Antidepressant-Like Effects of n-Butylidenephthalide Using In Vivo and In Silico Approaches

Background: The plant-derived compound n-butylidenephthalide (BP) is an isobenzofuranone that has shown neuropharmacological effects on preclinical models of Parkinson's, Alzheimer's, and amyotrophic lateral sclerosis. Methods: This study evaluated the anti-inflammatory, antinociceptive, anxiolytic-like, hypnotic, anticonvulsant, and antidepressant-like effects of BP (50-200 mg/kg p.o.) using Balb/c mice in acute assays. This study also evaluated the antidepressant-like effects of BP in a mouse model of reserpine-induced depression-like behavior for 20 days. Inhibitors involved in the molecular process of depression and in silico studies were used to evaluate a possible mechanism of action for the antidepressant-like effects of BP. Results: BP induced low anti-inflammatory effects, showed low anticonvulsant effects, and lacked hypnotic effects or motor impairment in acute assays. The antidepressant-like effects of BP (100-200 mg/kg p.o.) were comparable to amitriptyline (25 mg/kg p.o.) in acute assays. The participation of serotonergic and adrenergic systems is involved in the acute antidepressant-like effects of BP. In the reserpine-induced depression model, BP (100 mg/kg p.o.) showed antidepressant-like effects in one of the two antidepressant tests, but with a lower effect than amitriptyline (20 mg/kg p.o.). Conclusions: BP (100 and 200 mg/kg) showed antidepressant-like effects in acute assays and, to a lesser extent, in a reserpine-induced chronic model of depression-like behavior.