Evaluation of ethanol leaf extract of Ocimum sanctum in experimental models of anxiety and depression

Context: Recent studies reveal the co-occurrence of both anxiety and depressive disorders in many clinical conditions, which has introduced the concept of mixed anxiety and depressive disorders (MADD). Objective: The study evaluated the ethanol leaf extract of Ocimum sanctum (OS) Linn. (Labiatae), a prominent medicinal plant, against both anxiety and depressive disorder, to evaluate its potency in combating MADD. Materials and methods: Swiss albino mice weighing 20--25 g were used. Gross behavior was observed through Digiscan animal activity monitor. Depression was studied through tail suspension test (TST) and forced swim test (FST). Anxiety experiments included light dark test, elevated plus maze test, and holeboard test. Further, rotarod test was also used to study any defects in motor coordination. Discussion and conclusion: OS at 200 mg/kg showed motor-depressant activity as evaluated with locomotor activity and stereotypy measures. OS at 50 mg/kg shortened the immobility time in the TST and FST, respectively, indicating a possible antidepressant activity. Further, a diminution in the anxiety response at a dose of 50 mg/kg, p.o. body weight was also observed against light dark, elevated plus maze, and holeboard tests, which signifies its antianxiety activity. No defects were observed in the motor coordination of the mice in the rotarod test. Thus, the OS extract shows antianxiety and antidepressant properties at the same dose and can be a potential therapeutic agent against mixed anxiety and depressive syndrome.