Efeitos do extrato hidroalcoólico de Erythrina velutina em parâmetros comportamentais e neuroquímicos em modelo animal de depressão induzida por estresse crônico imprevisível

Abstract

Depression is a multifactorial and highly disabling disorder, associated with therapeutic limitations and cognitive deficits. The chronic unpredictable stress (CUS) model is widely used to investigate potential antidepressant treatments. Erythrina velutina Willd. is traditionally used in folk medicine as a sedative and anxiolytic, yet lacks experimental evidence in animal models of depression. This study investigated the behavioral and neurochemical effects of the hydroalcoholic extract of Erythrina velutina in male Swiss mice subjected to CUS for 21 days. The animals were exposed to CUS and treated with either saline or E. velutina at doses of 50 mg/kg (EV50) and 100 mg/kg (EV100), orally, for seven days (from day 15 to day 21). Behavioral assessments included the open field, tail suspension, Y-maze, passive avoidance, and object recognition tests, in addition to body weight monitoring and quantification of reduced glutathione (GSH) levels in the prefrontal cortex, hippocampus, and striatum. The CUS protocol induced depressive-like behavior, confirmed by increased immobility in the tail suspension test and reduced rearing in the open field. Treatment with EV100 reduced immobility time, suggesting an antidepressant-like effect, but was associated with impaired performance in the Y-maze, with no consistent effects on other cognitive parameters. Regarding GSH levels, the extract did not cause reductions under any experimental condition, suggesting the absence of deleterious effects and a possible stress- dependent modulation. Additionally, an increase in body weight was observed in mice treated with both doses. In conclusion, under the evaluated conditions, the hydroalcoholic extract of E. velutina produced dose-and context-dependent effects, with the higher dose indicating potential antidepressant activity without consistently impairing cognitive performance, while maintaining GSH levels and promoting weight gain. These initial findings provide novel evidence of the species’ therapeutic potential in a validated model of depression, reinforcing the need for further studies to elucidate its mechanisms of action.