Induction of murine cytochrome P4503A by the lichen constituents usnic and vulpinic acids.
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Animals↗
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Results for “USNIC ACID”
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[Synthesis of certain alkoxyhaloidphenoxyusnic acids and their derivatives].
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Benzofurans↗
[Intralymphatic therapy of tuberculosis].
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Benzofurans↗
[A new lichenic antibiotic].
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Anti-Bacterial Agents↗
Contributions to the complex study of some lichens-Usnea genus. Pharmacological studies on Usnea barbata and Usnea hirta species.
The pharmacological researches have been performed for Usnea barbata and Usnea hirta species using hydroalcoholic extracts. The acute toxicity has been determined and the following LD50 have been obtained: i. p. Usnea barbata 22.53g vegetal material/kg b. w.; Usnea hirta 21.02g vegetal material/kg b. w.; i. v. Usnea barbata 7.43 vegetal material/kg b. w.; Usnea hirta 4.52g vegetal material/kg b. w.; per os up to 32g vegetal material/kg b. w. no mortality has been recorded. It has been demonstrated that the antiinflammatory activity was comparable, sometimes superior to the phenylbutazone and hydrocortisone hemisuccinate; the analgesic activity was close to the noraminophenazone; the antipyretic activity was equal, sometimes superior to the aminophenazone. In Romania, Usnea barbata was mentioned in 1929 among the plants known by Romanian people with popular names: "Bear's beard", "Trees' dandruff", "Woman's long hair" (1). "Farmacia naturii" (2) and "Flora medicinală a Romaniei" (3) have mentioned that Usnea barbata (L) Mott contains usnic acid-substance with broad antibiotic spectrum. Lichens have made the subject of the multiple studies because of their old medical use (4). Besides the antibiotic properties noticed at lichens products (4) there have been discovered the following pharmacological actions: antiinflammatory (5), antitumoural, immunostimulatory (6, 7, 8, 9). The results of the researches made on lichens family within Romania's spontaneous flora (10) have determined us to study the two species: Usnea barbata (L) Mott and Usnea hirta (L) Wigg.
Administration, Oral↗
Intermediate reactive oxygen and nitrogen from macrophages induced by Brazilian lichens.
The activity of ten compounds isolated from Brazilian lichen over the release of hydrogen peroxide and nitric oxide was evaluated in the culture of peritoneal macrophage cells from mice. Salazinic, secalonic A and fumarprotocetraric acids were the compounds that induced the greatest release of H2O2, whereas 12R-usnic and diffractaic acids induced the release of NO. These results indicate that lichen products have potential immunological modulating activities.
Animals↗
Contact sensitivity to lichens and compositae in Frullania dermatitis.
48 patients with allergic contact dermatitis from Frullania were patch tested with a lichen mix, compositae and lichen acids. 27 were sensitive to Frullania and lichens. Parmelia caperata and Parmelia reticulata were positive in all, and in a descending order of positivity: Pseudovernia furfuracea, Evernia prunastri, Usnea spp, Ramalina lusitanica. d-Usnic and evernic acids and atranorin were the main responsible allergens.
Adult↗
A rapid screening method for detecting active compounds against erythromycin-resistant bacterial strains of Finnish origin.
A rapid and simple microdilution technique on 96-well microplate based on turbidimetry was optimized and validated for screening of antimicrobial activity against erythromycin-resistant bacterial strains of Streptococcus pyogenes and Staphylococcus simulans isolated from Finnish patients. Using S. pyogenes ATCC 12351 as reference strain the developed method was evaluated by reproducibility measurements and using parameters typically employed for screening methods, i.e. signal-to-background, signal-to-noise and a screening-window coefficient, the Z' factor. The method was further used for screening a group of natural compounds and their synthetic derivatives against resistant bacterial strains. Of these, octyl and dodecyl gallates, and usnic and ursolic acids were the most active. The described method is a rapid, homogeneous, cost-effective and easy-to-perform system for screening of new potential antimicrobial agents in drug discovery.
Anti-Bacterial Agents↗
The sensitizing capacity of atranorin.
The allergenic potential of the aromatic lichen substance atranorin has been investigated by means of the guinea pig maximization test of Magnusson & Kligman. Sensitivity was induced in 30% of the animals, which corresponds to a moderate allergenic capacity (grade III). This is in agreement with the clinically-observed frequency of 1.5% among our patients. A modified photoallergy test on the same animals was performed, but irradiation did not increase the number of positive reactions. 4 patients with proven contact sensitivity to atranorin, evernic, usnic or physodic acid, were examined with different dilutions from 0.001 to 0.1%. Irradiation of the test series did not provoke any clear-cut photoallergic reaction.
Adult↗
Photosensitivity and allergy to aromatic lichen acids, Compositae oleoresins and other plant substances.
Sixteen patients with verified light sensitivity to both UVB and UVA wavebands showed allergic reactions to various lichen plants (Parmelia spp., Hypogymnia spp., Pseudovernia spp., Cladonia spp., Platismatia spp., Physcia spp., Umbilicaria spp. and Cetraria spp.). Among the aromatic lichen compounds, atranorin was observed to be the most frequently involved allergen, but also several other isolated lichen acids were immunologically active: d-usnic, evernic, stictic, fumarprotocetraric, lobaric, salazinic, diffractaic and physodic/physodalic acid. Several patients showed allergy to other plant substances from other sources such as seven different species from the Compositae family, alantolactone, balsam of Peru, colophony and wood tars. Sensitivity to known photosensitizers was observed in four patients. Aromatic lichen acids are UV-absorbing substances and several are evidently able to photosensitize human skin.
Cross Reactions↗
Photosensitivity and allergy to aromatic lichen acids, Compositae oleoresins and other plant substances.
Sixteen patients with verified light sensitivity to both UVB and UVA wavebands showed allergic reactions to various lichen plants (Parmelia spp., Hypogymnia spp., Pseuodovernia spp., Cladonia spp., Platismatia spp., Physcia spp., Umbilicaria spp. and Cetraria spp.). Among the aromatic lichen compounds, atranorin was observed to be the most frequently involved allergen but also several other isolated lichen acids were immunologically active: d-usnic, evernic, stictic, fumarprotocetraric, lobaric, salazinic, diffractaic and physodic/physodalic acid. Several patients showed allergy to other plant substances from other sources such as seven different species from the Compositae family, alantolactone, balsam of Peru, colophony and wood tars. Sensitivity to known photosensitizers was observed in four patients. Aromatic lichen acids are UV-absorbing substances and several are evidently able to photosensitive human skin.
Acids↗
Contact sensitivity to oak moss.
Oak moss allergy was the principle allergen in contact sensitivity to perfumes (45%); 31 patients reacting to oak moss were studied. The sensitivity was attributed to contact with perfumes in 20, lichens in 7 and unknown in 4. Atranorin was the most frequent allergen, followed by usnic, evernic and fumarprotocetraric acids. Concomitant allergy occurred to several lichen acids and also to balsam of Peru, colophony and other fragrance components.
Adolescent↗
Impact of fertilisation on phenol content and growth rate of Cladina stellaris: a test of the carbon-nutrient balance hypothesis.
Responses of concentrations of usnic (UA) and perlatolic (PA) acids and the relative growth rate (RGR) of a mat-forming lichen, Cladina stellaris, to enhanced N and P input were studied in a fertilisation experiment. It was predicted on the basis of carbon-nutrient balance (CNB) hypothesis that the concentrations of these phenolics would decline and the growth rate increase in response to increased nutrient uptake. The concentration of UA showed a convex response pattern to increased N input whereas the concentration of PA was non-responsive. An ecologically realistic, "moderate", N treatment clearly lowered the level of UA both with and without the P application. Applying P alone caused a significant increase in the level of UA. The RGR of C. stellaris did not respond to nutrient addition. The results indicate that even though the CNB hypothesis may be applicable in explaining concentrations of lichen secondary metabolites, it may be applied under a relatively narrow set of conditions. Especially inherited constraints in the growth of lichen fungi may seriously limit the responsiveness of lichens to short-time changes in the availability of resources. These limitations may also apply to other perennials adapted to nutrient-poor conditions.
Antifungal Agents↗