Assessment of sedative effects of Passiflora edulis f. flavicarpa and Passiflora alata extracts in mice, measured by telemetry.

Several Passiflora species have been used widely as a folk medicine due to their sedative and anxiolytic activities. In Brazil, a number of native plants of the genus Passiflora exist, but only Passiflora edulis f. flavicarpa (PE) and Passiflora alata (PA) are of commercial value. Thus, the aim of the present study was to investigate the sedative effects of aqueous extracts obtained from the pericarp as well as from the leaves of PE and PA in mice using radiotelemetry. Aqueous extracts from PE and PA were tested for effects on locomotion over 180 min in 300 mg/kg, 600 mg/kg and 1200 mg/kg, in male C57BL/6J mice after oral administration. For validation of the telemetry system, caffeine (negative control) and midazolam (positive control) were used. All tested extracts decreased locomotor activity in a dose-dependent manner in comparison to the control group. The two lower concentrations of each extract showed the highest decrease in locomotion after 24 min, while 1200 mg/kg had a significant sedative effect already after 18 min. Interestingly, aqueous extracts of PA were more active in comparison to aqueous extracts of PE and the pericarp extracts of both plants showed more pronounced effects on locomotor activity if compared to leaf extracts. In conclusion, the present study represents an innovative, objective approach to measure sedative effects of plant extracts with minimized handling-related stress and remote data collection.