An investigation of the allergenic constituents of Cladonia stellaris (Opiz) Pous & Vezda ('silver moss', 'reindeer moss' or 'reindeer lichen').
The sensitizing potency of Cladonia stellaris ('reindeer lichen', 'silver moss') extracts was determined in guinea pigs by a modified FCA (Freund's complete adjuvant) test. The lichen showed a moderate sensitizing potency. Similar investigations with pure common lichen constituents revealed a moderate sensitizing potency for fumarprotocetraric acid and atranorin and a weak one for evernic acid, stictic acid and both forms of usnic acid. Although generally weak, (-)-usnic acid was at least 2 x stronger than (+)-usnic acid. After separation of the Cladonia ether extract into 'usnic-acid-free' and 'usnic-acid-containing' fractions, perlatolic acid was identified as the main allergenic constituent of the 'usnic-acid-free' fraction. Stictic, evernic, fumarprotocetraric acid and atranorin were not detectable. Lichens and lichen products generally possess a weak to moderate sensitizing capacity. Compared with common sensitizers of occupational and environmental importance, these products play only a minor rôle.
Hausen
B M
BM
Department of Dermatology, University Hospital Hamburg, FRG.
Emde
L
L
Marks
V
V
D000818:Animals; D017449:Dermatitis, Allergic Contact / Q000209:etiology / Q000276:immunology*; D005260:Female; D006168:Guinea Pigs; D008011:Lichens / Q000737:chemistry / Q000276:immunology*; D010936:Plant Extracts
D010936:Plant Extracts