The Potential Link between Episodes of Diverticulitis or Hemorrhoidal Proctitis and Diets with Selected Plant Foods: A Case-Control Study

Diverticulitis and hemorrhoidal proctitis in the population are significant public health problems. We studied the potential association between the intake of certain plant foods and diverticulitis or hemorrhoidal episodes through a case-control study including 410 cases and 401 controls. We used a semiquantitative food frequency questionnaire. The intake was additionally quantified according to a 24 h recall. The plant foods or derived food products were categorized by their main chemical components into ethanol, caffeine/theine/theobromine, capsaicin, alliin, acids, eugenol, and miscellaneous foods such as curcumin. The mean score for overall intake of plant foods under consideration was 6.3 points, and this was significantly higher in cases (8.5) than in controls (4.1). Overall intake was similar in cases presenting with diverticulitis or hemorrhoidal proctitis. Cases had 13 times the odds of being in the upper quartile for overall intake (>7 points), compared to controls. Explanatory logistic regression models showed that the strongest association with diverticulitis and hemorrhoidal proctitis was shown by the chemical food group of capsaicin, followed by ethanol, eugenol, caffeine/theine/theobromine, and acids. Neither alliin nor miscellaneous food groups showed any association. High, frequent consumption of capsaicin, followed by ethanol, eugenol, caffeine/theine/theobromine, and acids increase the risk of diverticulitis and hemorrhoidal proctitis.

Dual role of eugenol on chronic gastric ulcer in rats: Low-dose healing efficacy and the worsening gastric lesion in high doses

This study evaluated the gastric healing activity of eugenol, the main bioactive compound from clove (Syzygium aromaticun) essential oil. Five groups of female Wistar rats were submitted to acetic acid-induced ulcer model and treated with Vehicle (1 mL/kg, p.o.), eugenol (1, 10 or 100 mg/kg, p.o) or omeprazole (20 mg/kg, p.o), twice a day, by seven or fourteen days. Macroscopic, microscopic and biochemical analyses were performed in the ulcerated site. Eugenol (1 mg/kg, p.o) administered by 7 or 14 days accelerated the gastric healing process by 33% and 52%, respectively. The healing actions of eugenol were accompanied by the rescue on the histological architecture and the normalization of the superoxide dismutase and catalase activity. Moreover, eugenol (1 mg/kg, p.o) reduced the gastric mucosal myeloperoxidase activity and increased the mucin secretion. In contrast, eugenol at a dose of 100 mg/kg administered by 7 days enhanced 49% the ulcerated area, but at 10 mg/kg did not change the ulcer area after 7 or 14 days of treatment. Thus, despite the undesirable results due to the worsening of the gastric lesion with the use of eugenol in high doses, the antiulcer potential of this compound is evident and manageable in an adequate dose.

Acute Administration of Methyleugenol Impairs Hippocampus-Dependent Contextual Fear Memory and Increases Anxiety-like Behavior in Mice

Methyleugenol (ME) as a natural essential oil in many plant species is widely used in human food and beverage for its fragrance and possible beneficial health effects. Previous chronic or subacute studies in rodents show that ME mainly causes liver toxicity. However, whether and how acute ME affects the central nervous system still remain elusive. Here, we found that ME administrated into the hippocampus impaired the acquisition of hippocampus-dependent contextual fear memory in mice (ME vs control: repeated-measures two-way ANOVA, F_(5,70) = 2.937, p < 0.05; Fisher test, p < 0.05, respectively, 53 ± 5.2% vs 73 ± 7.6% during trial 4 and 46.8 ± 6% vs 74.5 ± 9.3% during trial 5). Meanwhile, acute ME impaired hippocampal CA1 long-term potentiation (LTP; ME vs control: independent t-test, p < 0.01, 110.6 ± 1.8% vs 133.3 ± 5.6%) while facilitated long-term depression (LTD; p < 0.01, 75.7 ± 3.4% vs 88.6 ± 1.7%) in mice brain slices and inducing a decrease in learning-dependent phosphorylation of Ser831 (ME vs control: independent t-test, p < 0.001, 0.87 ± 0.03 vs 1.23 ± 0.03) and Ser845 (p < 0.01, 0.42 ± 0.07 vs 0.97 ± 0.14) sites of excitatory glutamate AMPA receptor subunit 1 (GluA1) in the hippocampus, which may be the underlying mechanisms of impairment of hippocampus-dependent learning. In addition, intrahippocampal infusion of ME also increased anxiety-like behaviors in mice. These results suggested that acute ME impaired the hippocampus function at behavioral, cellular, and molecular levels, indicating the potential risks of ME on the central nervous system.

Efficacy of Benzocaine, Eugenol, and Menthol as Anesthetics for Freshwater Angelfish

For the production and commercialization of ornamental fish species, it is indispensable to collect biometric data that facilitate the selection of animals for trade and genetic improvement of the stock. However, during the handling process, fish receive more stress if proper anesthetics are not used. Thus, application of appropriate anesthetics is an important tool for minimizing stress in animals. The objective of this study was to determine the effective concentrations of benzocaine, eugenol, and menthol for achieving anesthesia in Freshwater Angelfish Pterophyllum scalare and to develop induction and recovery response curves for different concentrations of these anesthetics. In total, 75 fish were exposed to five concentrations of the three anesthetics in a completely randomized design: benzocaine at 60, 85, 110, 135, and 160 mg/L; eugenol at 40, 80, 120, 160, and 200 mg/L; and menthol at 50, 75, 150, 200, and 250 mg/L. Each concentration (5 fish/concentration) consisted of five replicates, with each replicate represented by a single fish. The results indicated that the tested substances met the criteria of anesthetic efficiency. The effective concentrations of benzocaine, eugenol, and menthol for the anesthesia of Freshwater Angelfish were identified as 89.25, 90.6, and 92.1 mg/L, respectively.

Effect of repeated exposure to AQUI-S® on the viability and growth of Neoparamoeba perurans

There have been recent efforts amongst immunologists to develop approaches for following individual fish during challenges with viral and bacterial pathogens. This study contributes to assessing the feasibility of using such approaches to study amoebic gill disease (AGD). Neoparamoeba perurans, agent of AGD, has been responsible for widespread economic and fish loss in salmonid aquaculture. With the emergence of AGD in Europe, research into infection dynamics and host response has increased. This study investigated the effect of repeat exposure to anaesthesia, a necessary requirement when following disease progression in individual fish, on N. perurans. In vitro cultures of N. perurans were exposed every 4 days over a 28-day period to AQUI-S^® (isoeugenol), a popular anaesthetic choice for AGD challenges, at a concentration and duration required to sedate post-smolt salmonids. Population growth was measured by sequential counts of amoeba over the period, while viability of non-attached amoeba in the culture was assessed with a vital stain. AQUI-S^® was found to be a suitable choice for in vivo ectoparasitic challenges with N. perurans during which repetitive anaesthesia is required for analysis of disease progression.

Immunotherapeutic Potential of Eugenol Emulsion in Experimental Visceral Leishmaniasis

BACKGROUND

The therapy of visceral leishmaniasis (VL) is limited by resistance, toxicity and decreased bioavailability of the existing drugs coupled with dramatic increase in HIV-co-infection, non-availability of vaccines and down regulation of cell-mediated immunity (CMI). Thus, we envisaged combating the problem with plant-derived antileishmanial drug that could concomitantly mitigate the immune suppression of the infected hosts. Several plant-derived compounds have been found to exert leishmanicidal activity via immunomodulation. In this direction, we investigated the antileishmanial activity of eugenol emulsion (EE), complemented with its immunomodulatory and therapeutic efficacy in murine model of VL.

METHODOLOGY/PRINCIPAL FINDINGS

Oil-in-water emulsion of eugenol (EE) was prepared and size measured by dynamic light scattering (DLS). EE exhibited significant leishmanicidal activity with 50% inhibitory concentration of 8.43±0.96 μg ml-1 and 5.05±1.72 μg ml─1, respectively against the promastigotes and intracellular amastigotes of Leishmania donovani. For in vivo effectiveness, EE was administered intraperitoneally (25, 50 and 75 mg/kg b.w./day for 10 days) to 8 week-infected BALB/c mice. The cytotoxicity of EE was assessed in RAW 264.7 macrophages as well as in naive mice. EE induced a significant drop in hepatic and splenic parasite burdens as well as diminution in spleen and liver weights 10 days post-treatment, with augmentation of 24h-delayed type hypersensitivity (DTH) response and high IgG2a:IgG1, mirroring induction of CMI. Enhanced IFN-γ and IL-2 levels, with fall in disease-associated Th2 cytokines (IL-4 and IL-10) detected by flow cytometric bead-based array, substantiated the Th1 immune signature. Lymphoproliferation and nitric oxide release were significantly elevated upon antigen revoke in vitro. The immune-stimulatory activity of EE was further corroborated by expansion of IFN-γ producing CD4+ and CD8+ splenic T lymphocytes and up-regulation of CD80 and CD86 on peritoneal macrophages. EE treated groups exhibited induction of CD8+ central memory T cells as evidenced from CD62L and CD44 expression. No biochemical alterations in hepatic and renal enzymes were observed.

CONCLUSIONS

Our results demonstrate antileishmanial activity of EE, potentiated by Th1 immunostimulation without adverse side effects. The Th1 immune polarizing effect may help to alleviate the depressed CMI and hence complement the leishmanicidal activity.

Inhibition of key enzymes related to diabetes and hypertension by Eugenol in vitro and in alloxan-induced diabetic rats

The present study investigated the effect of treating diabetic rats with eugenol (EG). In vitro enzyme activity was measured in the presence of eugenol, and it was found to inhibit pancreatic α-amylase (IC(50) = 62.53 µg/mL) and lipase (IC(50) = 72.34 µg/mL) as well as angiotensin converting enzyme (ACE) activity (IC50 = 130.67 µg/mL). In vivo, EG reduced the activity of amylase in serum, pancreas and intestine also the peak level of glucose by 60% compared to diabetic rats. Furthermore, eugenol similar to acarbose reduced serum glycosylated hemoglobin (HbA1c), lipase and ACE levels. In addition, treatments with EG showed notable decrease in serum total-cholesterol, triglycerides and low density lipoprotein-cholesterol levels with an increase of high density lipoprotein-cholesterol. Overall, EG significantly reverted back to near normal the values of the biochemical biomarkers such as transaminases (AST&ALT), alkaline phosphatase (ALP), creatine phosphokinase (CPK) and gamma-glutamyl transpeptidase (GGT) activities, total-bilirubin, creatinine, urea and uric acid rates.

[Clinical and immunomodulating activity of root canal fillers]

The study revealed higher frequency and intensity of pain after root canal filling with paste Foredent or Zn-eugenol paste in patients with bronchial asthma and showed significant change in the level of sIgA in saliva fluid depending on the filling material and reflecting the effect of root pastes on the local immunity of the oral cavity.

Eugenol anesthesia in African clawed frogs (Xenopus laevis) of different body weights

The objective of this prospective study was to determine the duration of anesthesia in Xenopus laevis frogs of different body weights relative to exposure time in a eugenol (350 microL/L) bath. Two groups of 5 female frogs each weighing 7.5 +/- 2.1 g (small frogs) or 29.2 +/- 7.4 g (medium frogs) were used. The acetic acid test (AAT), withdrawal reflex, righting reflex, heart rate, and blood oxygen saturation were used to evaluate CNS depression after eugenol bath administration. No responses to the AAT, withdrawal reflex, and righting reflex were seen for 1 h (small frogs) or 0.5 h (medium frogs) after immersion in a eugenol bath for 5 or 10 min, respectively. Oxygen saturation was not affected by anesthesia, but heart rate was depressed for as long as 1 h in both groups of frogs. Surgical anesthesia evaluated by using skin and abdominal incisions revealed that small frogs were anesthetized for a maximum of 15 min compared with 30 min in medium frogs. Frogs showed no ill effects 24 h after eugenol bath administration. These results suggest that body weight is an important parameter to consider when using a eugenol bath for anesthesia of Xenopus frogs.

Quantitative risk assessment of contact sensitization: clinical data to assess utility of the model

BACKGROUND

Contact hypersensitivity quantitative risk assessment (QRA) for fragrance ingredients is being used to establish new international standards for all fragrance ingredients that are potential skin sensitizers.

OBJECTIVE

The objective was to evaluate the retrospective clinical data on three fragrance ingredients in order to provide a practical assessment of the predictive value of the QRA approach. It is important to have data to assess that the methodology provides a robust approach for primary prevention of contact sensitization induction for fragrance ingredients identified as potential sensitizers.

METHODS

This article reviews clinical data for three fragrance ingredients-cinnamic aldehyde, citral, and isoeugenol-to assess the utility of the QRA approach for fragrance ingredients.

RESULTS

This assessment suggests that had the QRA approach been available at the time standards were established for these fragrance ingredients, the clinical response might have been noticeably improved. Prospectively, with the establishment of QRA-derived standards, there should be a continued downward trend in patch test-positive rates for cinnamic aldehyde, citral, and isoeugenol over time.

CONCLUSION

While it is recognized that the availability of retrospective data is limited, a longitudinal review of these data gives confidence that the QRA approach should be an effective tool for primary prevention. This study also highlights the importance of continued active monitoring of clinical patch-test data for fragrance ingredients.

Frequency of allergic contact dermatitis to isoeugenol is increasing: a review of 3636 patients tested from 2001 to 2005

BACKGROUND

Isoeugenol is an important fragrance allergen. The cosmetic industry was recommended voluntarily to reduce concentrations of isoeugenol in finished cosmetic products from 0.2% to 0.02% in 1998. It was suspected that this would reduce the incidence of patch test positivity in individuals undergoing routine patch testing after approximately 2-3 years (the Dillarstone effect).

OBJECTIVES

To review our patch test data since the change in practice by industry, to see if there has been an observable decrease in isoeugenol contact sensitivity.

METHODS

We retrospectively analysed all subjects patch tested to isoeugenol 1% pet. in the St John's Department of Cutaneous Allergy over a period of 5 years, commencing 3 years after the changes.

RESULTS

We identified 3636 subjects, 97 of whom were positive for isoeugenol. Year-on-year incidence shows an increasing trend, with an overall incidence of 2.67%. Using the exact Cochran-Armitage test, this ascending trend is statistically significant (P = 0.0182). Seventy-two of 97 isoeugenol-positive subjects were also positive to fragrance mix I. Other fragrances positive in these 97 patients included Myroxylon pereirae (30%), Evernia prunastri (22%) and eugenol (15%).

CONCLUSIONS

We suspect that the increasing trend may be due to allergen substitution with compounds chemically related to isoeugenol, or which hydrolyse to isoeugenol itself.

Patch test results with patients' own perfumes, deodorants and shaving lotions: results of the IVDK 1998-2002

OBJECTIVE

Assessment of the value of patch testing patients' own perfumes, eau de toilette, deodorants and shaving lotions with regard to diagnosing contact allergy to fragrances, and an analysis of the spectrum of concurrent patch test reactions to single fragrance allergens.

STUDY DESIGN

Data of the Information Network of Departments of Dermatology (IVDK; http://www.ivdk.org) regarding patch test results with above products brought in by the patient, considered as possible cause of contact dermatitis, were retrospectively analysed. Between 1998 and 2002, 1468 patients were patch tested with 2557 single products (deodorants, n = 1094; eau de toilette, n = 598; perfume, n = 530; and pre- or after-shave, n = 325; remainder not classifiable), mostly 'as is'.

RESULTS

Positive reactions were observed in 129 patients (to 191 products). In 58 of these patients, no further patch test reactions to the fragrance mix (FM-I), Myroxylon pereirae resin (balsam of Peru) or 4-(4-hydroxy-4-methyl-pentyl)-3-cyclohexencarboxaldehyde (e.g. Lyral(R)) were found. A strong association between contact sensitivity to the above commercial allergens and positive reactions to products was observed. Some single compounds such as ylang-ylang oil, propolis and especially oak moss absolute are important allergens in the 'perfume-positive' subgroup, but less in a subgroup positive to own deodorants.

DISCUSSION

Patch testing this scope of products, brought in by the patient, can be regarded as a simple, safe and effective method to diagnose clinically relevant contact sensitization - the more so, as the composition of such products is ever-changing, and the sensitivity of established 'screening allergens' is thus insufficient.

[Case of cutaneous necrosis in African clawed frogs Xenopus laevis after the topical application of eugenol]

Case of cutaneous necrosis in African Clawed frogs Xenopus laevis after the topical application of eugenol. African Clawed frogs showed necrotic cutaneous lesions after a topical application of high concentrations of eugenol, an analgesic and anesthetic agent. Microscopically, ulceration of the epidermis, a loss of mucous and serous glands as well as an infiltration of inflammatory cells were observed.

Influence of eugenol-containing temporary cement on bonding of self-etching adhesives to dentin

PURPOSE

To investigate the influence of eugenol-containing temporary cement on bonding of resin composite to dentin mediated by self-etching adhesives.

MATERIALS AND METHODS

Flat dentin surfaces were produced by grinding of extracted human molars. The dentin surfaces were either used directly or after a one-week exposure to a zinc oxide-eugenol cement (IRM). A resin composite (Herculite XRV) was bonded to the dentin surfaces following treatment with 1 of 6 self-etching adhesives (AdheSE, Adper Prompt L-Pop, Clearfil SE Bond, iBond, OptiBond Solo Plus - Self-Etch Adhesive System, and Xeno III). An adhesive system containing 0.5 M EDTA as dentin conditioner (Gluma Classic) was included as negative control, and an etch-and-rinse adhesive system (OptiBond FL) was included as positive control. After storage in water at 37 degrees C for 1 week, the bonded specimens were fractured in shear (n = 8 in each group).

RESULTS

Previous contact of dentin with zinc oxide-eugenol cement significantly decreased the bond strength mediated by the negative control and did not affect the bond strength mediated by the positive control. For the self-etching adhesives, no effect was found of previous contact with zinc oxide-eugenol cement. With and without previous contact with zinc oxide-eugenol cement, the etch-and-rinse adhesive system yielded a significantly higher bond strength than all other adhesive systems.

CONCLUSION

Previous contact with zinc oxide-eugenol cement did not decrease the bond strength of resin composite to dentin mediated by self-etching adhesives. This finding suggests that eugenol-containing temporary cements may be safe to use in combination with self-etching adhesives.

Deodorants: an experimental provocation study with isoeugenol

Axillary dermatitis is common and overrepresented in people with contact allergy to fragrances. Many people suspect their deodorants to be the incriminating products. In order to investigate the significance of isoeugenol in deodorants for the development of axillary dermatitis when used by people with and without contact allergy to isoeugenol, patch tests with deodorants and ethanol solutions with isoeugenol, as well as repeated open application tests (ROAT) with roll-on deodorants with and without isoeugenol at various concentrations, were performed in 35 dermatitis patients, 10 without and 25 with contact allergy to isoeugenol. A positive ROAT was observed only in patients hypersensitive to isoeugenol (P<0.001) and only in the axilla to which the deodorants containing isoeugenol had been applied (P<0.001). Deodorants containing isoeugenol in the concentration range of 0.0063-0.2% used 2 times daily on healthy skin can thus elicit axillary dermatitis within a few weeks in people with contact allergy to isoeugenol.

Contact allergy to isoeugenol and its derivatives: problems with allergen substitution

A total of 2261 (808 male, 1453 female) consecutive patients attending contact dermatitis clinics were patch tested to isoeugenol and its derivatives listed in the EU Inventory of Fragrance Ingredients. Positive reactions were found to isoeugenol in 40, transisoeugenol in 40, isoeugenyl acetate in 19, isoeugenyl benzoate in 4, isoeugenyl phenylacetate in 16, isoeugenyl methyl ether in 6 and benzyl isoeugenyl ether in 2 patients. There was a concomitant reaction to isoeugenol in 36/40 of those positive to transisoeugenol, 13/19 of those to isoeugenyl acetate, 3/4 of those to isoeugenyl benzoate and 15/16 of those to isoeugenyl phenylacetate but in none of those 6 positive to isoeugenyl methyl ether and in neither of those 2 positive to benzyl isoeugenyl ether. Concomitant contact allergy between isoeugenol and its derivatives may occur through chemical cross-reactivity or local skin metabolism of the derivatives. It is more commonly observed with the esters rather than the ethers. Isoeugenyl acetate has been proposed as an alternative to isoeugenol, but there is a high degree of concomitant reactivity with isoeugenol.

Correlations of patch test reactivity and the repeated open application test (ROAT)/provocative use test (PUT)

The clinical relevance of patch test reactions is often difficult to determine. Use tests have been developed to further evaluate the significance of patch test results. We review studies that have defined correlations between the threshold concentrations at patch testing and the outcome of use tests for particular chemical allergens. Results of patch testing with serial dilutions of colophony, cinnamic aldehyde, and isoeugenol have shown concordance with the outcome of use tests. On the other hand, poor correlations between patch test reactivity and the use test were demonstrated in another study on isoeugenol and on studies on hydroxycitronellal, formaldehyde and chromium. These studies shed light on some factors that may influence the outcome of use tests. Individual factors such as patch test sensitivity, regional variations in reactivity and percutaneous penetration appear to play significant roles. Exposure dose, length of time of exposure, and other factors yet to be determined also affect degree of reactivity. Because patients with low thresholds in serial dilution patch testing are known to react to lower concentrations of products at use testing, results of these studies may be used to help identify subjects with a high risk of developing clinical disease. From the public health standpoint, data obtained may be used as a guide in limiting exposure concentrations in consumer products.

Mycetoma of the maxillary sinus: endodontic and microbiological correlations

OBJECTIVE

The purpose was to show the capacity of zinc oxide and eugenol to affect the growth of Aspergillus fumigatus.

STUDY DESIGN

An in vitro microbiological analysis was conducted on samples from infected maxillary sinuses and on 3 different endodontic sealers.

RESULTS

Tests showed that zinc oxide in solution favors the growth of Aspergillus fumigatus, while eugenol inhibits this growth, even when mixed with zinc oxide powder. This inhibiting effect decreases over time. A reduced effectiveness was demonstrated over a 75-day period.

CONCLUSIONS

The hypothesis is that the diminishing concentration of eugenol over time in endodontic sealers allows the zinc oxide to support growth of Aspergillus fumigatus. This is reinforced by clinical experience, where mycetoma has developed years after endodontic therapy with excess sealer in the maxillary sinus.

Correlation of tumors with DNA adducts from methyl eugenol and tamoxifen in rats

Data on percent tumors in male rats after administration of methyl eugenol, obtained from the National Toxicology Program, or tamoxifen were plotted on a linear scale for percent tumors against the dose on a logarithmic scale. Data on (32)P-postlabelled DNA adducts were plotted on the same graphs for each of these two compounds in order to correlate adduct formation and tumor incidence with dose. The resulting graph for methyl eugenol showed a linear response for both adduct formation and tumor incidence. The threshold dose of administered methyl eugenol for adduct formation (zero adducts) was 10(19.3) molecules of methyl eugenol/kg/day, which compared with a threshold of 10(20.1) molecules of methyl eugenol/kg/day for tumor formation; however, 30 adducts/10(8) nucleotides was the threshold for tumor formation. The dose of tamoxifen for adduct formation fit an exponential plot slightly better than a linear plot, but reached minimal values close to the threshold of 10(18.7) molecules of tamoxifen/kg/day for tumor formation. These data confirm that tumor formation coincides with adduct formation and that both have thresholds, or at least reach minimal values, above levels to which humans are exposed. Although the threshold dose for tumor formation from tamoxifen is only about 10x above the dose received by women at risk for breast cancer, this should be an adequate safety margin. The safety factor for methyl eugenol is several orders of magnitude; therefore, there should be no cause for concern for humans at current levels of exposure.

Contact allergy to fragrances: frequencies of sensitization from 1996 to 2002. Results of the IVDK*

Increasing frequencies of sensitization to the fragrance mix (FM) have been acknowledged as a serious problem for many years. It is well known that the single compounds (SCs) of the FM contribute differently to the FM patch rest reactions. In this study, we were interested in the time trends of the FM, the SCs, Myroxylon pereirae resin (MP; balsam of Peru) and oil of turpentine (OT) as possible further indicators of perfume allergy and analysed the data collected by the Information Network of Departments of Dermatology multicentre project from 1996 to 2002. During the study period (1996-2002), the FM [8% petrolatum (pet.)], MP (25% pet.) and OT (1% pet.) were tested in 59,298, 59,334 and 59,478 patients, respectively. SCs were tested in a selected group of patients, ranging from n = 1083 to n = 1924 per year. A significant increase in the proportions of patients with positive reactions to FM, MP and OT between 1996 and 1998 is noted, and a significant decline from 1999 to 2002 (Cochrane Armitage trend test, P < 0.0001). The highest frequency of sensitization to the FM was 13.1% in 1999, and the lowest 7.8% in 2002. The number of concomitant reactions to OT, a surrogate marker for terpenes, in FM-positive patients was significantly increased between 1997 and 1999. Reactions to SCs in FM-positive patients were observed in 29.9% (oak moss absolute) to 5.9% (geraniol). There was no time trend in reactions to SCs, although the relative share was increased for isoeugenol, cinnamic aldehyde and geraniol in 1999. In summary, we report for the first time, a significant decline in sensitization to the FM, very probably due to a reduced exposure (less potent allergens used in fine fragrances, possibly less use of natural ingredient-based cosmetics and lowered use concentration of important fragrance allergens). The differences in ranking of SCs could stimulate (a) a redefinition of the FM and (b) a differentiated preventive and regulatory approach, with oak moss and isoeugenol being regulated strictly by prohibition, concentration limits further reconsidered and/or health warnings and clearly less noxious substances like geraniol treated less restrictively.

Reproducible prediction of contact allergenic potency using the local lymph node assay

A considerable body of data has been accumulated which demonstrates that the local lymph node assay (LLNA) can provide a valuable estimation of the contact allergenic potency of a substance. This estimate is obtained via interpolation of the LLNA dose-response curve and is expressed as the concentration of the chemical required to evince a 3-fold stimulation of proliferation in lymph nodes draining the site of application compared to the vehicle-treated controls (EC3). It has also been shown that the EC3 estimates are reproducible and are stable over time. In the present work, we have extended this information by a demonstration of the inherent biological variability surrounding EC3 estimation, using data derived (from a single laboratory) from the testing of isoeugenol as a positive control. Isoeugenol gave EC3 values ranging from 0.5 to 2.6% (n = 29), with a mean and standard deviation of 1.2 +/- 0.6%. Given that EC3 values for a variety of contact allergens range over several orders of magnitude, these results further endorse the utility of EC3 values as a reliable indicator of human contact allergenic potency.

Fragrance allergy in patients with hand eczema - a clinical study

Fragrance allergy and hand eczema are both common among dermatological patients. Fragrance mix (FM) and its constituents have a recognized relevance to exposure to fine fragrances and cosmetic products. Based on extensive chemical analysis and database search, a new selection of fragrances was established, including 14 known fragrance allergens present in products to which hand exposure would occur. A non-irritating patch-test concentration for some fragrances was established in 212 consecutive patients. 658 consecutive patients presenting with hand eczema were patch tested with the European standard series and the developed selection of fragrances. 67 (10.2%) of the 658 patients had a positive reaction to 1 or more of our selection of fragrance chemicals present in the new selection. The most common reactions to fragrances not included in the FM were to citral, Lyral (hydroxyisohexyl-3-cyclohexene carboxaldehyde) and oxidized l-limonene. A concomitant reaction to the FM identified potential fragrance allergy in less than (1/2) of these patients. Exposure assessment and a statistically significant association between a positive patch test to our selected fragrances and patients' history support the relevance of this selection of fragrances. Those with a positive reaction to our selected fragrances were significantly more likely to have 1 or more positive patch tests in the standard series. This observation is the basis for the hypothesis concerning cross-reactivity and the effect of simultaneous exposure. The study found that fragrance allergy could be a common problem in patients with eczema on the hands.

Adverse reactions associated with the use of eugenol in dentistry

Eugenol is a material commonly used in dentistry with few reported side effects. It is not however, a bio-friendly material when in contact with oral soft tissues. It can produce both local irritative and cytotoxic effects, as well as hypersensitivity reactions. Here we report on two cases of adverse local reaction to eugenol, contained within a temporary restorative material and a temporary cementation material respectively, which illustrate these problems.

Occupational respiratory hypersensitivity in dental personnel

OBJECTIVE

The aim was to study the causes of respiratory hypersensitivity in dental personnel based on the statistics of the Finnish Register of Occupational Diseases (FROD; 1975-1998) and the patient material of the Finnish Institute of Occupational Health (FIOH; 1990-1998).

METHODS

Details about the cases of respiratory hypersensitivity were compiled from the FROD. The occupational rhinitis diagnoses studied at the FIOH were based on work-related symptoms and a change in the status of the nasal mucosa during challenge testing; and the diagnosis of occupational asthma based on reactions in challenge testing, or on IgE positivity and peak flow monitoring at work and during days off.

RESULTS

A total of 64 cases of occupational respiratory diseases (ORDs) was diagnosed in dental personnel during 1975 to 1998 according to the FROD; two cases in 1975 to 1989, and 62 in 1990 to 1998. Twenty-eight cases were of occupational asthma (18 caused by methacrylates), 28 occupational rhinitis (six caused by methacrylates), seven allergic alveolitis and one organic dust toxic syndrome (ODTS). The non-acrylate-material diagnosed in 1990-1998 at the FIOH comprised three cases of asthma and one of rhinitis caused by chloramine-T (sodium- N-chlorine- p-toluene sulphonamide); as well as one case of asthma, seven cases of rhinitis, and two cases of combined rhinitis and conjunctivitis caused by natural rubber latex (NRL). Furthermore, one case of occupational rhinitis caused by Nobetec containing colophony was diagnosed. The incidence rate (IR) of ORD increased from 0 in 1988 to a peak of 105.1 new cases per 100,000 working years in 1995. During the last observation year, i.e. 1998, the IR was 55 new cases per 100,000 workers. The IR in dental personnel was lower than in the whole working population in Finland up until 1992, but since then has been greater than in the whole population, peaking in 1995 when the IR of dental personnel was 2.55 times greater than in the whole population.

CONCLUSION

The present study shows the increasing frequency of respiratory hypersensitivity among dental personnel. Besides methacrylates, important causes of respiratory hypersensitivity are NRL and chloramine-T.

The time-dose-response relationship for elicitation of contact dermatitis in isoeugenol allergic individuals

The elicitation response in allergic contact dermatitis is dose dependent, but the time-concentration relationship for elicitation has not previously been described. In this study 27 isoeugenol-sensitive patients participated in serial dilution patch tests with isoeugenol and a double-blinded Repeated Open Application Test (ROAT) using two concentrations of isoeugenol, 0.2 and 0.05%. Seven controls without isoeugenol allergy were also included. The participants applied 3.72 +/- 1.57 (mean +/- SD) mg/cm(2) of coded isoeugenol solutions twice a day to a 3 x 3 cm(2) area on the volar aspect of the right and left arm, respectively. For each test site the applications continued until a reaction appeared or for a maximum of 28 days. The minimal criteria for a positive reaction regarded as allergic contact dermatitis was persistent erythema at the ROAT test site. All controls were negative and 16/24 (66.7%) of the included isoeugenol-sensitive subjects showed a positive ROAT to the 0.2% solution within the study period (Fisher's test, p = 0.0024). Ten of the positive patients also reacted to the 0.05% solution. The median number of days until a positive reaction to the 0.2% solution was 7 days and was 15 days for the 0.05% solution. There was a highly significant correlation between the patients' patch test threshold and the number of days until a positive ROAT. In conclusion, the time until an isoeugenol allergic individual reacts in a ROAT depends on the individual sensitivity as well as the exposure concentrations; for low concentrations of the allergen or low degree of sensitivity, the allergic contact dermatitis may develop after several weeks of exposure. Therefore, a negative ROAT after 7 days may be a false negative.

Methyleugenol in Ocimum basilicum L. Cv. genovese gigante

Ocimum basilicum cv. Genovese Gigante is the basil cultivar used the most in the production of a typical Italian sauce called pesto. The aromatic composition of plants at different growth stages was determined. Plants from different areas of northwestern Italy were analyzed at 4 and 6 weeks after sowing and showed methyleugenol and eugenol as the main components. The content of these compounds was correlated with plant height rather than plant age. Particularly, methyleugenol was predominant in plants up to 10 cm in height, whereas eugenol was prevalent in taller plants. These results are important in the evaluation of risk to human health posed by dietary ingestion of methyleugenol contained in pesto.

[Analysis of contact dermatitis by cytokines 4--Skin sensitization of biphenyl compounds]

Clove buds oil is one of very important natural essential oil with a typical spicy note and also known as a source of eugenol. These phenol compounds, which have the strong perfume of clove, are widely used not only as an analgesic and antiseptic agent in dentistry. However, the problem is that the phenol compounds caused sensitization on the skin occasionally. We reported that the skin sensitization by eugenol and its derivatives was detected in the guinea pig maximization test (GPMT) and also confirmed that dehydrodi-eugenol, a biphenyl compound of eugenol, did not show the skin sensitization. To discuss more, we examined the skin sensitization by several phenol compounds and its biphenyl ones. Consequently, we confirmed that the skin sensitization by biphenyl compounds more remarkably decreased than that by phenol compounds (monomer).

Isoeugenol is an important contact allergen: can it be safely replaced with isoeugenyl acetate?

The prevalence of contact allergy to the fragrance mix in individuals with eczema is up to 10%. Within the mix, isoeugenol (CAS 97-54-1) is an important individual allergen. Until May 1998, the IFRA (International Fragrance Association) guidelines suggested that isoeugenol could safely be used at a level of 0.2% in consumer products. In May 1998, IFRA recommended that isoeugenol should not be used at a level that exceeds 0.02% in consumer products, but did not provide guidance on allergen substitution. An alternative to isoeugenol, based on aroma and absence of guidelines on use, is isoeugenyl acetate (CAS 93-29-8). 155 consecutive subjects were patch tested to isoeugenyl acetate (1.2%, 0.4%, 0.13% eth.) and isoeugenol 1% pet. 6 (3.9%) had an allergic reaction to 1.2% isoeugenyl acetate at D4. The reactions to the other 2 dilutions tended to be graded. 8 individuals had at least a palpable erythema by D4 to isoeugenol 1% pet. The majority of individuals allergic to isoeugenol were also intolerant of isoeugenyl acetate. Effective labelling of fragrance substances on consumer products will facilitate monitoring of exposure.

Fragrance and contact allergens in vitro modulate the HLA-DR and E-cadherin expression on human epidermal Langerhans cells

BACKGROUND

Epidermal Langerhans cells (LCs) play a critical role in the induction of contact hypersensitivity. The LCs leave the skin, move to the regional lymph nodes and present the allergens embedded in the HLA-DR molecule to naive T-lymphocytes. To allow LC emigration from the epidermis, E-cadherin must be downregulated. In this study, we have examined the early events that occur in the human epidermis after exposure to three strong contact sensitizers and two commonly used fragrances by examining alterations of E-cadherin and HLA-DR expression.

METHODS

To determine whether E-cadherin and HLA-DR levels were modulated by allergens, flow cytometry was utilized to evaluate E-cadherin and HLA-DR expression on human epidermal LCs exposed to the different chemicals for 4 h at 37 degrees C.

RESULTS

In vitro stimulation with the contact sensitizers isoeugenol, cinnamaldehyde, 2,4, 6-trinitrobenzenesulfonic acid, Bandrowski'sbase, or p-phenylene diamine resulted in a dose-dependent decrease of HLA-DR expression on the surface of LCs without affecting the number of positive cells. These contact allergens induced a downregulation of E-cadherin expression as well as a significant decrease of the percentage of E-cadherin-positive cells. Incubation with an irritant, sodium lauryl sulfate, did not significantly change HLA-DR and E-cadherin expression.

CONCLUSIONS

Based on the alteration of E-cadherin and HLA-DR expression of human LCs under short-term exposure conditions, there was a clear difference between contact sensitizers and a well-characterized irritant. For the first time, the ability of fragrance allergens in dipropylene glycol, a widely used vehicle in fragrance and cosmetic industries, was demonstrated to induce human LC phenotypic alterations. In combination with a series of in vitro tests, this rapid and simple method should help to detect the sensitizing potential of a substance to be applied onto the human skin as an alternative to animal testing.

The relationship between habitual clove cigarette smoking and a specific pattern of dental decay in male bus drivers in Jakarta, Indonesia

This study has been conducted to establish the relationship between habitual smoking of clove cigarettes and a specific type of dental decay. A retrospective cohort study of 1,160 bus drivers in Jakarta who smoked clove cigarettes and non-smokers showed that a specific type of decay occurs in terms of form, location and pathology. The prevalence was 55.8%. The type of decay is affected by the number of years of smoking and the number of cigarettes smoked each day. Thirty-two percent of the lesions were on the buccal surfaces of the upper teeth, 39.3% on the buccal surfaces of the lower teeth, and 18% of palatal surfaces were affected. The prevalence of clove cigarette caries was related to years of smoking and numbers of cigarettes smoked per day. Of the men who smoked 10 years or less, 27% had caries. The prevalence increased to 79.6% for those smoking for 11-15 years. For those smoking for more than 15 years the prevalence was 89.3%. The relative risk of those smoking 7-12 cigarettes a day was 2.66 (p<0.0001) compared to those smoking 0-6 cigarettes a day. The relative risk increased to 3.19 in those smoking 13-18 cigarettes and 2.96 (p<0.0001) in men smoking more than 18 cigarettes per day.

Quantitative aspects of isoeugenol contact allergy assessed by use and patch tests

The clinical implications of sensitization to the fragrance material isoeugenol were studied in 19 subjects. Patch testing with serial dilutions of isoeugenol and a repeated open application test (ROAT) were performed. The minimum effect level under patch test conditions was below 0.01% isoeugenol in 4/19 (20%) of the test subjects. The ROAT was performed with a test solution of 0.2% isoeugenol in ethanol, which is the recommended maximum concentration used in perfumes, ethanol being applied as vehicle control. 4 weeks was the maximum exposure period. The upper arm was used as test site the 1st 14 days and the upper arm as well as the neck for the next 14 days. 12/19 (63%) of test subjects had a positive ROAT. 4 of the responders (33%) reacted beyond day 7, but none after day 14. Use testing on the neck 14 days did not add any further ROAT-positive cases, compared with testing on the upper arm. The sensitivity found on patch testing may be a guidance for the outcome of use tests with the same compound. In this study, all subjects with a positive use test to isoeugenol 0.2% in ethanol also demonstrated on patch testing a minimum effect level of 0.2% or lower. Data from serial dilution patch and use tests may contribute significant information to assessment of the relationship between patch test responses and clinical contact hypersensitivity, and thus the safety of allergens used in cosmetics.

Natural ingredients based cosmetics. Content of selected fragrance sensitizers

In the present study, we have investigated 42 cosmetic products based on natural ingredients for content of 11 fragrance substances: geraniol, hydroxycitronellal, eugenol, isoeugenol, cinnamic aldehyde, cinnamic alcohol, alpha-amylcinnamic aldehyde, citral, coumarin, dihydrocoumarin and alpha-hexylcinnamic aldehyde. The study revealed that the 91% (20/22) of the natural ingredients based perfumes contained 0.027%-7.706% of 1 to 7 of the target fragrances. Between 1 and 5 of the chemically defined synthetic constituents of fragrance mix were found in 82% (18/22) of the perfumes. 35% (7/20) of the other cosmetic products (shampoos, creams, tonics, etc) were found to contain 0.0003-0.0820% of 1 to 3 of the target fragrances. Relatively high concentrations of hydroxycitronellal, coumarin, cinnamic alcohol and alpha-amyl cinnamic aldehyde were found in some of the investigated products. The detection of hydroxycitronellal and alpha-hexylcinnamic aldehyde in some of the products demonstrates that artificial fragrances, i.e., compounds not yet regarded as natural substances, may be present in products claimed to be based on natural ingredients.