Antipsychotic-Like Activity of α-Asarone in Mice: A Preliminary Report

Alpha (α) - asarone is known to be one of the active compounds which have been discovered to be responsible for the therapeutic benefits of Acorus species. Previous studies have reported that Acorus calamus leaf extracts exerted the neuromodulatory effects on the nigrostriatal dopaminergic system. Therefore, the present study aimed to investigate the antipsychotic-like activity of α-asarone using a mouse model of apomorphine-induced stereotyped behaviour. Swiss albino male mice (bodyweight, 25-30g) were used for this study. In acute studies, α-asarone at different doses 1, 10, 30, 50, and 100 mg/kg bodyweight were administered orally one hour prior to apomorphine (5mg/kg, i.p.) injection respectively. Immediately after the injection of apomorphine, the mice were placed individually in cylindrical metal cages (18 cm in diameter and 19 cm in height) with the wall and floor consisting of vertical and horizontal metal bars and recorded for climbing time and climbing behaviour. The climbing behaviour was scored as 4 = four paws on the wall of the cage, 2 = two paws on the wall of the cage, 0 = four paws on the floor. The acute treatment of α-asarone (1-100 mg/kg, p.o.) exhibited an inverted bell-shaped dose-response in cage climbing behaviour. α-asarone at 30 and 50 mg/kg significantly decreased the apomorphine-induced cage climbing time and climbing behaviour in mice. These observed effects might be attributed due to the antidopaminergic property of α-asarone. Antagonism of dopamine D2 receptors is a common feature of the most clinically effective antipsychotic drugs, especially active against hallucinations and delusions. Overall, the present study uncovered the antidopaminergic effect of α-asarone; thereby α-asarone exhibited antipsychotic-like activity in mice. However, further neurochemical studies are warranted to explore the actual mechanism of action of α-asarone as a promising novel antipsychotic agent.