BACKGROUND

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.

OBJECTIVE

This study was conducted to establish the anxiolytic effect of extracts from the aerial parts of Sonchus oleraceus.

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.).

CONCLUSIONS

These data indicate that Sonchus oleraceus extract exerts an anxiolytic-like effect on mice.