Allergic contact dermatitis resulting from sensitivity to citrus peel, geraniol, and citral

The Anticancer Activities of Natural Terpenoids That Inhibit Both Melanoma and Non-Melanoma Skin Cancers

The prevalence of two major types of skin cancer, melanoma and non-melanoma skin cancer, has been increasing worldwide. Skin cancer incidence is estimated to rise continuously over the next 20 years due to ozone depletion and an increased life expectancy. Chemotherapeutic agents could affect healthy cells, and thus may be toxic to them and cause numerous side effects or drug resistance. Phytochemicals that are naturally occurring in fruits, plants, and herbs are known to possess various bioactive properties, including anticancer properties. Although the effects of phytochemicals are relatively milder than chemotherapeutic agents, the long-term intake of phytochemicals may be effective and safe in preventing tumor development in humans. Diverse phytochemicals have shown anti-tumorigenic activities for either melanoma or non-melanoma skin cancer. In this review, we focused on summarizing recent research findings of the natural and dietary terpenoids (eucalyptol, eugenol, geraniol, linalool, and ursolic acid) that have anticancer activities for both melanoma and non-melanoma skin cancers. These terpenoids may be helpful to protect skin collectively to prevent tumorigenesis of both melanoma and nonmelanoma skin cancers.

A spotlight on lime: a review about adverse reactions and clinical manifestations due to Citrus aurantiifolia

Lime (Citrus aurantiifolia) is a plant belonging to the family of Rutaceae and to the genus Citrus. The fruit is widely used in the United States, Mexico, Southeast Asia, Latin America, but is increasingly widespread all over the world. It is used as a fresh fruit, in the preparation of foods, sweets and drinks and its oils are used in the cosmetic and pharmaceutical industry. The main adverse reactions to lime seem to be represented by contact dermatitis, allergic and phototoxic type. In the context of allergic forms, several allergens have been identified in the citrus family, the main one being limonene, but no noteworthy cross-reactivity has been identified. However, a case of fruit protein contact dermatitis has been described, showing sensitization to other fruits, such as kiwi, avocado, pineapple and apple. There are several molecules responsible for phototoxic reactions and mainly belonging to the coumarin and furocoumarins families. Reactions related to ingesting the fruit or inhaling pollen from the tree appear to be rare, as there are no known cases reported in the literature. The increasing diffusion of lime in Europe must pay attention to possible adverse reactions due to contact with this fruit, which seem destined to increase in future years. Further importance must be placed on patch tests and on the possibility of using alternative extracts to classic fragrance mixes.

Lemon seed allergy: a case presentation

Background

We report a case of IgE-mediated hypersensitivity to lemon seed. We demonstrate for the first time a pattern of cross-sensitisation between seeds of citrus hybrid species from similar ancestral species origins.

Case report

Described is a case of a 26-year-old female with recurrent anaphylaxis on exposure to lemon seed with sensitisation shown on prick to prick testing. Prick to prick testing was also performed to a variety of citrus fruit seeds and edible foods from additional notable families of the Sapindale order.

Conclusion

In cases of unexplained or recurrent anaphylaxis in adult patients, citrus seed allergy should be considered.

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Allergic contact dermatitis to plants: understanding the chemistry will help our diagnostic approach

Allergic contact dermatitis due to plants is common. Potentially allergenic plants and plant products are found in many everyday environments, such as the home, the garden, the workplace, and recreational settings. By improving our knowledge of allergenic plant-derived chemical compounds, we will be better positioned to identify novel allergens. We review the most relevant chemical allergens that contribute to plant allergic contact dermatitis and propose a clinical classification system based on 5 major families of chemical sensitizers: α-methylene-γ-butyrolactones, quinones, phenol derivatives, terpenes, and miscellaneous structures (disulfides, isothiocyanates, and polyacetylenic derivates). We also describe the different clinical pictures of plant allergic contact dermatitis and review currently available patch test materials. A better understanding of the specific allergens involved in plant allergic contact dermatitis will help to predict cross-reactivity between different plant species or families.

Allergic contact cheilitis due to geraniol in food

Fragrance materials are present in many foods and are referred to as flavours and spices. However, despite their widespread use, there are few reports of allergic contact dermatitis caused by these additives. Here, we report contact allergy to geraniol in a patient who developed cheilitis on exposure to certain foods.

Women's Occupational Dermatologic Issues

With almost 65 million women in the workforce, their representation in various occupational sectors is crucial, as is their health and safety. Female-dominated occupations in health care and cosmetology along with their potential cutaneous exposures are reviewed. Proper evaluation and management are necessary to minimize the disability that can result from these illnesses.

Topical and oral CAM in acne: a review of the empirical evidence and a consideration of its context

INTRODUCTION

Acne is one of the commonest diseases to afflict humanity. Anecdotally, the use of CAM in acne is widespread. In this review the empirical evidence for the efficacy of CAM modalities is examined and the context for their use discussed.

METHODS

Searches were made of the MEDLINE, EMBASE, AMED (Allied and Complementary Medicines), Cochrane, and DARE databases using the search terms "acne" and "acne vulgaris" together with "alternative" and "complementary".

RESULTS

The identified studies examined a broad range of CAM modalities but were of generally poor methodological quality. Evidence suggests that many of these therapies are biologically plausible.

DISCUSSION AND CONCLUSION

Complementary therapies in acne should be viewed in a wider context than that of the very limited empiric evidence base that exists for their use. Further rigorously conducted trials should be conducted to define efficacy and adverse effect profiles of currently used CAM acne therapies.

Lipid transfer proteins and allergy to oranges

BACKGROUND

Lipid transfer proteins (LTPs) are relevant fruit allergens, recently proposed as model plant food allergens. No citrus fruit allergen has been characterized to date. We sought to identify and isolate citrus fruit LTPs and to explore their relevance in orange allergy.

METHODS

Twenty-seven patients, showing mainly oral allergy syndrome after orange ingestion, as well as positive prick responses and serum-specific IgE levels to orange, were selected. Natural orange and lemon LTPs, as well as a recombinant orange LTP isoform expressed in Pichia pastoris, were isolated by chromatographic methods and characterized by N-terminal amino acid sequencing and matrix-assisted laser desorption/ionizaion mass spectrometry, and DNA sequencing of the corresponding cDNA in the case of the recombinant allergen. Specific IgE determination, immunodetection, ELISA-inhibition assays and in vivo skin prick tests (SPTs) were performed with all three purified allergens and with the major peach LTP allergen, Pru p 3.

RESULTS

The natural allergens purified from orange (nCit s 3) and lemon (nCit l 3) showed very similar N-terminal amino acid sequences (18 out of 20 identical residues), typical of LTPs, and molecular masses of 9,610 and 9,618 Da, respectively. The recombinant orange isoform (rCit s 3) expressed in P. pastoris (16 out of 20 residues identical to its natural counterpart in the N-terminal region) presented 92 amino acid residues and 9,463 Da, and 67% sequence identity with rPru p 3. Of the 27 sera analyzed, specific IgE to the purified allergens was found in 54% for nCit l 3, 48% for nCit s 3, 46% for rCit s 3 and 37% for rPru p 3. Positive SPT responses were obtained in 7 out of 26 patients tested for nCit s 3, 3 out of 8 for nCit l 3 and 10 out of 26 for nPru p 3. ELISA-inhibition assays showed an equivalent IgE-binding pattern for the natural and recombinant orange LTPs, and IgE cross-reactivity among the purified orange, lemon and peach LTP allergens.

CONCLUSIONS

Members of the LTP allergen family are involved in allergy to oranges, displaying positive in vitro and in vivo reactions in 30-50% of the patients studied. Both orange and lemon allergens show cross-reactivity with the major peach allergen Pru p 3.

Herbals and asthma: usage patterns among a border population

BACKGROUND

The use of herbal products (HP) is rising in the US. Higher rates of HP use have been documented in the US/Mexico border population, as well as increasing concerns about herbal-related adverse events.

OBJECTIVE

To evaluate the prevalence of HP use in adult asthmatic patients requiring hospitalization and the frequency of HP documentation in medical records.

METHODS

We conducted a retrospective chart review of admissions for asthma to determine the frequency of HP documentation. Additionally, during a 12-month period, a bilingual interviewer conducted prospective, semistructured interviews with patients with asthma exacerbations to record data on HPs used specifically for the treatment of asthma.

RESULTS

A total of 67 cases were chart-reviewed retrospectively; 60 patients were interviewed prospectively. We found no documentation of HP use by chart review, while prospective interviews showed that 42% of patients reported using HPs for the treatment of asthma. The most common HPs used were oregano 28%, chamomile 20%, garlic 16%, eucalyptus 12%, and lime 12%. Ten patients reported taking an HP that could potentially exacerbate their asthma and 18 patients reported using an HP that could interact with other medications or cause other types of adverse events.

CONCLUSIONS

An obvious lack of documentation for HP use was observed in the medical records reviewed. Because a number of HPs that are commonly used by residents along the border can interact with antiasthmatic agents and/or result in compromised asthma control, questions about HP use should be included in routine history taking.

Citral a fragrance allergen and irritant

Citral is a well known contact allergen and a contact irritant. Routine patch testing in the past may have been restricted because of possible irritant (IR) patch test responses. 586 consecutive patients, with hand eczema, were patch tested with a selection of fragrances including citral 2% petrolatum and the European standard series. 28 of the patients showed a positive patch test reaction (+ to +++) to citral and 82 at least 1 IR patch test reaction and no positive patch test reaction to citral. A statistically significant association between a positive patch test reaction to citral and positive patch test reactions to other fragrances compared with IR reactions (n = 82) was established. The difference regarding fragrance history found between those with IR and positive reactions to citral was not significant. Citral could be an allergen and/or irritant, worthy of further more extensive studies.

Allergic contact dermatitis following exposure to essential oils

Allergic contact dermatitis from the topical use of essential oils is not widely recognized as an occupational hazard. Four cases of allergic contact dermatitis to essential oils occurring in three aromatherapists and one chemist with a particular interest in aromatherapy are described. All presented with predominantly hand dermatitis and demonstrated sensitization to multiple essential oils. One patient developed a recurrence of cutaneous symptoms following ingestion of lemongrass tea. Workers within this industry should be aware of the sensitization potential of these products and the risk of limiting their ability to continue employment.

Allergic contact dermatitis to plant extracts in patients with cosmetic dermatitis

Cosmetic contact allergy is commonly seen in patients undergoing patch testing, with fragrance one of the most frequently implicated ingredients. Many cosmetics contain plant extracts either as a fragrance or for medicinal properties. With a vogue for natural products there is an increase in their use. We have performed a prospective study over a 2-year period looking at the prevalence of contact allergy to plants in patients diagnosed with cosmetic dermatitis. In addition, we have performed a review of the products of two popular cosmetic companies, examining product labelling and the prevalence of use of plant extracts. We suggest that patients allergic to fragrance be advised to avoid plant extracts, which are separately labelled, in their personal care products.

Citral and testosterone interactions in inducing benign and atypical prostatic hyperplasia in rats

Citral is a monoterpene in wide use as an aromatic supplement in the cosmetics and food industries. Previous studies in our laboratory have shown that cutaneous application of citral on adolescent rats may induce benign prostatic hyperplasia (BPH)-like and even atypical hyperplastic changes in the ventral lobes. In the present study we investigate the possible interactions between citral and serum testosterone levels on the induction of hyperplastic changes in the ventral prostate of adolescent rats. In addition, the study includes a comparative analysis of normal intact rats showing circadian variations of serum testosterone levels and rats in whom this rhythmic pattern was abolished either by excessive supplementation of exogenous androgen or by castration. Our results demonstrate an induction of benign as well as atypical prostatic hyperplasia following citral application. The most severe atypical changes were noted in the citral-treated rats with high serum testosterone levels. Although the mechanism of action of citral is yet unknown, the present results suggest a synergism between citral and testosterone resulting in hyperplastic changes in the rat ventral prostate. In addition, the results reconfirm that serum testosterone levels fluctuate according to a circadian rhythm in intact young and adolescent male rats. The application of citral tends to lower the morning circadian peaks, and the circadian pattern was abolished in orchiectomized rats and in those treated with testosterone implants.

Immediate vasoactive effect of citral on the adolescent rat ventral prostate

The vasoactive effect of a fragrance compound, citral, on rat ventral prostate is presented. A combined method of Indian-ink perfusion and postfixation transparency was used. One single dose of citral applied on the back skin of the rat induced an immediate triple response-like effect on the prostatic vascular bed. A slight vasodilatation appeared already after 2 1/2 min, followed by a marked vasoconstriction process after 5-min postcitral administration. Toward the period of 10 min, a second vasodilatation process was noted which persisted for the following 24 hr of observation. This study has demonstrated that changes in the microvascularization of the rat prostate can be estimated by counting the number of carbon-stained blood vessels. The results obtained by this technique are closely related with the findings in the vascular network profile of the macroangiographic observations. The mechanism of action of citral on the microvascularization of the rat ventral prostate is yet unknown. Based on the present findings, we suggest that the neoplastic capacity of citral upon the prostatic epithelia is activated via a nonspecific inflammatory reaction modulated either by local release of neurotransmitters or throughout a direct effect of citral on the endothelial cells.

d-limonene exposure to humans by inhalation: uptake, distribution, elimination, and effects on the pulmonary function

The toxicokinetics of d-limonene were studied in human volunteers exposed by inhalation (2 h, work load 50 W) in an exposure chamber on three different occasions. The exposure concentrations were approximately 10, 225, and 450 mg/m3 d-limonene. The relative pulmonary uptake was high, approximately 70% of the amount supplied. The blood clearance of d-limonene observed in this study, 1.1 l kg-1 h-1, indicates that d-limonene is metabolized readily. About 1% of the total uptake was eliminated unchanged in the expired air after the end of exposure, while approximately 0.003% was eliminated in the urine. A long half-time in blood was observed in the slow elimination phase, which indicates accumulation in adipose tissues. A decrease in vital capacity was observed after exposure to d-limonene at a high exposure level. The subjects did not experience any irritative symptoms or symptoms related to the central nervous system (CNS).

Air oxidation of d-limonene (the citrus solvent) creates potent allergens

Products containing as much as 95% of d-limonene are used for, e.g., degreasing metal before industrial painting and for cleaning assemblies. Experimental studies on the sensitizing potential of limonene show diverging results. In a previous study, we found that the sensitizing potential of d-limonene increased with prolonged air exposure. The aim of this study was to make further chemical analyses, to identify compounds formed by air exposure of d-limonene and to study their allergenic potential. d-limonene was found to be a sensitizer after prolonged exposure to air according to 2 Freund's complete adjuvant test (FCAT) experiments and 1 guinea pig maximization test (GPMT) study. No significant response was obtained to d-limonene not air exposed, even if the animals were sensitized to oxidized d-limonene. 5 main oxidation products of d-limonene were identified. (R)-(-)-carvone and a mixture of cis and trans isomers of (+)-limonene oxide were found to be potent sensitizers, while no significant reactions were obtained in the animals induced with a mixture of cis and trans isomers of (-)-carveol. It can be concluded that air oxidation of d-limonene is essential for its sensitizing potential, and that potent allergens are created.