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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). Electronmicroscope 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). Key words: adrenal gland, dexamethasone, hypothalamo-pituitary-adrenocortical axis, stratum corneum, transepidermal

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 CORTand 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

Abstract- Psoriasis is a chronic, non-contagious skin condition characterized by inflamed and scaly lesions of skin. Whilst the pathogenesis of psoriasis is not known, psychological stress has been implicated as a potential trigger in the onset and exacerbation of the condition. Psychiatric and psychological factors play an important role in at least 30 % of dermatologic disorder and pathophysiologic link between psychological stress (PS) and disease expression remains unclear. Recent studies demonstrated PS-induced alterations in permeability barrier homeostasis, mediated by increased endogenous glucocorticoids. As activation of the hypothalamic pituitary adrenal axis (HPA) is critical to a successful stress response, we investigated this in patients with psoriasis. This study was performed on 55 patients (40 females and 15 males) visited our clinic for treatment of psoriasis in pharmacology department. We measured the rate of activation of HPA by hormonal changes. These patients displayed higher fasting blood sugar (FBS), epinephrine (Ep), adrenocorticotropin hormone (ACTH), aldosterone, prolactin, growth hormone and estradiol hormones value but diminished cortisol and corticotropin releasing factor (CRF). These results show that HPA and psychoneuroendocrine hormones have a significant role in psoriasis.