Effect of rapamycin and lithium carbonate on depression-like behavior and anxiety in skin melanoma

Abstract

Melanoma is the most malignant form of all skin tumors. There is a growing trend in the incidence of skin melanoma all over the world. 20% of patients develop depression, which affects their quality of life, desire for treatment, and survival. The tumor produces pro-inflammatory cytokines, which are transported to the central nervous system with the blood and lymph flow. This contributes to damage to the blood-brain barrier, as well as impaired neuronal function. Rapamycin is known to neuroprotective agent, it is used to treat neurodegenerative diseases. Lithium carbonate is used in the treatment of psycho-emotional disorders. The aim of the study was to evaluate the presence of depression-like behavior in animals in a model of peripheral tumor growth and using rapamycin and lithium carbonate. The experiments were carried out on C57BL/6 male mice, B16 melanoma tumor cells were injected, and treatment with rapamycin and lithium carbonate was carried out for 7 days. Using the open field test and forced swimming test, we analyzed the behavior of animals to assess motor and exploratory activities, to identify anxiety and depression-like behavior. It was noted to there is a slight increase in anxiety and depressive-like behavior in the model of tumor growth. The signs of depressive-like behavior was showed to decrease with the use of rapamycin. In addition, a decrease in general anxiety was shown in the lithium-treated group.