Non-clinical study of the anxiolytic effect of Citrus aurantium L. essential oil in an inclusion complex with 2-hydroxypropyl-β-cyclodextrin

Anxiety in the world population has increased significantly; the problem has encouraged studies regarding innovative alternatives for treatment. Research with Citrus aurantium L. essential oil (CEO) has revealed positive results with anxiolytic effects in both animals and humans. However, certain limitations affect its storage and preservation, its efficiency in therapy, and determination of adequate posologies. The potential use of cyclodextrins as drug carriers has been successfully explored. This study aims to assess the anxiolytic potential of a CEO/2-hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex. Preparation of the inclusion complex was performed using the Alpha 1-2 LDplus lyophilizer. To allow formation, and avoid loss of volatiles to the atmosphere, Limonene (LIM), the main compound in CEO, together with HPβ-CD in a molar ratio of (1: 1M) was dispersed in ethanol for 36 hours using a laboratory shaker at room temperature (25°C). Non-clinical murine pharmacological tests were performed for anxiety assessment in experimental and control groups. To assess anxiety and motor impairment, the animals were evaluated using the elevated plus maze, open field, and rota-rod tests. Satisfactory results of the anxiolytic effect of the OEC complexed in HP-β-CD were observed, with the indication of an potentiation of the effect with doses lower than 500 mg/kg and 250 mg/kg complexed, suggesting improvement in the anxiolytic properties of the OEC.