Efeito antidepressivo do trans-anetol em camundongos swiss fêmeas: estudo comportamental e neuroquímico

Abstract

Depression is a multifactorial disorder characterized by depressed mood. Research has identified a relationship between stress and depression. Stress promotes the unbridled increase of cortisol which in high amounts promotes structural and biochemical changes in the Central Nervous System (CNS) and may lead to Major Depressive Disorder (MDD). Due to the complexity of this disorder the investigation for new treatment alternatives is constant to obtain the well-being of patients. Thus, in this search for new treatments, substances originating from aromatic plants, especially essential oils, are shown to have several biological activities. Among these constituents, trans-anethole has been shown to be a molecule with potential antioxidant, anti-inflammatory and anxiolytic action. Due to these activities, we aimed to investigate whether trans-anethole has antidepressant action on adult female mice submitted for fourteen days to the unpredictable subchronic stress (ESI). Six groups were used, one non-stressed group and five groups that underwent ESI, which after the initial seven days of protocol were subdivided into ESI saline, ESI imipramine (15 mg / kg) and ESI treated with doses of 100,200 and 300 mg. / kg trans-anethole. At the end of the protocol, tail suspension tests, sucrose spraying were performed to evaluate antidepressant action and open field for locomotor activity, the animals were euthanized and the hippocampus was removed for neurochemical analysis. In the assessment of weight variation, the stress group had a reduction in weight gain compared to the non-stressed group, animals at 200 and 300 mg / kg had weight loss compared to the beginning of the protocol. In the sucrose spraying test, the three trans-anethole doses reduced the latency time; in the self-care time the 200 mg / kg dose was higher than the ESI group. In the tail suspension the immobility latency did not differ in trans-anethole doses, only the imipramine and control groups differed from ESI, in the immobility time the 200mg / kg dose had the best result differing from the ESI group. In the open field, trans-anethole (100 and 200mg / kg) was able to increase the amount of rearings in relation to stressed animals; In the parameter number of crossings the dose of 100mg / kg had the best performance; Finally in the time of stay in the center the dose of 200mg / kg was higher in relation to the stress group. In the neurochemical evaluation, cortisol was found at high level in the hippocampus of the ESI animals, all trans-anethole doses were able to significantly reduce its levels. By quantifying the serotoninergic pathway trans-anethole was able to reduce serotonin degradation at doses of 200 and 300mg / kg. In the dopaminergic route, the best doses were 100 and 300 mg / kg because they did not promote an increase of dopamine degradation. The results suggest that trans-anethole does not interfere with locomotor activity, and also promotes anhedonia behavior of animals submitted to a stress protocol, besides reducing cortisol levels and acting on serotonergic and dopaminergic pathways.