A SNP in the ABCC11 gene is the determinant of human earwax type.

Human earwax consists of wet and dry types. Dry earwax is frequent in East Asians, whereas wet earwax is common in other populations. Here we show that a SNP, 538G --> A (rs17822931), in the ABCC11 gene is responsible for determination of earwax type. The AA genotype corresponds to dry earwax, and GA and GG to wet type. A 27-bp deletion in ABCC11 exon 29 was also found in a few individuals of Asian ancestry. A functional assay demonstrated that cells with allele A show a lower excretory activity for cGMP than those with allele G. The allele A frequency shows a north-south and east-west downward geographical gradient; worldwide, it is highest in Chinese and Koreans, and a common dry-type haplotype is retained among various ethnic populations. These suggest that the allele A arose in northeast Asia and thereafter spread through the world. The 538G --> A SNP is the first example of DNA polymorphism determining a visible genetic trait.

Discovery of aromatic components with excellent fragrance properties and biological activities: ß-ionols with antimelanogenetic effects and their asymmetric syntheses.

Both enantiomers of dihydro-ß-ionol and ß-ionol, contained in the aromatic components of Osmanthus flower and of Hakuto peach, were obtained with high optical purity by lipase-catalyzed kinetic resolution of the racemates. It was found that all these enantiomers had different characteristic favorable scents and high antimelanogenetic effects. The absolute configuration and the enantiomer ratios of dihydro-ß-ionol in the aromatic components of Osmanthus flower and of Hakuto peach were determined. The asymmetric synthesis of (R)-dihydro-ß-ionol, one of the most valuable raw materials for fragrance and flavor, was performed from inexpensive ß-ionone via lipase-catalyzed dynamic kinetic resolution followed by reduction.

Effect of "rose essential oil" inhalation on stress-induced skin-barrier disruption in rats and humans.

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.

The effects of odor on cortisol and testosterone in healthy adults.

OBJECTIVES: This study aimed to verify the influence of odor on the endocrine system (Cortisol, Testosterone). MATERIAL AND METHODS: Three odors (Musk, Rose and Floral) and air were given to 16 healthy volunteers (8 males, 8 females), and cortisol (C) and testosterone (T) levels were measured before and after stimulation. RESULTS: Each odor decreased levels of C, indicating that odor can attenuate stress. In males, T decreased with Musk, but increased with Floral. In females, T significantly increased with Musk, but decreased with Rose and Floral. CONCLUSIONS: These results indicate that influences on hormone levels depend on the type of odor, and sex differences exist in response to odors.

Psychological and neuroendocrinological effects of odor of saffron (Crocus sativus).

AIM: The purpose of this study was to clarify the effects of saffron odor on symptoms unique to women, such as premenstrual syndrome (PMS), dysmenorrhea (menstrual pain) and irregular menstruation. MATERIALS AND METHODS: Thirty-five women with a normal sense of smell were exposed to saffron odor for 20 min. Saliva samples were then collected to measure levels of cortisol (C), testosterone (T) and 17-ß estradiol (E) by enzyme immunoassay, and the State-Trait Anxiety Inventory (STAI) was administered as a psychological test. RESULTS: Saffron odor significantly decreased C levels after short-term stimulation (20 min) in both follicular and luteal phases. E level after exposure to saffron odor was increased in both the follicular- and luteal-phase groups. STAI score decreased in the follicular and luteal phases in the saffron group. CONCLUSIONS: The present findings support the existence of physiological and psychological effects of saffron odor in women. Our results indicate that saffron odor exert some effects in the treatment of PMS, dysmenorrhea and irregular menstruation. This is the first report to suggest that saffron odor may be effective in treating menstrual distress.

"Green odor" inhalation by rats down-regulates stress-induced increases in Fos expression in stress-related forebrain regions.

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).