**Acknowledgements**

*Melatonin - The Hormone of Darkness and Its Therapeutic Potential and Perspectives*

studies; therefore, they do not have a sufficient recommended level.

**2.5 Melatonin in the treatment of hypersomnia**

vasoconstriction and MT2 receptor vasodilation. Thus, melatonin can act as a therapeutic agent in the treatment of cardiovascular diseases and hypertension resulting from comorbid diseases in sleep-dependent respiratory disorders. These effects of melatonin in carotid-dependent respiratory disorders were found as a result of a few

Hypersomnia, such as type I and type II narcolepsy, and idiopathic hypersomnia, are diseases of which the main clinical syndrome is excessive daytime sleepiness. At the same time, drowsiness, being one of the obligate syndromes of diseases, can be modulated by sleep disturbances, observed in these patients, associated with disturbances in sleep structure, and the stability of being in a slow-wave sleep. Currently, drugs approved by FDA, for example, include methylphenidate, modafinil, oxybate, and pitolisant. Methylphenidate, being an analogue of amphetamine, blocks the transport of dopamine and norepinephrine, increasing their concentration. This drug has a fairly large number of side effects. Modaphenyl is better tolerated but may cause psychological dependence on administration [75]. Oxybate and pitolisant are well tolerated. Pitolisant is currently undergoing an expansion of

indications up to 6 years of age in the treatment of types 1 and 2 narcolepsy.

recommended for use as a therapy for excessive daytime sleepiness [79].

A decrease in the secretion of melatonin is often observed with aging and diseases of various etiologies. Inadequate sleep hygiene, namely, excessive night illumination or night work, are the most common causes of suppression of pineal melatonin production, which has a chronobiological effect on the body. A decrease in the production of melatonin in some cases can be caused by neurodegeneration, accompanied by a change in the functioning of SCN, disrupting the operation of the circadic oscillator. The most common manifestations of epiphyseal deficiency of this hormone are various functional psychopathological disorders in the form of insomnia, anxiety, or depressive disorders. The role of melatonin is currently being actively discussed in the treatment of insomnia and the sleep-wake cycle disorder.

A few clinical studies demonstrate the effects in the treatment of the main

Melatonin can affect the severity of hypersomnia in these patients indirectly due to the effect on the architecture of night sleep. A positive impact on the architecture of night sleep is realized by increasing the representation of paradoxical sleep. The positive effects of melatonin administration in patients with hypersomnia in Parkinson's disease have been described, slowing down the decrease in the loss of dopamine-producing neurons and contributing to the suppression of dopamine transport [76]. Presumably, one of the causes of excessive daytime sleepiness in Parkinson's disease is the decrease in the concentration of melatonin [77]. The use of melatonin in patients with neurodegenerative diseases is promising, since a number of interesting effects of melatonin exposure were obtained on biological models. For example, melatonin, freely penetrating the blood-brain barrier, activates brain-derived neurotrophic factor and cyclooxygenase-10, suppressing plasma tumor necrosis factor (TNF-alpha) and IL-10 levels. In experiments, a decrease in the number of apoptotic cells induced by phenylhydrazine was demonstrated. These studies confirm the role of melatonin in neuroprotection and protection against apoptosis in oxidative damage to neurons [78]. According to domestic guidelines for the treatment of nonmotor manifestations of Parkinson's disease, melatonin is

**28**

**3. Conclusion**

We thank Pytin Vasiliy and Poverennova Irina (Samara Medical University).
