**5. Conclusions**

Current literature highlights the high bioavailability of melatonin in human studies. The different MEL supplements are available for the treatment of sleep disorders or the effects derived from jet lag and are mainly used to reset the circadian clock. In addition, melatonin acts as a central synchronizer, capable of regulating a wide range of physiological functions, such as glucose and body lipid metabolism. Additionally, human clinical trials have shown that melatonin treatment can help improve or alleviate some of the most dangerous cardiovascular events. Similarly, melatonin has antioxidant capacity and is capable of neutralizing a wide variety of reactive oxygen and nitrogen molecules and indirectly modulates the activity of the endogenous enzymatic antioxidant system. Due to this cardioprotective capacity against oxidative stress, and taking into account the inhibition of different inflammatory and apoptotic pathways, melatonin is capable of exerting neuroprotective capacity. These findings reveal the great capacity and therapeutic potential of this molecule to combat different neurodegenerative pathologies.
