Anxiolytic effects of Lippia citriodora in a mouce model of anxiety

Abstract

Lippia citriodora is commonly used in Iranian folk medicine for treatment of many disorders. Since there scientific data to prove the anxiolytic properties of this plant in Iran are scarce, we aimed to evaluate the sedative and anxiolytic activity of the leaf extract and essence of L. citriodora in an animal model of anxiety. The extract and the essence used were obtained after maceration and hydro-distillation of the leaves of L. citriodora, respectively. We evaluated the anti-anxiety profile and sedative activity of diazepam (1 mg/kg i.p. as the standard), hydroethanolic extract (200 and 400 mg/kg i.p.) and the essence (10, 15, and 50 mg/kg i.p.) of leaves of L. citriodora using elevated plus-maze and locomotor activity. We also used flumazenil, to find out if the possible effects are mediated through gamma-aminobutyric acid (GABA)/benzodiazepine receptor complex. The results showed that the essence of L. citriodora at a dose of 15 mg/kg is the most effective anxiolytic dose. Interestingly, flumazenil reversed this action of the essence as well as that of diazepam. The extract even at a dose of 400 mg/kg did not show significant anxiolytic effect. In locomotor activity studies, the essence caused sedation to a lesser extent than diazepam. The results suggest that the essence of this plant could be a better candidate for further analysis and fractionation. As the anxiolytic effect of the essence is reversed by flumazenil, it is possible that the GABA receptor could be involved in mediating these effects.

Effects of the aroma of lemone verbena (Aloysia citriodoraPaláu) essential oil on anxiety and the hemodynamic profile before cesarean section: A randomized clinical trial

“…Bonyani A. and colleagues evaluated the leaf extract essence of LV on mouse models in terms of its sedative and anxiolytic activity. They concluded that the essence of the leaf acts as an antianxiety agent like diazepam through the GABAergic system without any significant reduction of locomotor activity 34 . The results were the same as ours with the exception that we performed the study on humans instead of mice.…”

“…The latest trials have focused on the antianxiety effects of an edible extract of LV in animal models. 34 The results of an animal model study conducted by Razavi et al has demonstrated that intraperitoneal ethanolic and aqueous extracts of LV leaves have antianxiety effects which are probably due to the interaction between GABA receptors and LV ingredients. 35 We obtained similar results in our study but with a difference in the method of usage in which we used the fragrance type of LV instead of the intraperitoneal method.…”

Systematic review on the anxiolytic and hypnotic effects of flower extracts in in vivo pre‐clinical studies published from 2010 to 2020

“…In addition, to characterize the antidepressant effect, six authors resorted to forced swimming tests (Divyajyothi et al, 2015; Emon et al, 2022; Ioniță et al, 2019; Ishaq, 2016; Qazi et al, 2015; Vanzella et al, 2012) and three articles analyzed the tail suspension test (Divyajyothi et al, 2015; Emon et al, 2022; Vanzella et al, 2012). Regarding temporality, only Ioniță et al (2019), Mombeini et al (2017), Zhang et al (2016), and Rabbani et al (2011) conducted chronic trials of flower extracts effects. Mombeini et al (2017) reported that, in repeated trials, tolerance to the anxiolytic effect was generated at high doses.…”

“…produced an increase in the number of crossings.Of the articles in the review, only 6 of 24 performed the LDB test to measure anxiolytic activity. All of them concluded that the extracts had anxiolytic activity compared to the vehicle, and onlyRabbani et al (2011) stated that one of the extracts was not statistically comparable to diazepam; however, no author made a statistical comparison of the extracts versus diazepam that could conclude that they had a similar effect.…”