Inhibitory Effect of Melatonin on the Proliferation of Breast Cancer Cells MDA-MB-468 by Antioxidants Superoxide Dismutase and Glutathione Peroxidase

OBJECTIVE: The purpose of this study was to determine the inhibitory effect of melatonin on breast cancer cells MDA-MB-468 by the antioxidant superoxide dismutase and glutathione peroxidase. METHODS: This research was an in-vitro experimental study using MDA-MB-468 breast cancer cells from ATCC, treated with melatonin at concentrations of 1.5 mM, 2 mM, and 2.5 mM, with a 24-hour incubation. Cytotoxicity was examined using WST-8. SOD and GPx levels were measured using ELISA. Data analysis was performed using SPSS 27.0 with a one-way ANOVA parametric test, followed by post-hoc LSD analysis. RESULT: The IC₅₀ of melatonin in MDA-MB-468 breast cancer cells was 1.9 mM. There was a significant increase in SOD antioxidant levels (p = 0.000) in the melatonin concentration groups of 1.5 mM, 2 mM, and 2.5 mM. An increase in GPx antioxidant levels was also observed at the same concentrations (1.5 mM, 2 mM, and 2.5 mM), but it was not statistically significant (p > 0.05). CONCLUSION: Melatonin at concentrations of 1.5 mM, 2 mM, and 2.5 mM acts as an antiproliferative agent in MDA-MB-468 cells by significantly increasing the antioxidant activity of SOD and increasing GPx activity, although not significantly.