Passiflora incarnata L. (Passionflower) extracts elicit GABA currents in hippocampal neurons in vitro, and show anxiogenic and anticonvulsant effects in vivo, varying with extraction method

Phytomedicine. 2010 Oct;17(12):940-9. doi: 10.1016/j.phymed.2010.03.002. Epub 2010 Apr 10.


Potential mechanisms of Passiflora incarnata extracts and the effect of extraction methods on ingredients and biological effects were explored. Using the same batch of plant material, total flavonoid yields as measured by high-performance liquid chromatography coupled to diode array detection (HPLC-DAD) increased substantially with hot versus cold extraction methods. Whole Passiflora extract induced prominent, dose-dependent direct GABA(A) currents in hippocampal slices, but the expected modulation of synaptic GABA(A) currents was not seen. GABA was found to be a prominent ingredient of Passiflora extract, and GABA currents were absent when amino acids were removed from the extract. Five different extracts, prepared from a single batch of Passiflora incarnata, were administered to CF-1 mice for 1 week in their drinking water prior to evaluation of their behavioral effects. Anticonvulsant effects against PTZ-induced seizures were seen in mice that received 2 of the 5 Passiflora extracts. Instead of the anxiolytic effects described by others, anxiogenic effects in the elevated plus maze were seen in mice receiving any of the 5 Passiflora extracts.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anticonvulsants / pharmacology
  • Anticonvulsants / therapeutic use*
  • Anxiety / chemically induced
  • Anxiety / drug therapy*
  • Dose-Response Relationship, Drug
  • Flavonoids / adverse effects
  • Flavonoids / pharmacology
  • Flavonoids / therapeutic use
  • GABA Agonists / pharmacology
  • GABA Agonists / therapeutic use*
  • Hippocampus / drug effects*
  • Hippocampus / physiology
  • Male
  • Maze Learning
  • Mice
  • Mice, Inbred Strains
  • Passiflora / chemistry*
  • Pentylenetetrazole
  • Phytotherapy
  • Plant Extracts / adverse effects
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Seizures / drug therapy*
  • Temperature
  • gamma-Aminobutyric Acid / pharmacology
  • gamma-Aminobutyric Acid / therapeutic use


  • Anticonvulsants
  • Flavonoids
  • GABA Agonists
  • Plant Extracts
  • gamma-Aminobutyric Acid
  • Pentylenetetrazole