R-(+)- andS-(−)-carvone: influence of chirality on locomotion activity in mice

The effects of carvone on the locomotion activity (LA) of mice depends on the chirality of this terpene ketone and the circadian rhythm of mice, the latter assessed by using a light-barrier cage upon administration of analeptics and sedative drugs. (−)-Carvone, the so-called ‘spearmint carvone’, showed more sedative and relaxing effects, whereas (+)-carvone, the ‘caraway carvone’, demonstrated both sedation and activation effects on the LA of mice, e.g. (−)-carvone showed only in amphetamine pre-treated ‘morning mice’ a relaxant effect, while with other analeptics pre-treated mice nearly no alteration of the LA could be observed. (+)-Cavone slightly counteracted the stimulating effect of LA with metamphetamine, phenobarbital and cathine pre-treated ‘morning mice’, but decreased the LA when the mice were pre-treated with other analeptics, especially amphetamine. Mice in the resting phase showed a similar reaction upon sniffing (−)-carvone as before; only pre-treatment with caffeine led to a stimulation. In the late morning a moderate reduction of the animal's LA upon sniffing (+)-carvone vapour was observed after pre-treatment with most of the analeptics, except with amphetamine, where strong over-agitation could be counteracted entirely.