Behavioral and electrophysiological evidence for attenuation of CNS by aqueous extract from Citrus aurantium (CaL) flowers in rat

Anxiety disorders have a relatively high prevalence in most countries. Chemical drugs used to treat anxiety have some unwanted side effects. Therefore, using medicinal plants is useful. Citrus aurantium L. (CaL) flowers are used in Iran to treat anxiety as a folk medicine. We investigated its anxiolytic and sedative effects. We used elevated plus maze and pentobarbital sodium sleeping time tests to evaluate the anxiolytic and sedative effects of CaL flowers on CNS, respectively. In addition, by using extracellular single unit recording technique, we evaluated the depressant action of CaL on neuronal activity of basolateral amygdale (BLA), one of the major structures involved in anxiety. CaL flower aqueous extract (62.5, 125 mg/kg) increased the percentage of time spent in open arms and reduced the percent of time spent in closed arms (p < 0.05). It also reduced locomotor activity at 250 mg/kg (p < 0.05). CaL flower aqueous extract (125, 250 mg/kg) prolonged the duration of pentobarbital sleeping time [(p < 0.05) and (p < 0.01), respectively] and shortened the onset of sleep in rats (p < 0.05). CaL reduced the firing rate of BLA neurons (p < 0.05). Our data suggests that CaL flowers have sedative and anxiolytic effects.