Anxiolytic-like effect of Citrus limon (L.) Burm f. essential oil inhalation on mice

Abstract

Experimental in vivo study aimed to characterize the anxiolytic-like effect of the Citrus limon fruit peel's essential oil (CLEO) in animal models of anxiety, besides evaluating the viability J774.A1 cells in vitro through the MTT reduction method at the concentrations of 10 and 100 µg/mL. The anxiolytic behavior was evaluated in Swiss mice (n = 8) using the methodology of Elevated Plus-Maze (EPM) and Open-Field (OF). CLEO was tested by inhalation at the doses of 100, 200, and 400 µL, and as control, animals were subjected to inhalation of the vehicle (saline solution 0.9% + Tween80®) and intraperitoneal administration of diazepam (1.5 mg/kg). In the cell viability assay, it was observed that none of the concentrations showed cytotoxicity. OF test showed significant anxiolytic activity at all tested doses of OECL, compared to the control group, without changing the motor performance of the animals. Corroborating OF data, the EPM test confirmed anxiolytic activity in at least two doses of the tested oil (200 and 400 µL), justified by the number of entries and increase in the percentage of time in the open arms. The data analysis of this study evidenced that inhalation of OECL was able to induce an anxiolytic behavior in mice; however, further studies are required to ensure its safe use by the population. .A1 através do método de redução do MTT nas concentrações de 10 e 100 µg/mL. O comportamento ansiolítico foi avaliado em camundongos Swiss (n = 8), utilizando a metodologia do Labirinto em Cruz Elevado (LCE) e do Campo Aberto (CA). O OECL foi testado por inalação nas doses de 100, 200 e 400 µL, e como controle, os grupos foram submetidos à inalação do veículo (Solução fisiológica 0,9% + Tween80®) e administração intraperitoneal de diazepam (1,5 mg/kg). No ensaio de viabilidade celular, observou-se que nenhuma das concentrações apresentou citotoxicidade. O teste de CA demonstrou atividade ansiolítica significativa em todas as doses testadas do OECL, comparada ao grupo controle, sem alterar a performance motora dos animais. Corroborando os dados do CA, o teste do LCE confirmou a atividade ansiolítica em pelo menos duas das doses do óleo testadas (200 e 400 µL), justificada pelo número de entradas e aumento na percentagem de tempo nos braços abertos. A análise dos dados deste estudo evidenciou que a inalação do OECL foi capaz de induzir um comportamento ansiolítico em camundongos; entretanto, outros estudos são necessários para garantir o seu uso seguro pela população.Palavras-chave: Ansiolítico. Citrus limon. Óleo essencial. Inalação. Camundongos.

Citrus Essential Oils in Aromatherapy: Therapeutic Effects and Mechanisms

“…Furthermore, aromatherapy involving BEO has been observed to help in improving mood, and symptoms of mild stress and facilitating sleep induction [ 101 ]. The commonly used EOs from citrus in aromatherapy (in the form of aroma-sticks) in clinical studies are lemon ( Citrus limon (L.) Osbeck ) [ 102 ], bergamot ( Citrus bergamia ) [ 103 ] and orange sweet ( Citrus sinensis (L.) Osbeck ) [ 104 ] along with EOs from other herbs, such as lavender ( Lavandula angustifolia Mill . ), frankincense ( Boswellia carterii ), and peppermint ( Mentha piperita ) [ 105 , 106 ].…”