Search Results (35)

The increasing incidence of dermatological diseases prompts the search for new natural methods of treatments, and lichens, with their special symbiotic structure, are a little-known and promising source of biologically active substances. Seven lichen species, Cladonia unicialis (L.) Weber ex F.H. Wigg. (Cladoniaceae), Evernia prunastri (L.) Ach. (Parmeliaceae), Hypogymnia physodes (L.) Nyl. (Parmaliaceae), Parmelia sulcata (Taylor) (Parmeliaceae), Physcia adscendens (Fr.) H. Olivier (Physciaceae), Pseudoevernia furfuracea (L.) Zopf (Parmeliaceae), and Xanthoria parietina (L.) Th. Fr. (Teloschistaceae), were used in our experiment. We identified different metabolites in the acetone extracts of all the lichen species. Based on the high-performance liquid chromatography analysis, the content of lichen substances in the extracts was evaluated. The impact of the individual lichen-specific reference substances, compared to the lichen extracts, on the viability of keratinocytes (HaCaT cell line) and fibroblasts (BJ cell line) and on the activity of selected skin-related enzymes was investigated. Our results revealed that only emodin anthrone at a concentration of 200 mg/L was cytotoxic to keratinocytes and fibroblasts in both cell viability assays. In turn, the C. uncialis extract was only cytotoxic to keratinocytes when used at the same concentration. The other tested treatments showed a positive effect on cell viability and no cytotoxicity or indeterminate cytotoxicity (shown in only one of the tests). Elastase and collagenase activities were inhibited by most of the lichen extracts. In turn, the individual lichen compounds (with the exception of evernic acid) generally had an undesirable stimulatory effect on hyaluronidase and collagenase activity. In addition, almost all the tested compounds and extracts showed anti-inflammatory activity. This suggests that some lichen compounds hold promise as potential ingredients in dermatological and skincare products, but their safety and efficacy require further study. The high cytotoxicity of emodin anthrone highlights its potential use in the treatment of hyperproliferative skin diseases such as psoriasis. Full article

Lichens are symbiotic organisms that effectively survive in harsh environments, including arid regions. Maintaining viability with an almost complete loss of water and the rapid restoration of metabolism during rehydration distinguishes lichens from most eukaryotic organisms. The lichen Xanthoria parietina is known to have high stress tolerance, possessing diverse defense mechanisms, including the presence of the bright-orange pigment parietin. While several studies have demonstrated the photoprotective and antioxidant properties of this anthraquinone, the role of parietin in the tolerance of lichens to desiccation is not clear yet. Thalli, which are exposed to solar radiation and become bright orange, may require enhanced desiccation tolerance. Here, we showed differences in the anatomy of naturally pale and bright-orange thalli of X. parietina and visualized parietin crystals on the surface of the upper cortex. Parietin was extracted from bright-orange thalli by acetone rinsing and quantified using HPLC. Although acetone rinsing did not affect PSII activity, thalli without parietin had higher levels of lipid peroxidation and a lower membrane stability index in response to desiccation. Furthermore, highly pigmented thalli possess thicker cell walls and, according to thermogravimetric analysis, higher water-holding capacities than pale thalli. Thus, parietin may play a role in desiccation tolerance by stabilizing mycobiont membranes, providing an antioxidative defense, and changing the morphology of the upper cortex of X. parietina. Full article

In lichens, secondary metabolites have been shown to protect against biotic stresses such as pathogen attacks and grazing, and abiotic stresses such as ultraviolet (UV) and high photosynthetically active radiation (PAR). Lichen secondary metabolites are known to have strong antioxidant activity, and while theoretically they may have roles in tolerance to other abiotic stresses, these roles remain largely unclear. Here, we used the acetone rinsing method to harmlessly remove most of the secondary metabolites from the thalli of six lichen species. This enabled us to compare the effects of desiccation on thalli with and without the presence of secondary metabolites. Results showed that in general, the presence of lichen substances reduces the effects of desiccation stress. For all species, substances significantly improved the photosystem two (PSII) activity of the photobiont during either desiccation or rehydration. In the mycobiont, in four of the six species, the presence of substances reduced membrane damage, which was assessed by measuring ion leakage during rehydration following desiccation. However, in one species, secondary metabolites had no effect, while in another the presence of substances increased membrane damage. Nevertheless, it seems clear that in addition to their more established roles in protecting lichens against pathogen attacks and grazing, lichen substances can also play a role in aiding desiccation tolerance. Full article

Bioremediation utilizes living organisms such as plants, microbes and their enzymatic products to reduce toxicity in xenobiotic compounds. Microbial-mediated bioremediation is cost effective and sustainable and in situ application is easily implemented. Either naturally occurring metabolic activity can be utilized during bioremediation for the degradation, transformation or accumulation of substances, or microbial augmentation with non-native species can be exploited. Despite the perceived low potential for the biological degradation of some recalcitrant compounds, successful steps towards bioremediation have been made, including with asbestos minerals, which are prevalent in building stock (created prior to the year 2000) in New Zealand. Evidence of the in situ biodegradation of asbestos fibres was investigated in samples taken from a retired asbestos mine, asbestos-contaminated soils and biofilm or lichen-covered asbestos-containing building materials. Microbial diversity within the biofilms to be associated with the asbestos-containing samples was investigated using internal transcribed spacer and 16S DNA amplicon sequencing, supplemented with isolation and culturing on agar plates. A range of fungal and bacterial species were found, including some known to produce siderophores. Changes to fibre structure and morphology were analysed using Transmission Electron Microscopy and Energy-Dispersive X-ray Spectroscopy. Chrysotile fibrils from asbestos-containing material (ACMs), asbestos-containing soils, and asbestos incorporated into lichen material showed signs of amorphisation and dissolution across their length, which could be related to biological activity. Full article

Leishmaniasis is considered one of the most untreated tropical diseases in the world. In this study, we investigated the in vitro leishmanicidal activity and cytotoxicity of various isolated lichen substances, including atranorin (1), usnic acid (2), gyrophoric acid (3), salazinic acid (4), galbinic acid (5), and parietin (6), and some semi-synthetic imine derivatives of usnic acid (7, 8, 9) and atranorin (10, 11, 12, 13). Imine condensation reactions with hydrazine and several amines were assisted by microwave heating, an efficient and eco-friendly energy source. The most interesting result was obtained for compound 2, which has high leishmanicidal activity but also high cytotoxicity. This cytotoxicity was mitigated in its derivative, 9, with better selectivity and high antileishmanic activity. This result may indicate that the usnic acid derivative (9) obtained using condensation with two cyclohexylamine groups is a promising lead compound for the discovery of new semisynthetic antiparasitic drugs. Full article

The lichenized fungal genus Fissurina with mostly slit-like lirellae, belongs to Graphidaceae and is mainly distributed in tropical and subtropical regions. A total of 17 Fissurina species have been reported from China. During a survey of the lichen diversity of southern China, a new species Fissurina wuyinensis K.J. Shi, Z.F. Jia and X. Zhao, sp. nov. was found, which is characterized by a corticolous thallus without detected secondary substances, uncarbonized lirellae, and an exposed disc with pruina, muriform and amyloid ascospores. Furthermore, two new records of F. pseudostromatica, F. subcomparimuralis have been identified by morphological, anatomical, chemical and molecular studies. Phylogenetic analyses of three loci (ITS, nuLSU and mtSSU) supported the position of these species within Fissurina. Detailed morphological descriptions as well as high-resolution photographs of the morphology and anatomy of the three species are provided, as well as a comparison and discussion of the characteristics of similar species. The studied specimens were deposited in the Fungarium of the College of Life Sciences, Liaocheng University (LCUF). Full article

In this work, we collected samples of lichens from the oaks of Pădurea Troianul, in the area of Teleorman county, to analyze the air quality, using the lichen biodiversity index and its determining factor. We transplanted them to the points to be monitored and analyzed them to detect and quantify the concentration of heavy metals or other toxic substances accumulated in the lichen biomass. This research was conducted at transplant sites, where five sample sites were chosen. We investigated the concentrations of the heavy metals Cd, Pb and Hg, making a comparison between the concentrations indicated by lichens and conventional measurements. The sampling, observation and analysis of lichens, we carried out in the months of September, October and November 2021, because in September the temperatures are higher and the degree of precipitation is lower than in November, so we followed a development of lichens covering different periods in terms of temperature and humidity. The comparison was made starting from the contamination factors obtained and measured in the sampling station. The application of the biomonitoring method allows obtaining an exact index of the purity of the atmosphere based on the tolerance of the transplanted lichens, the results being obtained quickly. Full article

In order to provide data for lichenologists studying taxonomy, Chaenothecopsis xishuiensis is supported and proposed as a new species from China based on phenotypic, molecular, and metabolite data. It is characterised by leprose thallus, single, conical to hemispherical apothecia, nonbranching stipe, cylindrical, eight-spored asci, and nonseptate and brown spores, and this lichenised fungus contains atranorin and zeorin in the thallus. In addition, Lecanora pseudargentata is reported for the first time as a new record from China. This species is characterised by red-brown to dark brown apothecial discs, eight-spored asci, nonseptate, hyaline spores, and the presence of atranorin and gangaleoidin. The biological activity of its lichen substances is discussed. Full article

Nasal sprays are medical devices useful for preventing infection and the subsequent spread of airborne pathogens. The effectiveness of these devices depends on the activity of chosen compounds which can create a physical barrier against viral uptake as well as incorporate different substances with antiviral activity. Among antiviral compounds, UA, a dibenzofuran derived from lichens, has the mechanical ability to modify its structure by creating a branch capable of forming a protective barrier. The mechanical ability of UA to protect cells from virus infection was investigated by analyzing the branching capacity of UA, and then the protection mechanism in an in vitro model was also studied. As expected, UA at 37 °C was able to create a barrier confirming its ramification property. At the same time, UA was able to block the infection of Vero E6 and HNEpC cells by interfering with a biological interaction between cells and viruses as revealed also by the UA quantification. Therefore, UA can block virus activity through a mechanical barrier effect without altering the physiological nasal homeostasis. The findings of this research could be of great relevance in view of the growing alarm regarding the spread of airborne viral diseases. Full article

Lichen metabolites represent a wide range of substances with a variety of biological effects. The present study was designed to analyze the potential antiproliferative, antimicrobial and antioxidative effects of several extracts from lichens (Pseudevernia furfuracea, Lobaria pulmonaria, Cetraria islandica, Evernia prunastri, Stereocaulon tomentosum, Xanthoria elegans and Umbilicaria hirsuta) and their secondary metabolites (atranorin, physodic acid, evernic acid and gyrophoric acid). The crude extract, as well as the isolated metabolites, showed potent antiproliferative, cytotoxic activity on a broad range of cancer cell lines in 2D (monolayer) and 3D (spheroid) models. Furthermore, antioxidant (2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) and in vitro antimicrobial activities were assessed. Data showed that the lichen extracts, as well as the compounds present, possessed biological potential in the studied assays. It was also observed that the extracts were more efficient and their major compounds showed strong effects as antiproliferative, antioxidant and antibacterial agents. Moreover, we demonstrated the 2D and 3D models’ importance to drug discovery for further in vivo studies. Despite the fact that lichen compounds have been neglected by the scientific community for long periods, nowadays they are objects of investigation based on their promising effects. Full article

Lichens are a source of various biologically active compounds. However, the knowledge about them is still scarce, and their use in medicine is limited. This study aimed to investigate the therapeutic potential of the lichen Platismatia glauca and its major metabolite caperatic acid in regard to their potential application in the treatment of central nervous system diseases, especially neurodegenerative diseases and brain tumours, such as glioblastoma. First, we performed the phytochemical analysis of the tested P. glauca extracts based on FT-IR derivative spectroscopic and gas chromatographic results. Next the antioxidant properties were determined, and moderate anti-radical activity, strong chelating properties of Cu²⁺ and Fe²⁺ ions, and a mild effect on the antioxidant enzymes of the tested extracts and caperatic acid were proved. Subsequently, the influence of the tested extracts and caperatic acid on cholinergic transmission was determined by in vitro and in silico studies confirming that inhibitory effect on butyrylcholinesterase is stronger than against acetylcholinesterase. We also confirmed the anti-inflammatory properties of P. glauca extracts and caperatic acid using a COX-2 and hyaluronidase inhibition models. Moreover, our studies show the cytotoxic and pro-apoptotic activity of the P. glauca extracts against T98G and U-138 MG glioblastoma multiforme cell lines. In conclusion, it is possible to assume that P. glauca extracts and especially caperatic acid can be regarded as the source of the valuable substances to finding new therapies of central nervous system diseases. Full article

Peyronie’s disease (PD) is a fibrotic disorder of the tunica albuginea of the penis. Conservative medical therapy includes oral and/or injective active substances. Until now, only two PD patients who recovered after medical treatment are described in the literature. This article describes three new cases of PD patients who achieved complete resorption of plaque following antioxidant treatment. Case Presentations: Case 1. The patient was a 34-year-old man, a smoker, with lateral-left penile curvature (40 degrees), penile pain, and good penile rigidity. The patient was treated with combined therapy (oral antioxidants + Propolis creme). At follow-up, after about 29 months of treatment, we observed the disappearance of the acquired penile deformity. The ultrasound examination no longer showed any plaque. Case 2. The patient was a 32-year-old man with chronic prostatitis, penile lichen sclerosus, lateral-left penile curvature (10 degrees), a palpable lump, and good penile rigidity. The patient was treated with combined therapy (oral antioxidants + Propolis creme + penile injections of pentoxifylline). After 33 months of treatment, at follow-up, we observed the disappearance of the penile deformity. Ultrasound examinations no longer showed any plaque. Case 3. The patient was a 33-year-old man with penile pain, dorsal penile curvature (30 degrees), and good penile rigidity. The patient was treated with combined therapy (oral antioxidants + Propolis creme + penile injections of pentoxifylline). At follow-up, after 41 months of treatment, the penile pain was no longer present, and the ultrasound study no longer showed any plaque. Conclusions: Although our study presents a limited number of cases, it is a matter of fact that these patients obtained full regression in the affected area. We believe our experience may be very useful for urological clinical practice. Full article

Atranorin (ATR) is a secondary metabolite of lichens. While previous studies investigated the effects of this substance predominantly in an in vitro environment, in our study we investigated the basic physicochemical properties, the binding affinity to human serum albumin (HSA), basic pharmacokinetics, and, mainly, on the systematic effects of ATR in vivo. Sporadic studies describe its effects during, predominantly, cancer. This project is original in terms of testing the efficacy of ATR on a healthy organism, where we can possibly attribute negative effects directly to ATR and not to the disease. For the experiment, 24 Sprague Dawley rats (Velaz, Únetice, Czech Republic) were used. The animals were divided into four groups. The first group (n = 6) included healthy males as control intact rats (♂INT) and the second group (n = 6) included healthy females as control intact rats (♀INT). Groups three and four (♂ATR/n = 6 and ♀ATR/n = 6) consisted of animals with daily administered ATR (10mg/kg body weight) in an ethanol–water solution per os for a one-month period. Our results demonstrate that ATR binds to HSA near the binding site TRP214 and acts on a systemic level. ATR caused mild anemia during the treatment. However, based on the levels of hepatic enzymes in the blood (ALT, ALP, or bilirubin levels), thiobarbituric acid reactive substances (TBARS), or liver histology, no impact on liver was recorded. Significantly increased creatinine and lactate dehydrogenase levels together with increased defecation activity during behavioral testing may indicate the anabolic effect of ATR in skeletal muscles. Interestingly, ATR changed some forms of behavior. ATR at a dose of 10 mg/kg body weight is non-toxic and, therefore, could be used in further research. Full article

Fungi involved in lichen symbioses produce a large array of secondary metabolites that are often diagnostic in the taxonomic delimitation of lichens. The most common lichen secondary metabolites—polyketides—are synthesized by polyketide synthases, particularly by Type I PKS (TI-PKS). Here, we present a comparative genomic analysis of the TI-PKS gene content of 23 lichen-forming fungal genomes from Ascomycota, including the de novo sequenced genome of Bacidia rubella. Firstly, we identify a putative atranorin cluster in B. rubella. Secondly, we provide an overview of TI-PKS gene diversity in lichen-forming fungi, and the most comprehensive Type I PKS phylogeny of lichen-forming fungi to date, including 624 sequences. We reveal a high number of biosynthetic gene clusters and examine their domain composition in the context of previously characterized genes, confirming that PKS genes outnumber known secondary substances. Moreover, two novel groups of reducing PKSs were identified. Although many PKSs remain without functional assignments, our findings highlight that genes from lichen-forming fungi represent an untapped source of novel polyketide compounds. Full article

Free radicals play a critical role in the chemical processes that occur in all cells. Pharmaceutical companies manufacture a variety of synthetically prepared antioxidants, but it is known that many of these can be carcinogenic. As a result, efforts are being made to find natural antioxidants that do not have these side effects. Lichens may be suitable candidates because they contain secondary metabolites with proven antioxidant properties. This could be explained by the presence of compounds with phenolic groups in lichens. The radical scavenging reaction is a chemical reaction governed by stoichiometry, and our aim is to determine the efficacy of these reactions. The aim of this study is to compare metabolite activity based on the same amount of substance involved in radical scavenging, calculated in micromoles rather than weight concentration. This provides an accurate way of comparing radical scavenging activity. We tested superoxide anion scavenging activity and free radical scavenging activity of isolated lichen secondary metabolites and their mixtures in different ratios. The following compounds were isolated and tested for antioxidant activity: gyrophoric acid (Umbilicaria hirsuta), evernic acid (Evernia prunastri), physodic acid, 3-hydroxyphysodic acid, physodalic acid and atranorin (Hypogymnia physodes), and usnic acid (as a synthetic compound). Of all the tested compounds, 3-hydroxyphysodic acid, as well as mixtures containing this metabolite, showed the strongest scavenging activity. The results also demonstrated that calculation by amount of substance leads to a new consideration of antioxidant activity. Full article