Acute effects of bergamot oil on anxiety‐related behaviour and corticosterone level in rats

Abstract

Bergamot essential oil (BEO), Citrus aurantium subsp. bergamia (Risso) Wright & Arn. (Rutaceae), is used widely in aromatherapy to reduce stress and anxiety despite limited scientific evidence. A previous study showed that BEO significantly increased gamma-aminobutyric acid levels in rat hippocampus, suggesting potential anxiolytic properties. The aim of this study was to investigate the effect of BEO (1.0%, 2.5% and 5.0% w/w) administered to rats on both anxiety-related behaviours (the elevated plus-maze (EPM) and hole-board tests) and stress-induced levels of plasma corticosterone in comparison with the effects of diazepam. Inhalation of BEO (1% and 2.5%) and injection of diazepam (1 mg/kg, i.p.) significantly increased the percentage of open arm entries on the EPM. The percentage time spent in the open arms was also significantly enhanced following administration of either BEO (2.5% and 5%) or diazepam. Total arm entries were significantly increased with the highest dose (5%), suggesting an increase in locomotor activity. In the hole-board test, 2.5% BEO and diazepam significantly increased the number of head dips. 2.5% BEO and diazepam attenuated the corticosterone response to acute stress caused by exposure to the EPM. In conclusion, both BEO and diazepam exhibited anxiolytic-like behaviours and attenuated HPA axis activity by reducing the corticosterone response to stress.

Essential oils from Citrus x aurantium and Citrus x latifolia (Rutaceae) have anesthetic activity and are effective in reducing ion loss in silver catfish ( Rhamdia quelen )

“…Besides EOCA and EOCL, other EOs that showed anxiolytic-like effects in animal models, such as C. x aurantium, C. x reticulata, Foeniculum vulgare and Lippia alba (limonene-carvone chemotype), have limonene as a major component (Gargano et al, 2008;Faturi et al, 2010;Saiyudthong, Marsden, 2011;Hatano et al, 2012;Mesfin et al, 2014). Limonene directly binds to the adenosine A 2A receptor, which may induce sedative effects (Park et al, 2011) and also demonstrated direct vasorelaxant effects (Kang et al, 2013).…”

Role of D-Limonene in Autophagy Induced by Bergamot Essential Oil in SH-SY5Y Neuroblastoma Cells

“…Further experiments are needed to elucidate the mechanisms through which BEO modulates autophagy and to assign a potential role for this process in the pharmacological effects of BEO reported in animal models of diseases, including anxiety [20], cerebral ischemia [18] or pain [15], [21].…”

“…The latter point has been addressed by a number of studies which, indeed, documented that BEO may affect synaptic transmission in rodents. In fact, BEO modulates release of specific amino acid neurotransmitters in discrete brain regions under both basal [17] and pathological conditions [18], produces a dose-related sequence of sedative and stimulatory behavioural effects in normal rats [19], exerts anxiolytic effects in the elevated plus-maze and hole-board tests [20] and neuroprotective effects against exicitotoxic [18], nociceptive [21] and allodynic stimuli [15], yet the underlying molecular mechanisms have not been conclusively established and need to be further investigated.…”

Effects of Bergamot (<b><i>Citrus bergamia</i></b> (Risso) Wright &#38; Arn.) Essential Oil Aromatherapy on Mood States, Parasympathetic Nervous System Activity, and Salivary Cortisol Levels in 41 Healthy Females

“…Today, it is widely used in aromatherapy for reducing stress and anxiety [3]. According to most recent research, it counteracts anxiety behavior in rats via the stress response pathway, reducing the activity of the hypothalamus-pituitary-adrenocortical axis (HPA) [3].…”

“…), which belongs to the Citreae tribe in the Aurantioideae subfamily of the Rutaceae plant family, originates from the Mediterranean ecoregion, particularly from southern Italy and Greece. Its volatile oil, which is produced from the exocarp by means of cold pressing [1], is in high demand for a wide range of perfumes, cosmetics, and especially for aromatherapy [2,3]. …”