Melatonin protects mast cells against cytotoxicity mediated by chemical stimuli PMACI: Possible clinical use

•PMACI induces cytotoxicity on mast cells in a dose and time dependent manner.•Melatonin protects the mast cells against PMACI chemical stimuli.•Pharmacological doses of melatonin are the most effective for cytoprotection.•The action of melatonin is mediated via dependent and independent membrane receptors.•Melatonin could be a stabilizing cell molecule in various inflammatory conditions.

Melatonin has documented cytoprotective effects on a wide variety of immune cells. The mechanism of action on mast cells (RBL-2H3) still remains in the dark. We found that melatonin significantly attenuated phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-induced cytotoxicity in a concentration and time-dependent manner. It appears that the effect of melatonin on mast cells is two-fold: dependent (MT1 and MT2) and independent membrane receptors. In conclusion, melatonin treatment reduced the cytotoxicity, mediated by PMACI, and could provide a useful therapeutic option in processes where an excessive activation of mast cells occurs.