Potential utility of melatonin as an antioxidant therapy in the management of sickle cell anemia

This study aimed to assess antioxidant effects of melatonin treatment compared to N‐acetylcysteine (NAC) and to their combination in a sickle cell suspension. Sickle erythrocytes were suspended in phosphate‐buffered saline, pH 7.4, composing external control group. They were also suspended and incubated at 37°C either in the absence (experimental control group) or in the presence of NAC, melatonin and their combination at concentrations of 100 pm , 100 nm and 100 μm for 1 hr (treatment groups). The melatonin influences were evaluated by spectrophotometric [hemolysis degree, catalase (CAT), glutathione S‐transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), glucose‐6‐phosphate dehydrogenase (G6PDH), and superoxide dismutase (SOD) activities] and chromatographic methods [glutathione (GSH) and malondialdehyde (MDA) levels]. Incubation period was able to cause a rise about 64% on hemolysis degree as well as practically doubled the lipid peroxidation levels (P < 0.01). However, almost all antioxidants tested treatments neutralized this incubation effect observed in MDA levels. Among the antioxidant biomarkers evaluated, we observed a modulating effect of combined treatment on GPx and SOD activities (P < 0.01), which showed ~25% decrease in their activities. In addition, we found an antioxidant dose‐dependent effect for melatonin on lipid peroxidation (r = ?0.29; P = 0.03) and for combined antioxidant treatments also on MDA levels (r = ?0.37; P = 0.01) and on SOD activity (r = ?0.54; P < 0.01). Hence, these findings contribute with important insight that melatonin individually or in combination with NAC may be useful for sickle cell anemia management.