Passionflower study demonstrates anti-anxiety effect of chrysin
A study in rats showed that the flavonoid compound chrysin, found in passionflower (Passiflora incarnata), had "a clear anxiolytic effect" when injected at a dose of 1 mg/kg. Apigenin, on the other hand, an important compound in chamomile (Matricaria recutita), had sedative effects at a dose of 25 mg/kg, but demonstrated no anxiolytic effects. The researchers theorized that the anxiolytic effect of chrysin could be related to activation of the GABAA receptor, because it was blocked by administration of the benzodiazepine drug flumazenil. However, flumazenil failed to block the sedative effects of either of the two flavonoids, leading the researchers to conclude that these effects are not due to interaction with GABA receptors. Zanoli P, Avallone R, Baraldi M. Behavioral characterisation of the flavonoids apigenin and chrysin. Fitoterapia 2000; 71: S117-S123.
