Antidepressant- and anxiolytic-like effect of novel 5-hydroxytryptamine3 receptor antagonist 2-[4-(3-chlorophenyl) piperazin-1-yl]-1,8-naphthyridine -3-carboxylic acid (7e)-: An approach using rodent behavioral antidepressant and anxiolytic test battery

Aim: Depression and anxiety are among the most common and prevalent forms of mental disorder. The 5-hydroxytryptamine3 (5-HT 3 ) receptor antagonists modulate serotonergic pathways and show antidepressant- and anxiolytic-like effect in various animal models of depression. The present study was designed to investigate the antidepressant and anxiolytic potential of 2-[4-(3-chlorophenyl) piperazin-1-yl]- 1,8-naphthyridine-3-carboxylic acid (7e), a novel 5-HT 3 receptor antagonist in rodent behavioral models of depression and anxiety. Materials and Methods: The compound 7e was tested using different behavioral models for depression and anxiety such as forced swim test (FST), tail suspension test (TST), mechanistic models such as 5-hydroxytryptophan (5-HTP)-induced head twitch, elevated plus maze (EPM), hole-board (HB) test, open field test (OFT), and light and dark (L and D) aversion test. Results: The compound 7e (1 and 2 mg/kg, intraperitoneally [i.p.]) exhibits antidepressant-like effect in FST. In addition, compound 7e (0.5, 1 and 2 mg/kg, i.p.) exhibits antidepressant-like effect in TST after acute treatment without any significant effect on base line spontaneous locomotor activity. Moreover, compound 7e (2 mg/kg, i.p.) potentiated the 5-HTP-induced head twitch responses in mice. In interaction studies, compound 7e (0.5 mg/kg, i.p.) potentiated the antidepressant effect of bupropion. Furthermore, compound 7e also exhibited anxiolytic-like effect in EPM, HB test, OFT, and L and D aversion test. Conclusion: These preliminary studies reveal that compound 7e exhibits antidepressant- and anxiolytic-like effect in behavioral rodent models of depression and anxiety.