The aqueous extracts of Passiflora alata and Passiflora edulis reduce anxiety-related behaviors without affecting memory process in rats

Several species of Passiflora have been employed widely as a folk medicine because of sedative and tranquillizer activities. In this study, we evaluate the effects on anxiety and memory process of two popularly used Passiflora species. To this aim, male Wistar rats (weighing 250-300 g) were intraperitoneally injected with the aqueous extract of Passiflora alata or Passiflora edulis (25, 50, 100, or 150 mg/kg; single injection) 30 minutes prior to the elevated plus-maze test, inhibitory avoidance test, or habituation to an open-field apparatus. The effects of both species of Passiflora were compared with that of diazepam (1 mg/kg), a standard anxiolytic drug. Our findings revealed that, similar to diazepam, the treatment with P. alata (100 and 150 mg/kg) and P. edulis (50, 100, and 150 mg/kg) induced anxiolytic-like effects in rats. Memory was not affected by the treatment with any dose of P. alata or P. edulis, but diazepam disrupted memory process in rats. Phytochemical analysis showed that the content of flavonoids of the aqueous extract of P. edulis is almost twice that of P. alata. These differences in contents of flavonoids could explain the lower active doses of the aqueous extract of P. edulis in inducing anxiolytic-like effects compared to P. alata. In conclusion, our findings suggest that, distinct from diazepam, the aqueous extract of both species of Passiflora induced anxiolytic-like effects in rats without disrupting memory process.