BACKGROUND: The fragrance terpene R-limonene is a very weak sensitizer but forms allergenic oxidation products upon contact with air. Oxidized (ox.) limonene is a frequent cause of contact allergy in clinical testing. OBJECTIVES: This study investigates the sensitizing potencies of ox. and non-ox. limonene and of structurally closely related limonene hydroperoxides. The clinical importance of the difference in sensitizing potency of two hydroperoxides in autoxidized limonene was studied. PATIENTS/ METHODS: Ox. and non-ox. limonene were investigated in the murine local lymph node assay (LLNA). Limonene hydroperoxides were investigated using a modified LLNA involving non-pooled lymph nodes and statistical calculations; patch testing of patients with known contact allergy to ox. limonene was performed. RESULTS: A marked increase in the sensitizing potency of ox. limonene compared with that of pure limonene was observed in the LLNA. One analogue, limonene-1-hydroperoxide, was a significantly more potent sensitizer than the other hydroperoxides and gave more positive test reactions in the allergic patients. CONCLUSIONS: The results support that hydroperoxides have a specific reactivity indicating that oxygen-centred radicals are important in hapten-protein complex formation of hydroperoxides. The primary oxidation products of ox. limonene, the hydroperoxides, have an important impact on the sensitizing capacity of the oxidation mixture.
BACKGROUND: The fragrance terpeneR-limonene is a very weak sensitizer but forms allergenic oxidation products upon contact with air. Oxidized (ox.) limonene is a frequent cause of contact allergy in clinical testing. OBJECTIVES: This study investigates the sensitizing potencies of ox. and non-ox. limonene and of structurally closely related limonene hydroperoxides. The clinical importance of the difference in sensitizing potency of two hydroperoxides in autoxidized limonene was studied. PATIENTS/ METHODS: Ox. and non-ox. limonene were investigated in the murine local lymph node assay (LLNA). Limonene hydroperoxides were investigated using a modified LLNA involving non-pooled lymph nodes and statistical calculations; patch testing of patients with known contact allergy to ox. limonene was performed. RESULTS: A marked increase in the sensitizing potency of ox. limonene compared with that of pure limonene was observed in the LLNA. One analogue, limonene-1-hydroperoxide, was a significantly more potent sensitizer than the other hydroperoxides and gave more positive test reactions in the allergicpatients. CONCLUSIONS: The results support that hydroperoxides have a specific reactivity indicating that oxygen-centred radicals are important in hapten-protein complex formation of hydroperoxides. The primary oxidation products of ox. limonene, the hydroperoxides, have an important impact on the sensitizing capacity of the oxidation mixture.
Authors: Victor Chubukov; Florence Mingardon; Wendy Schackwitz; Edward E K Baidoo; Jorge Alonso-Gutierrez; Qijun Hu; Taek Soon Lee; Jay D Keasling; Aindrila Mukhopadhyay Journal: Appl Environ Microbiol Date: 2015-05-01 Impact factor: 4.792
Authors: Robin A Herbert; Thomas Eng; Uriel Martinez; Brenda Wang; Sasha Langley; Kenneth Wan; Venkataramana Pidatala; Elijah Hoffman; Joseph C Chen; Mina J Bissell; James B Brown; Aindrila Mukhopadhyay; Jenny C Mortimer Journal: Environ Toxicol Chem Date: 2019-07-26 Impact factor: 3.742