Article

Effect of "Rose Essential Oil" Inhalation on Stress-Induced Skin-Barrier Disruption in Rats and Humans

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

In stressed animals, several brain regions (e.g., hypothalamic paraventricular nucleus [PVN]) exhibit neuronal activation, which increases plasma adrenocorticotropic hormone (ACTH) and glucocorticoids. We previously reported that so-called "green odor" inhibits stress-induced activation of the hypothalamo-pituitary-adrenocortical axis (HPA axis) and thereby prevents the chronic stress-induced disruption of the skin barrier. Here, we investigated whether rose essential oil, another sedative odorant, inhibits the stress-induced 1) increases in PVN neuronal activity in rats and plasma glucocorticoids (corticosterone [CORT] in rats and cortisol in humans) and 2) skin-barrier disruption in rats and humans. The results showed that in rats subjected to acute restraint stress, rose essential oil inhalation significantly inhibited the increase in plasma CORT and reduced the increases in the number of c-Fos-positive cells in PVN. Inhalation of rose essential oil significantly inhibited the following effects of chronic stress: 1) the elevation of transepidermal water loss (TEWL), an index of the disruption of skin-barrier function, in both rats and humans and 2) the increase in the salivary concentration of cortisol in humans. These results suggest that in rats and humans, chronic stress-induced disruption of the skin barrier can be limited or prevented by rose essential oil inhalation, possibly through its inhibitory effect on the HPA axis.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... For instance, Lehrner et al. (2005) reported that ambient odors of orange and lavender reduced anxiety and improved mood in patients awaiting medical treatment. Common anxiety-reducing odors found effective for both humans and rodents include lavender, orange, rose, and citrus (Chioca et al. 2013;de Almeida et al. 2004;Faturi et al. 2010;Fukada et al. 2012;Kuriyama et al. 2005;Kiecolt-Glaser et al. 2008;Lehrner et al. 2005;Razaghi et al. 2020;Viana et al. 2016). Furthermore, De Almeida e al. (2004) found that the anxiolytic efficacy of such pleasant odors was equivalent to that of diazepam as measured by frequency of visits and time spent on the open arms of an elevated plus maze (EPM). ...
... However, to our knowledge, previous rodent studies have focused only on novel odors (de Almeida et al. 2004;Faturi et al. 2010;Fukada et al. 2012), so it remains unclear if the anxiolytic responses to familiar odors can be enhanced by association with positive experiences. To address this issue, we compared the anxiolytic effects of novel odors to odors previously paired with positive experiences (maternal care) in female and male rats. ...
... Nonetheless, males as well as females showed some signs of anxiety reduction during odorant stimulation. In the EPM, female rats made a larger number of partial (forepaw only) open arm entries during both familiar and novel odor stimulation compared to air stimulation, whereas male rats exhibited reduced grooming frequency in the OFT under both novel and familiar odor conditions, consistent with previous studies demonstrating the anxiolytic effects of novel as well as familiar odors (de Almeida et al. 2004;Faturi et al. 2010;Fukada et al. 2012;Hansson et al. 2011;Labonte et al. 2012;Moody et al. 1988;Viana et al. 2016). In contrast to memory-based anxiolytic effects, perception-based (or experience-independent) anxiolytic effects showed no marked sex differences, suggesting distinct neurological mechanisms and (or) differential sensitivity to hormonal influences. ...
Article
Odor stimuli are widely reported to promote relaxation and reduce anxiety in humans and rodents. However, it remains unclear if this anxiolytic efficacy can be further enhanced by association with positive experiences. Therefore, we compared the effects of a novel odor to a familiar odor previously paired with a positive experience on anxiety-like behaviors in rats. One group of Wistar–Imamichi female and male pups was exposed to an odor stimulus with their dams during postnatal days (PNDs) 8–12, whereas another control group was exposed to perfused air during the same period. Starting on PND 42, all animals were examined in the open field test (OFT) and elevated plus maze (EPM) test during exposure to scent-free air (vehicle), a novel odor, or the positive-familiar odor from postnatal exposure. In the EPM, female rats entered open arms with all 4 paws (complete entry) more frequently and spent more time on open arms during exposure to the positive-familiar odor than during exposure to air or a novel odor, whereas partial open arm entries with forepaws only were increased during exposure to both novel and positive-familiar odors compared to air. In contrast, male rats demonstrated no significant increase in open arm activity during positive-familiar odor exposure, but did show equally reduced grooming frequency during novel and familiar-positive odor exposure in the OFT. Exposure to positive-familiar odors may be an effective and safe method for anxiety reduction, especially in females.
... After inhaling an essential oil mixture of bergamot, geranium, lavender, and clary sage, the EEG of a middle-aged woman under stress revealed that alpha waves were significantly increased in the left and right prefrontal cortex [15]. In addition, it has been reported that inhalation of rose essential oil inhibited the increase in salivary cortisol levels in healthy college students exposed to stress [16]. Igarashi et al. [17] used near-infrared spectroscopy (NIRS) to reveal that the olfactory stimulation using rose oil and orange oil significantly decreased the concentration of oxyhemoglobin in the left and right prefrontal cortex. ...
... This method records electrophysiological signals generated by brain activity by attaching a sensor to the surface of the scalp. The electrical signals mentioned correspond to the following frequency bands: delta (0-4 Hz), theta (4-8 Hz), alpha (8)(9)(10)(11)(12) and beta (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Human actions, thoughts, and emotions can alter the brain wave activity at different frequencies. ...
... This method records electrophysiological signals generated by brain activity by attaching a sensor to the surface of the scalp. The electrical signals mentioned correspond to the following frequency bands: delta (0-4 Hz), theta (4-8 Hz), alpha (8-12 Hz) and beta (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Human actions, thoughts, and emotions can alter the brain wave activity at different frequencies. ...
Article
Full-text available
This study investigated the effects of olfactory stimulation with aroma oils on the psychophysiological responses in women. Ten aromatic oils (lavender, rosemary, rose, eucalyptus, jasmine, geranium, chamomile, clary sage, thyme, and peppermint) were used on 23 women aged between 20 and 60 years. They inhaled the scent for 90 s through a glass funnel attached to their lab apron, 10 cm below their nose, while the pump was activated. Electroencephalography, blood pressure, and pulse rate were measured before and during inhalation of the aroma oils. The relative alpha (RA) power spectrums indicating relaxation and resting state of the brain significantly increased when lavender, rosemary, eucalyptus, jasmine, chamomile, clary sage, and thyme oils were inhaled compared to those of before olfactory stimulation. The ratio of alpha to high beta (RAHB), an indicator of brain stability and relaxation, significantly increased when rosemary, jasmine, clary sage, and peppermint oils were inhaled. The relative low beta (RLB) power spectrum, an indicator of brain activity in the absence of stress, significantly increased when stimulated with lavender, rosemary, rose, and geranium scents. Further, systolic blood pressure significantly decreased after introduction of all 10 types of aromatic oils, which indicates stress reduction. Thus, olfactory stimulation with aroma oil had a stabilizing effect on the prefrontal cortex and brain activity and decreased systolic blood pressure.
... This is especially important since congruency between visual and olfactory information mediates the activation of crossmodal semantic representations much stronger than each sensory modality on its own [43]. Previous findings in psychology also showed the arousing [5,39,23] and relaxing [31,28,20,15] effects of different scents on humans, which is very important to consider in the design of interactive olfactory interfaces in HCI. This prior work indicates the potential to convey basic, but yet informative messages, to a person (i.e. ...
... These five stimuli were selected based on prior work. Lavender and rose demonstrated a relaxing effect on people (see [31,28,20,15]), while lemon and peppermint were used to increase alertness (see [5,39,23]). The scents of lemon and peppermint have already been extensively used in a number of simulated driving studies [30,5,39,49,36,16]. ...
... In Study 1, both this message and the scent of rose were rated most relaxing. Such perception of the rose scent also matches the results from the previous work [20,15]. ...
Conference Paper
Full-text available
The sense of smell is well known to provide very vivid experiences and to mediate a strong activation of crossmodal semantic representations. Despite a growing number of olfactory HCI prototypes, there have been only a few attempts to study the sense of smell as an interaction modality. Here, we focus on the exploration of olfaction for in-car interaction design by establishing a mapping between three different driving-related messages ("Slow down", "Fill gas", "Passing by a point of interest") and four scents (lemon, lavender, peppermint, rose). The results of our first study demonstrate strong associations between, for instance, the "Slow down" message and the scent of lemon, the "Fill gas" message and the scent of peppermint, the "Passing by a point of interest" message and the scent of rose. These findings have been confirmed in our second study, where participants expressed their mapping preferences while performing a simulated driving task.
... Similarly, anxiolytic effects have been described during labor, when rose essential oil is inhaled and used in footbaths [32]. In this concern, it has been suggested that these effects could be mediated by the action of the aromatic extract on the HPA axis, since its exposure decreases salivary cortisol levels in healthy female students subjected either to chronic or acute stressful situations [33]. Animal studies using rose odor have also evidenced its positive influence on behavior. ...
... Rose essential oil has an anti-conflict effect in ICR male mice [34], a potential anxiolytic effect in Wistar male rats [35], and in Mongolian gerbils [36]. Similar to human data, acute rose essential oil inhalation decreases GC plasma levels in rats subjected to acute restraint stress [33], and reduces adrenocorticotropic hormone plasma levels in C57BL/6J male mice exposed to predator odor [37]. Most importantly, it has been pointed out that the anxiolytic profile of rose odor strengthens after chronic inhalation in rodents [36]. ...
Article
Full-text available
Chronic distress-induced hypothalamic-pituitary-adrenal axis deregulations have been associated with the development of neuropsychiatric disorders such as anxiety and depression. Currently available drugs treating such pathological conditions have limited efficacy and diverse side effects, revealing the need of new safer strategies. Aromatic plant-based compounds are largely used in herbal medicine due to their therapeutic properties on mood, physiology, and general well-being. The purpose of this study was to investigate the effects of 2-phenylethyl alcohol (PEA), one of the pharmacologically active constituents of rose essential oil, on chronic corticosterone (CORT)-induced behavioral and neurobiological changes in female mice. Animals followed a prolonged PEA inhalation exposure (30 min per day) for 15 consecutive days prior to behavioral evaluation with open-field, forced swim and novelty-suppressed feeding tests. CORT treatment induced an anxio-depressive-like phenotype, evidenced by a reduced locomotor activity in the open-field, and an increased latency to feed in the novelty-suppressed feeding paradigms. To elucidate the neural correlates of our behavioral results, immunohistochemistry was further performed to provide a global map of neural activity based on cerebral cFos expression. The altered feeding behavior was accompanied by a significant decrease in the number of cFos-positive cells in the olfactory bulb, and altered functional brain connectivity as shown by cross-correlation-based network analysis. CORT-induced behavioral and neurobiological alterations were reversed by prolonged PEA inhalation, suggesting a therapeutic action that allows regulating the activity of neural circuits involved in sensory, emotional and feeding behaviors. These findings might contribute to better understand the therapeutic potential of PEA on anxio-depressive symptoms.
... Similarly, anxiolytic effects have been described during labor, when rose essential oil is inhaled and used in footbaths [32]. In this concern, it has been suggested that these effects could be mediated by the action of the aromatic extract on the HPA axis, since its exposure decreases salivary cortisol levels in healthy female students subjected either to chronic or acute stressful situations [33]. Animal studies using rose odor have also evidenced its positive influence on behavior. ...
... Rose essential oil has an anti-conflict effect in ICR male mice [34], a potential anxiolytic effect in Wistar male rats [35], and in Mongolian gerbils [36]. Similar to human data, acute rose essential oil inhalation decreases GC plasma levels in rats subjected to acute restraint stress [33], and reduces adrenocorticotropic hormone plasma levels in C57BL/6J male mice exposed to predator odor [37]. Most importantly, it has been pointed out that the anxiolytic profile of rose odor strengthens after chronic inhalation in rodents [36]. ...
Preprint
Full-text available
Chronic distress-induced hypothalamic-pituitary-adrenal axis deregulations have been associated with the development of neuropsychiatric disorders such as anxiety and depression. Currently available drugs treating such pathological conditions have limited efficacy and diverse side effects, revealing the need of new safer strategies. Aromatic plant-based compounds are largely used in herbal medicine due to their therapeutic properties on mood, physiology, and general well-being. The purpose of this study was to investigate the effects of 2-phenylethyl alcohol (PEA), one of the pharmacologically active constituents of rose essential oil, on chronic corticosterone (CORT)-induced behavioral and neurobiological changes in female mice. Animals followed a prolonged PEA inhalation exposure (30 min per day) for 15 consecutive days prior to behavioral evaluation with open-field, forced swim and novelty-suppressed feeding tests. CORT treatment induced an anxio-depressive-like phenotype, evidenced by a reduced locomotor activity in the open-field, and an increased latency to feed in the novelty-suppressed feeding paradigms. To elucidate the neural correlates of our behavioral results, cerebral cFos expression analysis was further performed to provide a global map of neuronal activity. The altered feeding behavior was accompanied by a significant decrease in the number of cFos-positive cells in the olfactory bulb, and altered brain connectivity as shown by cross-correlation-based network analysis. CORT-induced behavioral and neurobiological alterations were reversed by prolonged PEA inhalation, suggesting a therapeutic action that allows regulating the activity of neural circuits involved in sensory, emotional and feeding behaviors. These findings might contribute to better understand the therapeutic potential of PEA on anxio-depressive symptoms.
... Antiacne citronella grass Cymbopogon nardus [142] palmarosa Cymbopogan martini [144] Artemisin Artemisia annua [143] Geranium Geranium rotundifolium [148] n.a. 1 Nigella sativa [146] Skin aging geranium Geranium rotundifolium [148] patchouli Pogostemon cablin [149] nutmeg Myristica fragrans [149] citronella Cymbopogon nardus [149] Clove Syzygium aromaticum [149] n.a. 1 Pluchea dioscoridis [150] n.a. 1 Erigeron bonariensis [150] shell ginger Alpinia zerumbet [151] lemon Citrus lemon [152] lavender Lavandula officinalis [153] Sage Salvia officinalis [153] rosehip Rosa canina [154] carrot Daucus carota [57] Anti-wrinkle patchouli Pogostemon cablin [149,155] nutmeg Myristica fragrans [149] citronella Cymbopogon nardus [149] Clove Syzygium aromaticum [149] ylang-ylang Cananga odorata [156] carrot Daucus carota [57] neroli Citrus sinensis [157] rosehip Rosa canina [154] Moisturizer n.a. 1 Hypericum perforatum [117] rosehip Rosa canina [158][159][160] sandalwood Santalum spicatum [161] chamomile Matricaria chamomilla [162] Oily skin geranium Geranium rotundifolium [141] neroli Citrus sinensis [157] ylang-ylang Cananga odorata [156] 1 There is no defined a name for the specific essential oil. ...
... The moisturizing role in the latter essential oil is ascribed to its high content in azulene [141,162]. However, rose essential oil has been reported as the most powerful substance for maintaining the moisture loss from skin, becoming an essential component of formulations for keeping skin hydration, lightening dark spots, eliminating pimples, and reducing fine lines and wrinkles [159,160]. The latter effect has been also ascribed to patchouli and ylang-ylang essential oil, with the later contributing also to tissue regeneration [155,156]. ...
Article
Full-text available
The current consumer demands together with the international regulations have pushed the cosmetic industry to seek new active ingredients from natural renewable sources for manufacturing more eco-sustainability and safe products, with botanical extract being an almost unlimited source of these new actives. Essential oils (EOs) emerge as very common natural ingredients in cosmetics and toiletries as a result of both their odorous character for the design and manufacturing of fragrances and perfumes, and the many beneficial properties of their individual components (EOCs), e.g., anti-inflammatory, antimicrobial and antioxidant properties, and, nowadays, the cosmetic industry includes EOs or different mixtures of their individual components (EOCs), either as active ingredients or as preservatives, in various product ranges (e.g., moisturizers, lotions and cleanser in skin care cosmetics; conditioners, masks or antidandruff products in hair care products; lipsticks, or fragrances in perfumery). However, the unique chemical profile of each individual essential oil is associated with different benefits, and hence it is difficult to generalize their potential applications in cosmetics and toiletries, which often require the effort of formulators in seeking suitable mixtures of EOs or EOCs for obtaining specific benefits in the final products. This work presents an updated review of the available literature related to the most recent advances in the application of EOs and EOCs in the manufacturing of cosmetic products. Furthermore, some specific aspects related to the safety of EOs and EOCs in cosmetics will be discussed. It is expected that the information contained in this comprehensive review can be exploited by formulators in the design and optimization of cosmetic formulations containing botanical extracts.
... The stress-suppressing effects of certain smell have been recognized, and the effects of fragrances on human psychophysiological activity have been studied for a long time [10]. Granqvist et al. [9] pointed out that, in stressful situations, access to adult attachment figures (e.g., ro- [118] Thyme Several lines of evidence in human studies suggest the stress suppression effects of essential oils, such as lavender [82][83][84][85][86], rose [91], rosemary [86], bergamot [93][94][95], chamomile [83], grapefruit [97], and neroli (Citrus aurantium L. var. amara) obtained from the flowers of bitter orange [98]. ...
... Li et al. [113] demonstrated that lemongrass oil and its major component, citral, may affect the activities of drug-metabolizing enzymes and reduce the oxidative stress in the liver. Fukada et al. [91] reported that the destruction of the skin barrier due to chronic stress can be restricted or prevented by rose essential oil inhalation on the HPA axis in rats and human. Sadiki et al. [114] demonstrated that the essential oil of Tetraclinis (Tetraclinis articulata) could be a potent pharmacological agent against dementia by modulating the cholinergic activity and promoting antioxidant action in the rat hippocampus. ...
Article
Full-text available
The stress response in the brain is not fully understood, although stress is one of the risk factors for developing mental disorders. On the other hand, the stimulation of the olfactory system can influence stress levels, and a certain smell has been empirically known to have a stress-suppressing effect, indeed. In this review, we first outline what stress is and previous studies on stress-responsive biomarkers (stress markers) in the brain. Subsequently, we confirm the olfactory system and review previous studies on the relationship between smell and stress response by species, such as humans, rats, and mice. Numerous studies demonstrated the stress-suppressing effects of aroma. There are also investigations showing the effects of odor that induce stress in experimental animals. In addition, we introduce recent studies on the effects of aroma of coffee beans and essential oils, such as lavender, cypress, α-pinene, and thyme linalool on the behavior and the expression of stress marker candidates in the brain. The transfer of volatile components into the brain is also discussed while using the results of thyme linalool as an example. These studies may provide a good opportunity to connect chemical research at the molecular level with neuropharmacological approaches in the future.
... Rose flower is widely used in aromatherapy to bring emotional well-being or reduce nervous tension and stress-related problems, as supported by clinical studies [24,37]. A role in reinforcing the skin barrier function has also been clearly demonstrated [38]. Although the benefits of rose oil are known to be mediated through the olfactory system [39], OR involvement is rarely mentioned. ...
... A decrease in the appearance of under-eye dark circles, compared to a placebo, can be observed after both 7 days (−7.2%) and 28 days (−6.5%), in a panel of women volunteers with fine lines on the upper cheeks and a stressful lifestyle. If rose oil was already known to induce relaxing effects following transdermal adsorption [24] and to limit chronic stress-induced disruption of the skin barrier after inhalation [38], the current study adds new scientific data on the benefits of using a specific rose extract in topical application. ...
Article
Full-text available
Olfactory receptors (ORs) are expressed and active in various human tissues, including the skin. Although the sense of smell plays an important physiological role in the regulation of mood and stress, a link between olfactive compounds, ORs, and skin stress has yet to be established. This study aims to investigate the role of newly identified skin ORs and agonists in the modulation of skin stress. Screening for odorant molecules was done with cAMP functional assay to identify OR agonists. RT-qPCR and immunofluorescence microscopy were conducted to identify and quantify ORs in epidermal keratinocytes (NHEKs) and human skin explants, as well as to evaluate specific markers (G6PDH, loricrin, and γH2AX) of stress-induced skin alterations. A randomized double-blinded, split-face clinical study was performed on a panel of stressed women to measure the benefits of OR agonist treatment for skin. Three new ORs (OR10A6, OR2AG2, and OR11H4) were identified in skin. A specific Rose extract and its major constituent (phenylethyl alcohol) were found to activate these ORs. The extract composition was revealed by both GC/FID and GC/MS analyses simultaneously and showed the presence of 34 volatiles molecules. Moreover, epinephrine induces a skin stress response characterized by increased expression of G6PD, loricrin, and γH2AX biomarkers, and a decrease of OR expression. These effects were prevented in the presence of rose extract and its benefits were confirmed clinically by a decrease in the appearance of under-eye dark circles. Altogether, our findings suggest that ORs may represent a new, promising way to treat stress-associated skin disorders.
... In addition to this, long-term use of RO in high concentrations decreases stress (19). Furthermore, rose extract has analgesic effects in mice (18). ...
... Hypnotic and antiseizure effects of geraniol compounds were shown in behavioral animal studies (29). In a study, researchers demonstrated that citronellol prevents not only the action of convulsants PTZ and picrotoxin, but also preserves the mice against maximal electroshock-evoked seizures (19). ...
Article
ABSTRACT Objective: Rose oil (from Rosa damascene) has several effects which are analgesic, antispasmodic, antioxidant and neuroprotective role. Its antiepileptic effect has not been yet studied enough. In the present study, it was aimed to investigate acute effects of rose oil on the epileptiform activity in penicillin-induced epilepsy model in rats. Methods: Forty-two male Wistar rats weighing 230 to 260 g were divided into six groups with seven rats in each group. Control (+Penicillin), RO alone, Diazepam, and different doses of Rose oil including 100, 500 and 1000 mg/kg. Rats were pretreated with different doses of RO 30 min prior to penicillin treatment. Electrocorticogram recordings were taken from each animal for 2 hours after penicillin treatment. Results: Only the dose of 100 mg/kg of rose oil reduced significantly epileptic spike-wave frequency of epileptiform activity. However, comparing in terms of latency and spike-wave amplitude of epileptiform activity, there were no significant difference between the groups. Conclusions: In conclusion, acute administration of rose oil reduces spike-wave frequency of penicillin-induced epileptiform activity in rats. Therefore, these findings indicate that rose oil has antiepileptic effects.
... Rose oil is also used in the preparation of various skin creams/ointments as a fragrance or perfuming agents. Flowers of R. alba and its essential oil were reported various biological activities like-antioxidant, antimicrobial, [7][8][9] memory enhancing [10,11] , antistress [12] and antiallergic [13,14] . ...
Article
Full-text available
Rosa alba L. is a perennial flowering shrub belonging to the Rosaceae family. Diabetes is treated in Assam, India, with a decoction of its flower. But to date, there is no scientific evidence for its antidiabetic potential. Therefore, in addition to toxicity investigations, the current study aimed to determine its antidiabetic potential to support conventional claims. In-silico toxicity profiling for the phytoconstituents of the plant was predicted as non-toxic, non-mutagenic, and non-carcinogenic in mice and rats. The Total phenolic and total flavonoid contents were determined and found to be higher in the ethanolic extract than in the aqueous extract of the flower. Antidiabetic activity of orally administered aqueous and alcoholic extracts (200 mg/kg body weight) was evaluated against the high-fat diet fed with a low dose of streptozotocin-induced diabetic rats. Treatment of these extracts significantly (p<0.001) reduced the blood glucose level and lipid profile in induced-diabetic rats without affecting their liver and kidney functions. It was also shown that the liver and pancreatic tissues of animals treated with extracts had enhanced histopathologic architecture. The findings of the study revealed that the flowers of R. alba are a safe herbal remedy for controlling diabetes.
... Samples after irradiation showed a significant reduction in the donor potential in comparison with nonirradiated oil, nevertheless in all studied concentrations ability of scavenging DPPH is higher than positive control of quercetin. Both γ-irradiated and non-irradiated oil samples demonstrate an increase in scavenging abilities towards ABTS and NO in a concentration-dependent manner [41,42]. ...
... The olfactory sense also has a strong influence on emotion and wellbeing (Warrenburg, 2005). Different odours have been demonstrated to modulate mood, and feelings of stress and anxiety (Lehrner et al., 2000;Fukada et al., 2011;Kaimal et al., 2020). During and following the years of COVID-19 infection the impact to olfaction due to infection complications became a significant metric for long-COVID effects (Kapoor et al., 2021;Tan et al., 2022;Paranhos et al., 2023). ...
Article
Full-text available
Olfaction is understudied in neuroimaging research compared to other senses, but there is growing evidence of its therapeutic benefits on mood and well-being. Olfactory imagery can provide similar health benefits as olfactory interventions. Harnessing crossmodal visual-olfactory interactions can facilitate olfactory imagery. Understanding and employing these cross-modal interactions between visual and olfactory stimuli could aid in the research and applications of olfaction and olfactory imagery interventions for health and wellbeing. This review examines current knowledge, debates, and research on olfaction, olfactive imagery, and crossmodal visual-olfactory integration. A total of 56 papers, identified using the PRISMA method, were evaluated to identify key brain regions, research themes and methods used to determine the suitability of fNIRS as a tool for studying these topics. The review identified fNIRS-compatible protocols and brain regions within the fNIRS recording depth of approximately 1.5 cm associated with olfactory imagery and crossmodal visual-olfactory integration. Commonly cited regions include the orbitofrontal cortex, inferior frontal gyrus and dorsolateral prefrontal cortex. The findings of this review indicate that fNIRS would be a suitable tool for research into these processes. Additionally, fNIRS suitability for use in naturalistic settings may lead to the development of new research approaches with greater ecological validity compared to existing neuroimaging techniques.
... The aromatic water made from the plant is used as a flavoring agent in the preparation of jam, cake, and drinks [4]. Several scientific approaches determined that R. alba exhibits various pharmacological activities including antioxidant [5], antimicrobial [6], antifertility and teratogenic activity [7], cytotoxic and genotoxic activity [8], memory enhancing activity [9] stress induced skin barrier disruption activity [10], bradykinin antagonist activity [11]. Chemically the plant contains geraniol, heneicosane, nonadecane, citronellol, linalool, β phenylethyl alcohol, nerol, neral, geranial, eugenol, methyleugenol, nonadecene, eicosane, and tricosane [12], tannins, ellagitannins, and flavonoids [13], aliphatic hydrocarbons, minerals, alcohols, aldehydes, monoterpenoids, sesqiterpene, benzyl benzoate, allo-aromadendrene, β selinene [14]. ...
Article
Full-text available
Introduction: rheumatoid arthritis characterized by joint inflammation and pain,affecting millions of peoples around the world. Traditional system of medicine hadproven to be preventive and treating physical and mental illness. Objective: theobjective of the study is to assess anti-arthritic potential of the plant Rosa alba L byconsidering CFA, formaldehyde and turpentine oil induced arthritic model. Materialand Method: ethanolic extract and its ethyl acetate fraction were considered for thestudy and quercetin was quantitatively estimated by high performance thin layer chromatographic(HPTLC) method. Moreover, hematological and biochemical studies(IL-6) were performed in blood and serum of wistar albino rat. Then histopathologicalstudies had also been performed on rat hind paw joint. Result: phytochemicalscreening estimated the presence of carbohydrates, phenolic compounds, flavonoids,phytosterols, amino acids and fixed oil in ethanolic extract and ethyl acetate fraction ofthe plant. Amount of quercetin in the flowers of the plant was found to be 0.26% w/wby quantitative HPTLC method. The level of proinflammatory cytokines, interleukin(IL-6) was considerably decreased (p<0.001) in the fraction treated group of rats at400 mg/kg b.w by considering complete freund’s adjuvant (CFA) induced arthritic model. Conclusion: Ameliorated hematological,hematological, biochemical and histopathologicalparameters confirmed the antiarthritic potential of the plant.
... Clary Sage ↓ | Lavender ↓ | Ylang ylang ↓ | Marjoram ↓ | Neroli ↓ | Rose ↓ | Rosemary ↓ | Limonene ↑↓ | Bergamot ↓ | Basil ↓ | (Atsumi & Tonosaki, 2007), (Ceccarelli et al., 2004), (Choi et al., 2014), (Cho et al., 2013), (Field et al., 2008), (Fukada et al., 2012), (Kim et al., 2012), , (Shiina et al., 2008), (Tang et al., 2019). ...
Article
i>Posttraumatic stress disorder (PTSD) is a multi-faceted, symptomatic mental health diagnosis often accompanied with various physical and psychological comorbidities. The complexity of this diagnosis makes treatment difficult, thereby suggesting that all options, including alternative approaches to care, should be explored. Aromatherapy from plant essential oils is an increasingly utilized integrative health modality. Essential oils are lipophilic, volatile aromatic metabolites in plants consisting of various natural chemical constituents that permeate the blood stream and influence neurobiological responses. This qualitative phenomenological study sought to understand the impact of aromatherapy from Bergamot essential oil on managing PTSD symptomology. A two-week pilot study was conducted consisting of 12 first responder, medical, firefighter and military men and women presenting with symptoms of PTSD in San Diego, California. Data collected from the interviews identified that the bergamot essential oil produced a calming effect, improved sleep, reduced anxiety, increased positive mood, enhanced concentration and reduced avoidance behavior. Participants in the research study reported that aromatherapy of bergamot essential oil helped mitigate certain symptoms of PTSD from the symptom clusters of arousal, negative mood, and avoidance behavior. This modality could help practitioners and treatment clinics facilitate an adaptive recovery, by providing a calm and safe atmosphere to engage with clients to execute trauma focused therapy more effectively. Aromatherapy provides a non-invasive and promising modality that would best serve the mental health field for practitioners and their overseeing organizations to further research, educate and implement this therapy in facilitating an adaptive recovery and management of PTSD symptoms.</i
... In urban humans, for example, physical and mental health is better in people who live on streets with trees (Kardan et al., 2015;Taylor et al., 2015). Window views or photographs of verdant natural scenes can improve well-being, including increasing the health of hospital patients and the self-reported mood of office workers; and even just the smell of plants can be stress-reducing (Fukada et al., 2012;Ulrich, 1984;Weber & Heuberger, 2008;Wise & Taylor, 2002). ...
Article
Current frameworks for designing and evaluating good enclosures and "enrichments" typically focus on animals' active interactions with these features. This has undoubtedly improved the welfare of zoo-housed animals over the last 30 years or more. However, literature reviews from this same period identify persistent gaps in how such frameworks are applied: experiences and behaviors that do not rely on active interaction with stimuli or resources are largely ignored, when evaluating the welfare value of enclosures and enrichments within them. Here, we review research evidence demonstrating that active interaction is not always a reliable measure of welfare value showing that items that elicit little or no interaction can nevertheless still reduce stress and improve well-being. This evidence largely comes from research on humans, lab animals and farm animals, but also from some zoo studies too. We then investigate why. We review psychology and ethology literatures to show that such welfare benefits can arise from five, non-mutually exclusive, processes or mechanisms that are well-understood in humans and domestic animals: (1) some motivations are sated quickly by interaction with resources, yet still have large welfare benefits; (2) active interaction may just be a way to achieve a goal or solve a problem, without being beneficial for welfare in itself; (3) having opportunities for choice and control may be inherently beneficial, even when not acted on; (4) some enclosure features meet social needs for structure, landmarks, and blocked sightlines; and (5) some stimuli may be preferred because they signaled good environments to an animal's ancestors. We use this information to identify improved ways of enhancing and assessing zoo animal welfare. Incorporating these concepts should expand the scope of behaviors and subjective experiences that are targeted, to now include those that involve little active interaction and yet still are important for good welfare.
... Cortisol is a measure of stress and can be modulated by the presence of an anxiolytic fragrance. In a study involving university students during their exam period, Rose essential oil inhalation was found to modulate cortisol levels, as well as skin conductance (Fukada et al., 2011). ...
Article
Full-text available
There are a number of key features which make olfaction difficult to study; subjective processes of odor detection, discrimination and identification, and individualistic odor hedonic perception and associated odor memories. In this systematic review we explore the role functional near-infrared spectroscopy (fNIRS) has played in understanding olfactory perception in humans. fNIRS is an optical neuroimaging technique able to measure changes in brain hemodynamics and oxygenation related to neural electrical activity. Adhering to PRISMA guidelines, results of this search found that generally the majority of studies involving healthy adult subjects observed increased activity in response to odors. Other population types were also observed, such as infants, individuals with autism, attention deficit hyperactivity disorder (ADHD), post-traumatic stress disorder (PTSD), mild cognitive impairment (MCI) and dysosmia. fNIRS coverage heavily favored the prefrontal cortex, temporal and parietal regions. This review finds that odor induced cortical activation is dependent on multiple factors, such as odorant type, gender and population type. This review also finds that there is room for improvement in areas such as participant diversity, use of wearable fNIRS systems, physiological monitoring and multi-distance channels.
... The citrus fragrance has been shown to have a beneficial effect on the mental states and immune function of patients who are depressed [13]. It has also been demonstrated that rose essential oils prevent the disruption of the skin barrier and the elevation of salivary cortisol in humans caused by stress [14], and that the aromas of orange and lavender counteract the anxiety experienced by patients in a setting similar to that of a dental office [15]. ...
Chapter
Full-text available
Olfaction and gustation are important survival mechanisms. These sensory modalities also have an impact on memory and emotions. Olfactory stimulation has recently been used in virtual reality environments to treat emotional distress. There is evidence that olfactory and gustatory stimuli reach the insula, where they influence a number of other brain networks. There is little research on the use of smell and taste during mindfulness, but it will be shown that they can foster balanced emotional responses. In this chapter, we will look at how to incorporate olfactory and gustatory memory-based experiences during mindfulness exercises to bring about emotional homeostasis.
... Olfactory stimuli in particular hold significant potential for enhancing presence and psychophysiological benefits [26][27][28], due to the direct path that odors take through the limbic system, which is associated with memory formation and emotions [29]. This pathway allows odors to evoke powerful emotions and memories in individuals and manipulate our psychological and physiological states [30][31][32][33][34][35]. ...
Article
Astronauts on long-duration missions are at an increased risk of developing adverse behavioral conditions due to prolonged periods in isolated, confined, and extreme (ICE) environments. Sleep loss, sensory deprivation and monotony, and loss in social connectedness can further exacerbate their conditions and decrement performance, thus jeopardizing mission success. Future missions will require crews to travel distances that make current countermeasures increasingly difficult, as they rely on proximity to Earth. We have developed a multi-sensory virtual reality (VR) environment as a potential tool to maintain the long-term behavioral health of astronauts. We conducted a within-subjects study (N = 10) to compare the effectiveness of our VR environment with and without the incorporation of digital scents. Prior to the VR experience, subjects completed a public speaking task to elevate stress levels and emulate the stressful conditions that astronauts might encounter on a mission. The virtual nature environment features a small, forested area with localized scents that are dispersed based on the user's location in the VR environment. For example, floral scents were emitted when the user was near the field of flowers. The Positive and Negative Affect Schedule (PANAS) and the 6-item State-Trait Anxiety Inventory (STAI-6) questionnaires were administered to record subjective data on the participant's state affect and anxiety throughout the experiment. Participants reported significantly lower STAI-6 scores after the VR experience when scents were present than in the control condition (p = 0.03). Compared to the stressed state, PANAS Negative Affect (p = 0.003) and STAI-6 (p = 0.001) scores decreased after the VR with scents condition. STAI-6 scores (p = 0.013) also decreased from baseline when olfactory stimuli were added. These results suggest that the addition of olfactory stimuli to the VR environment aided in reducing negative affect and state anxiety levels. In addition, our results indicate that the use of multisensory VR environments are a promising countermeasure to support behavioral health during long-duration exploration missions.
... In healthy adults also, inhalation of RDM caused a 40% decrease in sympathetic activity and a 30% decline in adrenaline concentration (Haze, Sakai, & Gozu, 2002). In another study conducted by Fukada et al., inhalation of rose essential oil could prevent the activation of hypothalamopituitary-adrenocortical axis to reduce anxiety (Fukada, Kano, Miyoshi, Komaki, & Watanabe, 2012). Moreover, the stress system activity, through glucocorticoid receptor resistance and cognitive function, was greatly affected by the inhalation of RDM essential oil (Ghoshooni et al., 2017). ...
Article
Recent studies have reported conflicting findings on the antianxiety, antidepressant, and anti‐stress properties of Rosa Damascena Mill (RDM). Therefore, the present systematic review and meta‐analysis were conducted on the effects of RDM for treating anxiety, depression, and stress amongst adults. The online data sources of Cochrane Central Register of Controlled Trials, PubMed, Scopus, Web of Science, Embase, ProQuest, and Scientific Information Database were searched from inception to June 30, 2021. The randomized controlled trials (RCTs), which examined the effects of RDM (in any form of administration) on adults' anxiety, depression, and stress, were included. A random‐effects model was applied to pool the data, and a total of 32 publications were included. The results of the meta‐analysis revealed that administration of RDM significantly reduced state anxiety (effect size [ES]: 24, standardized mean difference [SMD]: −1.74, 95% confidence interval [CI]: −2.29, −1.20; p < .001), depression (ES: 7, SMD: −0.87, 95% CI: −1.47, −0.28; p = .004), and stress (ES: 4, SMD: −1.33, 95% CI: −1.98, −0.69; p < .001). However, the treatment had no significant effect on trait anxiety (ES: 6, weighted mean difference: −0.75, 95% CI: −1.93, 0.43; p = .214). The association between the total administration dosage and/or duration of RDM and the changes in state anxiety and depression was not dose‐dependent. Most RCTs had a fair methodological quality based on the Cochrane risk of bias assessment tool. Besides, the quality of evidence ranged from very low to moderate according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Hence, further high‐quality RCTs are needed to draw reliable conclusions regarding the use of RDM for treating adults' anxiety, depression, and stress.
... Rosa alba L. essential oil, known as Bulgarian rose oil of white rose, has been defined as "original, exclusively fine, only suitable for the highest perfumery" (Degraf 2003). Fukada et al. (2011) found that in an experimental model of acute stress in rats, inhalation with Rosa alba L. essential oil (supplied by Kanebo Cosmetics) lowered corticosterone levels almost twice. Water extract of calyces of Rosa alba from India might be a useful memory restorative agent in the treatment of cognitive disorders (Naikwade et al. 2009). ...
Article
Full-text available
Bulgarian Rosa alba L. essential oil is widely used in perfumery, cosmetics and pharmacy. The scarce data about its cytotoxic/genotoxic effect and anti-cytotoxic/anti-genotoxic potential gave us a reason to set our aim: i) to study its cytotoxic/genotoxic activities, iii) to explore its cytoprotective/genoprotective potential against the experimental mutagen N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) in two experimental test-systems - barley and human lymphocytes using appropriate endpoints and iii) to assess its antioxidant properties. Findings about chemical composition of rose essential oil would help us to explain its activities. Chromatogaphic profile of rose essential oil was obtained by Gas Chromatography-Mass Spectrometry and quantificaton of particular constituents was done with a Gas Chromatography-FID system. Superoxide anion radical scavenging, DPPH inhibition and iron ion chelating activity were used to study a possible antioxidant potential of the rose oil. Its defense potential was investigated by induction of chromosome aberrations and micronuclei in both test-systems. Cytogenetic analysis showed a low cytotoxic effect in both test-systems and no high genotoxic effect in human lymphocytes in vitro in a dose-dependent manner. Rose oil possessed a well-expressed anti-cytotoxic/antigenotoxic potential against MNNG manifested by decreasing both of chromosome aberrations and micronuclei regardless of the experimental schemes used. A well expressed concentration-depended free radical scavenging activity of the essential oil was obtained. Current data suggest a promising ethnopharmacological potential of Bulgarian white rose essential oil.
... Rosa alba L. essential oil, known as Bulgarian rose oil of white rose, has been defined as "original, exclusively fine, only suitable for the highest perfumery" (Degraf 2003). Fukada et al. (2011) found that in an experimental model of acute stress in rats, inhalation with Rosa alba L. essential oil (supplied by Kanebo Cosmetics) lowered corticosterone levels almost twice. Water extract of calyces of Rosa alba from India might be a useful memory restorative agent in the treatment of cognitive disorders (Naikwade et al. 2009). ...
... Rose oil also maintains the skinbarrier disruption in both rats and humans. It also increases the salivary concentration of cortisol in humans by controlling the elevation of transepidermal water loss [38]. Pharmacology underlying the suppressive effects of rose essential oil on the HPA axis and TEWL (transepidermal water loss) is not known but two possibilities are there. ...
Article
Full-text available
Background Rosa alba L. belongs to the family Rosaceae. This species is widely cultivated in Europe, Asia, North America, and Northwest Africa due to its fragrance, ornamental, and medicinal values. It is commonly known as white oil-bearing rose, white rose, white rose of York, backyard rose, and sufaid gulab. Main text Rosa alba L. has many biological properties like antioxidant, antimicrobial, antifungal, antifertility, teratogenic, memory enhancing, cytotoxic, and genotoxic activities. The essential oil of Rosa alba L. possesses good antimicrobial activity and consists of many chemical constituents like- citronellol, geraniol, nerol, linalool, citral, carvacrol, eugenol, etc. Conclusion This article briefly reviews the cultivation, traditional uses, phytochemistry, and biological activities of Rosa alba L. Many research papers have been published on the proposed plant and still, there is a very vast scope of research on it. Therefore, this review will be very fruitful for those scientists who are doing or plan to do research work on this plant. All the scientific findings written in this review are explored from Google web, Google Scholar, PubMed, ScienceDirect, Medicinal and Aromatic Plants Abstracts (MAPA), and SciFinder. To date, it is the first systematic review article of such kind, on this plant.
... Rose essence and extracts are known to treat epileptic seizures and prevent the formation of dark neurons in hippocampus regions in pentylentetrazol (PTZ)induced rats (Homayoun et al. 2015;Kheirabadi et al. 2008). In stressed rats, olfactory stimulation by rose essential oils was reported to inhibit stress-induced hypothalamic paraventricullar nucleus activity and hypothalamo-pituitary-adrenocortical axis activation (Fukada et al. 2011;Matsukawa et al. 2011;Rakhshandah et al. 2010). Also, CNS modulatory effects of rose oils were attributed to its GABAergic activity (Maleki et al. 2013;Nyeem et al. 2006). ...
Chapter
Sickle cell anemia (SCA) is an inherited disorder in the β-globin chain of hemoglobin that affects millions of people around the world, especially children. This disease prevalently occurs in some Mediterranean and Saharan Africa. For the treatment of SCA patients, a wide range of drugs have been explored by targeting antisickling activity, γ-globulin induction, antiplatelet effect, etc., but hardly a few drugs have shown potential to combat with this complex disease phenomenon. In spite of unprecedented advances in modern system of medicine, people in the disease-prone area have been taking traditional medicinal plants or plant-derived products to increase the life span of patients. Moreover, numerous clinical trials have been going on for the use of natural products under the purview of symptomatic management of SCA. This chapter is focused on the effect of natural products in pure form or characterized phytoconstituents on particularly inhibition of hemoglobin polymerization. This summarized information will be beneficial for further exploration of new therapeutics in the treatment arena of SCA.
... Rose essence and extracts are known to treat epileptic seizures and prevent the formation of dark neurons in hippocampus regions in pentylentetrazol (PTZ)induced rats (Homayoun et al. 2015;Kheirabadi et al. 2008). In stressed rats, olfactory stimulation by rose essential oils was reported to inhibit stress-induced hypothalamic paraventricullar nucleus activity and hypothalamo-pituitary-adrenocortical axis activation (Fukada et al. 2011;Matsukawa et al. 2011;Rakhshandah et al. 2010). Also, CNS modulatory effects of rose oils were attributed to its GABAergic activity (Maleki et al. 2013;Nyeem et al. 2006). ...
... Rose essence and extracts are known to treat epileptic seizures and prevent the formation of dark neurons in hippocampus regions in pentylentetrazol (PTZ)induced rats (Homayoun et al. 2015;Kheirabadi et al. 2008). In stressed rats, olfactory stimulation by rose essential oils was reported to inhibit stress-induced hypothalamic paraventricullar nucleus activity and hypothalamo-pituitary-adrenocortical axis activation (Fukada et al. 2011;Matsukawa et al. 2011;Rakhshandah et al. 2010). Also, CNS modulatory effects of rose oils were attributed to its GABAergic activity (Maleki et al. 2013;Nyeem et al. 2006). ...
Chapter
Presently, neurological disorders form a major proportion of non-communicable diseases. Their incidence has increased due to several factors such as lifestyle changes, changes in dietary patterns, and increased psychological stress. Due to increase in awareness regarding these disorders by health-care professionals and general public, increasing number of cases are diagnosed with every passing year. This presents a challenge, especially in under-developed and developing countries, where the public health-care systems are not well established and penetration of health insurance cover is relatively much lower. Alternative medicine has traditionally been used in several cultures around the world to treat neurological problems. Essential oils and other plant volatiles have a long history of traditional use for ameliorating symptoms of neurological and psychological disorders. Essential oils of lavender, rose, lemon balm, etc. have shown good promise. Further, modern research has validated some of the claims with regard to relieving of neural and psychological issues by plant VOCs. Some of these have been shown to modulate key enzymes that are targets for depression therapy. In the present chapter we have presented an overview of above, and toward the end we have attempted to identify lacunas in this area which may help to formulate future research strategies.
... In this study, the application of 6-h restraint stress increased the CORT levels in rats while inhalation exposure to 1-MN at 50 mg/m 3 significantly reduced the stress. These results suggest that 1-MN interacts with the HPA axis similarly to many volatile compounds [3,11,[27][28][29][30][31]. The non-linear effect on the stress level, as observed in this study, was also reported for other organic solvents like 1,2,4-trimethylbenzene (pseudocumene [PS]) or 1,2,3-trimethylbenzene (hemimellitene [HM]) [32][33][34]. ...
Article
Full-text available
Objectives: This paper reports on the trend of the stressogenic stimulus caused by a repeated exposure to 1-methylnaphthalene (1-MN) vapors at the nominal concentrations of 0 mg/m3 (the control restrainer), 50 mg/m3 or 200 mg/m3 in the nose-only inhalation system, by analyzing the serum corticosterone (CORT) levels in rats. Material and methods: Three groups of rats were exposed in restrainers to 1-MN vapors at the nominal concentrations of 0 mg/m3, 50 mg/m3 or 200 mg/m3 for 5 days. One control group of animals spent all the time during the experiment in an individually ventilated plastic cage. The serum CORT concentrations were determined in all 4 groups of the rats. The blood samples drawn from the tail vein were collected every day after termination of the 6-h exposure. On the fifth day, blood samples were collected 15 min, 30 min, 45 min, 1 h, and 3 h after termination of the 6-h exposure. Results: On the fifth day of the study, no statistically significant changes in body weights between all groups of animals were found. After 5 days of the observation, increased food intake in the control groups was noted. Significantly higher CORT concentrations in the rats exposed to 1-MN at 200 mg/m3 and in the animals from the control restrainer were found, comparing to the animals exposed to 1-MN at 50 mg/m3 and the animals from the control cage. Conclusions: The application of 6-h restraining induced high concentrations of the stress hormone, CORT, in the blood of rats. The short-term exposure of rats to 1-MN non-linearly reduced the restraint stress measured with CORT concentration.
... Recently, Takagi et al. [48] reported that fragrance inhalation of grapefruit essential oil recovers the reduction in the salivary level of secretory immunoglobulin A by mental stress in humans, indicating that the inhalation of grapefruit essential oil induced stress free actions. In addition, previous studies suggested that fragrance administration of oils though other than grapefruit essential oil attenuated an increase in salivary cortisol concentration to mental stress in humans [49,50] or plasma ACTH level to physical stress in rats, while decreased the stress-induced activity of prefrontal cortex which regulates the activity of the hypothalamic-pituitary-adrenal axis in humans [51]. Indeed, we confirmed that plasma ACTH level decreased with cortisol level with the grapefruit fragrance inhalation (Fig. 7). ...
Article
Full-text available
Fragrance inhalation of essential oils is widely used in aromatherapy, and it is known to affect blood pressure (BP) and heart rate (HR) via autonomic control of circulation. In this study, we aimed to test the hypothesis that the changes in hemodynamics with fragrance inhalation were observed along with changes in muscle sympathetic nerve activity (MSNA). In study 1, thirteen healthy men were exposed to fragrance stimulation of grapefruit essential oil for 10 min, and BP, HR, and MSNA were continuously measured. In study 2, another nine healthy men were exposed to the same fragrance stimulation; responses in BP and HR were continuously measured, and plasma noradrenaline and cortisol concentrations were determined. We found that diastolic BP increased significantly during fragrance inhalation, while the other variables remained unchanged in both studies. Although MSNA burst frequency, burst incidence, and total activity remained unchanged during fragrance inhalation, we found a significant linear correlation between changes in diastolic BP in the last 5 min of fragrance inhalation and changes in MSNA burst frequency. The plasma cortisol concentration decreased significantly at 10 min of fragrance inhalation, though the noradrenaline concentration remained unchanged. These results suggest, for the first time, that changes in BP with fragrance inhalation of essential oil are associated with changes in MSNA even with decreased stress hormone.
... Indeed, it is known that responses to odors can elicit emotion with the influence of physiological states. For example, rose essential oil can reduce stress (Fukada et al., 2012) and ambient odor of orange and lavender can attenuate anxiety and improve mood in a dental office (Lehrner et al., 2000(Lehrner et al., , 2005. In addition, other researchers have shown that colors have an effect on our emotions and moods. ...
Thesis
Full-text available
This doctorate aims to contribute to a better understanding of the link, several times demonstrated, between odors and colors. It is organized in 4 parts corresponding to 4 major studies carried out in different countries, France, Lebanon and Taiwan, as well as in different regions within the same country (urban Lebanon, rural Lebanon). The first study carried out in the three countries aimed at demonstrating the impact of culture on the construction of the odor-color link. The results obtained revealed a significant effect of the participants' place of residence on the construction of the link but also the predominant role of the "function of the odor" (food, cosmetics, industrial ...). The second intercultural study between France and Lebanon focused more specifically on the methodology used to carry out odor - color tests. Indeed, in the literature, two types of procedures are generally used: presentation of physical colors that the participant can see or absence of presentation of physical colors and the use of color names (blue, green, red, ...). The comparison of these two methods revealed an equally important effect between the procedure, the culture and the function of the odor on the odor-color association. The data also revealed that colors have the capacity of olfactory evocation. To better understand this phenomenon, we performed an fMRI study. This third study using fMRI showed that the olfactory evocation power of abstract color arrangements was different from that obtained from colored figurative visual representations. The cognitive processes involved in an olfactory evocation from colors arrangement, is more complex and multimodal involving olfactory, emotional, visio-spatial, language and memory processes. The final part of this Ph.D. examined how emotional evidenced by fMRI could interfere with the construction of the odor - color link. The study was carried out in France as well as in two rural and urban areas of Lebanon. The results showed that the affect associated with an odor influenced the odor-color link, but above all, that the preferential choice of certain affects was linked to the socioeconomic and cultural situation of the participant. This thesis is therefore a contribution to a better understanding of the link between odors and colors. It has demonstrated its complexity with a proven effect of the odor function in the country, the methodology used and the place of residence and socio-cultural level of the participant. However, it stresses the need for a multidisciplinary approach to understand even more precisely the whole workings
... In this latter study, lavender and rose oils did not produce any anti-depressant or anxiolytic effects. However, rose oil had anxiolytic effects in rats in another report (de Almeida et al., 2004) and was also shown to reduce the corticosterone induction response (Fukada et al., 2012). Besides essential oils, another odour has been tested in several stress models: a mixture of trans-2-hexenal and cis-3-hexenol called Green Odour (GO), which evokes in humans the smell of fresh cut grass. ...
Article
Adaptations to the ever changing social and physical environment are necessary, sometimes involving the stress response. Olfaction is a chemical sense allowing the detection of molecules in the air, and many species rely on it for social recognition and fundamental functions such as feeding or reproduction. This non-exhaustive literature review addresses three topics at the intersection of sensory biology and stress biology, in order to raise awareness and enlighten our understanding of animal behaviour. First, we show that stress and associated emotions, such as fear, can alter odour perception, from the sensor (peripheral nervous system) to the interpretation of the sensory input (brain). This can be of relevance for understanding the behavioural consequences of negative experiences and depression-like states. Second, odours involved in animal chemical communication can signal danger in the form of predators or stressed conspecifics, and in turn induce stress in recipient animals, as a form of chemical empathy. Finally, we review some of the evidence for the use of odours as stress-relief agents. There is no clear evidence of treatment efficacy and it might be that under the labels of inhalation aromatherapy, aromachology or pheromone therapy, a lack of perspective has led to the conflation of various biological phenomena: an alleged spontaneous olfactory effect on stress relief, environmental enrichment or the recall of positive emotional states. Careful experimental design and critical analysis are paramount to clearly evaluate this promising intervention. The world around us shapes our emotions, which in turn affect our perception. There might be a huge animal welfare potential to harvest from improved knowledge in the studies of stress and olfaction interactions, this will eventually allow us to show more empathy to animals in our care.
... Rats exposure to rose oil elicits anti-stress effects and suppresses corticosterone levels in the plasma [35]. It was reported that these effects may involve suppression of the hypothalamic-pituitary-adrenocortical axis activation. ...
Article
Full-text available
Rose oil has traditionally been used to treat psychiatric disorders, but the scientific basis of this treatment remains poorly understood. The main odor component of rose oil is 2-phenylethanol (2-PE), but the neuropsychological effects of 2-PE have not been investigated in detail. Thus, we aimed to investigate the effects of 2-PE on mouse behavior. We first investigated whether 2-PE is attractive or repulsive to mice. After 2-PE inhalation, the mice underwent a series of behavioral experiments, such as the elevated plus maze, open field, Y-maze, tail-suspension, and Porsolt forced-swim tests. Mice did not have a strong interest in 2-PE but were not repelled by it nor were fearful. In the open field test, mice that had inhaled 2-PE spent less time in the center area, while in the tail suspension test, their immobility time decreased. There was no change in cognitive function, activity level, muscle strength, or aggression in these mice. Our results suggest that 2-PE elicits neuropsychological effects that alter the behavior of mice and may also elicit anti-depressive effects. Inhalation of rose oil containing 2-PE may be effective against depression and stress-related diseases.
... Regarding emotional state, it has been found that 4-Hydroxy-3-methoxybenzaldehyde (vanillin) attenuated depressive symptoms in a rat model of chronic depression [7], whereas Citrus sinensis (sweet orange) essential oil induced anxiolytic effects in rats in the elevated plus-maze [10] and 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde (l-perillaldehyde) exhibited antidepressant-like effects in stress-induced depression-like model mice via olfactory nervous system function [8]. Regarding physiological function, terpinyl acetate and phenethyl alcohol was found to increase sleep time in mice [9], whereas Rosa alba (rose) essential oil prevented skin barrier disruption in rats and humans [11], and Cananga odorata (Ylang-Ylang) essential oil decreased blood pressure in humans [12]. Thus, odorants may provide a useful tool for treating a range of conditions in humans. ...
Article
Full-text available
Some components of the neural circuits underlying innate odor-evoked responses have recently been elucidated. Odor information detected by the olfactory receptors is transmitted from the olfactory bulb to the cortical amygdala, where physiological and emotional states such as attraction or avoidance are controlled. Thus, activation of specific olfactory receptors can elicit changes in physiological and/or psychological state. Here, we examined on the odorant Hex-Hex Mix, which has been reported to induce anti-fatigue effects. Fatigue is a prevalent condition that is often related to overwork and psychological stress. Various anti-fatigue treatments have been developed, including supplements and odorants. However, the mechanisms underlying the anti-fatigue effects of these substances are currently unclear. In the present study, we analyzed the involvement of the olfactory system in the mechanisms underlying this effect. We identified the human olfactory receptors activated by Hex-Hex Mix, and evaluated whether activation of these olfactory receptors by a newly developed odorant elicited a similar anti-fatigue effect to Hex-Hex Mix. We assessed anti-fatigue effects with behavioral tests, and 17 healthy males performed the 2-back test as a fatigue-inducing task with or without exposure to the new odorant. Immediately before and after the task, participants performed a cognitive task to evaluate their level of mental fatigue. We found that the difference value of the correct response rate on the cognitive task in the evaluation session was significantly different between in the odorant condition and in the without-odorant condition during the fatigue-inducing session suggesting that the new odorant may improve performance in the fatigue-inducing condition. The results indicated that the new odorant activates the same olfactory receptors as Hex-Hex Mix, which has been reported to induce anti-fatigue effects. Our findings suggest that the olfactory receptors in the olfactory system may be involved in the attenuation of fatigue.
... It has been previously known that the elevated cortisol concentration in the body due to stress is associated with decreased skin barrier function [20,21]. Thus, we Table 1. ...
Article
The aim of this study was to evaluate the effect of consumption of coffee polyphenols (CPPs) on the autonomic nervous system activity and decreased skin barrier function caused by sodium dodecyl sulfate (SDS) treatment. In this single-blind, placebo-controlled study, ten healthy male subjects consumed either a beverage containing CPPs or a placebo beverage for four weeks. CPPs significantly suppressed the deterioration in skin barrier function and skin moisture content induced by SDS treatment after the third week. Furthermore, in the heart rate variability analysis, CPPs significantly produced an increase in parasympathetic nervous activity, and a decrease in sympathetic nervous activity after the four weeks of beverage consumption. These results suggest that CPPs might influence the regulation of the autonomic nervous system and contribute to the suppressive effect on deterioration of skin barrier function.
... Evidences of the anxiolytic effect of rose hip have been previously discussed [174], but these data provide a new perspective on the beneficial effect of Rosa species for skin health. Relaxing properties of Rosa damascena oil inhalation resulted in a decrease in transepidermial water loss, a common skin damage feature induced by chronic stress [185]. ...
Article
Full-text available
Rosa species, rose hips, are widespread wild plants that have been traditionally used as medicinal compounds for the treatment of a wide variety of diseases. The therapeutic potential of these plants is based on its antioxidant effects caused by or associated with its phytochemical composition, which includes ascorbic acid, phenolic compounds and healthy fatty acids among others. Over the last few years, medicinal interest in rose hips has increased as a consequence of recent research that has studied its potential application as a treatment for several diseases including skin disorders, hepatotoxicity, renal disturbances, diarrhoea, inflammatory disorders, arthritis, diabetes, hyperlipidaemia, obesity and cancer. In this review, the role of different species ofRosain the prevention of treatment of various disorders related to oxidative stress, is examined, focusing on new therapeutic approaches from a molecular point of view.
Article
Cognitive efficiency, characterized by the rapid and accurate processing of information, significantly enhances work and learning outcomes. This efficiency manifests in improved time management, decision-making, learning capabilities, and creativity. While the influence of thermal, acoustic, and lighting conditions on cognitive performance has been extensively studied, the role of olfactory stimuli remains underexplored. Olfactory perception, distinguished by its intensity, speed of perception, and the breadth of stimuli, plays a pivotal role in cognitive efficiency. This review investigates the mechanisms through which odor environments influence cognitive performance. We analyze how odor environments can affect cognitive efficiency through two different scenarios (work and sleep) and pathways (direct and indirect effects). Current research, which mainly focuses on the interplay between odors, emotional responses, and cognitive efficiency through both subjective and objective measures, is thoroughly analyzed. We highlight existing research gaps and suggest future directions for investigating the influence of odor environments on cognitive efficiency. This review aims to establish a theoretical basis for managing and leveraging odor environments in workplace settings.
Article
Full-text available
Rosa spp., commonly known as rosehips, are wild plants that have traditionally been employed as herbal remedies for the treatment of a wide range of disorders. Rosehip is a storehouse of vitamins, including A, B complex, C, and E. Among phytonutrients, vitamin C is found in the highest amount. As rosehips contain significant levels of vitamin C, they are perfect candidates for the development of skincare formulations that can be effectively used in the treatment of different skin disorders (i.e., scarring, anti-aging, hyperpigmentation, wrinkles, melasma, and atopic dermatitis). This research focuses on the vitamin C content of several Rosa sp. by their botanical and geographic origins, which according to research studies are in the following order: R. rugosa > R. montana > R. canina > R. dumalis, with lower levels in R. villosa and R. arvensis, respectively. Among rosehip species, R. canina is the most extensively studied species which also displays significant amounts of bioactive compounds, but also antioxidant, and antimicrobial activities (e.g., against Propionibacterium acnes, Staphylococcus aureus, S, epidermis, and S. haemolyticus). The investigation also highlights the use of rosehip extracts and oils to minimise the harmful effects of acne, which primarily affects teenagers in terms of their physical appearance (e.g., scarring, hyperpigmentation, imperfections), as well as their moral character (e.g., low self-confidence, bullying). Additionally, for higher vitamin C content from various rosehip species, the traditional (i.e., infusion, maceration, Soxhlet extraction) and contemporary extraction methods (i.e., supercritical fluid extraction, microwave-assisted, ultrasonic-assisted, and enzyme-assisted extractions) are highlighted, finally choosing the best extraction method for increased bioactive compounds, with emphasis on vitamin C content. Consequently, the current research focuses on assessing the potential of rosehip extracts as medicinal agents against various skin conditions, and the use of rosehip concentrations in skincare formulations (such as toner, serum, lotion, and sunscreen). Up-to-date studies have revealed that rosehip extracts are perfect candidates as topical application products in the form of nanoemulsions. Extensive in vivo studies have revealed that rosehip extracts also exhibit specific activities against multiple skin disorders (i.e., wound healing, collagen synthesis, atopic dermatitis, melasma, and anti-aging effects). Overall, with multiple dermatological actions and efficacies, rosehip extracts and oils are promising agents that require a thorough investigation of their functioning processes to enable their safe use in the skincare industry.
Article
Full-text available
The purpose of this systematic overview is to establish the impact of inhalation and topical application of Rosa damascena essential oil in aromatherapy practice. A bibliometric analysis using the different scientific databases was conducted to examine scientific documents related to "rose aromatherapy" and "Rosa damascena aromatherapy". Microsoft Excel and VOSviewer software were used to extract and visualize information. Founded on a review of 93 papers, the scent of rose essential oil has applications in aromatherapy for reducing anxiety, alleviating pain, improving sleep quality, as well as alleviating physiological symptoms during menopause and PMS. It aids in mitigating stress and reducing stress and reducing depression and fatigue, for relaxation and improving cognitive function, among other benefits. Ultimately, rose essential oil is safe and suitable for self-administration via inhalation or topical application, either alone or with other essential oils.
Article
Full-text available
Night creams play a pivotal role in skincare routines by safeguarding against nocturnal moisture loss and promoting a smooth, wrinkle-free complexion. However, conventional formulations of night creams often incorporate synthetic active substances, potentially leading to adverse effects over prolonged use. Addressing this concern involves substituting these synthetic compounds with natural ingredients, particularly essential oils, renowned for their diverse skincare benefits encompassing anti-acne, anti-aging, anti-wrinkle, and moisturizing properties. A systematic review was conducted to establish a foundation for future investigations, focusing on the integration of essential oils in night cream formulations. The outcomes revealed that various night cream formulations, enriched with essential oils derived from natural ingredients such as rosemary oil, camellia oil, clove oil, geranium oil, lemongrass oil, rosehip oil, and sandalwood oil, demonstrate remarkable efficacy in preserving skin moisture. The versatility of essential oils has been showcased in the development of night creams, boasting diverse beneficial effects across skincare concerns. This systematic investigation highlights the potential of essential oil-based night creams, which have recently gained traction in the global market. The burgeoning introduction of these products signifies an escalating demand for such skincare solutions and points towards promising prospects for future advancements in essential oil-based night creams.
Article
Full-text available
Stress responses, which are crucial for survival, are evolutionally conserved throughout the animal kingdom. The most common endocrine axis among stress responses is that triggered by corticotropin-releasing hormone neurons (CRHNs) in the hypothalamus. Signals of various stressors are detected by different sensory systems and relayed through individual neural circuits that converge on hypothalamic CRHNs to initiate common stress hormone responses. To investigate the neurocircuitry mechanisms underlying stress hormone responses induced by a variety of stressors, researchers have recently developed new approaches employing retrograde transsynaptic viral tracers, providing a wealth of information about various types of neural circuits that control the activity of CRHNs in response to stress stimuli. Here, we review earlier and more recent findings on the stress neurocircuits that converge on CRHNs, focusing particularly on olfactory systems that excite or suppress the activities of CRHNs and lead to the initiation of stress responses. Because smells are arguably the most important signals that enable animals to properly cope with environmental changes and survive, unveiling the regulatory mechanisms by which smells control stress responses would provide broad insight into how stress-related environmental cues are perceived in the animal brain.
Article
Full-text available
Background: As a common fragrance ingredient, α-ionone is widely used in cosmetics, perfume, and hygiene products. Nevertheless, little information is available for its biological activities on the skin. In this study, we investigated the effect of α-ionone on keratinocyte functions associated with skin barrier repair and further evaluated its skin barrier recovery capacity to explore its therapeutic potential for the treatment of skin barrier disruption. Methods: The effect of α-ionone on the keratinocyte functions including cell proliferation, migration, and production of hyaluronic acid (HA) and human β-defensin-2 (HBD-2) were examined in vitro using human immortalized keratinocytes (HaCaT cells) as experimental model. The barrier recovery effects of topical hydrogels containing 0.1% or 1% α-ionone were tested on the volar forearm of 31 healthy volunteers by measuring transepidermal water loss (TEWL) and stratum corneum (SC) hydration following barrier disruption induced by repeated tape-stripping. The statistical significance was evaluated by one-way analysis of variance (ANOVA) followed by a Dunnett's post-hoc test. Results: α-ionone promoted HaCaT cell proliferation (P<0.01) dose-dependently in the 10 to 50 µM range. Meanwhile, it also increased the intracellular cyclic adenosine monophosphate (cAMP) levels (P<0.05). Furthermore, HaCaT cells treated with α-ionone (10, 25, 50 µM) showed enhanced cell migration (P<0.05), up-regulated gene expression of hyaluronic acid synthases 2 (HAS2) (P<0.05), HAS3 (P<0.01), and HBD-2 (P<0.05), and enhanced production of HA (P<0.01) and HBD-2 (P<0.05) in the culture supernatant. These beneficial actions of α-ionone were abrogated by cAMP inhibitor, suggesting that its effects are cAMP-mediated in HaCaT cells. In vivo study showed that topical application of α-ionone-containing hydrogels accelerated the epidermal barrier recovery of human skin after barrier disruption by tape stripping. Treatment with hydrogel containing 1% α-ionone resulted in a significant increase of above 15% in the barrier recovery rate at day 7 post-treatment when compared to the vehicle control (P<0.01). Conclusions: These results demonstrated the role of α-ionone in the improvement of keratinocyte functions and the epidermal barrier recovery. These findings suggest possible therapeutic application of α-ionone in the treatment of skin barrier disruption.
Article
Rosa gallica has been previously reported to display anti‐inflammatory, anti‐oxidative, and anti‐skin wrinkle activities. However, the effect of Rosa gallica on skin hydration and its active components are largely unknown. Herein, we aimed to investigate the skin hydration effect of rose petal extract (RPE) in humans and elucidate the underlying molecular mechanism. A double‐blinded clinical study was performed to investigate the effect of RPE on skin hydration. Stratum corneum moisture analysis demonstrated that RPE treatment significantly improved hydration levels in human skin. Furthermore, HAS2 and hyaluronic acid levels were notably increased by RPE in keratinocytes and 3D human skin equivalent model. By comparing the modulatory effect on HAS2 expression, cyanidin‐3,5‐O‐diglucoside (CDG) was identified as the most potent compound in RPE likely responsible for skin hydration. The kinase activity of GLK, an upstream regulator of MAPK signaling, was increased by CDG in a dose‐dependent manner. Importantly, silencing GLK reversed CDG‐mediated HAS2 upregulation, further supporting the involvement of GLK in the CDG‐mediated effects. Binding of CDG to GLK was confirmed by pull‐down assay and computer modeling. These findings suggest that RPE and its active component CDG increases skin hydration by upregulating HAS2 expression through modulating the GLK‐MAP2K‐MAPK signaling pathway.
Article
Objectives: Rheumatoid arthritis characterized by joint inflammation and pain,affecting millions of peoples around the world. Traditional system of medicine had proven to be preventive and treating physical and mental illness. The aim of the study is to assess anti-arthritic potential of the plant Rosa alba L by considering complete freund's adjuvant, formaldehyde and turpentine oil induced arthritic model. Methods: Ethanolic extract and its ethyl acetate fraction were considered for the study and quercetin was quantitatively estimated by high performance thin layer chromatographic (HPTLC) method. Moreover, hematological and biochemical studies were performed in blood and serum of wistar albino rat. Then histopathological studies had also been performed on rat hind paw joint. Results: Phytochemical screening estimated the presence of carbohydrates, phenolic compounds, flavonoids, phytosterols, amino acids and fixed oil in ethanolic extract and ethyl acetate fraction of the plant. Amount of quercetin in the flowers of the plant was found to be 0.26%w/w by quantitative HPTLC method. Paw edema significantly decreased (P<0.001) by extract and fraction of the plant in dose dependant manner by considering formaldehyde and turpentine induced acute arthritic model. The level of proinflammatory cytokines, interleukin (IL-6) was considerably decreased (P<0.001) in the fraction treated group of rats at 400 mg/kg b.w by considering complete freund's adjuvant (CFA) induced arthritic model. Conclusions: Ameliorated hematological, biochemical and histopathological parameters confirmed the antiarthritic potential of the plant.
Chapter
The relationship between stress and skin health has been documented since ancient times. This chapter provides an overview of the biological pathways believed to play a role in the relationship between psychosocial stress and the physical appearance of skin. It summarizes the clinically important relationships and emphasizes areas of significant academic, clinical, and commercial impact. The molecular factors that comprise the central (systemic) and cutaneous (peripheral) stress axes provide important background for the clinical effects of stress on skin health. Psychosocial stress affects skin health through complex interactions with neuroendocrine, immune, and microbial networks. The understanding of the classic hypothalamic‐pituitary‐adrenal stress axis has expanded to include its cutaneous analog, considering a likely bidirectional relationship between the systemic and local stress response. Emerging studies of the skin microbiome highlight the importance of commensal bacteria and demonstrate microbial activation of the stress axis.
Article
Full-text available
Skin is the largest external organ of the human body. It acts as a barrier to protect the human body from environmental pollution, mechanical stress, and excessive water loss. The defensive function resides primarily on top of the epidermis layer commonly known as stratum corneum (SC). Human SC consists of three major lipids, namely ceramide, free fatty acid, and cholesterol that comprise approximately 50%, 25%, and 25% of the total lipid mass, respectively. The optimal composition of SC lipids is the vital epidermal barrier function of the skin. On the other hand, skin barrier serves to limit passive water loss from the body, reduces chemical absorption from the environment, and prevents microbial infection. In contrast, epidermal lipids are important to maintain the cell structure, growth and differentiation, cohesion and desquamation as well as formation of a permeability barrier. Multiple non-invasive in vivo approaches were implemented on a regular basis to monitor skin physiological and intercellular lipid properties. The measurement of different parameters such as transepidermal water loss (TEWL), hydration level, skin elasticity, collagen intensity, melanin content, sebum, pH, and tape stripping is essential to evaluate the epidermal barrier function. Novel non-invasive techniques such as tape stripping, ultrasound imaging, and laser confocal microscopy offer higher possibility of accurate and detailed characterisation of skin barrier. To date, these techniques have also been widely used to determine the effects of herbal plants in dermatology. Herbal plants have been traditionally used for ages to treat a variety of skin diseases, as reported by the World Health Organisation (WHO). Their availability, lower cost, and minimal or no side effects have created awareness among society, thus increase the demand for natural sources as the remedy to treat various skin diseases. This paper reviews several non-invasive techniques and evaluations of herbal-based product in dermatology.
Article
Unpleasant odors impair our mood and may affect physical health, even when the odorants are not toxic. A possible cause for such negative effects is stress induced by odors; however, whether the unpleasantness itself elicited stress or not has not been clear. Thus, we examined whether unpleasantness of odors induced the stress responses of emotion, the hypothalamic-pituitary-adrenal (HPA) axis, and the sympathetic nervous system (SNS). Six experiments were conducted, where salivary cortisol or salivary alpha amylase (sAA), markers for activities of the HPA and the SNS, respectively, were measured, along with subjective ratings of odors and emotion. First, the responses to three malodors listed in the Offensive Odor Control Law in Japan were examined. While these odors were rated as unpleasant, and exposure to them increased anxiety, no response of the HPA was observed (experiment 1, n = 69). In contrast, an increase of the SNS activity was observed after exposure to two of the three malodors, while the SNS did not respond to pleasant odors (experiments 2-4, n = 35, 34 and 30). To examine the effect of unpleasantness further, the SNS response was examined while subjective unpleasantness of odors was manipulated by adding negative verbal information (experiment 5, n = 92), or by mixing in a pleasant odor (experiment 6, n = 35). The SNS responses upon inhalation of the same odorous substances were found to be dependent on whether they were perceived as unpleasant. Finally, a correlation analysis on the pooled data from experiments 2-6 showed that the odor-elicited SNS activity and anxiety were strongly correlated with perceived unpleasantness of odors. These results suggest that subjective unpleasantness of odors per se can induce the stress response of emotion and the SNS.
Article
Essential oils are usually used in aromatherapy to alleviate anxiety symptoms. Compared 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 that used in clinical researches had been proved 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 anxiolytic effect in rodents, while two-thirds of them are alcohols and terpenes. Monoamine neurotransmitters, amino acid neurotransmitters and hypothalamic-pituitary-adrenal axis are thought to play important roles in the anxiolytic effects of essential oils.
Article
Introduction The epidermal barrier functions to limit skin infection and inflammation by inhibiting irritant and immunogen invasion. Abundant evidence suggests that psychological stress stemming from crowding, isolation, nicotine smoking, insomnia, mental arithmetic tasks, physical pain, real life‐stressors (examinations and marital strain), and lack of positive personality traits may impart both acute and chronic epidermal dysfunction. Materials/Methods A review of PubMed and EMBASE databases was conducted to identify all English case‐control, cross‐sectional, and randomized control trials that report the effect of stress on epidermal barrier function. The authors’ conclusions are based on available evidence from 21 studies that met the inclusion and exclusion criteria. Results Psychological stressors upregulate the hypothalamic‐pituitary‐adrenal axis to stimulate local and systemic stress hormone production, ultimately leading to aberrant barrier dysfunction, characterized by decreased epidermal lipids and structural protein production, decreased stratum corneum hydration, and increased transepidermal water loss. Discussion This evidence‐based review explores the adverse effects of psychological stressors on epidermal barrier function. Future investigations using more real‐life stressors are needed to further elucidate their impact on skin physiology as well as to identify practical stress‐relieving therapies that minimize and restore epidermal barrier dysfunction, particularly in at‐risk populations. This article is protected by copyright. All rights reserved.
Article
Exposure to certain natural stimuli improves people's moods, reduces stress, enhances stress resilience, and promotes mental and physical health. Laboratory studies and real estate prices also reveal that humans prefer environments containing a broad range of natural stimuli. Potential mediators of these outcomes include: 1) therapeutic effects of specific natural products; 2) positive affective responses to stimuli that signalled safety and resources to our evolutionary ancestors; 3) attraction to environments that satisfy innate needs to explore and understand; and 4) ease of sensory processing, due to the stimuli's "evolutionary familiarity" and/or their fractal, self-repeating properties. These processes, and the benefits humans gain from natural stimuli, seem to be largely innate. They thus have strong implications for other species (including laboratory, farm and zoo animals living in environments devoid of natural stimuli), suggesting that they too may have nature-related "sensory needs". By promoting positive affect and stress resilience, preferred natural stimuli (including views, sounds and odours) could potentially provide effective and efficient ways to improve captive animal well-being.
Article
Full-text available
( This reprinted article originally appeared in the Journal of Experimental Psychology, 1935, Vol 18, 643–662. The following abstract of the original article appeared in PA, Vol 10:1863.) In this study pairs of conflicting stimuli, both being inherent aspects of the same symbols, were presented simultaneously (a name of one color printed in the ink of another color—a word stimulus and a color stimulus). The difference in time for reading the words printed in colors and the same words printed in black is the measure of the interference of color stimuli on reading words. The difference in the time for naming the colors in which the words are printed and the same colors printed in squares is the measure of the interference of conflicting word stimuli on naming colors. The interference of conflicting color stimuli on the time for reading 100 words (each word naming a color unlike the ink-color of its print) caused an increase of 2.3 sec or 5.6% over the normal time for reading the same words printed in black. This increase is not reliable, but the interference of conflicting word stimuli on the time for naming 100 colors (each color being the print of a word which names another color) caused an increase of 47.0 sec or 74.3% of the normal time for naming colors printed in squares.… (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Full-text available
Stress is the leading psychopathological cause for several mental disorders. Physiological and psychological responses to stress are mediated by the hypothalamic?pituitary?adrenal (HPA), sympathoadrenal system (SAS), and brain monoaminergic systems (BMS). Eugenol is reported to substantially modulate brain functions by regulating voltage-gated cation channels and release of neurotransmitters. This study was designed to evaluate the anti-stress effect of eugenol in the 4-h restraint model using rats. Ulcer index was measured as a parameter of the stress response. HPA axis and the SAS were monitored by estimating plasma corticosterone and norepinephrine (NE), respectively. Analysis of NE, serotonin (5-HT), dopamine, and their metabolites in discrete brain regions was performed to understand the role of BMS in the anti-stress effect of eugenol. Stress exposure increased the ulcer index as well as plasma corticosterone and NE levels. Eugenol pretreatment for 7 days decreased the stress-induced increase in ulcer index and plasma corticosterone but not NE levels, indicating a preferential effect on the HPA axis. Furthermore, eugenol showed a ?U?-shaped dose?response curve in decreasing ulcer index and plasma corticosterone levels. Eugenol also reversed the stress-induced changes in 5-HT levels in all brain regions, whereas NE levels were reversed in all brain regions except hippocampus. These results suggest that eugenol possesses significant anti-stress activity in the 4-h restraint model and the effect is due to modulation of HPA and BMS.
Article
Full-text available
One increasingly popular type of alternative therapy is aromatherapy, but scientific validation in this field is still rare. The aim of this study was to investigate the effect of rose oil (Rosa damascena Mill, Rosaceae) on human autonomic parameters and emotional responses in healthy subjects after transdermal absorption. In order to exclude any olfactory stimulation the inhalation of the fragrances was prevented by breathing masks. Forty healthy volunteers participated in the experiments. Five autonomic parameters, i.e. blood pressure, breathing rate, blood oxygen saturation, pulse rate, and skin temperature, were recorded. Emotional responses were assessed by means of rating scales. Compared to placebo, rose oil caused significant decreases of breathing rate, blood oxygen saturation and systolic blood pressure, which indicate a decrease of autonomic arousal. At the emotional level, subjects in the rose oil group rated themselves as more calm, more relaxed and less alert than subjects in the control group. These findings are likely to represent a relaxing effect of the rose oil and provide some evidence for the use of rose oil in aromatherapy, such as causing relief of depression and stress in humans.
Article
Full-text available
The hypothalamic paraventricular nucleus is the primary controller of hypothalamo-pituitary-adrenocortical glucocorticoid release. In performing this function, the paraventricular nucleus summates a variety of information from both external and internal sources into a net secretory signal to the adrenal cortex. In this review, we will provide an overview of neuronal circuit mechanisms governing activation and inhibition of hypophysiotrophic neurons, highlight recent developments in our understanding of nonsynaptic mechanisms regulating paraventricular cellular activity, including dendritic neuropeptide release, direct steroid feedback, cytokine cascades and gaseous neurotransmission, and illustrate the capacity for hypophysiotrophic, neurohypophysial and preautonomic paraventricular effector pathways to work together in control of glucocorticoid release. The current state of knowledge reveals the paraventricular nucleus to be a dynamic entity, capable of integrating diverse classes of signals into control of adrenocortical activation.
Article
Full-text available
Our past results provide considerable evidence that activation of neurons somewhere in the region of the dorsomedial hypothalamus (DMH) plays a key role in the generation of many of the effects typically seen in "emotional" stress in rats, including activation of the hypothalamic-pituitary-adrenal (HPA) axis, the neuroendocrine hallmark of the generalized response to stress, and sympathetically mediated tachycardia. More recently, we demonstrated that (1) the tachycardia resulting either from chemical stimulation of the DMH or from experimental stress is markedly attenuated by microinjection of the GABAA receptor agonist muscimol, a neuronal inhibitor, into the medullary raphe pallidus (RP); and (2) the specific subregion of the DMH mediating stimulation-induced tachycardia corresponds to the dorsal hypothalamic area (DHA), a site where neurons projecting to the RP are densely concentrated. Thus, the pathway from neurons in the DHA to sympathetic premotor neurons in the RP may constitute a key relay mediating the increases in heart rate seen in emotional stress--a role that had never been proposed previously for either of these regions. Instead, sympathetic premotor neurons were known to exist in the RP but had been most closely associated with sympathetic thermoregulatory mechanisms, including activation of brown fat, the principal means for nonshivering thermogenesis in rats, and cutaneous vasoconstriction in the tail, an important method of conserving body heat in this species. These sympathetic effects serve to maintain body temperature in a cold environment or to increase it in fever--and are typically accompanied by tachycardia. Interestingly, we and others have now shown that (1) disinhibition of neurons in the DMH also increases body temperature, at least in part through activation of brown fat, (2) microinjection of the neuronal inhibitor muscimol into the DMH reduces experimental fever and the associated tachycardia in rats. We hypothesize that activation of neurons in the DMH mediates both the increased body temperature and cardiac stimulation produced in rats by experimental "emotional" stress and fever, and that these effects are mediated in large part through direct projections to sympathetic premotor neurons in the RP. Thus, this pathway may constitute a common effector circuit upon which a variety of forebrain inputs converge in response to diverse environmental challenges.
Article
Full-text available
Animals respond to stress by activating a wide array of behavioral and physiological responses that are collectively referred to as the stress response. Corticotropin-releasing factor (CRF) plays a central role in the stress response by regulating the hypothalamic-pituitary-adrenal (HPA) axis. In response to stress, CRF initiates a cascade of events that culminate in the release of glucocorticoids from the adrenal cortex. As a result of the great number of physiological and behavioral effects exerted by glucocorticoids, several mechanisms have evolved to control HPA axis activation and integrate the stress response. Glucocorticoid feedback inhibition plays a prominent role in regulating the magnitude and duration of glucocorticoid release. In addition to glucocorticoid feedback, the HPA axis is regulated at the level of the hypothalamus by a diverse group of afferent projections from limbic, midbrain, and brain stem nuclei. The stress response is also mediated in part by brain stem noradrenergic neurons, sympathetic andrenomedullary circuits, and parasympathetic systems. In summary, the aim of this review is to discuss the role of the HPA axis in the integration of adaptive responses to stress. We also identify and briefly describe the major neuronal and endocrine systems that contribute to the regulation of the HPA axis and the maintenance of homeostasis in the face of aversive stimuli.
Article
Chronic maternal stress during pregnancy results in the "prenatally stressed" offspring displaying behavioral and neuroendocrine alterations that persist into adulthood. We investigated how inhalation of green odor (a mixture of equal amounts of trans-2-hexenal and cis-3-hexenol) by stressed dams might alter certain indices of prenatal stress in their offspring. These indices were depression-like behavior (increased immobility time in the forced-swim test) and acute restraint stress-induced changes in hypothalamo-pituitary-adrenocortical (HPA) axis activity [plasma corticosterone (CORT) and ACTH levels and the number of Fos-immunoreactive cells in the hypothalamic paraventricular nucleus (an index of neuronal activity)]. Pregnant rats were exposed to restraint stress for 60 min/day for 10 days (gestational days 10-19). The prenatally stressed offspring exhibited significant increases in depression-like behavior and in restraint stress-induced ACTH, CORT, and Fos responses, unless their dam had been exposed to green odor. The behavioral effect of the odor was also seen in offspring that were fostered by unstressed dams. The results obtained in the dams themselves were as follows. In vehicle-exposed stressed dams, but not in green odor-exposed ones, total body and adrenal weights were significantly decreased or increased, respectively. Depression-like behavior was not observed in the vehicle-exposed stressed dams themselves. Green odor inhalation prevented the impairment of maternal behavior induced by restraint stress. Thus, exposure of dams to stress may affect both the fetal brain and fetal HPA axis, and also maternal behavior, leading to altered behavioral and neuroendocrine responses in the offspring. Such effects may be prevented by the stressed dams inhaling green odor.
Article
The aim of the present study was to investigate the effects of academic stress on periodontal health, in relation to inflammatory markers in gingival crevicular fluid (GCF) and cortisol in saliva. The study included 20 healthy dental hygienists (females: mean age 29.3 +/- 8.5 SD) and was conducted during a major exam period and 4 weeks later after the exams. A clinical examination was performed and GCF was collected from four sites in each subject on these two occasions. Interleukin (IL)-1beta, IL-4, IL-6, IL-10 levels were determined using Luminex 100 and cortisol amounts by radioimmunoassay (RIA (125)I). Students registered their perceived stress on a visual analogue scale (VAS). Significance of the findings was determined using paired t-test, Wilcoxon-matched pair and Spearman's rank correlations. Students had higher amounts of dental plaque (P < 0.007) and gingival inflammation (P < 0.001) during the exam period compared with after the exams. The amounts of IL-6 and IL-10 in GCF were significantly increased during the time of examinations. The median level of cortisol in saliva was also significantly raised during the exam period compared with after the exams, 20.52 nmol/l (range: 11.91-27.34) and 16.41 nmol/l (range: 10.91-24.17) respectively, P < 001. The results from the VAS registration revealed a significant difference (P < 001) between the two occasions. Academic stress appears to affect periodontal health, shown by more plaque accumulation, gingival inflammation and increased amounts of IL-6, IL-10 in GCF and cortisol in saliva.
Article
Thesis (Ph. D.)--George Peabody College for Teachers, 1933.
Article
In the present study, on rats, a quantitative analysis of Fos protein immunohistochemistry was performed as a way of investigating the effects of inhalation of green odor (a mixture of equal amounts of trans-2-hexenal and cis-3-hexenol) on the neuronal activations in stress-related forebrain regions induced by acute and repeated stress. Rats were exposed to restraint stress for 90 min each day for 1, 2, 4, 7, or 11 consecutive days. The hypothalamic paraventricular nucleus (PVN), amygdala, hippocampus and paraventricular thalamic nucleus (PVT) were examined. Both acute and repeated restraint stress increased Fos-positive cells in the entire hypothalamic PVN, in the central and medial amygdala, and in PVT, although these responses declined upon repeated exposure to such stress. The stress-induced Fos responses were much weaker in rats that inhaled green odor during each day's restraint. No increases in Fos-positive cells were observed in the hippocampus in acutely stressed rats. The Fos-immunoreactive response to acute stress shown by the piriform cortex did not differ significantly between the vehicle+stress and green+stress groups. Green odor had inhibitory effects on the stress-induced corticosterone response, body-weight loss, and adrenal hypertrophy. These results suggest that in rats, green odor inhalation may, in an as yet unknown way, act on the brain to suppress activity in the neuronal networks involved in stress-related responses (such as activation of the hypothalamo-pituitary-adrenocortical axis and activation of the sympathetic nervous system, as well as stress-induced fear responses).
Article
The three major classes of neurons in the paraventricular nucleus (PVH) provide a rich model for studying hormonal and neural influences on multiple neuropeptides expressed in individual cells. A great deal of previous work has examined this problem at the immunohistochemical level, where hormonal and neural influences on peptide levels have been established. In situ hybridization methods were used here to determine whether these effects are accompanied by measurable changes in neuropeptide mRNA levels. In the first series of experiments, the time-course of corticosterone replacement effects on corticotropin-releasing hormone (CRH) mRNA levels in parvicellular neuroendocrine cells of adrenalectomized animals were determined, and a dose-response curve was established. CRH mRNA hybridization remains maximal with plasma levels of steroid up to about 50 ng/ml, then declines sharply between about 60-130 ng/ml, and is just detectable at higher levels. We confirmed that corticosterone decreases vasopressin mRNA levels in this cell group and showed that levels of preproenkephalin mRNA are also decreased, whereas no significant changes in cholecystokinin, beta-preprotachykinin, and angiotensinogen mRNA levels could be detected. Thus, corticosterone decreases some neuropeptide mRNA levels and has no influence on others in this cell group. Tyrosine hydroxylase mRNA hybridization is also unaffected in this part of the nucleus. In a second group of experiments, the cell-type specificity of corticosterone influences was examined. It was found that while the hormone depresses CRH mRNA levels in parvicellular neurons, it increases such levels in PVH neurons with descending projections, in certain magnocellular neurosecretory neurons, and in a part of the central nucleus of the amygdala, whereas no influence was detected in the rostral lateral hypothalamic area. Furthermore, the stimulatory effects of corticosterone have different threshold levels in different cell groups. Thus, in different types of neurons, corticosterone may increase, decrease, or have no influence on CRH mRNA levels. In contrast, while corticosterone depresses vasopressin mRNA levels in parvicellular CRH neurons, it has no obvious effects on vasopressin mRNA levels in magnocellular or descending neurons; as with CRH, the effects of corticosterone on vasopressin mRNA levels are cell-type specific. In a third series of experiments it was shown that glucocorticoid receptor and mineralocorticoid receptor mRNAs are found in all three cell types in the PVH and that corticosterone tends to produce modest increases in mRNA levels for both receptors. Finally, it was shown that unilateral catecholamine-depleting knife cuts do not change mRNA levels for any of the neuropeptides (or steroid hormone receptors) examined here, although dramatic changes in neuropeptide levels themselves have been shown.4+
Article
An easy to prepare cannula and simple procedure is described for chronic cannulation of the jugular vein of the rat. Cannulas permit blood sampling without disturbance to the animal and remain patent for as long as 2 mth.
Article
Experiments using two retrogradely transported fluorescent dyes (bisbenzimide-true blue, and Evans blue-granular blue) were performed in order to determine whether the same or different populations of neurons of the paraventricular nucleus of the hypothalamus (PVH) project to the pituitary gland, dorsal vagal complex, and spinal cord in the rat. The results suggest that cells projecting to the pituitary gland are concentrated in the magnocellular core of the nucleus, while the descending connections arise primarily from the surrounding parvocellular division. The occurrence of neurons double-labeled with both dyes further indicate that at lease 10-15% of the labeled cells in the parvocellular division send divergent axon collaterals to the dorsal vagal complex and to the spinal cord. Cell counts suggest that at least 1,500 cells in the PVH project to the medulla and/or spinal cord. These results, combined with a cytoarchitectonic analysis, show that the PVH consists of eight distinct subdivisions, three magnocellular and five parvocellular. The lateral hypothalamic area and zona incerta also contain a large number of cells projecting to the dorsomedial medulla and spinal cord; approximately 15% of such cells are the double-labeled following injections of separate tracers into these two regions of the same animal.
Article
Angiotensin II (ANG II) has been recognized recently as one of the stress hormones that participate in various stress-induced responses, including sympathetic (pressor, tachycardiac, and hyperthermic) and neuroendocrine responses. Brain ANG II receptors have been identified in many brain regions involved in the stress responses. During stress-exposure, ANG II increases in the plasma and in the brain. Central administration of ANG II induces stress responses, whereas central blockade of ANG II receptors results in the inhibition of the sympathetic and neuroendocrine responses to stress. All these findings indicate that ANG II and its receptors contribute to the development of various sympathetic and neuroendocrine responses during stress exposure. This review focuses on the role of brain ANG II receptors in the stress-induced responses.
Article
Previous studies have suggested that psychological stress delays cutaneous barrier recovery following acute barrier disruption, and that sedative drugs block this delay. A sedative effect of some odorants has been reported. In the present study, we demonstrate that odorant inhalation affects cutaneous barrier homeostasis in both mice and humans. Odorants with a sedative effect prevented the delay of skin barrier recovery induced by stress after acute barrier disruption. Other odorants did not show this effect.
Article
This study tested the hypothesis that the activation pattern of enkephalinergic (ENKergic) neurons within the paraventricular nucleus of the hypothalamus (PVH) in response to psychogenic stress is identical whether in response to repeated exposure to the same stress (homotypic; immobilization) or to a novel stress (heterotypic; air jet puff). Rats were assigned to either acute or chronic immobilization stress paradigms (90 min/day for 1 or 10 days, respectively). The chronic group was then subjected to an additional 90-min session of either heterotypic or homotypic stress. A single 90-min stress session (immobilization or air jet) increased PVH-ENK heteronuclear (hn) RNA expression. In chronically stressed rats, exposure to an additional stress session (whether homotypic or heterotypic) continued to stimulate ENK hnRNA expression. Acute immobilization caused a marked increase in the numbers of Fos-immunoreactive and Fos-ENK double-labeled cells in the dorsal and ventral medial parvicellular, and lateral parvicellular subdivisions of the PVH. Chronic immobilization caused an attenuated Fos response ( approximately 66%) to subsequent immobilization. In contrast, chronic immobilization did not impair ENKergic neuron activation within the PVH following homotypic or heterotypic stress. These results indicate that within the PVH, chronic psychogenic stress markedly attenuates the Fos response, whereas ENKergic neurons resist habituation, principally within the ventral neuroendocrine portion of the nucleus. This suggests an increase in ENK effect during chronic stress exposure. Homotypic (immobilization) and heterotypic (air jet) psychogenic stressors produce similar responses, including Fos, ENK-Fos, and ENK hnRNA, within each subdivision of the PVH, suggesting similar processing for painless neurogenic stimuli.
Article
Previous reports have demonstrated that stressful stimuli markedly influenced physiological conditions and homeostasis. In this study, we examined the influence of high population density environment on barrier function and water retention property of skin in mice. Overcrowding stress induced dramatic body weight reduction and significant increase in adrenal gland weight. Macroscopic skin appearance showed moderate exfoliation and slight wrinkle formation in the stress group. Moreover epidermis hyperplasia not concomitant with inflammatory reactions such as infiltration of immunocytes and vasodilation was observed in the skin from the stress group. Skin surface conductance in the stress group was significantly lower than in the control group. On the other hand, transepidermal water loss in the stress group increased significantly, compared to the control group. Moreover, transdermal penetration of indomethacin and nicotinic acid amide was enhanced significantly. These results suggest that overcrowding stress induced impairment of barrier function and water retention property. To elucidate the mechanism of overcrowding stress-induce dry skin, contents of ceramide and pyrrolidone carboxylic acid, which are the important compounds contributing to those functions were evaluated. Both of them in stratum corneum declined significantly in the stress group. Taken together, these results demonstrate that overcrowding stress induced dry skin, and that the impairment of barrier function and water retention property correlated with decrease in ceramide and pyrrolidone carboxylic acid.
Article
Hypothalamic-pituitary-adrenal (HPA) responses to stress are initiated by parvicellular neurosecretory neurons in the medial parvicellular (mp) part of the paraventricular hypothalamic nucleus (PVH), which express corticotropin-releasing factor (CRF), among other neuropeptides. We have used an approach guided by patterns of stress-induced Fos expression to explore the manner in which anatomically and phenotypically defined components of the mpPVH respond to acute vs. repeated restraint stress. Hormonal indices of HPA activation in animals exposed to the last of 14 daily repeated restraint sessions were significantly lower than those in rats receiving a single restraint episode. Although this habituation was paralleled by global decrements in activation patterns across all PVH compartments, clear spatial-temporal differences in recruitment profiles were noted between dorsal and ventral aspects of the mpPVH. Thus, acute restraint provoked a biphasic Fos induction, which occurred first within the mpPVH and in an adjoining population of somatostatinergic cells in the periventricular region and only later within other aspects of the PVH. By contrast, Fos responses of habituated animals were monophasic and focused decisively within a discrete ventral aspect of the mpPVH. The ventral population was identified as comprising neurons that express CRF and/or enkephalin and, to a lesser extent, growth hormone-releasing factor. These results indicate a lack of homogeneity among stress-responsive parvicellular neurosecretory neurons and suggest that distinct complements of CRF cells may be preferentially involved in initiating HPA responses to acute stress and sustaining them in the repeated condition.
Article
Over the past decade, great progress has been made toward elucidating the structure and function of the stratum corneum (SC), the outermost layer of the epidermis. SC cells (corneocytes) protect against desiccation and environmental challenge by regulating water flux and retention. Maintenance of an optimal level of hydration by the SC is largely dependent on several factors. First, intercellular lamellar lipids, organized predominantly in an orthorhombic gel phase, provide an effective barrier to the passage of water through the tissue. Secondly, the diffusion path length also retards water loss, since water must traverse the tortuous path created by the SC layers and corneocyte envelopes. Thirdly, and equally important, is natural moisturizing factor (NMF), a complex mixture of low-molecular-weight, water-soluble compounds first formed within the corneocytes by degradation of the histidine-rich protein known as filaggrin. Each maturation step leading to the formation of an effective moisture barrier--including corneocyte strengthening, lipid processing, and NMF generation--is influenced by the level of SC hydration. These processes, as well as the final step of corneodesmolysis that mediates exfoliation, are often disturbed upon environmental challenge, resulting in dry, flaky skin conditions. The present paper reviews our current understanding of the biology of the SC, particularly its homeostatic mechanisms of hydration.
Article
To investigate the effect of green odor on the elevation of the plasma adrenocorticotropic hormone (ACTH) levels and body temperature (T(b)) induced by stress, adult male rats were subjected to a 2-h immobilization stress and exposed to green odor or its vehicle only. In comparison with the vehicle group, animals in the green odor group showed a significant reduction in plasma ACTH levels at the end of the stress when green odor was applied during the stress. The elevated plasma ACTH levels 2 days after the stress were reduced by green odor applied 0, 1, 2, 4 or 6 h after the beginning of the stress. Neither the immediate nor the long-lasting plasma ACTH response was affected by a prestress treatment of green odor. T(b) elevation was evident following the end of the stress and during the light phase the day after the stress. Both the immediate and the long-lasting elevations in T(b) were attenuated by green odor. These data suggest that green odor extracted from green leaves has a relieving effect on plasma ACTH and T(b) levels induced by an immobilization stress for not only immediate but also long-lasting periods.
Article
The effect of rose oil inhalation (1.0%, 2.5%, and 5.0% w/w) on the elevated plus-maze (EPM) test was investigated in adult male rats and compared with the effect of diazepam (DZP) (1.0 and 2.0 mg/kg) administered intraperitoneally 30 min before testing. Exposure to rose oil produced an anxiolytic-like effect similar to DZP (anxiolytic reference drug). Thus, at some concentrations, rose oil significantly increased the number of visits to and time spent in the open arms of the EPM. Anxiolytic-like properties of rose oil were observed using the EPM, being consistent with other behavioral and clinical studies.
Article
Although many skin disorders, including psoriasis and atopic dermatitis, are adversely affected by psychologic stress (PS), the pathophysiologic link between PS and disease expression remains unclear. Recent studies demonstrated PS-induced alterations in permeability barrier homeostasis, mediated by increased endogenous glucocorticoids. Here, we assessed the mechanisms by which PS alters stratum corneum (SC) function. Insomniac psychologic stress (IPS) altered both barrier homeostasis and SC integrity. IPS decreased epidermal cell proliferation, impaired epidermal differentiation, and decreased the density and size of corneodesmosomes (CD), which was linked to degradation of CD proteins (e.g., desmoglein1). Barrier compromise was linked to decreased production and secretion of lamellar bodies (LB), which in turn could be attributed to a decrease in de novo synthesis of epidermal lipids. Topical physiologic lipids (equimolar cholesterol, ceramides, and free fatty acids) normalized both barrier homeostasis and SC integrity in IPS mice, further evidence that lipid deficiency accounted for these functional abnormalities. Thus, PS inhibition of epidermal lipid synthesis results in decreased LB formation and secretion, as well as decreased CD, compromising both permeability barrier homeostasis and SC integrity. These studies suggest that topical treatment with epidermal physiologic lipids could be beneficial in stress-induced, barrier-associated dermatoses, such as psoriasis and atopic dermatitis.
Article
Most epidermal functions can be considered as protective, or more specifically, as defensive in nature. Yet, the term "barrier function" is often used synonymously with only one such defensive function, though arguably its most important, i.e., permeability barrier homeostasis. Regardless of their relative importance, these protective cutaneous functions largely reside in the stratum corneum (SC). In this review, I first explore the ways in which the multiple defensive functions of the SC are linked and interrelated, either by their shared localization or by common biochemical processes; how they are co-regulated in response to specific stressors; and how alterations in one defensive function impact other protective functions. Then, the structural and biochemical basis for these defensive functions is reviewed, including metabolic responses and signaling mechanisms of barrier homeostasis. Finally, the clinical consequences and therapeutic implications of this integrated perspective are provided.
Article
Like few other organs, the skin is continuously exposed to multiple exogenous and endogenous stressors. Superimposed on this is the impact of psychological stress on skin physiology and pathology. Here, we review the "brain-skin connection," which may underlie inflammatory skin diseases triggered or aggravated by stress, and we summarize relevant general principles of skin neuroimmunology and neuroendocrinology. Specifically, we portray the skin and its appendages as both a prominent target of key stress mediators (such as corticotropin-releasing hormone, ACTH, cortisol, catecholamines, prolactin, substance P, and nerve growth factor) and a potent source of these prototypic, immunomodulatory mediators of the stress responses. We delineate current views on the role of mast cell-dependent neurogenic skin inflammation and discuss the available evidence that the skin has established a fully functional peripheral equivalent of the hypothalamic-pituitary-adrenal axis as an independent, local stress response system. To cope with stress-induced oxidative damage, the skin and hair follicles also express melatonin, probably the most potent neuroendocrine antioxidant. Lastly, we outline major, as-yet unmet challenges in cutaneous stress research, particularly in the study of the cross-talk between peripheral and systemic responses to psychological stress and in the identification of promising molecular targets for therapeutic stress intervention.
Article
The specific physiological responses induced by inhaling R-(-)- as well as S-(+)-linalool in 24 human subjects undergoing experimental stress were investigated in this study. Various physiological parameters of the autonomous nervous system (heart rate, blood pressure, electrodermal activity) as well as the endocrine system (salivary cortisol) were monitored. The study clearly indicated that odorants can modulate salivary cortisol levels, with both linalool enantiomers exerting relaxing effects. Concerning blood pressure and heart rate, S-(+)-linalool acted as an activating agent in contrast to electrodermal activity. R-(-)-linalool proved to be stress-relieving as determined by heart rate. In conclusion, the results revealed that (1) chirality crucially influences the physiological effects of odorants and that (2) odorants may act differently on certain physiological parameters.
Article
We investigated whether inhalation of green odor (a mixture of equal amounts of trans-2-hexenal and cis-3-hexenol) prevents the skin-barrier disruption induced by chronic restraint stress in rats. To this end, transepidermal water loss (TEWL) was measured as an index of the disruption of skin-barrier function, whereas light- and electron-microscope examinations were performed to observe histological changes in the skin of the stressed animals. In addition, the effects on TEWL induced by chronic administration of a glucocorticoid, dexamethasone (DEX), were examined. Chronic restraint stress (8 h per day for 14 days) increased TEWL (vehicle + stress group). This effect (and the chronic stress–induced increase in adrenal weight) was prevented in rats that inhaled green odor at the beginning of each day's restraint (2 h each day for 14 days; green odor + stress group). Electron-microscope studies revealed that rats in the green odor + stress group possessed sufficient intercorneocyte lipids to create an effective skin barrier, although these had apparently been decreased in the vehicle + stress group. Daily administration of DEX for 14 days increased TEWL. The present results suggest that chronic stress–induced disruption of the skin barrier in rats can be reduced or prevented by green odor (possibly at least in part through an inhibitory effect on the stress-induced activation of the hypothalamo-pituitary-adrenocortical axis).
Stress and brain angiotensin receptors
  • T Watanabe
  • T Fujjioka
  • M Hashimoto
  • S Nakamura