Exploring the effects of habitat management on grassland biodiversity: A case study from northern Serbia

Grasslands represent a biodiversity hotspot in the European agricultural landscape, their restoration is necessary and offers a great opportunity to mitigate or halt harmful processes. These measures require a comprehensive knowledge of historical landscape changes, but also adequate management strategies. The required data was gathered from the sand grasslands of northern Serbia, as this habitat is of high conservation priority. This area also has a long history of different habitat management approaches (grazing and mowing versus unmanaged), which has been documented over of the last two decades. This dataset enabled us to quantify the effects of different measures across multiple taxa (plants, insect pollinators, and birds). We linked the gathered data on plants, pollinators, and birds with habitat management measures. Our results show that, at the taxon level, the adopted management strategies were beneficial for species richness, abundance, and composition, as the highest diversity of plant, insect pollinator, and bird species was found in managed areas. Thus, an innovative modelling approach was adopted in this work to identify and explain the effects of management practices on changes in habitat communities. The findings yielded can be used in the decision making as well as development of new management programmes. We thus posit that, when restoring and establishing particular communities, priority needs to be given to species with a broad ecological response. We recommend using the decision tree as a suitable machine learning model for this purpose.

Biological Activity of Genus Hypericum Sect. Hypericum Species-H. tetrapterum, H. maculatum subsp. immaculatum, H. triquetrifolium

St. John's wort (Hypericum perforatum, Hypericaceae) has long been used in traditional medicine as a potent remedy, while many other species of this genus have not been thoroughly investigated. The study aimed to detect the biological activity, including antioxidant, antihyperglycemic, anticholinergic, antimicrobial and monoaminoxidase inhibitory potential, of water-alcoholic extracts of three species autochthonous for Serbia and Greece from plant genus Hypericum (section Hypericum-H. tetrapterum, H. maculatum ssp. immaculatum and H. triquetrifolium), followed by phytochemical profiling. The highest amount of phenolics was recorded in H. maculatum subsp. immaculatum extract, while the highest abundance of flavonoids was characteristic of H. tetrapterum extract. Hypericin and hyperforin, quercetin, and its flavonoid, rutin, were present in all of the evaluated species. The evaluated species were good scavengers of DPPH, OH and NO radicals, as well as potent reducers of ferric ions in FRAP assay. Furthermore, the evaluated species were shown as potent inhibitors of monoaminoxidase A and α-glucosidase and modest inhibitors of acetylcholinesterase, monoaminoxidase B and α-amylase. No anti-Candida activity was recorded, but the extracts were effective against MRSA Staphylococcus aureus and Enterococcus sp., as well as against Proteus mirabilis. The obtained results strongly highlight the need for further in vivo studies in order to better define the potential of the medicinal application of the studied species.

St. John's Wort Herbal Teas - Biological Potential and Chemometric Approach to Quality Control

St. John's wort has been used for centuries in traditional medicine of many cultures, and nowadays it is well-known as a clinically important antidepressant drug. Considering the rising market demand for Hyperici herba, quality control of crude drug is of paramount importance. In this paper we performed HPLC-DAD chemical profiling of St. John's wort tea samples obtained at local markets, pharmacies and health food stores in the Balkan Peninsula countries, Austria and Turkey. Furthermore, water alcoholic extracts of the collected samples were evaluated in terms of their antioxidant potential, as well as the ability to inhibit biologically important enzymes such as acetylcholinesterase, monoamine oxidases A and B (MAO-A and MAO-B), α-amylase and α-glucosidase. Significant variability within the samples in the quantities of hypericin, hyperforin, rutin, quercetin, gallic, chlorogenic, caffeic and p-hydroxybenzoic acid was noticed. Chemotaxonomic modelling enabled the identification of three clusters of samples based on the quantities of rutin, hypericin and hyperforin. Generally, the extracts exhibited a significant potential to inhibit MAO-A (median IC₅₀ = 10.01 μg/mL) and α-glucosidase (median IC₅₀ = 12.40 μg/mL). The results of antioxidant potential evaluation suggest strong neutralization of hydroxyl and nitroso radicals, but moderate inhibition of lipid peroxidation process. Overall, the conducted study emphasizes the possibility of St. John's wort teas quality control, taking into account unavoidable variability of chemical profile as well. The stated is of great importance when grinding degree of herbal material excludes taxonomic identification of biological origin as an option within quality control.

HPLC–MS/MS profiling of wild-growing scentless chamomile

Scentless chamomile (Tripleurospermum inodorum = M. inodora) is a plant belonging to Anthemideae tribe of Asteraceae family, with phenotype similar to the common chamomile, a plant used in human consumption in the form of herbal tea infusion. In order to be able to understand possible health-promoting properties and adverse effects of the scentless chamomile's consumption, it is of essence to examine its chemical composition. The aim of the study was to perform phenolic profiling using high-performance liquid chromatography–tandem mass spectroscopy (HPLC–MS/MS), in comparison to the common chamomile. In the investigated extracts, qualitative and quantitative analyses enabled the identification of 66 compounds based on their retention times, mass (MS/MS) spectra, and analysis of their characteristic fragmentation patterns in MS/MS Product Ion Scan experiments. A new HPLC–MS/MS method for quantitation of common plant metabolites was hereby developed, enabling quantitation of 47 compounds. All examined M. inodora samples have relatively high combined phenolic and flavonoid contents (25.2–51.9 mg/g). Apigenin, apigenin-7-O-glucoside, luteolin, luteolin-7-O-glucoside, quinic acid, and 5-O-caffeoyl quinic acid were the compounds with highest concentration in both inodorous and common chamomile. The results obtained hereby represent the first and most detailed chemical profile of scentless chamomile so far.

Impact of origin and biological source on chemical composition, anticholinesterase and antioxidant properties of some St. John's wort species (Hypericum spp., Hypericaceae) from the Central Balkans

The study shows the influence of the origin of plant material and biological source on the in vitro antioxidant (neutralization of DPPH and OH radical, nitric oxide, and inhibition of lipid peroxidation) and anticholinesterase activity of chemically characterized and quantified ethanol extracts of ten St. John's wort samples. The investigated samples were: five Hypericum perforatum species representatives collected at different localities, one commercial sample of Hyperici herba purchased at a local market and four Hypericum species autochtonous to the Balkan Peninsula (H. maculatum subsp. immaculatum, H. olympicum, H. richeri subsp. grisebachii and H. barbatum). All the examined extracts exhibited notable antioxidant potential, but in most of the cases indigenous Hypericum species expressed stronger effects compared to the original source of the drug, H. perforatum. The changes in the content of phenolic compounds, especially flavonoids, hyperforin and hypericin, related to the source of the drug affected the investigated activities. Since all of the investigated species have shown prominent inhibition of acetylcholinesterase in vitro activity, they could be further investigated as potential substances in preventing of Alzheimer's disease.