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Updated: Jun 27, 2026
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Humanized Mediator Release Assay as a Read-Out for Allergen Potency
Published on: June 29, 2021
Limonene hydroperoxide analogues differ in allergenic activity.
Johanna Bråred Christensson1, Staffan Johansson, Lina Hagvall
1Dermatochemistry and Skin Allergy, Department of Chemistry, University of Gothenburg, SE-412 96 Gothenburg, Sweden. jacpth01@geh.regionh.dk
Contact Dermatitis
|December 17, 2008
Summary
Oxidized limonene, a common allergen, is significantly more sensitizing than pure limonene due to its hydroperoxide oxidation products. Limonene-1-hydroperoxide is a particularly potent sensitizer, explaining clinical allergies to oxidized limonene.
Area of Science:
- Dermatology
- Toxicology
- Allergy Research
Background:
- R-limonene, a fragrance terpene, is a weak sensitizer but forms potent allergenic oxidation products.
- Oxidized limonene is frequently identified as a cause of contact allergy in clinical settings.
Purpose of the Study:
- To compare the sensitizing potencies of oxidized (ox.) and non-oxidized limonene.
- To investigate the sensitizing capacity of limonene hydroperoxides, key oxidation products.
- To assess the clinical relevance of differing hydroperoxide sensitizing potencies.
Main Methods:
- Murine local lymph node assay (LLNA) for ox. and non-ox. limonene.
- Modified LLNA with statistical analysis for limonene hydroperoxides.
- Patch testing on patients with known oxidized limonene allergy.
Main Results:
- Oxidized limonene demonstrated markedly increased sensitizing potency compared to pure limonene in LLNA.
- Limonene-1-hydroperoxide was identified as a significantly more potent sensitizer than other hydroperoxides.
- Higher positive reactions were observed in allergic patients tested with limonene-1-hydroperoxide.
Conclusions:
- Hydroperoxides exhibit specific reactivity, suggesting oxygen-centered radicals are crucial in hapten-protein complex formation.
- The primary oxidation products, hydroperoxides, significantly influence the sensitizing capacity of oxidized limonene mixtures.
- These findings clarify the mechanism behind oxidized limonene-induced contact allergy.
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