Efficacy and safety of silexan, a new, orally administered lavender oil preparation, in subthreshold anxiety disorder - evidence from clinical trials

The efficacy of oral Lavandula angustifolia Mill. essential oil on menopausal symptoms, serum lipid profile, and cortisol concentration in postmenopausal women: A triple-blind, randomized, controlled trial

OBJECTIVE

To determine the effect of oral Lavandula angustifolia Mill. essential oil (LEO) on menopausal symptoms, serum cortisol level, and lipid profile in postmenopausal women.

METHODS

This was a triple-blind parallel-armed randomized trial. Seventy-two postmenopausal women aged 50-65 years referring to healthcare centers in Tabriz, Iran with a score of 15-42 on the Green scale were included from May 10, 2022 to May 22, 2023. The participants were randomly assigned to two groups with a 1:1 ratio and using four and six blocks. One group received LEO soft gel 80 mg per day, and another group received a similar placebo for 60 days. A demographic questionnaire and a Greene menopause symptom scale were used for data collection. The lipid profile (total cholesterol, triglyceride, LDL, HDL) and the serum levels of cortisol were measured using biochemical methods. Chi-square, Fisher's exact tests, Independent samples t-test, Analysis of Covariance (ANCOVA), Repeated measure ANOVA, and Paired sample t-test were utilized for analyses. A p-value less than 0.05 was considered statistically significant.

RESULTS

The demographic and personal characteristics of the participants were similar. After two months of intervention, all symptoms in psychological, physical, vasomotor, anxiety, depression, and sexual dysfunction domains were significantly relieved (decreased) among both groups (p < 0.003), except for sexual dysfunction, the reduction of which was not significant in the placebo group (p = 0.317). The mean (SD) total score of menopausal symptoms reduced from 27.4 (6.3) at baseline to 17.7 (4.9) at the end of the study in the LEO group (p < 0.001). It also decreased from 27.4 (7.1) to 17.6 (5.1) in the placebo group (p < 0.001). However, between-group analyses revealed that this reduction was significantly greater in the LEO group compared to the placebo group only in the sexual dysfunction (Mean (SD): 1.3 (0.6) vs. 1.0 (0.5); adjusted mean difference (95% confidence interval); p: - 0.35 (-0.67 to -0.02); 0.039). No significant within-group changes or between-group differences were observed (p > 0.05) in terms of studied serum markers.

CONCLUSION

The oral LEO exhibited a significant enhancement in sexual dysfunction among postmenopausal women. Therefore, it can be used alongside other therapies to improve sexual dysfunction during menopause. LEO did not affect lipid profile and serum cortisol level in this study.

Natural Compounds in the Battle against Microorganisms-Linalool

The purpose of this article is to present recent studies on the antimicrobial properties of linalool, the mechanism of action on cells and detoxification processes. The current trend of employing compounds present in essential oils to support antibiotic therapy is becoming increasingly popular. Naturally occurring monoterpene constituents of essential oils are undergoing detailed studies to understand their detailed effects on the human body, both independently and in doses correlated with currently used pharmaceuticals. One such compound is linalool, which is commonly found in many herbs and is used to flavor black tea. This compound is an excellent fragrance additive for cosmetics, enhancing the preservative effect of the formulations used in them or acting as an anti-inflammatory on mild skin lesions. Previous studies have shown that it is extremely important due to its broad spectrum of biological activities, i.e., antioxidant, anti-inflammatory, anticancer, cardioprotective and antimicrobial. Among opportunistic hospital strains, it is most active against Gram-negative bacteria. The mechanism of action of linalool against microorganisms is still under intensive investigation. One of the key aspects of linalool research is biotransformation, through which its susceptibility to detoxification processes is determined.

Effects of Lavender on Anxiety, Depression, and Physiological Parameters: Systematic Review and Meta-Analysis

PURPOSE

The recent evidence suggested substantial anxiolytic efficacy of lavender. The aim of this study was to examine the efficacy of lavender for anxiety, depression, and physiological parameters and to elucidate the differential effects of lavender on anxiety and depression by study characteristics.

METHODS

A systematic review and meta-analysis was performed following the PRISMA guidelines. We searched PubMed, Embase, Cochrane Library, Web of Science, and Cumulative Index of Nursing and Allied Health Literature databases for randomized controlled trials investigating the efficacy of lavender on anxiety, depression, or physiological parameters in humans. We assessed the risk of bias within studies with the revised Cochrane risk of bias tool for randomized trials. We used random effect model to estimate the average effect and computed bias-corrected standardized mean difference as effect size metric, Hedges' ĝ for all outcomes.

RESULTS

Lavender was superior to placebo or no treatment in reducing anxiety (Hedges' ĝ = -0.72, 95% confidence interval [CI] -0.90 to -0.55, p value <.001), depression (Hedges' ĝ = -0.43, 95% CI, -0.59 to -0.27, p value <.001), and systolic blood pressure (Hedges' ĝ = -0.23, 95% CI, -0.41to -0.05, p value = .01). The moderator analysis by meta-regression indicated that route of administration accounted 6.5% (p value = .187) for the heterogeneity in anxiolytic effects, sessions of treatment accounted 13.2% (p value = .055), and participants' health state accounted 8.9% (p value = .131) for the variance in anxiolytic effects.

CONCLUSION

Lavender aromatherapy showed substantial effect in reducing anxiety and depression, and sessions of administration increased the anxiolytic effects. The effects on physiological parameters showed small with inconsistent significances and randomized controlled trials on the effect of lavender on depression were scarce. Future trials on depression and physiological parameters are recommended, and increasing the sessions of administration is recommended.

Tea tree oil extract causes mitochondrial superoxide production and apoptosis as an anticancer agent, promoting tumor infiltrating neutrophils cytotoxic for breast cancer to induce tumor regression

The antitumor activity of the tea tree oil (TTO) derived product, Melaleuca Alternifolia Concentrate (MAC) was characterized mechanistically at the molecular and cellular level. MAC was analyzed for its anticancer activity against human prostate (LNCaP) and breast (MCF-7) cancer cell lines growing in vitro. MAC (0.02-0.06% v/v) dose-dependently induced the intrinsic (mitochondrial) apoptotic pathway in both the LNCaP and MCF-7 cell lines, involving increased mitochondrial superoxide production, loss of mitochondrial membrane potential (MMP), caspase 3/7 activation, as well as the presence of TUNEL⁺ and cleaved-PARP⁺ cell populations. At concentrations of 0.01-0.04% v/v, MAC caused cell cycle arrest in the G_0/1-phase, as well as autophagy. The in vivo anticancer actions of MAC were examined as a treatment in the FVB/N c-Neu murine model for spontaneously arising breast cancers. Intratumoral MAC injections (1-4% v/v) significantly suppressed tumor progression in a dose-dependent manner and was associated with greater levels of tumor infiltrating neutrophils exhibiting anticancer cytotoxic activity. Induction of breast cancer cell death by MAC via the mitochondrial apoptotic pathway was also replicated occurring in tumors treated in vivo. In conclusion, our data highlights the potential for the Melaleuca-derived MAC product inducing anticancer neutrophil influx, supporting its application as a novel therapeutic agent.

Silexan does not affect driving performance after single and multiple dose applications: Results from a double-blind, placebo and reference-controlled study in healthy volunteers

Anxiolytic drugs often have sedative effects that impair the ability to drive. Our double-blind, randomized crossover trial investigated the effect of Silexan, a non-sedating, anxiolytic herbal medicinal product, on driving performance in healthy volunteers. Part 1 aimed at demonstrating equivalence between 80 mg/d Silexan and placebo. Part 2 was performed to demonstrate superiority of 160 and 320 mg Silexan over 1 mg lorazepam and included a placebo arm for assay sensitivity. Driving performance was assessed in a validated, alcohol-calibrated simulator test. The primary outcome was the standard deviation of the lane position (SDLP). Secondary outcomes included driving errors and sleepiness. Fifty and 25 subjects were randomized in Parts 1 and 2, respectively. In Part 1, Silexan 80 mg was confirmed to be equivalent to placebo after single administration (equivalence range: δ = ±2 cm). The 95% confidence interval (CI) for the SDLP marginal mean value difference Silexan-placebo for single administration was -1.43; +1.38 and thus similar to the 95% CI of -1.45; +0.79 cm for 7 days' multiple dosing. In Part 2, 95% CIs for SDLP marginal mean value differences to lorazepam were -8.58; -5.42 cm for Silexan 160 mg and -8.65; -5.45 cm for 320 mg (p < 0.001). Confirmatory results were supported by secondary outcomes, where results for Silexan were comparable to placebo and more favorable than for lorazepam. The study demonstrates that single doses of up to 320 mg Silexan and multiple doses of 80 mg/d have no adverse effect on driving performance.

Neurotrophic Properties of Silexan, an Essential Oil from the Flowers of Lavender-Preclinical Evidence for Antidepressant-Like Properties

BACKGROUND

Silexan, a special essential oil from flowering tops of lavandula angustifolia, is used to treat subsyndromal anxiety disorders. In a recent clinical trial, Silexan also showed antidepressant effects in patients suffering from mixed anxiety-depression (ICD-10 F41.2). Since preclinical data explaining antidepressant properties of Silexan are missing, we decided to investigate if Silexan also shows antidepressant-like effects in vitro as well as in vivo models.

METHODS

We used the forced swimming test (FST) in rats as a simple behavioral test indicative of antidepressant activity in vivo. As environmental events and other risk factors contribute to depression through converging molecular and cellular mechanisms that disrupt neuronal function and morphology-resulting in dysfunction of the circuitry that is essential for mood regulation and cognitive function-we investigated the neurotrophic properties of Silexan in neuronal cell lines and primary hippocampal neurons.

RESULTS

The antidepressant activity of Silexan (30 mg/kg BW) in the FST was comparable to the tricyclic antidepressant imipramine (20 mg/kg BW) after 9-day treatment. Silexan triggered neurite outgrowth and synaptogenesis in 2 different neuronal cell models and led to a significant increase in synaptogenesis in primary hippocampal neurons. Silexan led to a significant phosphorylation of protein kinase A and subsequent CREB phosphorylation.

CONCLUSION

Taken together, Silexan demonstrates antidepressant-like effects in cellular as well as animal models for antidepressant activity. Therefore, our data provides preclinical evidence for the clinical antidepressant effects of Silexan in patients with mixed depression and anxiety.

Pharmacological basis of the anxiolytic and antidepressant properties of Silexan®, an essential oil from the flowers of lavender

Silexan®, a proprietary essential oil manufactured by steam distillation from Lavandula angustifolia flowers showed pronounced anxiolytic effects in patients with subthreshold anxiety disorders and was also efficacious in patients with Generalized Anxiety disorder (GAD). Moreover, evidences for antidepressant-like properties of Silexan® have been observed in anxious patients suffering from comorbid depressive symptoms and in patients with mixed anxiety-depression disorder (ICD-10 F41.2). In accordance with the clinical data Silexan® is active in several behavioral models in rodents at rather low concentrations indicating potent anxiolytic and antidepressive properties. As possible mechanism of action a moderate inhibition of voltage dependent calcium channels (VDCC) has been found showing some similarities to the anxiolytic drug pregabalin. However, while pregabalin mainly inhibits P/Q-type channels by binding to a modulatory subunit, Silexan® moderately inhibits mainly T-type and N-type channels and to some extent P/Q-type channels. Unlike pregabalin Silexan® is free of hypnotic or sedative side effects and seems to be devoid of any abuse potential. With respect to its specific antidepressant like properties Silexan® improves several aspects of neuroplasticity which seems to be the common final pathway of all antidepressant drugs. As a potential mechanism of its effects on neuroplasticity an activation of the transcription factor CREB via activation of intracellular signaling kinases like PKA and MAPK has been found. Since the concentrations of Silexan® needed to inhibit VDCC function and to improve neuroplasticity are quite similar, the effects of Silexan® on PKA or MAPK could constitute a common intracellular signaling cascade leading to VDCC modulation as well as CREB activation and improved neuroplasticity.

The best route of administration of lavender for anxiety: a systematic review and network meta-analysis

BACKGROUND

There is preliminary evidence for lavender as an anxiolytic agent through various routes of administration. Our goal is to elucidate the best route of administration for lavender as a treatment for anxiety.

METHODS

Thirteen electronic search engines were systematically scanned for relevant publications. The relevant articles were included after the title and abstract screening followed by the full-text screening. This study included randomized control trials reporting lavender for the treatment of anxiety. The protocol was registered in PROSPERO (CRD42017076711). Frequentist network meta-analysis and Bayesian meta-regression were conducted to report the best treatment modality and the effect of covariates on the effectiveness as an anxiolytic. Treatment arms were ordered according P-scores, where higher P-score indicates better treatment choice.

RESULTS

Forty studies were eligible for qualitative analysis, and 32 were included in quantitative analysis. Lavender aromatherapy was the best approach for the treatment of anxiety among other lavender modalities at the first week recording [Standardized Mean Difference (SMD) = -0.57, 95% CI (-1.14-0.01), P-score = 0.72], in addition to achieve at the first time points [SMD = -0, 95% CI (-0.97 ̶ -0.16), P-score = 0.69], compared to placebo; however, lavender massage along with foot bath were found to be the most efficacious for anxiety treatment at the study endpoint [SMD = -1.10, 95% CI = (-7.41 ̶ 5.21), P-score = 0.65]. Furthermore, network meta-regression revealed that the duration of therapy influenced treatment, suggesting Silexan (oral lavender) 80 mg (first rank probability = .116) as the favorable option for anxiety in long-term treatment.

CONCLUSIONS

Lavender aromatherapy is, clinically, superior in short-duration, while Silexan (oral lavender) 80 mg is preferable for long-term treatment of anxiety.

Influence of lavender oil inhalation on vital signs and anxiety: A randomized clinical trial

OBJECTIVE

To investigate the effectiveness of lavender oil (Lavandula angustifolia Mill) inhalation on anxiety, mood, and vital signs (blood pressure, respiratory rate, heart rate, and saturation) of patients undergoing oral surgery. Vital signs were considered as primary outcome measures. Paired anxiety tests were used as secondary outcome measures.

METHODS

Patients who had dental anxiety according to the Dental Anxiety Questionnaire (DAQ) were enrolled in the study. One hundred twenty-six patients who were undergoing wisdom tooth removal under local anaesthesia were randomly assigned to the lavender oil and control groups. Paired anxiety tests (Modified Dental Anxiety Scale and State-Trait Anxiety Inventory-State Scale were performed. Vital signs were noted pre-, intra-, and post-operatively. Visual analogue scale (VAS) results were assessed. The patients' degree of satisfaction was noted.

RESULTS

Pre-operative anxiety levels were similar in both groups. Significant changes in blood pressure were observed in the lavender oil group post-operatively (p < .05). Most (79.4%) of the patients in the lavender oil group enjoyed the scent, 89.68% were satisfied with their experience, and 97.62% of the patients stated that they would prefer the same protocol when needed.

CONCLUSION

Inhalation of lavender oil, which is one of the most powerful anxiolytic essential oils, reduces peri-operative anxiety and can be prospectively considered in future studies for its potential sedative characteristics in patients undergoing surgical procedures under local anaesthesia.

TRIAL REGISTRATION NUMBER

NCT03722771 (Influence of Lavender Oil on Vital Signs in Oral Surgery Patients) https://clinicaltrials.gov/ct2/show/NCT03722771.

Efficacy of Silexan in subthreshold anxiety: meta-analysis of randomised, placebo-controlled trials

Subthreshold psychiatric disorders do not fully meet the diagnostic criteria of syndromal disorders but may be associated with comparable disability. To investigate the anxiolytic effect of Silexan, an active substance from lavender oil for oral administration, in patients with subthreshold anxiety, a meta-analysis that included all published trials with Silexan in this indication was performed. Three randomised, placebo-controlled trials in subthreshold anxiety disorders (anxiety disorder not otherwise specified, restlessness and agitation, mixed anxiety and depressive disorder) were included. Eligible participants with a baseline Hamilton Anxiety Rating Scale (HAMA) total score ≥ 18 points received 1 × 80 mg/day Silexan or placebo for 10 weeks. Outcomes included the HAMA, the Pittsburgh Sleep Quality Index, the Zung Self-rating Anxiety Scale, the Clinical Global Impressions questionnaire and the SF-36 health status inventory. Data were analysed using meta-analysis based on pooled raw data of individual patients (random effects models). A total of 697 patients were assessed for efficacy. Silexan was superior to placebo in reducing the HAMA total score during 10 weeks' treatment [mean value difference, 95% confidence interval: 3.83 (1.28; 6.37) points]. Superiority was comparably pronounced for psychic and somatic anxiety as well as for observer- and self-rated anxiety. Silexan had a beneficial effect on sleep (secondary to the anxiolytic effect) without causing sedation and improved the patients' health-related quality of life. Adverse event incidence in both treatment groups was comparable [risk ratio: 1.06 (0.85; 1.33)]. Silexan has a significant and clinically meaningful anxiolytic effect in subthreshold anxiety. The results cannot be generalised to other lavender oil products.

Linalool Odor-Induced Anxiolytic Effects in Mice

In folk medicine, it has long been believed that odorous compounds derived from plant extracts can have anxiolytic effects. Among them, linalool, one of the terpene alcohols in lavender extracts, has been reported to have the anxiolytic effects. However, the anxiolytic nature of the linalool odor itself as well as its potential action through the olfactory system has not been thoroughly examined. In this study, we examined the anxiolytic effects of linalool odor with light/dark box test and with elevated plus maze (EPM), and found that linalool odor has an anxiolytic effect without motor impairment in mice. The effect was not observed in anosmic mice, indicating that it was triggered by olfactory input evoked by linalool odor. Furthermore, the effect was antagonized by flumazenil, indicating that the linalool odor-induced anxiolytic effect was mediated by γ-aminobutyric acid (GABA)ergic transmission via benzodiazepine (BDZ)-responsive GABA_A receptors. These results provide information about the potential central neuronal mechanisms underlying the odor-induced anxiolytic effects and the foundation for exploring clinical application of linalool odor in anxiety treatments.

Therapeutical strategies for anxiety and anxiety-like disorders using plant-derived natural compounds and plant extracts

Anxiety and anxiety-like disorders describe many mental disorders, yet fear is a common overwhelming symptom often leading to depression. Currently two basic strategies are discussed to treat anxiety: pharmacotherapy or psychotherapy. In the pharmacotherapeutical clinical approach, several conventional synthetic anxiolytic drugs are being used with several adverse effects. Therefore, studies to find suitable safe medicines from natural sources are being sought by researchers. The results of a plethora experimental studies demonstrated that dietary phytochemicals like alkaloids, terpenes, flavonoids, phenolic acids, lignans, cinnamates, and saponins or various plant extracts with the mixture of different phytochemicals possess anxiolytic effects in a wide range of animal models of anxiety. The involved mechanisms of anxiolytics action include interaction with γ-aminobutyric acid A receptors at benzodiazepine (BZD) and non-BZD sites with various affinity to different subunits, serotonergic 5-hydrodytryptamine receptors, noradrenergic and dopaminergic systems, glutamate receptors, and cannabinoid receptors. This review focuses on the use of both plant-derived natural compounds and plant extracts with anxiolytic effects, describing their biological effects and clinical application.

Silexan in generalized anxiety disorder: investigation of the therapeutic dosage range in a pooled data set

Silexan, a special active substance produced from Lavandula angustifolia, is efficacious in subsyndromal anxiety at a dose of 80 mg/day, but its effective dosage in generalized anxiety disorder (GAD) has yet to be defined. In two double-blind, placebo-controlled trials, daily doses of 10, 40, 80, and 160 mg silexan were administered for 10 weeks. A total of 925 adults with GAD according to Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria and a Hamilton Anxiety Scale (HAMA) total score of at least 18 points were analyzed for efficacy. We assessed the change versus baseline for the HAMA and the Covi Anxiety Scale, the Clinical Global Impressions scale, the Sheehan Disability Scale, and the SF-36 health status questionnaire using analysis of variance and covariance. Silexan 160 mg/day was superior to placebo for all efficacy outcomes investigated, with responder rates exceeding 60% on the basis of HAMA and Clinical Global Impressions criteria. For the 80 mg/day dosage, superiority over placebo could be shown in one trial as well as in the pooled analysis. The risk of adverse events under silexan was similar to placebo for all dosages investigated. In GAD silexan 160 mg/day is efficacious whereas 80 mg/day may represent the lower end of the therapeutic range. Daily doses up to 160 mg were well tolerated.

Therapeutic Effects of Phytochemicals and Medicinal Herbs on Depression

Background. Depression is a recurrent, common, and potentially life-threatening psychiatric disease related to multiple assignable causes. Although conventional antidepressant therapy can help relieve symptoms of depression and prevent relapse of the illness, complementary therapies are required due to disadvantage of the current therapy such as adverse effects. Moreover, a number of studies have researched adjunctive therapeutic approaches to improve outcomes for depression patients. Purpose. One potential complementary method with conventional antidepressants involves the use of medicinal herbs and phytochemicals that provide therapeutic benefits. Studies have revealed beneficial effects of medical herbs and phytochemicals on depression and their central nervous system mechanism. Here, we summarize the current knowledge of the therapeutic benefits of phytochemicals and medicinal herbs against depression and describe their detailed mechanisms. Sections. There are two sections, phytochemicals against depression and medical herbs against depression, in this review. Conclusion. Use of phytomedicine may be an alternative option for the treatment of depression in case conventional drugs are not applicable due to their side effects, low effectiveness, or inaccessibility. However, the efficacy and safety of these phytomedicine treatments for depression have to be supported by clinical studies.

The Effect of (-)-Linalool on the Metabolic Activity of Liver CYP Enzymes in Rats

(-)-Linalool is the major floral scent occurring mainly in families Lamiaceae, Lauraceae and Rutaceae and is the main active compound of lavender oil. The purpose of this study was to reveal the influence of subchronic systemic treatment with (-)-linalool on the metabolic activity of CYP2A, 2B, 2C6, 2C11 and 3A in rat liver microsomes (RLM). The second aim was to reveal possible inhibitory effect of (-)-linalool on CYP2C6 in vitro. Wistar albino male rats were treated with (-)-linalool intragastrically at the doses of 40, 120, and 360 mg/kg/day for 13 days. Treatment with (-)-linalool at the dose of 360 mg/kg increased the metabolic activity of CYP2A assessed with testosterone as a probe substrate. (-)-Linalool showed weak competitive inhibition of CYP2C6 in rat liver microsomes, with IC50 of 84 μM with use of diclofenac as a probe substrate.

Unraveling the rat blood genome-wide transcriptome after oral administration of lavender oil by a two-color dye-swap DNA microarray approach

Lavender oil (LO) is a commonly used essential oil in aromatherapy as non-traditional medicine. With an aim to demonstrate LO effects on the body, we have recently established an animal model investigating the influence of orally administered LO in rat tissues, genome-wide. In this brief, we investigate the effect of LO ingestion in the blood of rat. Rats were administered LO at usual therapeutic dose (5 mg/kg) in humans, and following collection of the venous blood from the heart and extraction of total RNA, the differentially expressed genes were screened using a 4 × 44-K whole-genome rat chip (Agilent microarray platform; Agilent Technologies, Palo Alto, CA, USA) in conjunction with a two-color dye-swap approach. A total of 834 differentially expressed genes in the blood were identified: 362 up-regulated and 472 down-regulated. These genes were functionally categorized using bioinformatics tools. The gene expression inventory of rat blood transcriptome under LO, a first report, has been deposited into the Gene Expression Omnibus (GEO): GSE67499. The data will be a valuable resource in examining the effects of natural products, and which could also serve as a human model for further functional analysis and investigation.

Efficacy of orally administered Silexan in patients with anxiety-related restlessness and disturbed sleep--A randomized, placebo-controlled trial

The anxiolytic effect of Silexan, a patented active substance with an essential oil produced from Lavandula angustifolia flowers, was investigated in patients with anxiety-related restlessness and disturbed sleep. 170 out-patients with a diagnosis of restlessness (ICD-10 R45.1), a Hamilton Anxiety Scale (HAMA) total score ≥18 points and ≥2 points for HAMA items 'Tension' and 'Insomnia' participated in this randomized, double-blind trial and received 80mg Silexan or placebo once daily for 10 weeks. Patients with clinically important other psychiatric or neurological disorders potentially interfering with the assessment of treatment efficacy were excluded. Outcome variables were the HAMA as well as the Pittsburgh Sleep Quality Index (PSQI), the Zung Self-rating Anxiety Scale, a State Check inventory and the Clinical Global Impressions questionnaire. In the Silexan group the HAMA total score decreased from an average of 25.5±6.0 points at baseline to 13.7±7.0 points at treatment end, compared to a decrease from 26.5±6.1 to 16.9±9.8 for placebo, corresponding to decreases of 12.0 and 9.3 points (marginal means), respectively (group difference: p=0.03, ANCOVA with factor treatment and baseline value as covariate). In all outcome measures the treatment effect of Silexan was more pronounced than with placebo. According to the HAMA, 48.8% and 33.3% of the patients were responders (Silexan, placebo; reduction ≥50%; p=0.04) and 31.4% and 22.6% achieved remission (HAMA<10; p=0.20). 33.7% (Silexan) and 35.7% (placebo) of the participants reported adverse events. The study confirms the calming and anxiolytic efficacy of Silexan.

A Systematic Review of the Anxiolytic-Like Effects of Essential Oils in Animal Models

The clinical efficacy of standardized essential oils (such as Lavender officinalis), in treating anxiety disorders strongly suggests that these natural products are an important candidate source for new anxiolytic drugs. A systematic review of essential oils, their bioactive constituents, and anxiolytic-like activity is conducted. The essential oil with the best profile is Lavendula angustifolia, which has already been tested in controlled clinical trials with positive results. Citrus aurantium using different routes of administration also showed significant effects in several animal models, and was corroborated by different research groups. Other promising essential oils are Citrus sinensis and bergamot oil, which showed certain clinical anxiolytic actions; along with Achillea wilhemsii, Alpinia zerumbet, Citrus aurantium, and Spiranthera odoratissima, which, like Lavendula angustifolia, appear to exert anxiolytic-like effects without GABA/benzodiazepine activity, thus differing in their mechanisms of action from the benzodiazepines. The anxiolytic activity of 25 compounds commonly found in essential oils is also discussed.

Unraveling the Rat Intestine, Spleen and Liver Genome-Wide Transcriptome after the Oral Administration of Lavender Oil by a Two-Color Dye-Swap DNA Microarray Approach

The use of lavender oil (LO)--a commonly, used oil in aromatherapy, with well-defined volatile components linalool and linalyl acetate--in non-traditional medicine is increasing globally. To understand and demonstrate the potential positive effects of LO on the body, we have established an animal model in this current study, investigating the orally administered LO effects genome wide in the rat small intestine, spleen, and liver. The rats were administered LO at 5 mg/kg (usual therapeutic dose in humans) followed by the screening of differentially expressed genes in the tissues, using a 4×44-K whole-genome rat chip (Agilent microarray platform; Agilent Technologies, Palo Alto, CA, USA) in conjunction with a dye-swap approach, a novelty of this study. Fourteen days after LO treatment and compared with a control group (sham), a total of 156 and 154 up (≧ 1.5-fold)- and down (≦ 0.75-fold)-regulated genes, 174 and 66 up- (≧ 1.5-fold)- and down (≦ 0.75-fold)-regulated genes, and 222 and 322 up- (≧ 1.5-fold)- and down (≦ 0.75-fold)-regulated genes showed differential expression at the mRNA level in the small intestine, spleen and liver, respectively. The reverse transcription-polymerase chain reaction (RT-PCR) validation of highly up- and down-regulated genes confirmed the regulation of the Papd4, Lrp1b, Alb, Cyr61, Cyp2c, and Cxcl1 genes by LO as examples in these tissues. Using bioinformatics, including Ingenuity Pathway Analysis (IPA), differentially expressed genes were functionally categorized by their Gene Ontology (GO) and biological function and network analysis, revealing their diverse functions and potential roles in LO-mediated effects in rat. Further IPA analysis in particular unraveled the presence of novel genes, such as Papd4, Or8k5, Gprc5b, Taar5, Trpc6, Pld2 and Onecut3 (up-regulated top molecules) and Tnf, Slc45a4, Slc25a23 and Samt4 (down-regulated top molecules), to be influenced by LO treatment in the small intestine, spleen and liver, respectively. These results are the first such inventory of genes that are affected by lavender essential oil (LO) in an animal model, forming the basis for further in-depth bioinformatics and functional analyses and investigation.

Lavender oil preparation Silexan is effective in generalized anxiety disorder--a randomized, double-blind comparison to placebo and paroxetine

The anxiolytic efficacy of the orally administered lavender oil preparation Silexan was investigated in generalized anxiety disorder (GAD) in comparison to placebo and paroxetine. In this randomized, double-blind, double-dummy trial 539 adults with GAD according to DSM-5 criteria and a Hamilton Anxiety Scale (HAMA) total score ⩾ 18 points participated and received 160 or 80 mg Silexan, 20 mg paroxetine, or placebo once daily for 10 wk. The primary efficacy endpoint was the HAMA total score reduction between baseline and treatment end. The HAMA total score decreased by 14.1 ± 9.3 points for Silexan 160 mg/d, 12.8 ± 8.7 points for Silexan 80 mg/d, 11.3 ± 8.0 points for paroxetine, and 9.5 ± 9.0 points for placebo (mean ± s.d.). Silexan 160 and 80 mg/d were superior to placebo in reducing the HAMA total score (p < 0.01) whereas paroxetine showed a trend towards significance (p = 0.10) in the full analysis set. The difference between paroxetine and placebo was more pronounced in the analysis of observed cases (HAMA total score reduction: p < 0.01). In the Silexan 160 mg/d group 73/121 patients (60.3%) showed a HAMA total score reduction ⩾ 50% of the baseline value and 56 (46.3%) had a total score <10 points at treatment end, compared to 70/135 (51.9%) and 45 (33.3%) for Silexan 80 mg/d, 57/132 (43.2%) and 45 (34.1%) for paroxetine, and 51/135 (37.8%) and 40 (29.6%) for placebo. In addition, Silexan showed a pronounced antidepressant effect and improved general mental health and health-related quality of life. Incidence densities of adverse events (AEs) were 0.006 AEs/d for Silexan 160 mg/d, 0.008 AEs/d for 80 mg/d, 0.011 AEs/d for paroxetine, and 0.008 AEs/d for placebo. In GAD Silexan is more efficacious than placebo. AE rates for Silexan were comparable to placebo and lower than for the active control paroxetine.

A case series on the use of lavendula oil capsules in patients suffering from major depressive disorder and symptoms of psychomotor agitation, insomnia and anxiety

OBJECTIVE

Symptoms of agitation, anxiety and insomnia are frequent among patients with major depressive disorder (MDD) during the first weeks of psychiatric care. But a substantial number of patients declines taking pharmaceutical medication to avoid side effects. Therefore, an alternative herbal medication is needed. Clinical studies demonstrated that lavender oil capsules, termed Lasea®, have an anxiolytic effect comparable to Lorazepam and significantly reduce insomnia and agitation in non-depressed patients. Therefore, the aim of this retrospective case series was to analyze the effectiveness of Lasea® for patients with MDD and symptoms of anxiety, insomnia and psychomotor agitation.

DESIGN

Eight cases were analyzed retrospectively regarding the dosage, length of treatment, possible side effects and effectiveness of Lasea®.

SETTING

All cases were treated at the Department of Psychiatry at Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin in a naturalistic setting.

MAIN OUTCOME MEASURE

Effectiveness was measured by a change in the Hamilton Rating Scale for Depression (HAMD-17) total score and subscores.

RESULTS

In 6 cases, the combination of Lasea® and an antidepressant resulted in a reduction of MDD. Lasea® also reduced agitation in 6 cases. Psychological anxiety was reduced in 5, somatic anxiety in 4 cases whereas sleep-onset and sleep-maintenance insomnia improved in 3 cases each.

CONCLUSIONS

The results demonstrate that Lasea® reduces some of the anxiety related symptoms and sleep disturbances in MDD patients. Furthermore Lasea® significantly reduces psychomotor agitation. Additionally, the results indicate a significant global improvement stemming from the combinational therapy of Lasea® and antidepressant medication.

A randomized, controlled cross-over trial of dermally-applied lavender (Lavandula angustifolia) oil as a treatment of agitated behaviour in dementia

BACKGROUND

Lavender essential oil shows evidence of sedative properties in neurophysiological and animal studies but clinical trials of its effectiveness as a treatment of agitation in people with dementia have shown mixed results. Study methods have varied widely, however, making comparisons hazardous. To help remedy previous methodological shortcomings, we delivered high grade lavender oil in specified amounts to nursing home residents whose agitated behaviours were recorded objectively.

METHODS

64 nursing home residents with frequent physically agitated behaviours were entered into a randomized, single-blind cross-over trial of dermally-applied, neurophysiologically active, high purity 30% lavender oil versus an inactive control oil. A blinded observer counted the presence or absence of target behaviours and rated participants' predominant affect during each minute for 30 minutes prior to exposure and for 60 minutes afterwards.

RESULTS

Lavender oil did not prove superior to the control oil in reducing the frequency of physically agitated behaviours or in improving participants' affect.

CONCLUSIONS

Studies of essential oils are constrained by their variable formulations and uncertain pharmacokinetics and so optimal dosing and delivery regimens remain speculative. Notwithstanding this, topically delivered, high strength, pure lavender oil had no discernible effect on affect and behaviour in a well-defined clinical sample.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN 12609000569202).

An orally administered lavandula oil preparation (Silexan) for anxiety disorder and related conditions: an evidence based review

OBJECTIVE

Silexan is a lavender oil preparation in gelatine capsules containing 80 mg. We reviewed the clinical trials investigating the anxiolytic efficacy and tolerability of Silexan as well as its safety and potential for drug interactions.

METHODS

Seven trials were included, among which four therapeutic trials had a treatment duration of 6 or 10 weeks.

RESULTS

In patients with subsyndromal anxiety or generalised anxiety disorder (GAD) an anxiolytic effect of Silexan was evident after 2 weeks. Patients treated with Silexan showed Hamilton Anxiety Scale (HAMA) total score decreases between 10.4 ± 7.1 and 12.0 ± 7.2 points at Week 6 and between 11.8 ± 7.7 and 16.0 ± 8.3 points at Week 10.

CONCLUSIONS

HAMA total score reductions between baseline and end of treatment were significantly superior to placebo in patients with subsyndromal anxiety and comparable to lorazepam in its starting dose in patients with GAD. Silexan had beneficial effects on typical co-morbidity symptoms of anxiety disorders, for example, disturbed sleep, somatic complaints, or decreased quality of life. Except for mild gastrointestinal symptoms, the drug was devoid of adverse effects and did not cause drug interactions or withdrawal symptoms at daily doses of 80 or 160 mg.

The best next drug in the course of generalized anxiety disorders: the "PN-GAD-algorithm"

OBJECTIVE

Today, there are many pharmacotherapeutic options for generalized anxiety disorder (GAD). The question is, which is the best medication for a particular patient at a particular moment? This is especially challenging because GAD is by definition a chronic disorder and new interventions should learn from earlier experiences. An algorithm which can help to use pretreatment information for drug selection is the "Pretreatment - Next Treatment (PN) - Algorithm". This article introduces an PN-algorithm for GAD.

METHODS AND RESULTS

For the development of a GAD-specific PN-algorithm, all possible pharmacological options for GAD are reviewed and brought into a rank order on the basis of scientific evidence regarding efficacy, tolerability, or price: (1) pregabalin, (2) venlafaxine XR, (3) selective serotonin reuptake inhibitors, (4) tricyclic antidepressants, (5) buspirone, (6) antipsychotics, (7) benzodiazepines, and (8) hydroxyzine. Based on this hierarchy and patient-specific information, a decision algorithm is derived, which allows to assess and evaluate pretreatment and to select the drug with no contraindications, limited negative or convincing positive effects, or the option which has not been used so far but which is the next compound in the hierarchy.

CONCLUSIONS

The "PN-GAD-algorithm" can be easily translated into a checklist to support clinical decision-making. It can also help to increase patient empowerment and cooperation in long-term treatment.

Lavender oil-potent anxiolytic properties via modulating voltage dependent calcium channels

Recent clinical data support the clinical use of oral lavender oil in patients suffering from subsyndromal anxiety. We identified the molecular mechanism of action that will alter the perception of lavender oil as a nonspecific ingredient of aromatherapy to a potent anxiolytic inhibiting voltage dependent calcium channels (VOCCs) as highly selective drug target. In contrast to previous publications where exorbitant high concentrations were used, the effects of lavender oil in behavioral, biochemical, and electrophysiological experiments were investigated in physiological concentrations in the nanomolar range, which correlate to a single dosage of 80 mg/d in humans that was used in clinical trials. We show for the first time that lavender oil bears some similarities with the established anxiolytic pregabalin. Lavender oil inhibits VOCCs in synaptosomes, primary hippocampal neurons and stably overexpressing cell lines in the same range such as pregabalin. Interestingly, Silexan does not primarily bind to P/Q type calcium channels such as pregabalin and does not interact with the binding site of pregabalin, the α2δ subunit of VOCCs. Lavender oil reduces non-selectively the calcium influx through several different types of VOCCs such as the N-type, P/Q-type and T-type VOCCs. In the hippocampus, one brain region important for anxiety disorders, we show that inhibition by lavender oil is mainly mediated via N-type and P/Q-type VOCCs. Taken together, we provide a pharmacological and molecular rationale for the clinical use of the oral application of lavender oil in patients suffering from anxiety.

The diagnosis and treatment of generalized anxiety disorder

BACKGROUND

Generalized anxiety disorder (GAD) is a common and serious disease with a lifetime prevalence of 4.3% to 5.9%. It is underdiagnosed in primary care.

METHODS

Recommendations on the treatment of GAD are given on the basis of all available findings from pertinent randomized trials, retrieved by a selective search of the literature.

RESULTS

Among psychotherapeutic techniques, various kinds of cognitive behavioral therapy (CBT) have been found useful in controlled trials. The drugs of first choice include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephine reuptake inhibitors (SNRIs), and the calcium-channel modulator pregabalin. Tricyclic antidepressants are also effective but have more adverse effects than SSRIs. Although benzodiazepines are effective anxiolytic agents for short-term use, they should not be given over the long term because of the danger of addiction. Buspirone, an azapirone, was found to be effective in a small number of trials, but the findings across trials are inconsistent. The response rate of GAD to CBT in published studies lies between 47% and 75%, while its response rate to drug treatment lies between 44% and 81%.

CONCLUSION

The treatment of GAD with CBT and drugs is evidence-based and has a good chance of improving the manifestations of the disorder.

Neuroprotective effects of inhaled lavender oil on scopolamine-induced dementia via anti-oxidative activities in rats

Lavender is used in traditional medicines in Asia, Europe, ancient Greece and Rome, and was mentioned in the Bible and in ancient Jewish texts. Also, lavender is reported to be an effective medical plant in treating inflammation, depression, stress and headache. The present study was undertaken in order to investigate the antioxidant and antiapoptotic activities of the lavender essential oils from Lavandula angustifolia ssp. angustifolia Mill. and Lavandula hybrida Rev. using superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) specific activities, total content of reduced glutathione (GSH), malondialdehyde (MDA) level (lipid peroxidation) and DNA fragmentation assays in male Wistar rats subjected to scopolamine-induced dementia rat model. In scopolamine-treated rats, lavender essential oils showed potent antioxidant and antiapoptotic activities. Subacute exposures (daily, for 7 continuous days) to lavender oils significantly increased antioxidant enzyme activities (SOD, GPX and CAT), total content of reduced GSH and reduced lipid peroxidation (MDA level) in rat temporal lobe homogenates, suggesting antioxidant potential. Also, DNA cleavage patterns were absent in the lavender groups, suggesting antiapoptotic activity. Taken together, our results suggest that antioxidant and antiapoptotic activities of the lavender essential oils are the major mechanisms for their potent neuroprotective effects against scopolamine-induced oxidative stress in the rat brain.

Lavender and the nervous system

Lavender is traditionally alleged to have a variety of therapeutic and curative properties, ranging from inducing relaxation to treating parasitic infections, burns, insect bites, and spasm. There is growing evidence suggesting that lavender oil may be an effective medicament in treatment of several neurological disorders. Several animal and human investigations suggest anxiolytic, mood stabilizer, sedative, analgesic, and anticonvulsive and neuroprotective properties for lavender. These studies raised the possibility of revival of lavender therapeutic efficacy in neurological disorders. In this paper, a survey on current experimental and clinical state of knowledge about the effect of lavender on the nervous system is given.

Characterization of anxiolytic and neuropharmacological activities of Silexan

Silexan is an essential oil produced from Lavandula angustifolia flowers with proven clinical efficacy for the treatment of anxiety disorders. The present study was conducted to assess its anxiolytic activity and to screen for neuropharmacological properties in rats and mice of either sex. Silexan (3, 10, and 30 mg/kg, intraperitoneally), lorazepam (5 mg/kg, p.o.), or diazepam (3 mg/kg, p.o.) were administered once daily for 7 consecutive days. Experiments were conducted 1 h after the last drug or vehicle administration. All the three doses of Silexan showed significant and dose-dependent anxiolytic activity in the used pharmacological models (open-field test, elevated plus-maze test, elevated zero-maze test, social interaction test, and novelty-induced suppressed feeding latency test), which was comparable to that of the standard anxiolytic agent lorazepam. In addition, Silexan amplified pentobarbital-induced sleeping time, but in contrast to diazepam was found to be devoid of any significant effect on locomotor activity and muscle-grip performance.

Effects of lavender oil inhalation on improving scopolamine-induced spatial memory impairment in laboratory rats

Lavender is reported to be an effective medical plant in treating inflammation, depression, stress and mild anxiety in Europe and the USA. The present study investigated the effects of two different lavender essential oils from Lavandula angustifolia ssp. angustifolia Mill. (Lamiaceae) and Lavandula hybrida Rev. (Lamiaceae) on neurological capacity of male Wistar rats subjected to scopolamine (0.7mg/kg)-induced dementia rat model. Chronic exposures to lavender essential oils (daily, for 7 continuous days) significantly reduced anxiety-like behavior and inhibited depression in elevated plus-maze and forced swimming tests, suggesting anxiolytic and antidepressant activity. Also, spatial memory performance in Y-maze and radial arm-maze tasks was improved, suggesting positive effects on memory formation. Taken together, multiple exposures to lavender essential oils could effectively reverse spatial memory deficits induced by dysfunction of the cholinergic system in the rat brain and might provide an opportunity for management neurological abnormalities in dementia conditions.

Effects of a high-fat diet and bamboo extract supplement on anxiety- and depression-like neurobehaviours in mice

High-fat diet is a major causative factor of overweight and obesity, which are associated with an increased risk of neuropsychiatric diseases, such as anxiety and depression. In the present study, we investigated the protective effects of bamboo extract (BEX) on anxiety- and depression-like neurobehaviours in mice treated with a high-fat diet. Male mice with CD-1 genetic background were treated for 2 months with either a standard or a high-fat diet (10 or 45 % energy from fat, respectively), with or without the BEX supplement (11 g dry mass per 17 MJ). The anxiety levels of mice were evaluated using open-field and hole-board tests, and depression was measured using the force-swimming test. The anxiety responses of the animals were found significantly increased after the high-fat diet treatment, and this elevation was effectively abolished by the BEX supplement. The high-fat diet seemed to have an anti-depressive effect in mice at the tested time point, but the effect of the BEX supplement on the depression level of the animals was not conclusive. The high-fat diet significantly decreased total glutathione content in the blood while the BEX supplement increased glutathione oxidation. In summary, the present study shows that decreased total glutathione concentration in the blood co-occurred with a high-fat treatment, high anxiety level and low depression level in mice, and when supplemented in a high-fat diet, BEX had an anxiolytic effect in mice.

Genetic differences in temperament determine whether lavender oil alleviates or exacerbates anxiety in sheep

Growing concerns about the risk of addiction to benzodiazepines have led to increasing interest in alternative therapies to treat anxiety and depression. Lavender oil (Lavendula augustifolia) is reportedly anxiolytic in a number of species but little is known about how it affects individuals that are more or less anxious when faced with a stressor. In this study, we used changes in locomotor activity and the plasma concentrations of cortisol to test whether lavender oil would reduce behavioral and endocrine correlates of anxiety in calm and nervous sheep exposed to an isolation stressor. During the non-breeding season, 'calm' or 'nervous' female sheep from the UWA temperament flock were exposed to a mask containing either 1 mL of 10% lavender oil (calm: n=8; nervous: n=8) or peanut oil (calm: n=8; nervous: n=8). After 30 min, each sheep was isolated for 5 min and then returned to the group. Blood was sampled prior to the mask, prior to isolation, 1 min and 30 min after isolation to profile changes in the plasma concentrations of cortisol. Agitation score, locomotor activity and vocalizations were recorded as correlates of anxiety associated with the isolation stressor. Irrespective of whether they were exposed to lavender oil, calm sheep had a lower agitation score (P<0.001), crossed the central lines of the isolation box less frequently (P<0.001), expressed fewer vocalizations (P<0.001) and had lower plasma concentrations of cortisol immediately after isolation (P<0.001) than nervous sheep. Exposure of calm sheep to lavender oil decreased the agitation score (P<0.001), frequency of vocalizations (P<0.05), decreased the number of crosses of the central lines of the isolation box (P<0.05), and the plasma concentrations of cortisol prior to isolation (P<0.05) (after mask application) compared to calm control sheep. Exposure of nervous sheep to lavender oil increased the frequency of vocalizations (P<0.05), the number of sheep attempting to escape (P<0.05) and the plasma concentrations of cortisol 30 min after isolation (P<0.05) compared to nervous control sheep. We conclude that genetic differences in temperament determine whether lavender oil alleviates or exacerbates the behavioral and/or endocrine correlates of anxiety in sheep.

[Silexan and narcosis : case report and possibilities of preoperative and perioperative management]

The increased use of phytotherapeutic drugs means that anesthetists are more often confronted with these drugs. In this case report possible problems which can occur are demonstrated exemplified by silexan. Silexan is a phytotherapeutic anxiolytic which is used in anxiety disorders. Because of its potential mechanism of action via the neurotransmitter gamma-aminobutyric acid (GABA) receptors interactions with narcotic drugs are possible. The case of an 18-year-old girl who underwent an operation under general anesthesia while taking silexan as long-term medication is presented. The desired depth of narcosis could only be reached by inhalative induction with sevoflurane after unsuccessful induction attempts using intravenous propofol and thiopental. Possible explanations for this route and inhalative induction as a possible alternative are discussed.