Search Results (3)

Evernia prunastri is a lichen widely distributed in the Northern Hemisphere. Its biological properties still need to be discovered. Therefore, our paper focuses on studies of E. prunastri extracts, including its main metabolites evernic acid (EA) or atranorin (ATR). Phytochemical profiles using chromatographic analysis were confirmed. The antioxidant activity was evaluated using in vitro chemical tests and in vitro enzymatic cells-free tests, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT). The anti-inflammatory potential using cyclooxygenase-2 (COX-2) and hyaluronidase were determined. The neuroprotective potential using acetylcholinesterase, (AChE), butyrylcholinesterase (BChE), and tyrosinase (Tyr) was estimated. The hypoglycemic activity was also confirmed (α-glucosidase). Principal component analysis was performed to determine the relationship between the biological activity of extracts. The inhibitory effect of EA and ATR on COX-2 AChE, BChE, Tyr, and α-glucosidase was evaluated using molecular docking techniques and confirmed for EA and ATR (besides α-glucosidase). The penetration of EA and ATR from extracts through the blood–brain barrier was confirmed using the parallel artificial membrane permeability assay blood–brain barrier test. In conclusion, depending on chemical surroundings and the concentration, the E. prunastri extracts, EA or ATR, showed attractive pleiotropic properties, which should be further investigated. Full article

It has been widely documented that the complex structure of forest ecosystems supports considerable bryophyte species and functional diversity. In this study, we assessed the diversity, distribution and ecological and phytogeographical features of bryophytes across a gradient of temperate forest types on Mt. Papuk. This is the largest and highest mountain in the lowland, Pannonian part of Croatia, with high geological diversity and various temperate forests covering 95% of the mountain. According to the predominant tree species (oak vs. beech), geological bedrock (calcareous vs. siliceous) and soil reaction (alkaline vs. acidic), 21 study plots were classified into four distinct forest types. In all, 184 bryophyte species (35 liverworts and 149 mosses) were recorded. Although the forest types investigated did not differ significantly with respect to species richness, each was characterized by a considerable number of diagnostic bryophyte species. According to our results, one of the main ecological factors determining the variability of the forest bryophyte composition was geological bedrock and the associated soil reaction. Basiphilous forests developed on carbonate bedrock harbored more thermophilous and nitrophilous bryophytes and were characterized by southern-temperate and Mediterranean–Atlantic biogeographic elements. In contrast, acidophilous forests growing on silicate bedrock were characterized by wide-boreal and boreo-arctic–montane elements, i.e., bryophytes indicating cooler habitats and nitrogen-deficient soils. Based on the results, we hypothesized that the main latitudinal biogeographic distinction between southern and northern biogeographic elements is driven more by geological substrate than by the main tree species in forest communities. The present study confirmed previous findings that bryophytes are good and specific habitat indicators and show associations with different forest types, which can help to understand the complexity, ecological microconditions and biogeographic characteristics of forest communities. Full article

Oak regeneration failures have been causing a slow decline in the occurrence of oak forest ecosystems in eastern North America. Accordingly, our study sought to determine a means of creating more vigorous and competitive oak seedlings by the addition of manganese (Mn) fertilizers. Seeds of northern red oak (Quercus rubra L.), chestnut oak (Quercus prinus L.), and red maple (Acer rubrum L.), one of oak’s major competitors in North America oak forest ecosystems, were sown in 0.7 liter pots that contained a growing medium mixture of peat moss, perlite, and sand in a ratio of 2:1:2, and germinated in a greenhouse. Three different chemical compound Mn fertilizer treatments—manganese chloride (0.16 mg L⁻¹ Mn, MnCl₂·4H₂O), nanoparticle manganese in the form of manganese hydroxide (0.01 mg/L Mn, nanoparticle Mn(OH)₂), and manganese hydroxide (0.01 mg L⁻¹ Mn, Mn(OH)₂)—and a treatment of Hoagland solution were applied to the planted seed. These treatments were compared to a control consisting of water, and treatments were applied twice a week over a 12 week period. Germination rates and seedling growth were measured over this period of time. At the end of 12 weeks seedlings were harvested, separated into roots, stem, and foliage for the purpose of biomass and nutrient analysis by seedling component. Northern red oak displayed a 100% germination success rate with MnCl₂·4H₂O and Mn(OH)₂ treatments, while red maple germination was reduced with the MnCl₂·4H₂O and nanoparticle Mn(OH)₂ treatments with only a 32% and 24% germination rate, respectively. The MnCl₂·4H₂O treatment produced the largest overall seedling size (basal diameter squared times the seedling height) of red maple with a 191.6% increase; however, the MnCl₂·4H₂O treatment produced the largest overall seedling size (basal diameter squared times the seedling height) of northern red oak and chestnut oak with an increase of 503.7% and 339.5%, respectively. The greatest increase in overall seedling size for northern red oak was with the Mn(OH)₂ treatment at 507.2%, and 601.2% for chestnut oak with the nanoparticle Mn(OH)₂ treatment. MnCl₂·4H₂O treatment significantly increased the oak foliar nitrogen (N) content. It appears that the application of Mn fertilizer can increase the germination and growth of these oak species while suppressing or having a lesser effect on red maple, thus creating a competitive advantage for oak over its competitor. Full article