Abstract
Effects of cinnamaldehyde on general behaviour, locomotor activity, body temperature and striatal levels of dopamine, serotonin and their metabolites were studied in mice. Cinnamaldehyde produced a decrease in the spontaneous activity at higher doses than 30 mg/kg, i.p., and produced a transient excitation or running fit prior to marked depression at higher doses than 100 mg/kg, i.p. Cinnamaldehyde at doses of 125 and 250 mg/kg, i.p., suppressed locomotor activity produced by apomorphine or methamphetamine. In reserpine-pretreated mice, running fit was produced with cinnamaldehyde at lower doses than those in normal mice. Cinnamaldehyde markedly reversed reserpine-induced hypothermia as did imipramine. Cinnamaldehyde at a dose of 500 mg/kg, i.p., significantly increased the striatal levels of 3, 4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid. These results suggest that cinnamaldehyde has central inhibitory and excitatory effects which may be derived from interaction with monoaminergic neurons in the central nervous system.
