Chronoimmunomodulation of melatonin on bactericidal activity of human blood phagocytes

Abstract

In this work we studied the chronoimmunomodulation effect of melatonin on blood phagocytes. This cells stimulated with melatonin and incubated with EPEC presented enhanced superoxide. Mononuclear (MN) and polymorphonuclear (PMN) phagocytes stimulated with melatonin in the presence of bacteria showed enhanced superoxide release.EPEC killing by MN phagocytes stimulated with melatonin was time dependent. The highest bactericidal index were observed over the period of 60 and 120 minutes of incubation. PMN phagocytes stimulated with melatonin, independently of time, showed increased in the bactericidal activity. Interactions between melatonin and phagocytes support the hypothesis of pineal chronomodulation microbicidal processes.