Abstract

The objective of the work was to investigate the effects of the essential oil ofZingiber officinale Roscoe (EOG - 25, 50 and 100 mg/kg, i.p) on the behavior and cognition of male Swiss mice (25 - 30 g), treated daily for 7 days.  In the 7^th day, animals were submitted to the elevated plus maze, open field and rota rod tests to evaluate anxiolytic, sedative and motor coordination effects, respectively. Memory tasks and cholinergic system effects of EOG were also assessed by the T-maze, passive avoidance, oxotremorine and pilocarpine-induced convulsions tests. EOG did not show anxiolytic effects in the elevated plus maze test, while it showed a sedative effect in the open field test at the doses of 50 and 100 mg/kg. EOG did not alter motor coordination of the animals, while it produced a cognitive impairment, in the passive avoidance test, in animals treated with the dose of 100 mg/kg. In the T-maze test, cognitive impairment was also evident and occurred in a dose-dependent manner. In addition, EOG (50 and 100 mg/kg, i.p.) blocked the oxotremorine-induced tremors and significantly increased the latency of pilocarpine-induced seizures, as well as animals survival. Altogether, our results suggest that EOG effects are, at least in part, dependent upon an antagonist action on the central muscarinic cholinergic system.     

Key words: Zingiber officinale Roscoe, memory, scopolamine, oxotremorine, pilocarpine.