Antioxidant Effect of Melatonin on the Functional Activity of Colostral Phagocytes in Diabetic Women

Abstract

Melatonin is involved in a number of physiological and oxidative processes, including functional regulation in human milk. The present study investigated the mechanisms of action of melatonin and its effects on the functional activity of colostral phagocytes in diabetic women. Colostrum samples were collected from normoglycemic (N = 38) and diabetic (N = 38) women. We determined melatonin concentration, superoxide release, bactericidal activity and intracellular Ca2+ release by colostral phagocytes treated or not with 8-(Diethylamino) octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8) and incubated with melatonin and its precursor (N-acetyl-serotonin-NAS), antagonist (luzindole) and agonist (chloromelatonin-CMLT). Melatonin concentration was higher in colostrum samples from hyperglycemic than normoglycemic mothers. Melatonin stimulated superoxide release by colostral phagocytes from normoglycemic but not hyperglycemic women. NAS increased superoxide, irrespective of glycemic status, whereas CMTL increased superoxide only in cells from the normoglycemic group. Phagocytic activity in colostrum increased significantly in the presence of melatonin, NAS and CMLT, irrespective of glycemic status. The bactericidal activity of colostral phagocytes against enterophatogenic Escherichia coli (EPEC) increased in the presence of melatonin or NAS in the normoglycemic group, but not in the hyperglycemic group. Luzindole blocked melatonin action on colostrum phagocytes. Phagocytes from the normoglycemic group treated with melatonin exhibited an increase in intracellular Ca2+ release. Phagocytes treated with TMB-8 (intracellular Ca2+ inhibitor) decreased superoxide, bactericidal activity and intracellular Ca2+ release in both groups. The results obtained suggest an interactive effect of glucose metabolism and melatonin on colostral phagocytes. In colostral phagocytes from normoglycemic mothers, melatonin likely increases the ability of colostrum to protect against EPEC and other infections. In diabetic mothers, because maternal hyperglycemia modifies the functional activity of colostrum phagocytes, melatonin effects are likely limited to anti-inflammatory processes, with low superoxide release and bactericidal activity.

The Effect of Melatonin Adsorbed to Polyethylene Glycol Microspheres on the Survival of MCF-7 Cells

“…Melatonin release in supernatant was extracted by affinity chromatography, concentrated by speed vacuum and determined using the ELISA kit (Immuno-Biological Laboratories, Hamburg, Germany) [20]. Reaction rates were measured by an absorbance plate-reading spectrophotometer with a 405-nm filter.…”

Maternal hypertension induces alterations in immunological factors of colostrum and human milk

“…Studies suggest that maternal characteristics can cause variations in the components of colostrum and milk, and these changes are dependent on the nutritional status or previous diseases of the mother (Olivares et al 2007;Teixeira et al 2010;França et al 2011aFrança et al , 2012aFrança et al , 2013Morceli et al 2011Morceli et al , 2013. This work shows the influence of maternal hypertension on proteins in milk.…”

“…The relationship between breastfeeding and the development of several chronic diseases, including obesity, diabetes and hypertension, has been studied (Taylor et al 2005;França et al 2011França et al , 2012aMorceli et al 2011Morceli et al , 2013. Breastfeeding reduces the incidence of acute illness and likely decreases the risk of numerous chronic diseases.…”

Nanoparticles of barium induce apoptosis in human phagocytes

“…31 The MN phagocytes were then washed two times with 199 medium at 4°C and immediately used in the assays.…”