Anxiolytic-Like and Antidepressant Effects of a 13H-indolo[2,3-a]thiopyrano[2,3-g]quinolizine Derivative

Abstract

Depressive and anxiety disorders constitute some of the most prevalent mental disorders around the world. For years, the development of new lead compounds for drug discovery in this field has been an area of great attention. Recently, a series of tetrahydrocarbazole derivatives have demonstrated important anxiolytic-like activity, associated with their structures and stereochemistry. Here, we present a study of the antidepressant effect and anxiolytic-like activity of a fused thiopyrano-piperidone-tetrahydrocarboline (compound 4). The antidepressant and anxiolytic-like effects of 4 (1–50 mg/kg p.o.) were assessed with the tail suspension test and the hole-board test, respectively. This study determined the possible mechanisms involved in the anxiolytic-like actions of 4 using inhibitors or neurotransmission and evaluated its interaction with 5HT2A receptors using a molecular docking study. As an analog to the tetrahydrocarbazole core, the tetrahydrocarboline derivative showed anxiolytic-like activity (ED50 = 13 mg/kg p.o.) in the hole-board test, with a comparable effect to the reference drug, 1.5 mg/kg clonazepam, with the possible participation of the serotonergic system.