Bergamot Essential Oil Attenuates Anxiety-Like Behaviour in Rats

The effect of aromatherapy intervention with Bergamot and Grapefruit essential oils on premenstrual syndrome and menstrual symptoms: a randomized controlled trial

BACKGROUND

Premenstrual syndrome and menstrual symptoms adversely affect approximately 80-95% of women of reproductive age. Aromatherapy interventions are used to reduce premenstrual syndrome and menstrual symptoms. This study was conducted to determine the effect of aromatherapy intervention with bergamot and grapefruit essential oils on premenstrual syndrome and menstrual symptoms.

METHODS

Ninety women with premenstrual syndrome were included the study. Participants were randomly divided into 3 groups: Bergamot(n = 30), Grapefruit(n = 30), Placebo(n = 30). Participants in each group were made to smell pure essential oil for 30 min 3 times a day for 4 days during the luteal phase of the menstrual cycle. The used was repeated in 3 menstrual cycles. "Premenstrual Syndrome Scale (PMSS)" was used to evaluate premenstrual syndrome and "Menstrual Symptom Questionnaire (MSQ)" was used to evaluate menstrual symptoms. All measurements were performed before and after the study.

RESULTS

The results showed that grapefruit essential oil was effective in reducing PMSS total score (p = 0.010) and sub-scale scores (depressive affect, anxiety, fatigue, depressive thoughts, appetite changes, sleep changes and bloating (p < 0.001), irritability (p = 0.024), pain (p = 0.047)). Although grapefruit essential oil had no effect on the total score of the MSQ. Grapefruit essential oil was found to be effective in reducing the MSQ scale sub-scale scores (menstrual pain symptoms (p = 0.024) and the use of coping methods with menstrual pain (p = 0.011)). Bergamot essential oil was found to be effective in reducing PMSS total score (p = 0.001) and PMSS sub-scale scores depressive affect (p = 0.013), irritability (p = 0.034), depressive thoughts and appetite changes (p = 0.026), pain (p = 0.001)). In addition, there was no effect on the menstrual syndrome scale and its sub-dimensions (p > 0.05).

CONCLUSION

Grapefruit essential oil was effective in reducing both premenstrual syndrome and menstrual symptoms, whereas bergamot essential oil was only effective in reducing premenstrual symptoms.

TRIAL REGISTRATION NUMBER

NCT06289764 (2024-02-01).

Ferulic Acid Alleviates Traumatic Brain Injury and Gastrointestinal Disorders by Promoting Ghrelin to Regulate the Microbiota-Brain-Gut Axis Inflammation and Pyroptosis

Traumatic brain injury (TBI) is a severe condition with a high mortality rate, affecting multiple organs, including the gastrointestinal (GI) tract. Ghrelin is a brain-gut peptide that regulates the microbiota-brain-gut axis, facilitating communication between the GI tract and the central nervous system. This study aimed to investigate the role of ferulic acid (FA) in regulating Ghrelin to improve TBI and GI disorders (GID) induced by controlled cortical impact (CCI). This study used CCI as the in vivo TBI model and scratch-induced injury of primary astrocytes as the in vitro TBI model. The role and mechanism of FA modulation of Ghrelin in ameliorating TBI and GID were explored using multi-omics and network pharmacology analyses. In vivo, results revealed that FA is the main active component of the Guanxin II compound and mimics its function. Significant improvement in GI hypomotility and brain injury was observed in the FA group compared to the CCI group. Concurrently, FA ameliorated intestinal barrier impairment triggered by CCI-induced reduction in the expression of Ghrelin and reduces the inflammatory response. Furthermore, 16S rRNA results indicated that CCI-induced TBI worsened gut microflora imbalance via the brain-gut axis, while gut dysbiosis aggravated brain injury. FA improved the dysbiosis of Bacteroidetes and Odoribacter mainly by targeting the Ghrelin-mediated inflammatory response. RNA-seq and network pharmacology analyses revealed that FA mainly affects inflammation-mediated pyroptosis pathways in the brain-gut axis. Additionally, experimental evidence demonstrated that FA reversed CCI-induced pyroptosis in rats and scratch injury-induced pyroptosis in astrocytes by promoting the binding of Ghrelin to GHSR, which suppressed the TLR4/NF-κB/NLRP3 pathway. Conclusively, FA could alleviate TBI and GID by promoting Ghrelin to regulate the microbiota-brain-gut axis inflammation via the Ghrelin/TLR4/NLRP3 pathway.

A Neural Circuit For Bergamot Essential Oil-Induced Anxiolytic Effects

Aromatic essential oils have been shown to relieve anxiety and enhance relaxation, although the neural circuits underlying these effects have remained unknown. Here, it is found that treatment with 1.0% bergamot essential oil (BEO) exerts anxiolytic-like effects through a neural circuit projecting from the anterior olfactory nucleus (AON) to the anterior cingulate cortex (ACC) in acute restraint stress model mice. Collectively, in vivo two-photon calcium imaging, viral tracing, and whole-cell patch clamp recordings show that inhalation exposure to 1.0% BEO can activate glutamatergic projections from the AON to GABAergic neurons in the ACC, which drives inhibition of local glutamatergic neurons (AONGlu→ACCGABA→Glu). Optogenetic or chemogenetic manipulation of this pathway can recapitulate or abolish the BEO-induced anxiolytic-like behavioral effects in mice with ARS. Beyond depicting a previously unrecognized pathway involved in stress response, this study provides a circuit mechanism for the effects of BEO and suggests a potential target for anxiety treatment.

The effect of lavender and bergamot oil applied via inhalation on the anxiety level and sleep quality of surgical intensive care unit patients

OBJECTIVE

Due to numerous stressors in intensive care, common psychosocial problems arise in patients. Among these, decreased anxiety and sleep quality are observed. This study aims to determine the effect of lavender and bergamot oil applied by inhalation on anxiety and sleep quality in surgical intensive care unit patients.

METHODS

Fifty-four patients hospitalized in the intensive care unit of a hospital in Istanbul, Turkey, were included in this study. They were randomly divided into three groups (Lavender, Bergamot, Control). Intervention groups were exposed to 3 drops of lavender oil or bergamot oil on pillows for 20 min, which were then placed 10 cm away from the patient's head. This intervention was applied for two nights. The patients' sleep quality and anxiety level were evaluated using the "State-Trait Anxiety Inventory (STAI)" and "Richard-Campbell Sleep Scale (RCSS)." Data were analyzed using Chi-square, independent t-test, One-way ANOVA tests.

RESULTS

According to our results, anxiety scores significantly decreased in the lavender and bergamot groups. Sleep quality scores significantly increased (p = <0.001). The control group showed lower sleep quality scores.

CONCLUSION

Lavender and bergamot oil inhalation appeared effective in reducing anxiety and improving sleep quality in surgical intensive care unit patients.

Motor behavior induced by bergamot essential oil in experimental tasks is differentially modulated by pretreatment with metabotropic glutamate receptor 2/3 or 5 antagonists

Bergamot essential oil shows anxiolytic-relaxant effects devoid of sedative action and motor impairment typical of benzodiazepines. Considering the potential for clinical of these effects, it is important to understand the underlying mechanisms of the phytocomplex. Modulation of glutamate group I and II metabotropic receptors is involved in stress and anxiety disorders, in cognition and emotions and increases locomotor activity and wakefulness. Interestingly, early data indicate that bergamot essential oil modulates glutamatergic transmission in specific manifestations of the central nervous system. The aim of this work is to investigate if selective antagonists of metabotropic glutamate 2/3 and 5 receptors affect behavioral parameters modulated by the phytocomplex. Male Wistar rats were used to measure behavioral parameters to correlate anxiety and motor activity using elevated plus maze (EPM), open field (OF), and rotarod tasks. Bergamot essential oil increases in EPM the time spent in open/closed arms and reduces total number of entries. The essential oil also increases immobility in EPM and OF and not affect motor coordination in rotarod. Pretreatment with the metabotropic glutamate antagonists does not affect the time spent in open/close arms, however, differently affects motor behavior measured after administration of phytocomplex. Particularly, glutamate 2/3 antagonist reverts immobility and glutamate 5 antagonist potentiates this parameter induced by the phytocomplex. Our data show that modulation of both metabotropic glutamate receptors is likely involved in some of behavioral effects of bergamot essential oil.

Fabrication of Citrus bergamia essential oil-loaded sodium caseinate/peach gum nanocomplexes: Physicochemical, spectral, and structural characterization

`The objective of current research was to encapsulate citrus bergamia essential oil (CBEO) in nanocomplexes composed of sodium caseinate (SC) and peach gum polysaccharide (PG) in various ratios (SC/PG-1:0, 0:1, 1:1, 1:3, and 3:1). The nanocomplexes formed by the combination of SC and PG in a ratio of 1:3 exhibited a zeta potential of -21.36 mV and a PDI of 0.25. The CBEO-loaded SC/PG (1:3) nanocomplexes revealed the maximum encapsulation efficiency (82.47 %) and loading capacity (1.85 %). FTIR also confirmed the secondary structure variations in response to different ratios of CBEO-loaded SC/PG nanocomplexes. In addition, the XRD and fluorescence spectroscopy analysis also revealed structural changes among CBEO nanocomplexes. The thermal capability of CBEO-loaded SC/PG (1:3) nanocomplexes via TGA showed the minimum weight loss among other complexes. SEM and CLSM analysis demonstrated the uniform distribution and spherical morphology of CBEO-loaded SC/PG (1:3) nanocomplexes. The antioxidant activity of free CBEO was significantly improved in CBEO-loaded nanocomplexes. Likewise, the inhibitory activity of CBEO-loaded nanocomplexes exhibited significantly higher antibacterial action against S. aureus and E. coli. The aforementioned perspective suggests that SC/PG nanocomplexes have potent potential to serve as highly effective nanocarriers with a broad spectrum of uses in the pharmaceutical and food sectors.

N-acetylcysteine ameliorates chemotherapy-induced impaired anxiety and depression-like behaviors by regulating inflammation, oxidative and cholinergic status, and BDNF release

Mood disorders caused by chemotherapy have become more important as the survival of cancer patients increases, and new studies in this field will contribute to the prevention of this disorder. For this purpose, we used methotrexate, a chemotherapeutic agent frequently preferred in oncological cases. Mtx was administered as a single dose of 100 mg/kg intraperitoneally to male Wistar albino rats. Since oxidative stress plays an important role in chemotherapy-induced emotional impairment, n-acetylcysteine (NAC), a potent antioxidant, was administered at 500 mg/kg in two doses before Mtx administration. We evaluated anxiety and depression-like behaviors 24 h after Mtx administration, as well as some oxidative and inflammatory markers in blood serum and hippocampal tissue, acetylcholinesterase activity (AChE), and brain-derived neurotrophic factor (BDNF) release in hippocampal tissue. In rats, Mtx induced anxiety and depression-like behaviors as well as abnormalities in oxidative and inflammatory markers in blood serum and hippocampal tissue, increased AChE activity in hippocampal tissue, and decreased BDNF release. NAC treatment was found to ameliorate Mtx-induced anxiety and depression-like behaviors, increase antioxidant capacity, reduce oxidative stress and inflammatory response, and regulate AChE activity and BDNF release. In conclusion, the fact that NAC treatment of Mtx was effective is important for revising the treatment strategies for individuals suffering from this disorder, and this effect is thought to be related to the antioxidant and anti-inflammatory power of NAC.

Effects and mechanisms of salidroside on the behavior of SPS-induced PTSD rats

Post-traumatic stress disorder (PTSD) is a complex mental disorder, closely associated with stress and traumatic events. Salidroside (Sal) has been reported to possess neuroprotective effects. However, the behavioral effects and mechanisms of Sal on PTSD remain unknown. In this study, we utilized a rat model of PTSD induced by single prolonged stress (SPS) and administered Sal intraperitoneally (25, 50, 75 mg/kg/d) for 14 days. We then examined the behavioral effects and underlying mechanisms of Sal on SPS-induced PTSD rats. Our findings demonstrated that Sal alleviated anxiety-like behavior and spatial learning and memory impairment in SPS-induced PTSD rats. Furthermore, Sal treatment preserved the histomorphology of the hippocampal region. It was observed that Sal protected against hippocampal neuronal apoptosis in PTSD rats by reducing the number of TUNEL-positive cells and modulating apoptosis-related proteins (Bcl-2 and Bax). Additionally, Sal inhibited the activation of the NF-κB/iNOS/COX-2 signaling pathway in the hippocampus of PTSD rats, thereby suppressing the release of inflammatory factors (TNF-α and IL-1β) and the activation of microglia. Notably, Sal increased the expression of synapse-associated proteins PSD95 and Synapsin I in the hippocampus, while also enhancing dendritic density in the region. In conclusion, our results demonstrated that Sal could attenuate SPS-induced PTSD-like behaviors by inhibiting hippocampal neuronal apoptosis, enhancing hippocampal synaptic plasticity, and reducing neuroinflammatory responses. These findings may provide a foundation for the potential clinical application of Sal in the treatment of PTSD.

Computational docking investigation of phytocompounds from bergamot essential oil against Serratia marcescens protease and FabI: Alternative pharmacological strategy

The rapid development of multi-drug resistant (MDR) pathogens adds urgency to search for novel and safe drugs having promising action on new and re-emerging infectious pathogens. Serratia marcescens is an MDR pathogen that causes several-healthcare associated infections. Curbing bacterial virulence, rather than inhibiting its growth, is a promising strategy to diminish the pathogenesis of infectious bacteria, reduce the development of antimicrobial resistance, and boost the host immune power to eradicate infections. Bergamot essential oil (BEO) is a remarkable source of promising therapeutics against pathogens. Therefore, the present investigation aimed to analyze the major phytocompounds from BEO against S. marcescens virulent proteins using in silico studies. The analysis of BEO phytocompounds was achieved by Gas chromatography-mass spectrometry (GC-MS) method. The molecular docking was carried out using the SP and XP docking protocol of the Glide program. The drug-likeness and pharmacokinetics properties (ADMET properties) were analyzed with SwissADME and pkCSM server. The results revealed that the major compounds present in BEO are Linalool (8.17%), D-Limonene (21.26%), and Linalyl acetate (26.91%). Molecular docking analysis revealed that these compounds docked strongly within the binding cavities of Serratia protease and FabI model which in turn curb the pathogenesis of this bacteria. Linalool interacted with the Serratia protease and FabI with a binding energy of - 3.130 kcal/mol and - 3.939 kcal/mol, respectively. Based on the pharmacokinetics findings all lead BEO phytocompounds appear to be promising drug candidates. Overall, these results represent a significant step in the development of plant-based compounds as a promising inhibitor of the virulent proteins of the MDR S. marcescens.

Citrus Essential Oils in Aromatherapy: Therapeutic Effects and Mechanisms

Citrus is one of the main fruit crops cultivated in tropical and subtropical regions worldwide. Approximately half (40-47%) of the fruit mass is inedible and discarded as waste after processing, which causes pollution to the environment. Essential oils (EOs) are aromatic compounds found in significant quantities in oil sacs or oil glands present in the leaves, flowers, and fruit peels (mainly the flavedo part). Citrus EO is a complex mixture of ~400 compounds and has been found to be useful in aromatic infusions for personal health care, perfumes, pharmaceuticals, color enhancers in foods and beverages, and aromatherapy. The citrus EOs possess a pleasant scent, and impart relaxing, calming, mood-uplifting, and cheer-enhancing effects. In aromatherapy, it is applied either in message oils or in diffusion sprays for homes and vehicle sittings. The diffusion creates a fresh feeling and enhances relaxation from stress and anxiety and helps uplifting mood and boosting emotional and physical energy. This review presents a comprehensive outlook on the composition, properties, characterization, and mechanism of action of the citrus EOs in various health-related issues, with a focus on its antioxidant properties.

To explore the potential molecular mechanism of complex rose-bergamot essential oil on anti-anxiety with facial spots based on network pharmacology

OBJECTIVE

To explore the potential mechanism of complex rose-bergamot essential oil against anxiety accompanied with facial spots through network pharmacology.

METHODS

The components of rose and bergamot essential oils were determined by GC-MS and obtained from literature, and their action targets were predicted by PubChem, SwissADME and SwissTargetPrediction databases. Using "Anxiety disorder" and "Facial pigmentation" as keywords, the relevant targets of anxiety disorder and facial spots were mined in the databases of DrugBank, TTD, GeneCards, and OMIM. The intersection targets of complex rose-bergamot essential oil and anxiety accompanied with facial spots diseases were obtained by making Venn diagram, respectively. Protein-protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of genes and genomes (KEGG) pathway enrichment analysis of intersection targets were carried out through STRING platform, Metascape, and KEGG Mapper databases. The "complex essential oil- component- target- pathway" network was constructed by Cytoscape software. The key active compounds and core targets were docked by AutoDock software.

RESULTS

A total of 34 active components of complex rose-bergamot essential oil and 405 corresponding targets were obtained. The intersection targets of complex essential oil with anxiety disorder and facial spot were 88 and 34, respectively, and the related KEGG pathways were 137 and 123 items, respectively. Neroli acetate, Neroli alcohol, and Linalool in complex rose-bergamot essential oil could play a therapeutic role in anxiety disorder by regulating key targets such as SLC6A4, GRIN2B and DRD2 to participate in the neuroactive ligand-receptor interaction and serotonergic synapse and other pathways, they also could play a role in the treatment of facial spots by regulating key targets such as EGFR, VEGFA, and PIK3CA in the PI3K-AKT, JAK-STAT and other signal pathways. The molecular docking between the key compounds and the core targets showed that the binding energy was less than 0 kcal /mol, indicating that the compound and the target could bind stably.

CONCLUSION

Complex rose-bergamot essential oil can play a role in the treatment of anxiety disorder with facial spots through the synergistic mechanism of multicomponent, multitarget, and multipathway.

Pharmacotechnological Advances for Clinical Translation of Essential Oils for the Treatment of Pain and Agitation in Severe Dementia

The demand for natural products is steadily increasing, and pharmacotechnological engineering is needed to allow rigorous investigation of their efficacy and safety in clinical conditions representing still unmet needs. Among aged patients affected by dementia, up to 80% of residents in nursing homes suffer from chronic pain and 97% from fluctuant neuropsychiatric symptoms (NPS), of which the most challenging is agitation. It is, at least in part, due to undertreated pain and treated with antipsychotics almost doubling the risk of death. In the frame of a scoping review assessing the existence of essential oils undergoing engineering pharmacotechnological processes using solid lipid nanoparticle delivery systems for clinical translation in pain and/or neuropsychiatric symptoms of dementia following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), here we identified that the sole essential oil engineered to overcome the criticisms of aromatherapy clinical trials in pain and dementia is the essential oil of bergamot (BEO). Therefore, we present the process leading to the actually ongoing randomized, double-blind, placebo-controlled NCT04321889 clinical trial to assess the efficacy and safety of intervention with bergamot in the management of agitation and pain in severe dementia to be followed also for the proof of concept of efficacy and safety of other essential oils.

Qualitative and quantitative analyses of chemical components of Citri Sarcodactylis Fructus from different origins based on UPLC-Q-Exactive Orbitrap-MS and GC-MS

Ultra-high-performance liquid chromatography-Q-Exactive Orbitrap-mass spectrometry (MS) and gas chromatography (GC)-MS were performed for the qualitative and quantitative analyses of Citri Sarcodactylis Fructus (CSF) from different origins. The contents of eight major CSF components, namely 5,7-dimethoxycoumarin, scopoletin, hesperidin, tangeretin, nobiletin, limonin, nomilin, and stachydrine, were quantitatively analyzed. Clustering analysis and principal component analysis (PCA) were, respectively, performed to classify and compare the 10 CSF batches. One hundred and two volatile components were identified accordingly by comparing retention times, reference standards, parent peaks, fragment peaks, and findings from relevant literature. Moreover, high content of 5,7-dimethoxycoumarin and stachydrine was detected in all the CSFs, especially in CSF-Zhe. Therefore, the high content component coumarin "5,7-dimethoxycoumarin" was suggested to be quality analysis component rather than hesperidin. Additionally, characteristic compounds were found to distinguish different CSFs. This work was a comprehensive study about the components of various CSF. It distinguished the basic differences in the compositions of CSF from different origins. Eventually, it provided experimental and systematic bases for the quality control analysis of CSF, which has potential application in the further research.

Upregulation of Cell Division Cycle 20 Expression Alters the Morphology of Neuronal Dendritic Spines in the Nucleus Accumbens by Promoting FMRP Ubiquitination

The nucleus accumbens (NAc) is the key area of the reward circuit, but its heterogeneity has been poorly studied. Using single-cell RNA sequencing, we revealed a subcluster of GABAergic neurons characterized by cell division cycle 20 (Cdc20) mRNA expression in the NAc of adult rats. We studied the coexpression of Cdc20 and Gad1 mRNA in the NAc neurons of adult rats and assessed Cdc20 protein expression in the NAc during rat development. Moreover, we microinjected AAV2/9-hSyn-Cdc20 with or without the dual-AAV system into the bilateral NAc for sparse labelling to observe changes in the synaptic morphology of mature neurons and assessed rat behaviours in open field and elevated plus maze tests. Furthermore, we performed the experiments with a Cdc20 inhibitor, Cdc20 overexpression AAV vector, and Cdc20 conditional knockout primary striatal neurons to understand the ubiquitination-dependent degradation of fragile X mental retardation protein (FMRP) in vitro and in vivo. We confirmed the mRNA expression of Cdc20 in the NAc GABAergic neurons of adult rats, and its protein level was decreased significantly 3 weeks post-birth. Upregulated Cdc20 expression in the bilateral NAc decreased the dendritic spine density in mature neurons and induced anxiety-like behaviour in rats. Cdc20-APC triggered FMRP degradation through K48-linked polyubiquitination in Neuro-2a cells and primary striatal neurons and downregulated FMRP expression in the NAc of adult rats. These data revealed that upregulation of Cdc20 in the bilateral NAc reduced dendritic spine density and led to anxiety-like behaviours, possibly by enhancing FMRP degradation via K48-linked polyubiquitination.

Translational Value of the Transdermal Administration of Bergamot Essential Oil and of Its Fractions

The essential oil of bergamot (BEO) has consistently proven antinociceptive and antiallodynic properties. Accordingly, the analgesic efficacy of the decolored essential oil (DEC), with higher levels of limonene, and the deterpenated (DET) fraction, with higher levels of linalool and linalyl acetate, was investigated using a formalin test after inhalation. The present study was aimed at characterizing the effects of BEO, its components with the highest pharmacological activity (represented by linalool, limonene, and linalyl acetate), and its DEC and DET fractions on the formalin test after transdermal administration relevant to clinical translation through topical application. To this aim, the schedule of intervention involved administration immediately after formalin injection or as a 5 min pretreatment followed by washout in ddY-strain mice. This study demonstrates, for the first time, the significant analgesic effect of all three constituents in the first and second phases, accounting for the efficacy of the essential oil in the formalin test. While all fractions revealed equal activity toward the phytocomplex in the early phase, the reduction in time of licking/biting during the late phase was more markedly induced by DEC. Moreover, pretreatment with BEO and its fractions followed by washout did not produce a significant reduction in licking/biting time in both phases of formalin-induced nociceptive response.

The Effect of Copaiba Oil Odor on Anxiety Relief in Adults under Mental Workload: A Randomized Controlled Trial

Background

Aromatherapy has been proved to be effective in alleviating anxiety in practices and research. Recently, copaiba oil (CPO) is popular in the market and is recommended for anxiety relief in aromatherapy practice. However, relevant scientific research is still lacking.

Methods

A randomized controlled trial was designed to evaluate the anxiety-relieving effect of CPO inhalation in 22 adults. Jojoba oil was used as the control treatment. N-back and mental arithmetic tasks were used as stress stimulation. CPO or control intervention was carried out after the n-back training phase. The State-Trait Anxiety Inventory (STAI), EEG activities, physiological indexes including heart rate (HR), blood pressure (BP), blood oxygen saturation, and salivary cortisol were assessed in different phases of the experimental process.

Results

There was no significant difference in the change of HR and BP between the CPO and control groups before odor intervention. The S-AI scores of the CPO treated participants decreased after the n-back and mental arithmetic tests and were significantly lower than those of the participants who received control treatments. The HR and salivary cortisol of participants who received CPO intervention significantly decreased during the n-back and mental arithmetic tests. Furthermore, a remarkable decrease of beta wave activity was observed in the left midfrontal region (F3) when the participant received the CPO intervention.

Conclusion

The study's findings supported that the CPO odor showed beneficial effects on alleviating anxiety based on several indicators in subjective, physiological, and EEG measurements.

Inhalation Aromatherapy via Brain-Targeted Nasal Delivery: Natural Volatiles or Essential Oils on Mood Disorders

Mood disorders, also often referred to as affective disorders, are a group of psychiatric illnesses that severely impact mood and its related functions. The high medical expenditures have placed a significant financial burden on patients and their families. Aromatherapy is an alternative and complementary treatment that utilizes essential oils (EOs) or volatile oils (VOs) to achieve major therapeutic goals. In general, EOs are volatile chemicals that enter the body primarily through skin absorption and/or nasal inhalation. In addition, they can work through oral administration. Inhalation aromatherapy has shown unique advantages for treating mood disorders, especially depression, anxiety and mental disorders such as sleep disorder, which have been validated over the last decade through clinical and animal studies. Accumulating evidence has shown that EOs or VOs can bypass the blood-brain barrier to target brain tissue through the nasal-brain pathway. Subsequently, they act on the cerebral cortex, thalamus, and limbic system in the brain to improve symptoms of anxiety, depression and improve sleep quality. Here, we review the natural aromatic plants' volatiles or essential oils used commonly as adjuncts to manage mood disorders and illustrate the mechanisms of inhalation aromatherapy, and mainly summarized the application of transnasal inhalation aromatherapy in depression, anxiety, and sleep disorders. We conclude that aromatherapy does not cause side-effects, which is vastly different from commonly used psychotropic drugs. Inhalation aromatherapy via brain-targeted nasal delivery offers potentially efficacious treatment for mental disorders and merits further study.

Antispasmodic Effect of Bergamot Essential Oil on Rat Isolated Gut Tissues

Preclinical data indicate that bergamot essential oil (BEO) can modulate the synaptic functions within the central nervous system (CNS). Particularly, several data shows that essential oil is endowed with reproducible analgesic and anxiolytic effects that may derived from the ability to modulate the excitatory and inhibitory neurotransmission in the CNS. Although there are differences in the functional complexity of the enteric nervous system (ENS), it is likely that the phytocomplex has biological properties in gut superimposable to those showed in the CNS. Accordingly, the aim of this study was to investigate ex-vivo the effect of bergamot essential oil and its main constituents on the contractile activity of rat isolated colon, jejunum and ileum induced by different muscle stimulants such as acetylcholine (10⁻⁶ M) and potassium chloride (80 mM). Our present data demonstrate that BEO inhibits cholinergically- and non cholinergically-mediated contractions in rat isolated gut and that linalool is the most active component. These results suggest that the phytocomplex might be useful in the treatment of spastic disorders in ENS mainly characterized by the presence of pain; incidentally, irritable bowel syndrome (IBS) is a painful condition in which a role for neurotransmitter dysfunction has been envisaged. More investigation is required for clinical translation of the present data.

Dexmedetomidine Alleviates Intracerebral Hemorrhage-Induced Anxiety-Like Behaviors in Mice Through the Inhibition of TRPV4 Opening

Post-stroke anxiety severely affects recovery in patients with intracerebral hemorrhage (ICH). Dexmedetomidine (Dex), a highly selective alpha 2 adrenal receptor (α2-AR) agonist, was recently found to exert an excellent protective effect against mental disorders including anxiety. The transient receptor potential vanilloid 4 (TRPV4) channel is involved in a series of diseases such as asthma, cancer, anxiety, and cardiac hypertrophy. This study examines whether Dex improved ICH-induced anxiety via the inhibition of TRPV4 channel opening. A rodent model of moderate ICH in the basal ganglia was established using autologous blood injection (20 μl). Mice were treated with Dex (25 μg/kg, intraperitoneal injection) every day for 3 days post-ICH. GSK1016790A (1 μmol/2 μl), an agonist of TRPV4, was administered via the left lateral ventricle. Thirty days post-ICH, post-stroke anxiety was evaluated by elevated plus-maze and open-field tests. Following behavioral tests, superoxide dismutase (SOD), malondialdehyde (MDA), astrocytic activation, and A1-and A2-type astrocytes were determined. Primary astrocytes were exposed to hemin to simulate ICH in vitro. Compared with sham-treated mice, Dex administration ameliorates ICH-induced decreases of distance and time in the open-arm, reduces distance and time in the central zone, increases astrocytic activation and A1-type astrocytes, elevates MDA content, downregulates total SOD contents, and decreases A2-type astrocytes. However, GSK1016790A partially reversed the neuroprotective effects of Dex. In addition, Dex significantly inhibited hemin-induced astrocytic activation in vitro. Dex improves ICH-induced anxiety-like behaviors in mice, and the mechanism might be associated with the inhibition of TRPV4-channel opening.

In Vitro Assessment of the Cytotoxic and Antiproliferative Profile of Natural Preparations Containing Bergamot, Orange and Clove Essential Oils

Medicinal plants and essential oils (EOs), in particular, were intensively studied in recent years as viable alternatives for antiproliferative chemical synthetic agents. In the same lines, the present study focuses on investigating the effects of natural preparations (emulsions) based on EOs obtained from Citrus bergamia Risso (bergamot-BEO), Citrus sinensis Osbeck (orange-OEO), and Syzygium aromaticum Merill et L. M. Perry (clove-CEO) on different healthy (human immortalized keratinocytes—HaCaT and primary human gingival fibroblasts—HGF) and human tumor cell lines (human melanoma—A375 and oral squamous carcinoma—SCC-4) in terms of the cells’ viability and cellular morphology. The obtained results indicate that the CEO emulsion (ECEO) induced a dose-dependent cytotoxic in both healthy (HaCaT and HGF) and tumor (A375 and SCC-4) cells. OEO emulsion (EOEO) increased cell viability percentage both for HaCaT and A375 cells and had an antiproliferative effect at the highest concentration in HGF and SCC-4 cells. BEO emulsion (EBEO) decreased the viability percentage of SCC-4 tumor cells. By associating OEO with CEO as a binary mixture in an emulsified formulation, the inhibition of tumor cell viability increases. The E(BEO/OEO) binary emulsion induced an antiproliferative effect on oral health and tumor cells, with a minimal effect on skin cells. The non-invasive tests performed to verify the safety of the test compound’s emulsions at skin level indicated that these compounds do not significantly modify the physiological skin parameters and can be considered safe for human skin.

Preclinical Characterization of Antinociceptive Effect of Bergamot Essential Oil and of Its Fractions for Rational Translation in Complementary Therapy

Bergamot essential oil (BEO) is endowed with consistent and reproducible antinociceptive and anti-allodynic properties when administered via an inhalation route. However, the effects of its main constituents and of its decolored (DEC) and deterpenated (DET) fractions, which are enriched in limonene or in linalool and linalyl acetate, respectively, on spontaneous motor activity related to anxiety and on formalin-induced licking/biting biphasic behavior have never been investigated before. Therefore, the present research aims to characterize the role of BEO components on an experimental pain model that is relevant to clinical translation. Under our present experimental conditions, a paper filter disc soaked with different volumes of the phytocomplex and of its fractions that was applied at the edge of the observation chamber allowed the effects on the spontaneous motor activity and on the formalin-induced nocifensive response in ddY-strain mice to be studied. The present research demonstrated the effects of the DEC fraction of BEO on motor activity and on formalin-induced licking/biting behavior for the first time, proving that limonene is implicated in reduced motor activity and that it is important for the analgesic effect.

Neuroprotective Potential of Limonene and Limonene Containing Natural Products

Limonene is a monoterpene confined to the family of Rutaceae, showing several biological properties such as antioxidant, anti-inflammatory, anticancer, antinociceptive and gastroprotective characteristics. Recently, there is notable interest in investigating the pharmacological effects of limonene in various chronic diseases due to its mitigating effect on oxidative stress and inflammation and regulating apoptotic cell death. There are several available studies demonstrating the neuroprotective role of limonene in neurodegenerative diseases, including Alzheimer's disease, multiple sclerosis, epilepsy, anxiety, and stroke. The high abundance of limonene in nature, its safety profile, and various mechanisms of action make this monoterpene a favorable molecule to be developed as a nutraceutical for preventive purposes and as an alternative agent or adjuvant to modern therapeutic drugs in curbing the onset and progression of neurodegenerative diseases. This manuscript presents a comprehensive review of the available scientific literature discussing the pharmacological activities of limonene or plant products containing limonene which attribute to the protective and therapeutic ability in neurodegenerative disorders. This review has been compiled based on the existing published articles confined to limonene or limonene-containing natural products investigated for their neurotherapeutic or neuroprotective potential. All the articles available in English or the abstract in English were extracted from different databases that offer an access to diverse journals. These databases are PubMed, Scopus, Google Scholar, and Science Direct. Collectively, this review emphasizes the neuroprotective potential of limonene against neurodegenerative and other neuroinflammatory diseases. The available data are indicative of the nutritional use of products containing limonene and the pharmacological actions and mechanisms of limonene and may direct future preclinical and clinical studies for the development of limonene as an alternative or complementary phytomedicine. The pharmacophore can also provide a blueprint for further drug discovery using numerous drug discovery tools.

Anxiolytic Effect of Two Tobacco Essential Oils (Nicotiana tabacum Linn.) on Mice

Tobacco (Nicotiana tabacum Linn.) is a famous traditional herb used in folk medicine. The essential oils of tobacco have been demonstrated in modern studies to possess antioxidant, anti-inflammatory, and neuroprotective properties, while its anxiolytic effect has not been reported. The purpose of this study was to evaluate the anxiolytic effect of Yunnan tobacco essential oil (YTO) and Zimbabwe tobacco essential oil (ZTO) on mice. The constituents of YTO and ZTO were analyzed by GC/MS. The anxiolytic effect of YTO and ZTO (0.1%, 1%, and 10%, v/v) on male ICR mice was evaluated in the light-dark box test (LDB) and the elevated plus maze test (EPM) test via inhalation and transdermal administration. After the behavioral tests, salivary corticosterone levels in mice were measured. The behavioral analysis showed that the administration of both YTO and ZTO elevated the time that the mice spent in the light chamber in the LDB test compared to the untreated control. In the EPM test, YTO and ZTO increased the time spent in open arms and the number of entries into the open arms. In addition, both YTO and ZTO significantly decreased salivary corticosterone levels in mice (p ≤ 0.001). In summary, our results demonstrated that inhalation and transdermal administration of both YTO and ZTO showed anxiolytic effect on male ICR mice.

Nono-titanium dioxide exposure during the adolescent period induces neurotoxicities in rats: Ameliorative potential of bergamot essential oil

INTRODUCTION

In adolescence, the brain is still maturing, and disorders in maturation may affect the normal development of the brain. Exposure to titanium dioxide nanoparticles (TiO₂ NPs) has various potential negative effects on the central nervous system. Bergamot essential oil (BEO) has been found to be effective for neuroprotection.

METHODS

The rats were injected intraperitoneally with TiO₂ NPs (20 mg/kg) and/or BEO (200 mg/kg). The endogenous antioxidant state and inflammatory parameters were estimated using ELISA kits, and then the memory ability and anxiety-like behavior in rats were assessed.

RESULTS

TiO₂ NPs exposure during the adolescent period induced anxiety-like behavior, cognitive impairment, neuroinflammation and oxidative damage in hippocampus, and BEO treatment could significantly ameliorate the neurotoxicities induced by TiO₂ NPs exposure.

CONCLUSION

Our results suggest that the negative effects of TiO₂ NPs exposure during the adolescent period on anxiety-like behavior and cognitive function may be related to oxidative stress and neuroinflammation induced by TiO₂ NPs exposure. In addition, BEO may ameliorate the neurotoxicities induced by TiO2 NPs exposure in adolescent rats through the antioxidant and anti-inflammatory activity of BEO.

Thigmotaxis in a virtual human open field test

Animal models are used to study neurobiological mechanisms in mental disorders. Although there has been significant progress in the understanding of neurobiological underpinnings of threat-related behaviors and anxiety, little progress was made with regard to new or improved treatments for mental disorders. A possible reason for this lack of success is the unknown predictive and cross-species translational validity of animal models used in preclinical studies. Re-translational approaches, therefore, seek to establish cross-species translational validity by identifying behavioral operations shared across species. To this end, we implemented a human open field test in virtual reality and measured behavioral indices derived from animal studies in three experiments (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textit{N}=31$$\end{document}N=31, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textit{N}=30$$\end{document}N=30, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textit{N}=80$$\end{document}N=80). In addition, we investigated the associations between anxious traits and such behaviors. Results indicated a strong similarity in behavior across species, i.e., participants in our study—like rodents in animal studies—preferred to stay in the outer region of the open field, as indexed by multiple behavioral parameters. However, correlational analyses did not clearly indicate that these behaviors were a function of anxious traits of participants. We conclude that the realized virtual open field test is able to elicit thigmotaxis and thus demonstrates cross-species validity of this aspect of the test. Modulatory effects of anxiety on human open field behavior should be examined further by incorporating possible threats in the virtual scenario and/or by examining participants with higher anxiety levels or anxiety disorder patients.

Development and Translation of NanoBEO, a Nanotechnology-Based Delivery System of Bergamot Essential Oil Deprived of Furocumarins, in the Control of Agitation in Severe Dementia

Dementia is one of the most common causes of disability worldwide characterized by memory loss, cognitive impairment, and behavioral and psychological symptoms (BPSD), including agitation. Treatment of the latter consists of the off-label use of harmful atypical antipsychotics, though a significant reduction is afforded by pain control. The use of an essential oil endowed with analgesic properties and devoid of toxicity would represent an important option for the management of agitation in dementia. Therefore, the aim of this study was to engineer a nanotechnology delivery system based on solid lipid nanoparticles loaded with bergamot essential oil (BEO) and devised in the pharmaceutical form of an odorless cream (NanoBEO) to confirm its analgesic efficacy for further development and application to control agitation in dementia. BEO has proven strong antinociceptive and anti-allodynic properties and, in its bergapten-free form, it is completely devoid of phototoxicity. NanoBEO has been studied in vivo confirming the previously reported analgesic activity of BEO to which is now added its anti-itching properties. Due to the nanotechnology delivery system, the stability of titrated BEO components is guaranteed. Finally, the latter invention, currently under patent consideration, is smell-devoid allowing efficacy and safety to be established in double-blind clinical trials; until now the latter studies have been impeded in aromatherapy by the strong odor of essential oils. A clinical trial NCT04321889 has been designed to provide information about the efficacy and safety of NanoBEO on agitation and pain in patients suffering from severe dementia.

Efficacy of Essential Oils in Pain: A Systematic Review and Meta-Analysis of Preclinical Evidence

Background: The demand for essential oils (EOs) has been steadily growing over the years. This is mirrored by a substantial increase in research concerned with EOs also in the field of inflammatory and neuropathic pain. The purpose of this present systematic review and meta-analysis is to investigate the preclinical evidence in favor of the working hypothesis of the analgesic properties of EOs, elucidating whether there is a consistent rational basis for translation into clinical settings.

Methods: A literature search has been conducted on databases relevant for medical scientific literature, i.e., PubMed/MEDLINE, Scopus, and Web of Science from database inception until November 2, 2020, following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) criteria for systematic reviews and meta-analyses.

Results: The search was conducted in order to answer the following PICOS (participants/population, interventions, comparisons, outcomes, and study design) question: are EOs efficacious in reducing acute nociceptive pain and/or neuropathic pain in mice experimental models? The search retrieved 2,491 records, leaving 954 studies to screen after the removal of duplicates. The title and abstract of all 954 studies were screened, which left 127 records to evaluate in full text. Of these, 30 articles were eligible for inclusion.

Conclusion: Most studies (27) assessed the analgesic properties of EOs on acute nociceptive pain models, e.g. the acetic acid writhings test, the formalin test, and the hot plate test. Unfortunately, efficacy in neuropathic pain models, which are a more suitable model for human conditions of chronic pain, had fewer results (only three studies). Moreover, some methodologies raised concerns in terms of the risk of bias. Therefore, EOs with proven efficacy in both types of pain were corroborated by methodologically consistent studies, like the EO of bergamot, which should be studied in clinical trials to enhance the translational impact of preclinical modeling on clinical pain research.

Bergamot essential oil attenuate aluminum-induced anxiety-like behavior through antioxidation, anti-inflammatory and GABA regulation in rats

A large number of studies showed that aluminum (Al) has potential neurotoxicity to human and animal bodies. Al-treated animals showed anxiety-like behavior, oxidative stress, neuroinflammation and γ-aminobutyric acid (GABA) changes. Bergamot essential oil (BEO) is a kind of well-known plant extract from the fresh fruit of bergamot. Previous studies suggested that BEO improved mood and relieved symptoms of stress-induced anxiety. This study was designed to study the effects of BEO on anxiety-like behavior, oxidative stress, neuroinflammation and GABA system in aluminum trichloride (AlCl₃) treated rats. Results showed that AlCl₃ exposure induced anxiety-like behavior in the elevated plus maze and the open field test. Moreover, AlCl₃ exposure decreased the level of GABA and the activity of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in the hippocampus (HP) and the frontal cortex (FC). In addition, AlCl₃ exposure increased the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the HP and the FC. To the contrary, co-administration of BEO and AlCl₃ improved the anxiety-like behavior, GABA system, oxidative stress and neuroinflammation. These results indicated that BEO can alleviate the anxiety-like behavior of AlCl₃-exposed rats through the combined action of antioxidant, anti-inflammatory and GABA regulation.

Pattern of treatment of behavioural and psychological symptoms of dementia and pain: evidence on pharmacoutilization from a large real-world sample and from a centre for cognitive disturbances and dementia

Purpose

Data concerning the number of diagnoses and of the drugs prescribed to patients affected by dementia are still scarce. Here we test whether or not (1) prescription of symptomatic drugs against Alzheimer’s disease (AD) may approximate the number of patients affected by dementia in Italy and (2) adherence to this treatment affects the pattern of prescription of drugs (i.e. antipsychotics and antidepressants) for behavioural and psychological symptoms of dementia (BPSD) and the previously reported limited prescription of analgesics.

Methods

This retrospective observational study concerns 84,235 subjects older than 60 years and registered in the provincial prescription database of the health district of Cosenza accounting for a population of 298,000 inhabitants. The prescribing pattern of antipsychotics, antidepressants, and analgesics has been investigated in patients receiving concurrent prescriptions of acetylcholinesterase inhibitors (AChEI) and/or memantine. Data from a single centre for cognitive disturbances and dementia (CDCD) in the same health district were used to explore at which stage dementia was diagnosed. The study was approved by Calabria Region Ethical Committee no. 31/2017 and registered on October 31, 2017.

Results

The data show that 859 patients are treated with AChEI and/or memantine; 420 patients (48.89%) receive at least 80% of the recommended medications. CDCD data indicate a delay in dementia diagnosis, which often was made when the patients were moderately to severely demented (Mini Mental State Examination, MMSE ≤ 20). Adherence did not influence prescription of most of the drugs explored, but use of non-steroidal anti-inflammatory drugs was higher in non-adherent patients. Antipsychotics and antidepressants are frequently used (20.61–20.71% and 42.37–51.43%, respectively), and this, at least in part, might stem from the observed under-treatment of chronic pain (opioids are prescribed in the 4.76% and 12.46% of adherent and non-adherent patients and gabapentin and pregabalin are used in the 4.29% and 4.07% of adherent and non-adherent patients respectively), resulting in more frequent BPSD. 16.43% of patients receive antipsychotics for longer than 6–12 weeks.

Conclusion

This 2-year period study, including a wide cohort of community demented patients, shows that dementia is diagnosed late and that prevalence of BPSD prescriptions is high and not impacted by adherence to anti-dementia drugs. The rate of prescription of potentially harmful antipsychotics and antidepressants appears to be high though whether the concomitantly observed limited prescription of analgesics might be a contributing factor needs to be further investigated. Our data support the development of strategies to improve the management of BPSD.

Effects of essential oils on central nervous system: Focus on mental health

Essential oils have been used as remedies since ancient times for the treatment of numerous illnesses on account of their wide range of biological activities. Recent preclinical and clinical studies have shown varying pharmacological responses in the nervous system leading to anxiolytic, antidepressant, sedative, and anticonvulsant effects. Experimentation in animal models has evidenced the involvement of multiple neurotransmitter systems in the mode of action of essential oils, resulting in measurable physiological effects in the brain. Additionally, clinical trials have demonstrated the influence of essential oils in physiological parameters such as blood pressure, heart rate, respiratory rate, brain waves composition, and cortisol serum levels with concomitant psychological effects. Although there is growing evidence of measurable effects of essential oils in animal brains, more clinical research is required to validate their influence in the human central nervous system. This will enable the development of essential oil-based drugs for the treatment of mental illnesses such as depression, anxiety and dementia.

Selected essential oils and their mechanisms for therapeutic use against public health disorders. An overview

Today, the numbers of people suffering from lifestyle diseases like diabetes, obesity, allergies and depression increases mainly in industrialised states. That does not only lower patients' quality of life but also severely stresses the health care systems of these countries. Essential oils (EO) have been in use as therapeutic remedies for centuries against various complaints, but still their effectiveness is being underestimated. In the last decades, a great number of controlled studies have supported efficacy of these volatile secondary plant metabolites for various therapeutic indications. Besides others, EO has antidepressant, anti-obesity, antidiabetic, antifirogenic and antiallergic effects. In this review the pharmacological mechanisms for selected EO are summarised and discussed with the main attention on their impact against public health disorders. Additionally, toxicity of these oils as well as possible drug interactions is presented.

Modification of brain waves and sleep parameters by Citrus reticulata Blanco. cv. Sai-Nam-Phueng essential oil

Background

Citrus essential oil (EO) has been used for mood elevation and sedative hypnotic purposes. However, scientific proofs of its central nervous system (CNS) action remained largely unexplored. This study investigated chemotypes, electrical brain waves and sleep-wake effects of the essential oil from Citrus reticulata in rat model.

Methods

Chemical contents of citrus EO were analyzed using gas chromatography-mass spectrometry (GC–MS). Male Wistar rats implanted with electrodes on the frontal and parietal skulls were used for electroencephalographic (EEG) recording while inhaling the citrus EO (200 μl on cotton wool). Diazepam (10 mg/kg, p.o.) was used as a standard anxiolytic drug. EEG frequency analyses were performed by using Fast Fourier transform. All data were statistical analyzed using One-way ANOVA followed by Tukey's test.

Results

GC–MS analysis revealed d-limonene (95.7%) as a major constituent of citrus EO. The EEG results showed that overall EEG patterns of citrus EO effects were relatively similar to that of diazepam. However, significant differences between treatments were seen from sleep-wake analyses. Diazepam significantly increased episode numbers of awake and non-rapid eye movement (REM) sleep and reduced averaged episode duration. On the other hand, the citrus EO significantly decreased REM sleep latency and increased total time and episode numbers of REM sleep.

Conclusion

These findings demonstrated unique CNS effects of C. reticulata EO with EEG fingerprints and sleep-wake profiles. The data might be useful for citrus essential oil sub-classification and clinical application.

Inhibition of Neuromuscular Contractions of Human and Rat Colon by Bergamot Essential Oil and Linalool: Evidence to Support a Therapeutic Action

Bergamot essential oil (BEO) added to food and drink promotes a citrus flavour. Folklore suggests benefits on gastrointestinal functions but with little supporting evidence. BEO and major constituents (linalool, limonene, linalyl acetate) were therefore examined for any ability to influence neuromuscular contractions of human and rat colon. Circular muscle strips (macroscopically-normal human colon obtained following ethical approval at cancer surgery; Sprague-Dawley rats) were suspended in baths (Krebs solution; 37 °C; 5% CO₂ in O₂) for measurement of neuronally-mediated contractions (prevented by tetrodotoxin or atropine) evoked by electrical field stimulation (5 Hz, 0.5 ms pulse width, 10s/minute, maximally-effective voltage), or contractions evoked by KCl (submaximally-effective concentrations). BEO and each constituent concentration dependently inhibited neuronally-mediated and KCl-induced contractions. In human: apparent pIC₅₀ for BEO (volume/volume Krebs), respectively, 3.8 ± 0.3 and 4.4 ± 0.3; I_max 55.8% ± 4.2% and 37.5% ± 4.2%. For the constituents, the rank order of potency differed in human (linalool > limonene >> linalyl-acetate) and rat colon (linalyl-acetate > limonene = linalool), but rank order of efficacy was similar (linalool >> (BEO) = linalyl-acetate >> limonene). Thus, linalool had high efficacy but greater potency in human colon (I_max 76.8% ± 6.9%; pIC₅₀ 6.7 ± 0.2; n = 4) compared with rat colon (I_max 75.3% ± 1.9%; pIC₅₀ 5.8 ± 0.1; n = 4). The ability of BEO and linalool to inhibit human colon neuromuscular contractility provides a mechanism for use as complementary treatments of intestinal disorders.

Role of 5-HT1A Receptor in the Anxiolytic-Relaxant Effects of Bergamot Essential Oil in Rodent

The essential oil obtained by the fresh fruit of Citrus bergamia Risso et Poiteau is used worldwide in aromatherapy to reduce pain, facilitate sleep induction, and/or minimize the effects of stress-induced anxiety. Preclinical pharmacological data demonstrate that bergamot essential oil (BEO) modulates specific neurotransmissions and shows an anxiolytic-relaxant effect not superimposable to that of the benzodiazepine diazepam, suggesting that neurotransmissions, other than GABAergic, could be involved. Several studies on essential oils indicate a role for serotonergic (5-HT) neurotransmission in anxiety. Interestingly, among serotonergic receptors, the 5-HT1A subtype seems to play a key role in the control of anxiety. Here, we report that modulation of the 5-HT1A receptor by selective agonist ((±)8-OH-DPAT) or antagonist (WAY-100635) may influence some of the anxiolytic-relaxant effects of BEO in Open Field and Elevated Plus Maze tests.

The effect of bergamot orange essence on anxiety, salivary cortisol, and alpha amylase in patients prior to laparoscopic cholecystectomy: A controlled trial study

BACKGROUND AND PURPOSE

This study aimed to determine the effect of bergamot orange essence on anxiety, salivary cortisol, and alpha amylase in patients prior to laparoscopic cholecystectomy.

MATERIAL AND METHODS

This clinical trial with pre-post design was conducted on 60 candidates for cholecystectomy. The participants were randomly divided into an intervention and a control group. The intervention group participants underwent aromatherapy using two drops of 3% bergamot orange essence, while the control group ones inhaled two drops of odourless grape seed oil. Anxiety mean score and salivary cortisol and alpha amylase levels were measured before and after the intervention.

RESULTS

A significant difference was found between the groups regarding anxiety (F = 9.00, p = 0.004) and alpha amylase level (F = 9.46, p = 0.003) after the intervention.

CONCLUSION

Bergamot orange essence decreased anxiety and salivary alpha amylase level. Therefore, this method can be used as a complementary technique to reduce patients' anxiety prior to laparoscopic cholecystectomy surgery.

IRCT REGISTRATION NUMBER

IRCT20171113037428N2. It is available in following website: https://www.irct.ir/trial/27696 REGISTRATION DATE: 03/25/2018.

The Effects of Essential Oils and Terpenes in Relation to Their Routes of Intake and Application

Essential oils have been used in multiple ways, i.e., inhaling, topically applying on the skin, and drinking. Thus, there are three major routes of intake or application involved: the olfactory system, the skin, and the gastro-intestinal system. Understanding these routes is important for clarifying the mechanisms of action of essential oils. Here we summarize the three systems involved, and the effects of essential oils and their constituents at the cellular and systems level. Many factors affect the rate of uptake of each chemical constituent included in essential oils. It is important to determine how much of each constituent is included in an essential oil and to use single chemical compounds to precisely test their effects. Studies have shown synergistic influences of the constituents, which affect the mechanisms of action of the essential oil constituents. For the skin and digestive system, the chemical components of essential oils can directly activate gamma aminobutyric acid (GABA) receptors and transient receptor potential channels (TRP) channels, whereas in the olfactory system, chemical components activate olfactory receptors. Here, GABA receptors and TRP channels could play a role, mostly when the signals are transferred to the olfactory bulb and the brain.

Anxiolytic Effect of Essential Oils and Their Constituents: A Review

Essential oils are usually used in aromatherapy to alleviate anxiety symptoms. In comparison to traditional drugs, essential oils have fewer side effects and more diversified application ways, including inhalation. This review provides a comprehensive overview of studies on anxiolytic effects of essential oils in preclinical and clinical trials. Most of the essential oils used in clinical studies have been proven to be anxiolytic in animal models. Inhalation and oral administration were two common methods for essential oil administration in preclinical and clinical trials. Massage was only used in the clinical trials, while intraperitoneal injection was only used in the preclinical trails. In addition to essential oils that are commonly used in aromatherapy, essential oils from many folk medicinal plants have also been reported to be anxiolytic. More than 20 compounds derived from essential oils have shown an anxiolytic effect in rodents, while two-thirds of them are alcohols and terpenes. Monoamine neurotransmitters, amino acid neurotransmitters, and the hypothalamic-pituitary-adrenal axis are thought to play important roles in the anxiolytic effects of essential oils.

Neuropharmacological Properties of the Essential Oil of Bergamot for the Clinical Management of Pain-Related BPSDs

BACKGROUND

Alzheimer's Disease (AD) accounts for approximately 50% of all cases of dementia and, in spite of the great effort for the development of disease-modifying drugs, a definitive treatment of cognitive impairment is not available yet. A perfect adherence to the current therapy of cognitive decline is needed for a better control of the disease and this is proven to reduce, though not completely abolish, the associated Behavioural and Psychological Symptoms of Dementia (BPSDs) from occurring. This cluster of symptoms, remarkably affecting patients' health-related quality of life (HRQL), is tightly associated with pain states. Antipsychotics are the only treatment for BPSDs. However, these drugs are more effective and safer in the short-term (6-12 weeks), they are able to manage aggression but not agitation and they cannot control pain. Aromatherapy with Melissa officinalis and Lavandula officinalis has been employed to handle BPSDs, but it has not provided strong evidence to offer relief from pain.

OBJECTIVE

Bergamot Essential Oil (BEO) exerts antinociceptive activity through several pharmacological mechanisms: in particular, it is able to enhance autophagy, a process undergoing derangement in chronic pain. Thus, the sound pharmacological basis for clinical translation of aromatherapy with BEO in the treatment of BPSDs has been pointed out.

CONCLUSION

The antinociceptive effects elicited by BEO in experimental pain models make it a possible candidate for the pharmacological management of pain-related BPSDs.

Anxiolytic-Like Effects of Bergamot Essential Oil Are Insensitive to Flumazenil in Rats

Anxiety disorders are one of the most common mental disorders, and benzodiazepines (BDZs), acting on gamma-aminobutyric acid type A (GABA-A) receptor complex, represent the most common antianxiety medications in the world. However, chronic BDZ use elicits several adverse reactions. Reportedly, aromatherapy is safer for the management of anxiety. Bergamot essential oil (BEO) extracted from Citrus bergamia Risso et Poiteau fruit, like other essential oils, is widely used in aromatherapy to relieve symptoms of stress-induced anxiety. Interestingly, preclinical data indicate that BEO induces anxiolytic-like/relaxant effects in animal behavioural tasks not superimposable to those of benzodiazepine diazepam. To better elucidate the involvement of GABAergic transmission, the present study examines the effects of pretreatment with flumazenil (FLZ), a benzodiazepine site antagonist, on BEO effects using open-field task (OFT) in rats. The data yielded show that FLZ does not significantly affect behavioural effects of the phytocomplex. These results demonstrate the lack of overlapping between BEO and BDZ behavioural effects, contributing to the characterization of the neurobiological profile of the essential oil for its rational use in aromatherapy.

Neuropharmacology of the Neuropsychiatric Symptoms of Dementia and Role of Pain: Essential Oil of Bergamot as a Novel Therapeutic Approach

Aging of the population makes of dementia a challenge for health systems worldwide. The cognitive disturbance is a serious but not the only issue in dementia; behavioral and psychological syndromes known as neuropsychiatric symptoms of dementia remarkably reduce the quality of life. The cluster of symptoms includes anxiety, depression, wandering, delusions, hallucinations, misidentifications, agitation and aggression. The pathophysiology of these symptoms implicates all the neurotransmitter systems, with a pivotal role for the glutamatergic neurotransmission. Imbalanced glutamatergic and GABAergic neurotransmissions, over-activation of the extrasynaptic N-methyl-D-aspartate (NMDA) receptors and alterations of the latter have been linked to the development of neuropsychiatric symptoms experienced by almost the entire demented population. Drugs with efficacy and safety for prevention or long term treatment of these disorders are not available yet. Aromatherapy provides the best evidence for positive outcomes in the control of agitation, the most resistant symptom. Demented patients often cannot verbalize pain, resulting in unrelieved symptoms and contributing to agitation. Bergamot essential oil provides extensive preclinical evidence of analgesic properties. Incidentally, the essential oil of bergamot induces anxyolitic-like effects devoid of sedation, typical of benzodiazepines, with a noteworthy advantage for demented patients. These data, together with the reported safety profile, form the rational basis for bergamot as a neurotherapeutic to be trialed for the control of behavioral and psychological symptoms of dementia.

Nectandra grandiflora essential oil and its isolated sesquiterpenoids minimize anxiety-related behaviors in mice through GABAergic mechanisms

Nectandra grandiflora Ness (Lauraceae) essential oil (EO) main constituent, the sesquiterpenoid (+)-dehydrofukinone (DHF), has sedative and anticonvulsant effects through GABAergic mechanisms. Other DHF-related sesquiterpenoids have been identified in the EO, such as, dehydrofukinone epoxide (DFX), eremophil-11-en-10-ol (ERM) and selin-11-en-4-α-ol (SEL). However, the neuronal effects of these compounds in mammals remain unknown. Therefore, the aim of this study was to evaluate the anxiolytic potential of the N. grandiflora EO and the isolated compounds in in mice. For this purpose, mice were administered orally with vehicle, 10, 30 or 100 mg/kg EO, DHF, DFX, ERM or SEL or 1 mg/kg diazepam. Locomotion and ethological parameters in the open field (OF) and elevated plus maze (EPM) were recorded. We also examined the effect of DFX, ERM and SEL on the membrane potential and calcium influx in synaptosomes, and the presence of the compounds in the cortical tissue using gas chromatography. EOs and isolated compounds reduced anxiety-related parameters in the EPM (open arms time and entries, end activity, head dipping) and OF (center time and entries, total rearing, unprotected rearing, sniffing, grooming) without alter ambulation or induce sedation. Flumazenil (2 mg/kg, i.p.) altered the anxiolytic-like effect of all treatments and vanished the DFX, ERM and SEL-induced changes in membrane potential. However, FMZ did not blocked the DFX-, ERM- and SEL-induced inhibition of calcium influx. Therefore, our results suggest that N. grandiflora EO and isolated compounds induced anxiolytic-like effect in mice due to positive modulation of GABAa receptors and/or inhibition of neuronal calcium influx.

Efficacy of bergamot: From anti-inflammatory and anti-oxidative mechanisms to clinical applications as preventive agent for cardiovascular morbidity, skin diseases, and mood alterations

We summarize the effects of bergamot (extract, juice, essential oil, and polyphenolic fraction) on cardiovascular, bone, inflammatory, skin diseases, mood alteration, anxiety, pain, and stress. This review included a total of 31 studies (20 studies on humans with 1709 subjects and 11 in animals (rats and mice)). In humans, bergamot-derived extract (BE) exerts positive effects on hyperlipidemia with an oral dose from 150 mg to 1000 mg/day of flavonoids administered from 30 to 180 days, demonstrating an effect on body weight and in modulating total cholesterol, triglycerides, LDL, and HDL. Studies in animals confirm promising data on glucose control (500/1000 mg/day of BE with a treatment lasting 30 days) are available in rats. In animals models, bergamot essential oil (BEO, 10 mg/kg or 20 mg/kg daily for 20 weeks) increases bone volume, decreases psoriatic plaques, increases skin collagen content, and promotes hair growth. Bergamot juice (20 mg/kg) is promising in terms of pro-inflammatory cytokine reduction. In humans, aromatherapy (from 15 to 30 min) does not appear to be useful in order to reduce stress, anxiety, and nausea, compared to placebo. Compared to baseline, BE topical application and BEO aromatherapy reduce blood diastolic and systolic pressure and could have a significant effect on improving mental conditions.

Evidence for accuracy of pain assessment and painkillers utilization in neuropsychiatric symptoms of dementia in Calabria region, Italy

During the clinical course of dementia, beside cognitive impairment and memory loss, a very complex challenge is posed by the neuropsychiatric symptoms (NPSs). Accurate evaluation and treatment of pain impacts positively the agitation of demented patients aged ≥ 65 years. To gather information on the utilization of pain killers in demented patients a preliminary survey has been conducted in collaboration with the Calabrian Pharmacovigilance Territorial Service of the health district of Catanzaro (Italy). The study has taken into consideration the prescriptions of acetylcholinesterase inhibitors and memantine during the period ranging from July 2015 to June 2016 and the percentage of patients treated against pain with non steroidal antinflammatory drugs, opioids, and anticonvulsants have been monitored. The latter have been evaluated statistically for difference between the treatment before (pre) and after (post) the settlement of acetylcholinesterase inhibitors (AChEI) or memantine therapy. The results do support accuracy in painkillers utilization in the course of dementia in the regional population of Calabria (Italy).