Melatonin and biological membrane bilayers: a never ending amity

Biological membrane, the most fluidic structure of a cell or an organelle, refrains the cells to progress toward apoptosis by sustaining their optimum environment. This bilayer-membrane equips all machineries required for cellular communication, limits the entry of foreign bodies, selectively transports molecules or ions depending on the need of the system but, it also acts as a first line defense against environmental insults. Due to the presence of a vast number of poly unsaturated fatty acids (PUFA), the biological membrane is highly prone to oxidative stress and as a consequence, acceleration in lipid peroxidation by free radicals, becomes a threat to cellular viability. Alterations in the biophysical state of bilayer caused by oxidative stress frequently occur in the in vivo as well as in vitro conditions. It has been well documented that the molecule, melatonin, exhibits profound coherence in neutralizing oxidative stress and thus, to normalize fluidity status of biological membranes. Aging associated decline in melatonin level with subsequent ascended lipid peroxidation and membrane viscosity found in almost all organisms further suggest the importance of melatonin in this context. Since disruption of membrane structure or even some modifications will cause a spectrum of diseases, keeping membrane intactness would be an adequate strategy to prevent these diseases. Considering the high permeability, safe and potent antioxidant capacity of melatonin, this molecule can be a superlative choice to alleviate membrane bilayer rigidity and its related ailments.