Parmotrema Tinctorum Research Articles

Inventarisasi Awal Liken Langka, Sensitif dan Toleran sebagai Bioindikator Polutan di Kabupaten Belitung Barat

The existence and population conditions of the rare, sensitive or tolerant lichens of Lobaria, Coccocarpia, Coenogonium, Dictyonema, Pseudocyphellaria, Sticta, Usnea, Leptogium, and Parmotrema tinctorum are not yet known in West Belitung Regency, so this research needs to be carried out. The method used in this research was exploratory descriptive with survey techniques and purposive sampling. The number of target lichen thallus was calculated from the entire area of the tree trunk with a height of 0-1.5 m. The lichens found in the Gunung Tajam area were Coccocarpia sp. with the highest number of thallus and the highest frequency of thallus (0.8%), followed by Coenogonium sp., Leptogium sp., and Usnea sp. with the same frequency of thallus (0.4%) while in the Batu Mentas area lichens were not found as the research target, but was dominated by fruticose lichen. Parmotrema tinctorum, the tolerant lichen, was not found at either location. The presence of sensitive lichens and the absence of tolerant lichens does not indicate that the locations have good air quality. It is recommended that the lichen population, especially P. tinctorum, be studied further so that air quality can be easily confirmed through the diversity and population of the lichens.

In-vitro Study on Anthelmintic and Insecticidal Activity of Macrolichens Collected from South Karnataka

In the present study, lichen samples were collected from the southern Karnataka state and were used for in-vitro anthelmintic and insecticidal activity. The three lichen samples Parmotrema tinctorum (Nyl.) Hale, Roccella montagnei Bèl. Emend. Awas, Everniastrum cirrhatum (Fr.) Hale was subjected to the extraction with solvents. The prepared extracts from the lichen species were evaluated for anthelmintic activity against Pheretima posthuma. 100% mortality was obtained from all the samples and it was compared with the reference drug albendazole for positive control. P. tinctorum methanolic extract showed the fastest result but on the other side, the slowest result was observed in the hexane extract. The insecticidal activity of the crude extracts of the lichens was tested against two insects Macrosiphum rosae (L.) and Sitophilus oryzae (L.). There was a 100% mortality rate observed in R. montagnei and E. cirrhatum methanolic extracts against M. rosae. In S. oryzae the methanolic extracts of P. tinctorum and E. cirrhatum with 75 and 50% mortality rates at 42 and 48 hours was observed. The promising results of lichen extracts towards insecticidal and anthelmintic activity were found to be a potential candidate for drug discovery and development against biopesticides.

Laboratory and field measurements of water relations, photosynthetic parameters, and hydration traits in macrolichens in a tropical lower montane rainforest in Thailand.

Ecophysiological studies of lichens in tropical Asia are rare, and additional studies can increase the understanding of lichen life in this region. The main aim of this study was to observe the relationships between water availability and photosynthetic parameters, as well as hydration trait parameters, in macrolichens during the rainy and dry seasons in a tropical forest. A total of 11 lichen species growing in a lower montane rainforest in Thailand were collected and studied. The results clearly showed that the specific thallus mass (STM), net photosynthetic rate (Pn), the potential quantum yield of primary photochemistry (Fv/Fm), chlorophyll content, and carotenoid content of almost all lichens were lower in the dry season than in the rainy season. Field measurements in the dry season revealed that only the foliose chlorolichen Parmotrema tinctorum was metabolically active and exhibited slight carbon assimilation. In the rainy season, all lichens started their photosynthesis in the early morning, reached maximal values, declined, and ceased when the thalli desiccated. The photosynthetically active period of the lichens was approximately 2-3h in the morning, and the activities of the cyanolichens ended approximately 30min after the chlorolichens. The hydration trait parameters, including the STM, maximal water content (WCmax), and water holding capacity (WHC), were greater in the cyanolichens. In addition, the maximal Pn (Pnmax) and optimal water content (WCopt) for Pn were also greater in the cyanolichens, but the maximal Fv/Fm (Fv/Fmmax) was lower. The cyanolichens compensated for their inability to use humid air to restore photosynthesis by having higher water content and storage, higher photosynthetic rates, and longer photosynthetically active periods. This study provides additional insights into lichen ecophysiology in tropical forests that can be useful for lichen conservation.

Tinctoric acid A-B, two new hopan-type triterpenoids from the Vietnamese lichen, Parmotrema tinctorum (Despr. ex Nyl.) hale with α-glucosidase inhibitory activity

Two new hopan-type triterpenoids, namely tinctoric acid A-B (1-2), were isolated from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR). The absolute configuration at C-22 of 1 was established through DP4 probability. Compounds 1-2 were evaluated for their inhibitory activity against α-glucosidase and found to be more potent than those of positive control (acarbose, IC50 168 µM) with values IC50 74.7 and 98.2 µM, respectively. Both of these compounds interacted well with enzyme α-glucosidase MAL32 through H-bonds and hydrophobic interaction.

Antihyperlipidemic and Antiobesity Effects of Parmotrema tinctorum Ethanolic Extract in Olive Oil-Induced Hyperlipidemic Rats

Antihyperlipidemic and Antiobesity Effects of Parmotrema tinctorum Ethanolic Extract in Olive Oil-Induced Hyperlipidemic Rats

Http://jeb.co.in./journal_issues/202311_nov23/paper_12.pdf

Aim: The aim of this research was to identify a suitable lichen species as a bio-indicator for heavy metals in the Himalayan habitats. Methodology: The study was conducted in a sacred grove located in Western Nepal. The grove was situated alongside the busy Mahakali National highway. Lichen samples were collected from different areas of the grove, ranging from the edge adjacent to the highway to the center. Standard protocols were employed to identify the collected lichen species. The heavy metal content in the samples were analyzed by subjecting them to acid digestion followed by AAS estimation. Results: Three lichen species were discovered: Bulbothrix meizospora, Parmotrema tinctorum, and Pyxine berteriana. Pyxine berteriana was collected near the highway, while Bulbothrix meizospora and Parmotrema tinctorum were collected away from it. The heavy metal bioaccumulation pattern observed was as follows: Fe>Al>Mg>Zn>Cu>Pb>Mn>Ni>Cd>Cr. Notably, Pyxine berteriana exhibited the highest metal concentrations among the three species. Interpretation: Based on the findings, it can be concluded that the Physcioid lichen Pyxine berteriana is the most resilient species in the region and can serve as an appropriate bio-indicator for studying the deposition of heavy metals in the ambient air. Key words: Physcioid lichens, Pyxine berteriana, Parmotrema tinctorum, Lichens, Sacred Grove

Fungal community inside lichen: a curious case of sparse diversity and high modularity

BackgroundLichens represent not only the mutualism of fungal and photosynthetic partners but also are composed of microbial consortium harboring diverse fungi known as endolichenic fungi. While endolichenic fungi are known to exert a remarkable influence on lichen ecology through their crucial roles in nutrient cycling, bioprospecting and biodiversity, the enigmatic community structures of these fungal inhabitants remain shrouded in mystery, awaiting further exploration and discovery. To address knowledge gap, we conducted metabarcoding on two lichens using 18S gene amplification, Dirinara applanta and Parmotrema tinctorum, and compared their microbial communities to those found in the pine bark to which the lichens were attached. Our hypothesis was that the endolichenic communities would exhibit distinct diversity patterns, community structures, network structures, and specialist composition compared to the surrounding epiphytic community.ResultsOur investigation has shed light on the clear demarcation between the endolichenic and epiphytic fungal communities, as they exhibit markedly different characteristics that set them apart from each other. This research demonstrated that the endolichenic communities are less diverse as compared to the epiphytic communities. Through community similarity analysis, we observed that two endolichenic communities are more similar to each other in terms of community composition than with the adjacent epiphytic communities. Moreover, we unveiled a striking contrast in the network structures between the endolichenic and epiphytic communities, as the former displayed a more modular and less nested features that is evocative of a potent host-filtration mechanism.ConclusionsThrough our investigation, we have discovered that lichens harbor less intricate and interconnected fungal communities compared to the neighboring epiphytic environment. These observations provide valuable insights into the metagenomic architecture of lichens and offer a tantalizing glimpse into the unique mycobiome.

Tinctorin, a new spiroterpenoid from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale growing in Vietnam

A new spiroterpenoid, namely tinctorin (1), along with one known compound, norreticulatin (2), were isolated from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their structures were elucidated by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. The absolute configuration of 2 was established for the first time. Compound 1 was evaluated for its inhibitory activity against α-glucosidase and found to be inactive.

Exploration of Lichenes in the Mutis Mount Area, Noepesu Village, West Miomaffo District

This study aims to explore and identify the types of Lichenes that exist at the Mutis Mount Area, Noepesu Village, West Miomaffo District, and the Biology Education Laboratory, University of Timor. This research was conducted for 6 months starting from May-October 2022. This research is descriptive qualitative research. Sampling used a purposive sampling method. The collected Lichenes were identified based on their characteristics using the determination key and then matched with the photo collection. Morphological observation of lichenes was conducted at the Biology Education Laboratory, University of Timor using a microscope. The result of observations and collections based on this research conducted in the Mutis Mount area found 29 species of Lichenes with 12 families, the species found were Septennium azureum, Parmotrema tinctorum, Parmotrema perlatum, Parmelia sulcate, Parmelia sp, Flavoparmelia afternoondians, Usnea hirta, Usnea sp 1, Pyxine subcinerea, Cryptothecia sp, Dirinaria sp, Lepraria Lobificans, Lepraria incana, Lepraria sp 1, Hydropunctaria maura, Candelariella sp, Arthonia ilicina, Arthonia Radiata, Arthonia Clemens, Graphis Scipta, Graphis sp1, Graphis sp2, Graphis sp3, Graphis sp4, Graphis sp5, Graphis sp6, Ramalina farinaceae, Cryptothechia striata, and Bacidia insularis. Lichenes were found in soil, weathered wood, tree trunks, and rocks with thallus morphology, namely Crustose, Foliose, Fructicose, and Squamulose.

Lichen biomonitoring of seasonal outdoor air quality at schools in an industrial city in Thailand

Poor air quality in school environments causes adverse health effects in children and decreases their academic performance. The main objective of this study was to use lichens as a biomonitoring tool for assessing outdoor air quality at schools in the industrial area of Laem Chabang municipality in Thailand. Thalli of the lichen Parmotrema tinctorum were transplanted from an unpolluted area to nine schools in the industrial area and to a control site. The lichens were exposed for four periods in the dry, hot, early rainy, and late rainy seasons, for 90days each. The concentrations of 14 elements, including As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, V, and Zn, were determined using inductively coupled plasma‒mass spectrometry (ICP‒MS), and 8 physiological parameters were measured. The concentrations of all 14 investigated elements were clearly higher at the schools than at the control site. The contamination factors (CFs) suggested that 9 out of the 14 elements, including As, Cd, Co, Cr, Cu, Mo, Pb, Sb, and Ti, heavily contaminated the school environments, especially Pb, the concentration of which was 3 to 11 times higher than at the control site. The most polluted time was the hot season as evidenced by the investigated elements, and the least polluted time was the late rainy season. The pollution load indices (PLIs) demonstrated that schools in the inner and middle zones clearly had higher pollution loads than the schools in the outer zone during the rainy seasons, while the hot and dry seasons showed similar pollution levels in all zones. The vitality indices (VIs) showed that the lower lichen vitalities at most schools were observed during the dry season and at the schools in the inner and middle zones. Accordingly, the air performance indices (APIs) revealed that poorer air quality at most schools was found during the dry season and at the schools in the inner and middle zones. This study clearly showed that the transplanted lichen P. tinctorum was an effective bioindicator of air quality in school environments. The results illustrated that all studied schools were contaminated by air pollutants; therefore, improving air quality at the schools is crucial and should be an urgent issue for maintaining good health and may benefit children's academic achievements and careers in the long run.

Assessing Seasonal Concentrations of Airborne Potentially Toxic Elements in Tropical Mountain Areas in Thailand Using the Transplanted Lichen Parmotrema Tinctorum (Despr. ex Nyl.) Hale

The atmosphere of mountain areas may be contaminated by pollutants originating mainly from road traffic, as well as tourist and community activities within such areas. This study mainly aimed to assess the concentrations of airborne potentially toxic elements (PTEs) in two mountain areas in Thailand using lichen biomonitoring. Thalli of the lichen Parmotrema tinctorum from the relatively unpolluted area in Khao Yai National Park (KYNP) were prepared and exposed at nine sites in the KYNP and nine sites in Doi Inthanon National Park (DINP) during the rainy and dry seasons. The lichen transplants were collected and analyzed for 15 PTEs, including Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, V, and Zn, using inductively coupled plasma-mass spectrometry. The result clearly showed that the atmosphere of many monitoring sites in both mountains were contaminated by the investigated PTEs. The contamination factors (CFs) revealed that several PTEs heavily contaminated the atmosphere at many monitoring sites. The pollution load indices (PLIs) clearly illustrated that the atmosphere of all sites had higher pollution loads in the dry season than in the rainy season, which was likely due to the higher numbers of motor vehicles and visitors. The highest pollution loads were observed at sites that had higher traffic density and human activities, including the park entrance site in the KYNP and the community site in the DINP. The lowest air pollution loads were discovered at the summit sites in both mountains. This study indicates that the atmosphere of mountain areas can be contaminated by some PTEs that are mainly produced by road traffic and local communities. It also confirms the ability of the transplanted lichen P. tinctorum to be an effective biomonitoring tool for airborne PTEs in natural environments.

Biomarkers of pollution by glyphosate in the lichens, Parmotrema tinctorium and Usnea barbata.

Glyphosate is a herbicide commonly used in agriculture for weed control. Current agricultural production demands vast amounts of this product, which are applied by ground or aerial spraying. The concomitant aerial currents promote glyphosate drift to vegetated or urban areas. In this context, we hypothesized that the lichens, Parmotrema tinctorum and Usnea barbata, could be sensitive to the action of glyphosate and therefore be used to bio-indicate the presence of this herbicide in areas affected by drift. Since living organisms respond in different ways to the action of herbicides, our interest was also to indicate biological markers responsive to the action of glyphosate, through concentrations and exposure times of the thallus, besides identifying the most sensitive species. We evaluated the effect of different concentrations (0.0, 4.8, 9.6, and 19.2 mg L-1) and exposure times (24, 48, and 72 hours) to glyphosate on the morphoanatomy, photobiont vitality, photosynthetic efficiency, and oxidative metabolism of the thalli. We found that the lichens, P. tinctorum and U. barbata, respond to glyphosate stress, with prospects for use in the biomonitoring of pollutant dispersal from plantation areas. When using P. tinctorum as a bioindicator, lichen morphoanatomy, photobiont vitality, and photosynthetic pigment concentration were efficient biomarkers for the effect of concentration and exposure time. For U. barbata, the lichenic morphoanatomy and the activity of SOD and APX enzymes were essential tools to indicate the herbicide action. Parmotrema tinctotum, however, was characterized as more sensitive in bio-indicating the presence of this herbicide to diagnose the air quality in urban areas or vegetation sectors adjacent to agricultural environments.

Impacts of Cd Pollution on the Vitality, Anatomy and Physiology of Two Morphologically Different Lichen Species of the Genera Parmotrema and Usnea, Evaluated under Experimental Conditions

The heavy metal Cd accumulates in trophic chains, constituting a toxic element for photosynthesizing organisms, including the algal photobionts of lichen. Thus, as lichens respond differently to heavy metal toxicity, we hypothesized that the species Parmotrema tinctorum and Usnea barbata, commonly sampled in the Cerrado ecoregion, could be sensitive to Cd and, therefore, be used to biomonitor the dispersion of this metal. We also aimed to indicate the responsiveness of biological markers to Cd in these species by exposing the thalli to simulated rainfall with increasing metal concentrations. We observed that both lichen species are responsive to Cd stress; however, different pathways are accessed. The synthesis of carotenoids by P. tinctorum and the production of antioxidant enzymes by U. barbata seem to constitute relevant response strategies to Cd-induced stress. The lichen morphoanatomy, cell viability, photobiont vitality index, chlorophyll a fluorescence, and chlorophyll a synthesis were efficient biomarkers for the effects of increasing Cd exposure in P. tinctorum, being the variables primarily associated with damage to the photobiont. For U. barbata, the lichen morphoanatomy, photochemistry, and antioxidant enzyme activity (catalase, superoxide dismutase and ascorbate peroxidase) were essential to reflect Cd toxicity. However, the species P. tinctorum was characterized as the most sensitive to Cd toxicity, constituting a good bioindicator for the presence of this metal. It can be used in the diagnosis of air quality in urban and industrial areas or even in forest areas influenced by Cd in phosphate fertilizers.

Tinctoride A, a New Hopan-Type Triterpenoic Peracid from the Thallus of Lichen Parmotrema Tinctorum (Despr. ex Nyl.) Hale

A new hopan-type triterpenoic peracid, tinctoride A (1), together with three known compounds, zeorin (2), 6β,22-dihydroxyhopane (3), and ergosterol peroxide (4), was isolated from Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their chemical structures were identified by extensive 1D and 2D NMR analysis and high-resolution mass spectroscopy and compared with those reported in the literature. The enzyme inhibitory potential of compounds 1–3 against α-glucosidase was investigated, exhibiting nil to weak inhibitory activity.

Macrofilaricidal Activity, Acute and Biochemical Effects of Three Lichen Species Found on Mount Cameroon.

Onchocerciasis is a parasitic infection affecting a relatively small population globally but has very devastating pathological outcomes. Ivermectin and recently moxidectin are the only drugs approved for clinical management of the disease, both of which have several limitations. In particular, they are efficacious against microfilariae (microfilaricidal) with no activity against adult worms (nonmacrofilaricidal). Promising anthelmintic activity has been reported in some lichens. This study investigated three lichens, Usnea articulata, Parmotrema tinctorum, and Heterodermia obscurata, found on Mount Cameroon, for potential macrofilaricidal activity. Organic extracts were screened for anti-Onchocerca activity against Onchocerca ochengi isolated from cattle skin using worm motility and MTT formazan assays. Toxicity of highly active extracts was investigated on monkey kidney epithelial (LLCMK2) cells and in BALB/c mice (2000 mg/kg body weight) including effects on liver enzymes. The methanol extract of P. tinctorum (Pammet) was the most active against adult male worms (IC50 = 8.1 μg/mL) with the highest selectivity index (SI = 21.3). U. articulata was the most active against the adult female (IC50 = 36.3 μg/mL) but had a low SI value (3.4). No mortality and no adverse effects were recorded in the acute toxicity test. These two most active extracts had no significant effect on liver enzymes, alanine aminotransferase, and aspartate (P values < 0.05), but a high AST : ALT ratio (2.59) for Pammet indicates likely reversible adverse hepatic toxicity. The high macrofilaricidal activity and selectivity of P. tinctorum suggest it is a potential source of new macrofilaricides which should be further investigated to identify its bioactive constituents.

Endolichenic Fungal Community Analysis by Pure Culture Isolation and Metabarcoding: A Case Study of Parmotrema tinctorum

Lichen is a symbiotic mutualism of mycobiont and photobiont that harbors diverse organisms including endolichenic fungi (ELF). Despite the taxonomic and ecological significance of ELF, no comparative investigation of an ELF community involving isolation of a pure culture and high-throughput sequencing has been conducted. Thus, we analyzed the ELF community in Parmotrema tinctorum by culture and metabarcoding. Alpha diversity of the ELF community was notably greater in metabarcoding than in culture-based analysis. Taxonomic proportions of the ELF community estimated by metabarcoding and by culture analyses showed remarkable differences: Sordariomycetes was the most dominant fungal class in culture-based analysis, while Dothideomycetes was the most abundant in metabarcoding analysis. Thirty-seven operational taxonomic units (OTUs) were commonly observed by culture- and metabarcoding-based analyses but relative abundances differed: most of common OTUs were underrepresented in metabarcoding. The ELF community differed in lichen segments and thalli in metabarcoding analysis. Dissimilarity of ELF community intra lichen thallus increased with thallus segment distance; inter-thallus ELF community dissimilarity was significantly greater than intra-thallus ELF community dissimilarity. Finally, we tested how many fungal sequence reads would be needed to ELF diversity with relationship assays between numbers of lichen segments and saturation patterns of OTU richness and sample coverage. At least 6000 sequence reads per lichen thallus were sufficient for prediction of overall ELF community diversity and 50,000 reads per thallus were enough to observe rare taxa of ELF.

TOXICOLOGICAL AND BEHAVIOR ANALYSES OF A FOLIOSE LICHEN PARMOTREMA TINCTORUM (DELISE EX NYL.) HALE EXTRACT USING ZEBRAFISH (DANIO RERIO) MODEL

Objective: The objective of the study was to evaluate the toxicity and behavior analysis with the extract of foliose lichen Parmotrema tinctorum against the adult zebrafish. Methods: The zebrafishes were exposed to different concentrations of P. tinctorum extract such as 50, 100, and 200 mg/ml for 7 days of exposure, in which the mortality and behavioral responses of zebrafishes were recorded. The standard histopathological examination was conducted with the lichen extracts of P. tinctorum. Results: The results revealed that P. tinctorum extract did not show any prominent behavior abnormalities in zebrafishes even at a high concentration of 200 mg/ml. The extract was found to have dose-dependent toxic to zebrafish and the number of neutrophil cells in the muscle bundles reduced at a high concentration. The results of the inflammatory marker gene expression using polymerase chain reaction results suggested that the dose-dependent suppression of tumor necrosis factor gene by the P. tinctorum lichen extract. Conclusion: Overall, concluded that the extract might contain anti-inflammatory induction properties and further tests are required to prove apoptosis and anticancer activity using other in vivo or in vitro techniques.

Parmotrema tinctorum as an indicator of edge effect and air quality in forested areas bordered by intensive agriculture.

Pollutants inhibit thallus growth and development or alter the metabolism and associated anatomical and morphophysiological characteristics of lichens. Since agricultural matrices can act as sources of pollution by dispersing agrochemicals to vegetation fragments, this study tested the hypothesis that Parmotrema tinctorum can serve as the indicator of edge effect in such fragments. In other words, we assumed the impact of pollutant accumulation to be greater at the vegetation edges and explored the utility of this lichen as a bioindicator of pollutants dispersed from agricultural matrices. Differences in the anatomical layers of P. tinctorum thalli sampled from the edge and center of four vegetation fragments (CER, SSF, SSC, and ENP) were evaluated, and the effects of agricultural matrices on macro- and micronutrient levels, heavy metal levels, and photosynthetic pigment content were analyzed. Anatomical layers were thicker in P. tinctorum thalli from the edges of SSC and ENP, indicating the need for photobiont protection at these sites. Edge effect was observed on Al accumulation in the thallus, indicating dispersion of this metal from agricultural matrices and its greater impact in the edge populations. Edge effect was also evident on photosynthetic pigment content, macro- and micronutrient levels, and heavy metal concentration in the thallus, and the values reflected high ecological imbalance currently verified at the edge of ENP, an area of permanent protection. In areas within ENP, chlorophyll a/b ratio reflected stress factors acting on the thallus, indicating that even legally protected areas are not free from the impact of atmospheric pollutants. P. tinctorum may serve as an effective indicator of edge effects and may be used for biomonitoring pollutant dispersion from agricultural matrices.

The metabolite 5-methyl-1,3-benzenediol and its derivative methyl-2,4-dihydroxy-6-methylbenzoate from the lichen Parmotrema tinctorum with potent apoptotic and anti-angiogenesis effects.

Nature has been a rich resource of novel anticancer agents, one such source being lichens, which represent the symbiosis between algae and fungi with diverse range of secondary metabolites having therapeutic significance. With respect to this, the present study evaluates the in vitro apoptogenic profile of secondary metabolites from the lichen Parmotrema tinctorum towards cancer cell lines. Treatment with TLC-purified fraction 1 from P. tinctorum resulted in significant reduction in the cell viabilities of cancer cells with IC50 values ranging between 1.2 and 12.8μg/ml. The potential anticancer effect of the bioactive fraction was further supported by Trypan blue cell viability, LDH and DNA fragmentation assays. At the cellular level, induction of apoptosis was confirmed through the activation of the caspase cascade and apoptotic cells accumulating in the Sub-G1 phase of cell cycle. Angiogenesis being one of the major characteristics needed for cancer growth, the ability of the lichen fraction to inhibit angiogenesis was checked through in ovo Yolk Sac Membrane (YSM) assay and was found to be significant. The study also verified the non-toxic nature of the bioactive fraction towards normal human peripheral lymphocytes. HPLC analysis and GC-MS characterisation of the bioactive fraction indicated the presence of 5-methyl-1,3-benzenediol and its derivative methyl-2,4-dihydroxy-6-methylbenzoate.

Chemical Composition and Antimicrobial Activity of Two Sri Lankan Lichens, Parmotrema rampoddense, and Parmotrema tinctorum against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus.

Introduction Medicinal utility of lichens is ascribed to the presence of various secondary metabolites of low molecular weight and they have been used in traditional medicine including Ayurveda in the treatment of wounds and skin disorders. Despite the urgent need to effectively address the antibiotic resistance worldwide, the discovery of new antibacterial drugs has declined in the recent past. This emphasizes the increasing importance of investigating and developing new classes of antibiotics that can withstand antibiotic resistance. Aims of the study. The present study was conducted to investigate the chemical composition and the antibacterial activity of hexane, ethanol, and aqueous extracts of Parmotrema rampoddense and Parmotrema tinctorum, two lichens collected from Belihuloya, Sri Lanka, against Gram-negative and Gram-positive bacteria including twenty clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Materials and methods. Phytochemical analysis, thin layer chromatography (TLC), and Gas Chromatography Mass Spectrometry (GC-MS) were performed to determine the chemical composition of the two lichens. Hexane, ethanol, and aqueous extracts of both lichens were tested against clinical isolate of Gram-negative and Gram-positive bacteria including twenty clinical isolates of MRSA. Bacterial susceptibility was tested using a disc diffusion assay. Minimum inhibitory concentration (MIC) was determined by a broth microdilution method. Vancomycin was used as the positive control. Results Alectorialic acid, atranorin, atraric acid, orcinol, and O-orsellinaldehyde were among the secondary metabolites identified by the TLC and GC-MS analysis. None of the lichen extracts were active against Gram-negative bacteria but both lichens showed a concentration-dependent activity against methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA. Ethanol extract of P. rampoddense showed the highest activity against MSSA with the MIC, 0.0192 mg/ml, but all MRSA isolates investigated showed MIC between 0.096 and 2.4 mg/ml for the same extract. Conclusion Both lichens, P. rampoddense and P. tinctorum, represent potentially important sources of future antimicrobial drugs. Further investigation on the ethanol extract of P. rampoddense will enable us to determine the most active phytoconstituents responsible for the activity, their mechanism of action against bacterial pathogens, and also their cytotoxicity against normal cells.