An investigation of the allergenic constituents of Cladonia stellaris (Opiz) Pous & VeŽda (‘silver moss’, ‘reindeer moss’ or ‘reindeer lichen’)

Abstract

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.

Potent activity of the lichen antibiotic (+)-usnic acid against clinical isolates of vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus

“…Good oral absorption and very low MIC values together make the compound a noteworthy candidate for clinical trials in lifethreatening VRE infections. Yet, it must be pointed out that there are case reports on severe toxicity (especially hepatotoxicity) and even of fulminant liver failure associated with use of usnic acid for weight loss (Durazo et al 2004) and that usnic acid allergy is also possible (Huneck 1999;Thune and Solberg 1980;Hausen et al 1993).…”

Current Results on Biological Activities of Lichen Secondary Metabolites: a Review

“…Atranorin Dahlquist and Fregert, 1980;Thune and Solberg, 1980;Gonçalo et al, 1988;Hausen et al, 1993;Stinchi et al, 1997;Aalto-Korte et al, 2005;Cabanillas et al, 2006Diffractaic acid Thune and Solberg, 1980Evernic acid Dahlquist and Fregert, 1980Thune and Solberg, 1980;Gonçalo et al, 1988;Hausen et al, 1993;Aalto-Korte et al, 2005;Cabanillas et al, 2006 Fumarprotocetraric acid Dahlquist andFregert, 1980;Thune and Solberg, 1980;Gonçalo et al, 1988;Hausen et al, 1993Lobaric acid Thune and Solberg, 1980Perlatolic acid Hausen et al, 1993Physodalic acid Thune, 1977Thune andSolberg, 1980 Physodic acid Thune, 1977;Thune and Solberg, 1980Salazinic acid Thune and Solberg, 1980Stictic acid Thune and Solberg, 1980Hausen et al, 1993 Usnic acid Mitchell andChampion, 1965;Thune and Solberg, 1980;Gonçalo et al, 1988;Hausen et al, 1993;Stinchi et al, 1997;Aalto-Korte et al, 2005;Cabanillas et al, 2006 Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 6/24/15 1:25 PM…”

Bioactive lichen metabolites: alpine habitats as an untapped source

“…In any case, it should be taken into account that lichen compounds may have side effects particularly when misused. Allergenic reactions have been described for some (Thune and Solberg 1980;Hausen et al 1993) as so as severe liver failures following about 500 mg/day ingestion of usnic acid in nutraceuticals marketed as weight-loss aids Neff et al 2004). Thus, applications derived from activities described for lichen compounds have to be thoroughsly studied, particularly in the antimicrobial, anticancer and anti-inflammatory domains.…”