Subject(s)
Daucus carota/adverse effects , Dermatitis, Allergic Contact/etiology , Allergens/adverse effects , Daucus carota/immunology , Dermatitis, Allergic Contact/immunology , Dermatitis, Allergic Contact/pathology , Diynes/adverse effects , Diynes/immunology , Fatty Alcohols/adverse effects , Fatty Alcohols/immunology , Humans , Male , Middle Aged , Patch TestsABSTRACT
BACKGROUND: Immediate hypersensitivity reactions to root vegetables of the Umbelliferae plant family (Apiaceae) is well known. Delayed-type hypersensitivity is rarely reported. OBJECTIVE: To report the first case of systemic contact dermatitis caused by root vegetables and some chemical implications. MATERIALS AND METHODS: Prick and patch testing were performed with fresh vegetables and selected allergens, and this was followed by high-performance liquid chromatography-mass spectrometry (MS)/MS analysis of the falcarinol syringe. RESULTS: The patient was contact-sensitive to celeriac, parsnip, and carrot, but tested negative to falcarinol. Subsequent analysis showed that the syringe contained falcarinol. CONCLUSION: The non-occupational sensitization resulting from both direct and systemic contact with Apiaceae root vegetables was apparently not caused by falcarinol.
Subject(s)
Dermatitis, Allergic Contact/etiology , Food Hypersensitivity/etiology , Vegetables/adverse effects , Adult , Apium/adverse effects , Conjunctivitis/etiology , Daucus carota/adverse effects , Diynes/adverse effects , Fatty Alcohols/adverse effects , Female , Hand Dermatoses/chemically induced , Hand Dermatoses/etiology , Humans , Pastinaca/adverse effects , Patch Tests , Rhinitis/etiology , Stomatitis/etiologyABSTRACT
The skin irritant polyyne falcarinol (panaxynol, carotatoxin) is found in carrots, parsley, celery, and in the medicinal plant Panax ginseng. In our ongoing search for new cannabinoid (CB) receptor ligands we have isolated falcarinol from the endemic Sardinian plant Seseli praecox. We show that falcarinol exhibits binding affinity to both human CB receptors but selectively alkylates the anandamide binding site in the CB(1) receptor (K(i)=594nM), acting as covalent inverse agonist in CB(1) receptor-transfected CHO cells. Given the inherent instability of purified falcarinol we repeatedly isolated this compound for biological characterization and one new polyyne was characterized. In human HaCaT keratinocytes falcarinol increased the expression of the pro-allergic chemokines IL-8 and CCL2/MCP-1 in a CB(1) receptor-dependent manner. Moreover, falcarinol inhibited the effects of anandamide on TNF-alpha stimulated keratinocytes. In vivo, falcarinol strongly aggravated histamine-induced oedema reactions in skin prick tests. Both effects were also obtained with the CB(1) receptor inverse agonist rimonabant, thus indicating the potential role of the CB(1) receptor in skin immunopharmacology. Our data suggest anti-allergic effects of anandamide and that falcarinol-associated dermatitis is due to antagonism of the CB(1) receptor in keratinocytes, leading to increased chemokine expression and aggravation of histamine action.
