Melatonin and brain barriers: The protection conferred by melatonin to the blood-brain barrier and blood-cerebrospinal fluid barrier
Rafael Mineiro, Maria Rodrigues Cardoso, Ana Catarina Duarte, Cecília R.A. Santos, José Cipolla‐Neto, Fernanda Gaspar do Amaral, Diana Costa, Telma Quintela
Abstract
• Melatonin exerts protective action in barriers integrity • The protective effect is due to anti-inflammatory and antioxidant melatonin properties. • Melatonin has the potential to facilitate the passage of a drug across brain barriers. • It is possible to use melatonin as a modulator of brain barriers functions. The blood–brain barrier and the blood-cerebrospinal fluid barrier separate the blood from brain tissue and cerebrospinal fluid. These brain barriers are important to maintain homeostasis and complex functions by protecting the brain from xenobiotics and harmful endogenous compounds. The disruption of brain barriers is a characteristic of neurologic diseases. Melatonin is a lipophilic hormone that is mainly produced by the pineal gland. The blood–brain barrier and the blood-cerebrospinal fluid barriers are melatonin-binding sites. Among the several melatonin actions, the most characteristic one is the regulation of sleep-wake cycles, melatonin has anti-inflammatory and antioxidant properties. Since brain barriers disruption can arise from inflammation and oxidative stress, knowing the influence of melatonin on the integrity of brain barriers is extremely important. Therefore, the objective of this review is to gather and discuss the available literature about the regulation of brain barriers by melatonin.