Anxiolytic-like effect of Sonchus oleraceus L. in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Sonchus oleraceus L. has been used as a general tonic in Brazilian folk medicine. Nevertheless, available scientific information regarding this species is scarce; there are no reports related to its possible effect on the central nervous system. AIM OF THE STUDY: This study was conducted to establish the anxiolytic effect of extracts from the aerial parts of Sonchus oleraceus. MATERIALS AND METHODS: This study evaluated the effect of hydroethanolic and dichloromethane extracts of Sonchus oleraceus in mice submitted to the elevated plus-maze and open-field tests. Clonazepam was used as the standard drug. RESULTS: In the elevated plus-maze test, the Sonchus oleraceus extracts increased the percentage of open arm entries (P<0.05) and time spent in the open-arm portions of the maze (P<0.05). The extracts induce an anti-thigmotactic effect, evidenced by increased locomotor activity into the central part of the open field set-up (P<0.05). The extracts administered at 30-300 mg/kg, p.o. had a similar anxiolytic effect to clonazepam (0.5 mg/kg, p.o.). CONCLUSION: These data indicate that Sonchus oleraceus extract exerts an anxiolytic-like effect on mice.