[Experimental study of the toxic convulsant properties of commercial preparations of essences of sage and hyssop (author's transl)].

Commercial preparations of essences of sage and hyssop have caused poisoning of human beings and were found to possess a convulsant action of central origin in animals. The convulsant effect of hyssop essence appears to be more powerful than that of sage in non-anaesthetized rats. The dose limit, below which the cortical phenomena are subclinical, is 0.08 g/kg for hyssop, while above 0.13 g/kg convulsions appear and become lethal above 1.25 g/kg. The same doses for essence of sage are respectively 0.3, 0.5 and 3.2 g/kg. The neurotoxicity of hyssop appears to be related to the presence of two terpene ketones, pinocamphone and isopinocamphone, the former of which has powerful convulsant properties, and is lethal at doses above 0.05 ml/kg. The toxicity of essence of sage is due to the presence of camphor which is well-known to possess convulsant properties.