Os efeitos da Ayahuasca em modelo animal de depressão

Abstract

Depression is a very common and highly disabling psychiatric disorder. Despite the large number of psychoactive drugs available for therapy, the success rate of antidepressant treatments generally does not exceed 60%. In this matter, the search for new therapies that may help to treat this pathology is of great interest. In this context, Ayahuasca (AYA) emerges as a possible alternative for the treatment of depression. AYA is a shamanic beverage resulting from the decoction of two plants: Banisteriopsis caapi and Psychotria viridis. Considering the above, the aim of this study was to evaluate the effect of subchronic administration of AYA in rats submitted to a model of depression elicited by chronic unpredictable stress (CUS). Analyzing the behavioral parameters, the depression model chosen was validated by the food test, although AYA did not prevent anhedonia caused by this model. In the open-field test, none of the analyzed parameters (number of crosses, grooming and rearing) were altered by any of the treatments. Analyzing the parameters of oxidative stress, levels of TBARS were increased in the cerebral cortex of the stress group in relation to the control group, and AYA counteracts this alteration. In the hippocampus, the sulfhydryl levels decreased in the stress group in relation to the control, and also AYA treatment prevent this change. Regarding nitrite levels, an increase in the stress and in AYA groups were observed in the cerebral cortex in relation to the control group. The antioxidant enzymes were also tested. Regarding superoxide dismutase in the AYA stress group, we found an increased in relation to the control in hippocampus samples. We demonstrated that activity of the catalase decreased in cerebral cortex of rats submitted to stress when compared to the control group, and AYA prevented this change. Our results showed that treatment with AYA was not able to prevent anhedonia caused by the CUS model. However, almost all changes in CUS-induced oxidative stress in cerebral cortex and hippocampus were prevented by AYA treatment.