Organic cultivation induced regulation in yield formation, grain quality attributes, and volatile organic compounds of fragrant rice.

Organic cultivation is an eco-friendly planting strategy. To explore the effects of organic cultivation on yield, grain quality, and volatile organic compounds of fragrant rice, the present study conducted a field experiment with organic cultivation and inorganic cultivation treatments over two subsequent growing seasons. The late season rice was sent for the determination of untargeted flavoromics using GC × GC-ToF-MS. Meanwhile, the GC × MS were used for the quantification of 2-acetyl-1-pyrroline. Our results showed that compared with inorganic cultivation, organic cultivation increased grain 2-AP and amylose contents by 21.19-26.10 % and 4.51-7.69 %, respectively. 5.89 %-15.55 % lower crude protein contents were recorded in organic cultivation. The results of untargeted flavoromics showed that organic cultivation caused the absence of 56 volatiles and the exclusive presence of 10 new volatiles compared with inorganic cultivation. In conclusion, organic cultivation produced fragrant rice with lower yield and higher 2-AP content as well as different flavor profiles.

Molecular docking predictions of fragrance binding to human leukocyte antigen molecules.

BACKGROUND: Over 4000 small chemicals have been identified as allergens capable of inducing skin sensitization. Many sensitizers are hypothesized to act as haptens producing novel antigens, which can be presented to T cells by human leukocyte antigens (HLAs). Recent studies suggest that some chemical allergens use hapten-independent mechanisms. OBJECTIVE: To determine whether molecular docking can identify HLA molecules that bind skin-sensitizing chemical allergens. METHODS: Structural models of HLA molecules were used as the basis for molecular docking of 22 chemical allergens. Allergens predicted to bind HLA-B*57:01 were tested for their ability to stimulate T cells by the use of proliferation and interferon-gamma enzyme-linked immunospot assays. RESULTS: Chemical allergens that did not satisfy the criteria for hapten activity in vitro were predicted to bind more strongly to common HLA isoforms than those with known hapten activity. HLA-B*57:01, which is an HLA allele required for drug hypersensitivity reactions, was predicted to bind several allergens, including benzyl benzoate, benzyl cinnamate, and benzyl salicylate. In in vitro T cell stimulation assays, benzyl salicylate and benzyl cinnamate were found to stimulate T cell responses from HLA-B*57:01 carriers. CONCLUSIONS: These data suggest that small-molecule skin sensitizers have the potential to interact with HLA, and show that T cell-based in vitro assays may be used to evaluate the immunogenicity of skin-sensitizing chemicals.

Aggregate exposure to common fragrance compounds: Comparison of the contribution of essential oils and cosmetics using probabilistic methods and the example of limonene.

The knowledge of aggregate exposure to different types of products is paramount in the risk assessment. The aim of this study was to compare the relative contribution of essential oils compared to cosmetics on the daily dermal exposure to limonene, an ubiquitous fragrance compound that can be an allergen depending on its degree of oxidation. Aggregate daily exposure to limonene was calculated among a panel of French volunteers using both essential oils and cosmetics, for 4 different specific zones, i.e. face and neck, chest, upper limbs and lower limbs. Calculations were made using a probabilistic Monte Carlo method and sensitivity analysis. The main strength of this work was the inclusion of essential oils in addition to cosmetics in the model. For the first time, the generated data could be used to compare the contribution of these two products in dermal exposure. Essential oils appear to be significant contributors to exposure to limonene particularly for the face. This work is a first step that will permit to determine the exposure to other fragrance compounds with sensitizing potential. These data will be useful for risk managers to consider the inclusion of essential oils in the overall burden of this pathology.

Effect of Fluorination on Skin Sensitization Potential and Fragrant Properties of Cinnamyl Compounds.

A series of three α- and three ß-fluorinated representatives of the family of cinnamate-derived odorants (cinnamaldehyde (1), cinnamyl alcohol (2), and ethyl cinnamate (3)) as used as fragrance ingredients is described. Olfactive evaluation shows that the fluorinated compounds exhibit a similar odor profile to their parent compounds, but the olfactive detection thresholds are clearly higher. In vitro evaluation of the skin sensitizing properties with three different assays indicates that α-fluorination of Michael acceptor systems 1 and 3 slightly improves the skin sensitization profile. α-Fluorocinnamyl alcohol 2b is a weaker skin sensitizer than cinnamyl alcohol 2a by in vitro tests and the fluorinated product drops below the sensitization threshold of the KeratinoSens® assay. On the other hand, ß-fluorination of compounds 1 - 3 results in highly reactive products which display a worsened in vitro skin sensitization profile.

Environmentally relevant concentrations of galaxolide (HHCB) and tonalide (AHTN) induced oxidative and genetic damage in Dreissena polymorpha.

Synthetic musk compounds (SMCs) are extensively used as fragrances in several personal care products and have been recognized as emerging aquatic pollutants. Among SMCs, galaxolide (HHCB) and tonalide (AHTN) are extensively used and have been measured in aquatic ecosystems worldwide. However, their potential risk to organisms remains largely unknown. The aim of this study was to investigate whether 21-day exposures to HHCB and AHTN concentrations frequently measured in aquatic ecosystems can induce oxidative and genetic damage in Dreissena polymorpha. The lipid peroxidation (LPO) and protein carbonyl content (PCC) were measured as oxidative stress indexes, while the DNA precipitation assay and the micronucleus test (MN test) were applied to investigate genetic injuries. HHCB induced significant increases in LPO and PCC levels, while AHTN enhanced only protein carbonylation. Moreover, significant increases in DNA strand breaks were caused by exposure to the highest concentrations of HHCB and AHTN tested in the present study, but no fixed genetic damage was observed.

Molecular profiling of contact dermatitis skin identifies allergen-dependent differences in immune response.

BACKGROUND: Allergic contact dermatitis (ACD) is the most common occupational disease. Although murine contact hypersensitivity provides a framework for understanding ACD, it carries important differences from its human counterpart. Unlike the contact hypersensitivity model, which is induced by potent sensitizers (ie, dinitrofluorobenzene), human ACD is induced by weak-to-moderate sensitizers (ie, nickel), which cannot induce reactions in mice. Distinct hapten-specific immune-polarizing responses to potent inducers were suggested in mice, with unclear relevance to human ACD. OBJECTIVE: We explored the possibility of distinct T-cell polarization responses in skin to common clinically relevant ACD allergens. METHODS: Gene-expression and cellular studies were performed on common allergens (ie, nickel, fragrance, and rubber) compared with petrolatum-occluded skin, using RT-PCR, gene arrays, and immunohistochemistry. RESULTS: Despite similar clinical reactions in all allergen groups, distinct immune polarizations characterized different allergens. Although the common ACD transcriptome consisted of 149 differentially expressed genes across all allergens versus petrolatum, a much larger gene set was uniquely altered by individual allergens. Nickel demonstrated the highest immune activation, with potent inductions of innate immunity, TH1/TH17 and a TH22 component. Fragrance, and to a lesser extent rubber, demonstrated a strong TH2 bias, some TH22 polarization, and smaller TH1/TH17 contributions. CONCLUSIONS: Our study offers new insights into the pathogenesis of ACD, expanding the understanding of T-cell activation and associated cytokines in allergen-reactive tissues. It is the first study that defines the common transcriptome of clinically relevant sensitizers in human skin and identifies unique pathways preferentially activated by different allergens, suggesting that ACD cannot be considered a single entity.

Antimicrobial activities of single aroma compounds.

Commercially available aroma samples were evaluated for their olfactory quality by professional perfumers and tested for their antimicrobial activity. Agar diffusion and agar-dilution were used as test methods and a set of two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and four Gram-negative bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris G, Klebsiella pneumoniae and Salmonella abony) and a yeast, Candida albicans, were the test microorganisms. All the investigated compounds were active against Gram-positive bacteria, especially beta-caryophyllene against Enterococcus faecalis (MIC 6 ppm), but only few substances showed activity towards Gram-negative bacteria, except for cinnamic acid, which was active against all (MIC 60 ppm) and Candida albicans, against which cinnamic acid and caryophyllene oxide showed high activity (MIC < 60 ppm).

The antibacterial activity of fragrance ingredients against Legionella pneumophila.

In the current study we investigated the antibacterial activity of fragrance ingredients against Legionella pneumophila, a causative agent of severe pneumonia. Among the 41 different fragrance ingredients tested, we found that the natural fragrance ingredients oakmoss (OM) and birch tar oil (BT), which contain many components, exhibit potent antibacterial activity. The minimum inhibitory concentration (MIC, % (v/v)) of OM and BT were 0.0020 and 0.0024, respectively and were lower than that of cinnamic aldehyde (0.0078), which has been previously shown to possess high antimicrobial activity. In a time-kill assay of OM and BT at MIC and two times MIC, the colony forming units (CFU) of the microbe were reduced to between 10(-3) to 10(-4) of the original CFU after 1 h co-incubation. After this time, the CFU gradually decreased in number, but remained above detection levels even after a 48-h co-incubation, except for BT at two times MIC. In contrast, at a concentration of 0.1% OM and BT (approximately 50 times MIC), CFU were not detected after co-incubation for 1 h. Another 18 fragrance ingredients including ketone, aldehyde, lactone, acid, phenol derivative, aliphatic alcohol and quinoline also exhibited a lesser degree of antibacterial activity against L. pneumophila at a MIC of less than 0.10.

Increased release of histamine in patients with respiratory symptoms related to perfume.

BACKGROUND: Environmental perfume exposure may cause respiratory symptoms. Individuals with asthma and perfume contact allergy report such symptoms more frequently than others. However, immunologic mechanisms have not been demonstrated and the symptoms are not associated with IgE-mediated allergy. The study aimed to investigate whether basophils from patients with respiratory symptoms related to perfume released more histamine in the presence of perfume as compared with healthy volunteers. METHODS: Histamine release was measured by the glass fibre method. Blood was obtained from healthy volunteers (n=20) and patients with respiratory symptoms related to perfume (n=17) attending a dermatological outpatient clinic for patch testing. The effect of an international brand perfume was investigated using the basophil histamine release test with perfume. Furthermore, basophils from a healthy non-atopic donor were incubated with participant's sera and histamine release induced by perfume was measured. RESULTS: In both groups incremental perfume concentrations showed a positive and significant (P<0.001) dose-response effect on the release of histamine. At the highest perfume concentration, the basophils released significantly (P<0.05) more histamine in patients as compared with healthy volunteers. No difference was found between the groups when sera were incubated with basophils from a healthy non-atopic donor. CONCLUSION: Perfume induces a dose-dependent non-IgE-mediated release of histamine from human peripheral blood basophils. Increased basophil reactivity to perfume was found in patients with respiratory symptoms related to perfume.

Evaluation of the sedative effect of fragrance on Filipinas using a biochemical marker.

The purpose of this study is to evaluate the usefulness of salivary amylase activity as an indicator of the acute psychological sedative effects of fragrances used in household products such as clothing softeners. Twenty seven healthy Philippine female subjects in their late 30 s were enrolled (38.7+/-5.2 yr). This study was undertaken to investigate the favorite fragrance of Asian and Pacific Islander women. Our results indicated that (i) a mixed floral fragrance might be a favorite fragrance for Filipinas; (ii) fragrances contained in a softener significantly induced a sedative effect in humans, as assessed by both analysis of the biochemical marker and subjective evaluation; (iii) salivary amylase activity has the potential to be an excellent indicator for the evaluation of the acute psychological sedative effects of fragrance.

The skin allergenic properties of chemicals may depend on contaminants--evidence from studies on coumarin.

BACKGROUND/AIMS: Positive patch tests are considered representative of a contact allergy to the tested chemical. However, contaminants and derivatives rather than the suspected chemical itself could be responsible for the allergic skin reactions. Here, we tested the importance of contaminants in the sensitizing and allergenic properties of coumarin in mice and humans. Coumarin, an ingredient in cosmetics and fragrances, was chosen as the reference chemical since conflicting results have been obtained regarding its ability to induce contact allergy. In some chemical preparations, this could be explained by the presence of coumarin derivatives endowed with allergenic properties. METHODS: In mice, three different coumarin preparations were tested in the local lymph node assay. In humans, we assessed the irritant and allergenic properties of highly pure coumarin in nonallergic and fragrance-allergic patients. RESULTS: Pure coumarin did not exhibit irritant or sensitizing properties in the local lymph node assay. In contrast, two other commercially available coumarins and three contaminants that were detected in these coumarin preparations were identified as weak and moderate sensitizers, respectively. In humans, pure coumarin was extremely well tolerated since only 1 out of 512 patients exhibited a positive patch test to the chemical. CONCLUSIONS: These results indicate that coumarin cannot be considered as a common contact allergen and further emphasize that purity of chemicals is mandatory for the assessment of their allergenicity.

Evaluation of the harmonizing effect of ylang-ylang oil on humans after inhalation.

Scientific evaluations of the effects of fragrances on humans are rather scarce. The aim of this investigation was to study the effects of ylang-ylang oil (Cananga odorata, Annonaceae) on hu-man physiological parameters and self-evaluation. Twenty-four healthy volunteers participated in the experiments. Fragrances were administered by inhalation. Physiological parameters recorded were skin temperature, pulse rate, breathing rate and blood pressure. Self-evaluation was assessed in terms of alertness, attentiveness, calmness, mood, relaxation and vigor. Additionally, fragrances were rated in terms of pleasantness, intensity and effect. The present investigation showed that ylang-ylang oil may be characterized by the concept of "harmonization" rather than relaxation/sedation. Compared to an odorless placebo, ylang-ylang oil caused significant decreases in blood pressure and pulse rate as well as significant increases of subjective attentiveness and alertness. Correlational analyses revealed that the observed effects are mainly due to a subjective odor experience.

Do perfume additives termed human pheromones warrant being termed pheromones?

Two studies of the effects of perfume additives, termed human pheromones by the authors, have conveyed the message that these substances can promote an increase in human sociosexual behaviour [Physiol. Behav. 75 (2003) R1; Arch. Sex. Behav. 27 (1998) R2]. The present paper presents an extended analysis of this data. It is shown that in neither study is there a statistically significant increase in any of the sociosexual behaviours for the experimental groups. In the control groups of both studies, there are, however, moderate but statistically significant decreases in the corresponding behaviour. Most notably, there is no support in data for the claim that the substances increase the attractiveness of the wearers of the substances to the other sex. It is concluded that more research using matched homogenous groups of participants is needed.

Further evaluation of quantitative structure--activity relationship models for the prediction of the skin sensitization potency of selected fragrance allergens.

Fragrance substances represent a very diverse group of chemicals; a proportion of them are associated with the ability to cause allergic reactions in the skin. Efforts to find substitute materials are hindered by the need to undertake animal testing for determining both skin sensitization hazard and potency. One strategy to avoid such testing is through an understanding of the relationships between chemical structure and skin sensitization, so-called structure-activity relationships. In recent work, we evaluated 2 groups of fragrance chemicals -- saturated aldehydes and alpha,beta-unsaturated aldehydes. Simple quantitative structure-activity relationship (QSAR) models relating the EC3 values [derived from the local lymph node assay (LLNA)] to physicochemical properties were developed for both sets of aldehydes. In the current study, we evaluated an additional group of carbonyl-containing compounds to test the predictive power of the developed QSARs and to extend their scope. The QSAR models were used to predict EC3 values of 10 newly selected compounds. Local lymph node assay data generated for these compounds demonstrated that the original QSARs were fairly accurate, but still required improvement. Development of these QSAR models has provided us with a better understanding of the potential mechanisms of action for aldehydes, and hence how to avoid or limit allergy. Knowledge generated from this work is being incorporated into new/improved rules for sensitization in the expert toxicity prediction system, deductive estimation of risk from existing knowledge (DEREK).

Analysis of mutual information content for EEG responses to odor stimulation for subjects classified by occupation.

To investigate the changes of cortico-cortical connectivity during odor stimulation of subjects classified by occupation, the mutual information content of EEGs was examined for general workers, perfume salespersons and professional perfume researchers. Analysis of the averaged-cross mutual information content (A-CMI) from the EEGs revealed that among the professional perfume researchers changes in the A-CMI values during odor stimulation were more apparent in the frontal region of the brain, while for the general workers and perfume salespersons such changes were more conspicuous in the overall posterior temporal, parietal and frontal regions. These results indicate that the brains of professional perfume researchers respond to odors mainly in the frontal region, reflecting the function of the orbitofrontal cortex (OFC) due to the occupational requirement of these subjects to discriminate or identify odors. During odor stimulation, the perfume salespersons, although relatively more exposed to odors than the general workers, showed similar changes to the general workers. The A-CMI value is in inverse proportion to psychological preferences of the professional perfume researchers and perfume salespersons, though this is not the case with the general workers. This result suggests that functional coupling for people who are occupationally exposed to odors may be related to psychological preference.

Regulation of plasma substance P and skin mast cells by odorants.

BACKGROUND: Mast cells stimulate inflammation and itch sensation in the skin by releasing various mediators when they are activated. Stress exacerbates some skin diseases. We have reported that inhalation of certain odorants modulates immune reactions in the skin. OBJECTIVE: The possible usage of odorants in the regulation of skin inflammation and itch sensation was to be examined. METHODS: Female volunteers were subjected to interview stress with or without odorant inhalation. Mice were immobilized while inhaling odorants. Toluidene blue-stained sections were analyzed for activated mast cells. Plasma substance P level was determined by enzyme-linked immunoassay. RESULTS: Interview stress induced plasma substance P only in volunteers who did not inhale odorants containing 2% 1,3-dimethoxy-5-methyl benzene (DMMB). Immobilization stress induced mast cell activation in mice and the activation was blocked by exposure to DMMB. CONCLUSIONS: Stress causes mast cell activation via an increase in substance P. The effect of stress is suppressed by inhalation of DMMB.

Patch testing in children, adults, and the elderly: influence of age and sex on sensitization patterns.

Patch testing was done on 2776 consecutive patients (76.5% female) with a locally revised standard series of 34 contact allergens and the results analyzed for age- and gender-specific differences. At least one positive epicutaneous test reaction occurred in 48.9% of patients. Nickel (20.9%), ethylmercuric chloride (13.2%), thimerosal (11.8%), fragrance mix (9.3%), metallic mercury (8.9%), palladium (5.8%), balsam of Peru (3.8%), copper (3.7%), cobalt (3.3%), and chromium (2.3%) were the 10 most important sensitizers. The following tested allergens with sensitization rates of more than 1% were not part of the usual standard series: ethylmercuric chloride, metallic mercury, copper, propolis (1.3%), propylene glycol (1.0%). Reactions to nickel, cobalt, and palladium, but not to chromium, were significantly more abundant in females (p < 0.002, chi-squared test). The overall sensitization rate was highest in children less than 10 years old (62%) and decreased steadily, to be lowest among patients more than 70 years old (34.9%). The rate of positive reactions to nickel and thimerosal decreased with age, while fragrance mix and metallic mercury stayed at the same level through all age groups.

Fungistatic activity of some perfumes against otomycotic pathogens.

The sporostatic effect of five otomycotic pathogens, i.e. Aspergillus niger, A. flavus, Absidia corymbifera, Penicillium nigricans and Candida albicans to nine different perfumes was determined on the basis of their spore germination. These organisms were isolated from patients suffering from fungal infection of the external auditory canal. Volatile vapours emanating from musk, phulwari, jasmine, nagchampa and bela caused approximately 100% inhibition in spore germination of all the test fungi. Volatiles emanating from chandan, khas and hina showed no inhibition for the test pathogens, displaying their resistant character to these perfumes.

Effects of chiral fragrances on human autonomic nervous system parameters and self-evaluation.

The effects of chiral fragrances (enantiomers of limonene and carvone) on the human autonomic nervous system (ANS) and on self-evaluation were studied in 20 healthy volunteers. Each fragrance was administered to each subject by inhalation using an A-A-B design. Individuals were tested in four separate sessions; in one session one fragrance was administered. ANS parameters recorded were skin temperature, skin conductance, breathing rate, pulse rate, blood oxygen saturation and systolic as well as diastolic blood pressure. Subjective experience was assessed in terms of mood, calmness and alertness on visual analog scales. In addition, fragrances were rated in terms of pleasantness, intensity and stimulating property. Inhalation of (+)-limonene led to increased systolic blood pressure, subjective alertness and restlessness. Inhalation of (-)-limonene caused an increase in systolic blood pressure but had no effects on psychological parameters. Inhalation of (-)-carvone caused increases in pulse rate, diastolic blood pressure and subjective restlessness. After inhalation of (+)-carvone increased levels of systolic as well as diastolic blood pressure were observed. Correlational analyses revealed that changes in both ANS parameters and self-evaluation were in part related to subjective evaluation of the odor and suggest that both pharmacological and psychological mechanisms are involved in the observed effects. In conclusion, the present study indicates that: (i) prolonged inhalation of fragrances influences ANS parameters as well as mental and emotional conditions; (ii) effects of fragrances are in part based on subjective evaluation of odor; (iii) chirality of odor molecules seems to be a central factor with respect to the biological activity of fragrances.

Potentiation of GABAA receptors expressed in Xenopus oocytes by perfume and phytoncid.

To study the effects of perfume and phytoncid on GABAA receptors, ionotropic GABAA receptors were expressed in Xenopus oocytes by injecting mRNAs that had been prepared from rat whole brain. Essential oil, perfume and such phytoncid as leaf alcohol, hinokitiol, pinene, eugenol, citronellol and citronellal potentiated the response in the presence of GABA at low concentrations (10 and 30 microM), possibly because they bound to the potentiation-site in GABAA receptors and increased the affinity of GABA to the receptors. Since it is known that the potentiation of GABAA receptors by benzodiazepine, barbiturate, steroids and anesthetics induces the anxiolytic, anticonvulsant and sedative activity or anesthetic effect, these results suggest the possibility that the intake of perfume or phytoncid through the lungs, the skin or the intestines modulates the neural transmission in the brain through ionotropic GABAA receptors and changes the frame of the human mind, as alcohol or tobacco does.