Efeito antidepressivo do (-)-α-bisabolol em camundongos C57BL/6 submetidos a um modelo de estresse crônico imprevisível

Abstract

Depression is a crippling disease that affects about 300 million people worldwide. It is characterized by symptoms of depressed mood, guilt and guilt, and can lead the individual to suicide. Its cause is not completely elucidated, however, there have been some hypotheses that justify its symptoms, such as a neuroendocrine and an infliction. There is a model, already characterized, called chronic unpredictable stress (CUS), which is used to induce depressive behavior in animals through environmental stressors. The most used treatment for evolution consists of pharmacotherapy with antidepressants. However, there is still resistance due to adverse effects, as well as the long latency period for the therapeutic effect. Thus, it is interesting to investigate new compounds with antidepressant potential. O (-)- α-bisabolol (BIS) is a sesquiterpene alcohol, which presents lipophilic and bioactive to the activities elucidated as anti-inflammatory, antispasmodic and neuroprotective. In order to reduce the pressure of conventional therapy, an antidepressant activity such as resistance of therapy, such as BIS, is sought. The objective of this work was to evaluate the antidepressant effect of (-)- α-bisabolol in C57BL / 6 mice with an unpredictable chronic stress model (ECI). The standard consisted in the experimental protocol of 28 days, for non-animals (n = 6-8), has been a rare environmental form, and the random species, for Guarness of unpredictability. From the 15th day oral groups: vehicle (saline + 3% Tween 80®), (-)-α-bisabolol at doses of 25 or 50 mg / kg, or Fluoxetine 10 mg / kg, as reference drug. To evaluate the locomotor activity, Forced Swim Test (TNF), TSC Suspension Test and Precision Test for sucrose solution), to perform the performance check anxiolytic (Labyrinth in Motion Test - LCE) and to evaluate pleasure memory (Y-labyrinth test). After 60 minutes of behavioral tests, the animals were euthanized by decapitation, and as brain areas (hippocampus and prefrontal cortex) were dissected and investigated the action of BIS on oxidative stress, and on the inflammatory senses. The results obtained with BIS have an antidepressant, anxiolytic and short-term effect in the dosages of 25mg / kg and 50mg / kg, and they weren’t submitted to locomotor activity, therefore, they presented doses, but not having a relaxing effect nor psychostimulant. At 50 mg / kg, BIS was able to reduce the levels of malondialdehyde (MDA) and hippocampus and reduce nitrate/nitrite levels in the prefrontal cortex, demonstrating its antioxidant effect. The ECI model increased the levels of the untested cytokines (IL-1β and TNF-α), however, (-) - α-bisabolol did not reduce. The results show that (-) - α-bisabolol has an antidepressant, anxiolytic and short-term memory protection effect. Other mechanisms of action for the antidepressant effect of (-) - α-bisabolol are of interest.