Table 1.

Studies of melatonin’s effects on antioxidant defenses in cancer cells.

Type of Cancer Cell	Melatonin Dosage	Effects	Authors
Human colorectal cancer SW-480 cell line	300 µM	Decreased catalase and SOD activity	[71]
Human colorectal carcinoma HCT-116 cell line	10−6 M	Decreased catalase and GSH-Px activity and increased lipid peroxidation	[23]
Human histiocytic lymphoma U937 cell line	0.5, 1, and 2 mM	Decreased SOD2 activity	[40]
Human hepatocellular carcinoma HepG2 cell line	0 to 20 mmol/L	Decreased SOD2 activity	[72]
Human HNSCCCal-27 cell line	100, 500,and 1500 μM	Decreased SOD2 activity	[20]
Human HNSCC Cal-27 cell line	100, 500, and 1000 μM	Decreased GPx activity	[31]
Human HNSCC Cal-27 cell line	100, 500, 1000, and 1500 μM	IR + aMT at 100 μM: increased GPx activitya MT at 1000 μM alone or combined with CDDP: decreased GPx activity	[19]
Xenograft mouse colon cancer (CT26 cell line)	20 mg/kg	Melatonin improved SOD and GPx activity in nontargeted tissues and reduced these two enzymes in the tumor tissue.	[73]