Central properties of the essential oil and the crude ethanol extract from aerial parts of Artemisia annua L.

The present study evaluated the central activity of the essential oil and the ethanolic extract from Artemisia annua L. in animals as a part of a psychopharmacological screening of this plant. The extract was prepared with fresh leaves in ethanol (AEE) and the essential oil (AEO) was obtained by hidrodestilation. The ED50 and the LD50 obtained for the essential oil were 470 mg/kg (correlation coefficient r = 0.97333 and linear regression y = -26.52x + 0.158) and 790 mg/kg, and for the extract, 450 mg/kg (correlation coefficient r = 0.99266 and linear regression y = -27.34 + 0.156) and more than 2 g/kg, respectively. The doses increased the latency time to convulsions induced by picrotoxin and pilocarpine but prevented the onset of pentylenotetrazol and strychnine induced seizures. In addition to, the products have caused marked inhibition in the Rota-rod assay. According to the results, the AEO has a high acute toxicity and a possible cholinergic action, and the AEE showed a possible central activity as dopaminergic and cholinergic agents, and did not present a significant acute toxicity. These differences should be due to chemical substances present in each product. These products had no significant effect as an anticonvulsant, while exhibited a strong depressant activity on the CNS. (C) 2003 Elsevier Ltd. All rights reserved.