxidative capacity and SOD level via MT1/AMPK pathway	[166]
Rats	Maintenance of mitochondrial homeostasis	Increases the activity of the respiratory chain complexes I and IV; reduces electron leakage and ROS generation	[167]

Abbreviations: ECV304 cell line, human umbilical vascular endothelial cell line; GSH, glutathione; XO, xanthine oxidase; MPO, myeloperoxidase; ERK, extracellular regulated kinase; Nrf2, nuclear factor erythroid 2-related factor 2; HO-1, heme oxygenase-1; GPx1, glutathione peroxidase 1; SOD, superoxide dismutase; FoxO3a, forkhead box O 3a; CAT, catalase; MT1, melatonin membrane receptor 1; AMPK, AMP-dependent protein kinase; ROS, reactive oxygen species.