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The Renaissance
Published in Scott M. Jackson, Skin Disease and the History of Dermatology, 2023
Mercurialis addressed lichen, known today as impetigo, a disease that can affect the whole body, but particularly arose on the face and chin. Lichen, per Mercurialis, was dangerous because it can spread over the entire face, and involve the eyes, or it may cause disfigurement; it was identified by its numerous round sores and broad plaques with itching, burning, and roughness.94 Mercurialis stirred up a controversy involving lichen and another ancient skin disease, mentagra (see Chapter 4), and he claimed that they two conditions were not the same as Pliny had suggested.95 His reasons: lichen was an old disease described by Hippocrates, and Pliny's mentagra was new; lichen of the chin, according to Galen, was painful and itchy, and dangerous, while Pliny's mentagra was not painful or dangerous; and finally, Pliny's mentagra affected the eminent men of Roman society, while lichen affected anyone.96 Such was the type of discourse that can be found throughout Mercurialis' work. Treatment for lichen includes the same administered for pruritus, scabies, and lepra. Mercurialis pointed out that lichen can evolve into scabies and lepra, thus completing a continuum of disease in which the main dermatologic diseases are all connected to one another.
Fungi and Water
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
There are about 200,000 fungus species found worldwide, among 1–1.5 million estimated species (4, 9). They are one of the most important groups of organisms on this planet. The kingdom Fungi is divided into four major phyla or divisions: Chytridiomycota, Zygomycota, Ascomycota, and Basidiomycota (1, 4–8). The two fungal phyla that produce large, visible fruit bodies are the Ascomycota and Basidiomycota. The Ascomycota contains at least 40,000 different species worldwide, including morels and truffles, cup fungi, and most of the lichens, as well as microscopic molds and yeasts (10). The group Basidiomycota, also known as basidiomycetes, contains from 30,000 to 35,000 different species and includes many familiar fungi, including edible and poisonous mushrooms, bracket fungi, chanterelles, and so on (10). Lichens are not fungi but arise from algae or cyanobacteria and live in common with some fungi.
Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
In the period 1980–1982, in a clinic in Norway, 7 of 2000 routinely tested patients revealed contact allergy to oakmoss absolute in perfumes. In three, the reactions to the perfumes were positive, in the others, they were not tested. The authors suggested that cosmetics containing lichen extracts are a much more important source of contact allergy than lichens encountered in nature (43).
Aqueous extract of oakmoss produces antihypertensive activity in L-NAME-induced hypertensive rats through sGC-cGMP pathway
Published in Clinical and Experimental Hypertension, 2021
Ayoub Amssayef, Mohammed Ajebli, Mohamed Eddouks
Lichens are a symbiotic association of a fungus with a green alga or cyanobacterium (8). Recently, there was a growing attention over lichens as a new source of bioactive molecules. Traditionally, more than 60 lichens genera are commonly used for treating wounds, respiratory and digestive disorder, inflammation, diabetes and hypertension (9). Besides, it has been reported that lichens contains more than 1050 secondary metabolites that exert a wide array of pharmacological activities including antibiotics, analgesic, anti-inflammatory and cytotoxic actions (9). Evernia prunastri (L.) or Oakmoss is a lichen species, belongs to Parmeliaceae family. In Morocco, Oakmoss is called “Lahiat alshaykh”, used in the traditional medicine to treat coughs, tuberculosis, anxiety, and stimulate appetite (10–12). Moreover, it has been proved that Oakmoss exhibits antioxidant, antimicrobial and anticancer properties (13).
Lichenochemicals: extraction, purification, characterization, and application as potential anticancer agents
Published in Expert Opinion on Drug Discovery, 2020
Mahshid Mohammadi, Vasudeo Zambare, Ladislav Malek, Christine Gottardo, Zacharias Suntres, Lew Christopher
Lichens have the potential to provide a host of biologically active, cytotoxic metabolites for therapeutic use. The interest in lichens as a natural source of cancer lichenochemicals is driven by several factors. Lichens are known to thrive in a variety of environments that can be characterized with extreme temperature amplitudes, UV radiation, limited nutrient supply, draught, etc. Their high adaptability is due to the unique protective mechanism they possess against environmental stress, which allow them to produce secondary metabolites with unique properties through different biosynthetic pathways. The synthesized lichenochemicals may exhibit a multitude of bioactivities in addition to their cytotoxic properties, such as antioxidant, antibiotic, antimutagenic, antifungal, antiviral, antiinflammatory, analgesic, enzyme inhibitory, and plant growth inhibitory effects. In addition, lichen compounds, such as usnic acid, gyrophoric acid, and lechanoic acid possess a broad spectrum of anticancer activities against multiple types of cancer cell lines. Furthermore, lichenochemicals are capable of inducing synergistic cytotoxic effects when acting together on human cancer cells. This explains why lichen extracts may sometimes have higher anticancer potency than individual lichen compounds.
Radiosensitizer effect of usnic acid on Biomphalaria glabrata embryos
Published in International Journal of Radiation Biology, 2018
F. T. J. Santos, W. N. Siqueira, M. L. O. Santos, H. A. M. F. Silva, J. L. F. Sá, T. S. Fernandes, N. H. Silva, E. J. França, E. B. Silva, A. M. M. A. Melo
Lichens, symbiotic associations between fungi and algae, are the source of a variety of bioactive compounds, mainly derived from their secondary metabolism and having applications in medicine, the textile industry, cosmetics and food (Kosanić et al. 2012; Manojlovic et al. 2012; Paudel et al. 2012). Usnic acid, dibenzofuran found in several species of lichens, is one of the most studied lichen metabolites and one of the few commercially available today. A number of biological activities are attributed to this metabolite, and its analgesic, antiviral, antiparasitic, antimicrobial, anti-inflammatory, antiproliferative, antitumor and antioxidant effects are reported (Shang et al. 2014; Su et al. 2014). Such characteristics make usnic acid a promising candidate for bioassays that can verify its radiosensitizing activity.