Anxiolytic-like and sedative actions of Rollinia mucosa: possible involvement of the GABA/benzodiazepine receptor complex.

This study evaluated possible CNS effects of a hexane extract of leaves from Rollinia mucosa (Jacq.) Baill. (Annonaceae). This plant extract induced anxiolytic-like actions similar to those induced by diazepam in the avoidance exploratory behavior paradigm. Its significant activity was shown at doses from 1.62 to 6.25 mg/kg. It also enhanced pentobarbital-induced hypnosis time, and at high doses produced motor coordination impairment. The benzodiazepine (BDZ) receptor binding, evaluated by in vitro autoradiography following a single administration of R. mucosa, revealed that this plant extract reduced BDZ binding in the hippocampus (29%), amygdala (26%), and temporal cortex of mice (36%). In conclusion, the present findings support the proposal that R. mucosa may induce central nervous system (CNS) depressant effects, presumably through an interaction with the GABA/benzodiazepine receptor complex.