Phenolic compounds as marker compounds for botanical origin determination of German propolis samples based on TLC and TLC-MS

Propolis, a complex mixture of different plant exudates collected and processed by honeybees, contains a wide range of bioactive substances. German propolis has so far only rarely been studied with respect to its constituents and botanical origin. To investigate the composition of specific phenolic constituents in bud extracts and German propolis, TLC and TLC-MS methods were developed. Ethanolic extracts from representative propolis samples and tree buds were analyzed by TLC. Compound assignment was achieved through mass spectrometric detection, and TLC using the DPPH assay was used to assess the antioxidant capacity.According to their TLC fingerprints, propolis samples were classified into three types (O/B/G) based on the results of former investigations. Identification of flavonoid aglycones and their methyl esters as well as acetates or butyrates was possible in both bud exudates of black poplar hybrids (Populus × canadensis Moench ‘Robusta’) and O-type propolis with TLC-MS. In aspen (Populus tremula L.) and B-type propolis, phenolic acid glycerols were detected as common constituents. Based on the marker compounds identified in the present study, black poplar hybrids and aspens were identified as major sources of the investigated propolis samples whereas horse chestnut (Aesculus hippocastanum L.) and birch (Betula pendula Roth) were of minor importance. The O-type pro-polis displayed superior antioxidant activity, but also contained higher amounts of potential allergens like caffeic acid derivatives than B-type propolis

Evaluating the feasibility of using the red mason bee (Osmia bicornis L.) in different experimental setups

Background: Evaluating hazards of pesticides to beneficial insects has become very important for the assessment and registration of pesticides. Test methods for honeybees are well established in the laboratory, under semi-field and field conditions. However, experiences in using other pollinators as model species are limited. Here we present results of various experiments on the red mason bee (Osmia bicornis L.), a solitary, commercially used bee species. The aim was to compare methodologies, to assess test parameters, and to evaluate the feasibility of using O. bicornis in late season, when this bee species would have already finished its life cycle under natural conditions. Results: Hatching times and hatching rates varied depending on temperature and season. Provisioning and reproduction of O. bicornis were very variable, weather-dependent and not always reliably reproducible between seasons. They were higher in early than in late season in the field. In late season cardboard tubes showed greater cell production than wooden boards. Conclusion: O. bicornis is a good study system under semi-field and field conditions: cocoons are easy to handle, and to monitor. Since hatching rate and cell production decreased over time, experiments are most recommended in early to mid season. Cardboard tubes can be used as standardised, inexpensive nesting devices. However, they do not allow continuous observation and pollen sampling, and involve time-consuming handling in the laboratory. Our experiment on nest material was conducted in late season and may not mirror conditions in spring and early summer.Keywords: solitary bees, field experiments, semi-field experiments, reproduction, hatching, nestin

Effect of selected plant extracts on the inhibition of enzymatic browning in fresh-cut apple

This study describes the evaluation of the antibrowning effect of 36 plant extracts, divided into three groups: (1) fruits, vegetables, and oil seeds, (2) herbs and tea plants, and (3) medicinal plants, on minimally processed fresh apples. The extracts were applied to fresh-cut apple slices as dipping solutions. Development of browning was analyzed by measuring L*, a*, and b* values. The greatest inhibition of browning was caused by extracts from pumpkin seed (group 1), hibiscus flower (group 2), and pelargonium root (group 3). However, the latter caused intense passive staining. The inhibitory potential might be attributable to the antioxidative activity of secondary plant metabolites, especially phenolic compounds. Furthermore, these bioactive substances might influence enzyme activity directly by acting as competitive or non-competitive inhibitors

Urinary miRNA profiles discriminate between obstruction-induced bladder dysfunction and healthy controls.

Urgency, frequency and incomplete emptying are the troublesome symptoms often shared between benign prostatic obstruction-induced (BLUTD) and neurogenic (NLUTD) lower urinary tract dysfunction. Previously, using bladder biopsies, we suggested a panel of miRNA biomarkers for different functional phenotypes of the bladder. Urine is a good source of circulating miRNAs, but sex- and age-matched controls are important for urinary metabolite comparison. In two groups of healthy subjects (average age 32 and 57 years old, respectively) the total protein and RNA content was very similar between age groups, but the number of secreted extracellular vesicles (uEVs) and expression of several miRNAs were higher in the young healthy male volunteers. Timing of urine collection was not important for these parameters. We also evaluated the suitability of urinary miRNAs for non-invasive diagnosis of bladder outlet obstruction (BOO). A three urinary miRNA signature (miR-10a-5p, miR-301b-3p and miR-363-3p) could discriminate between controls and patients with LUTD (BLUTD and NLUTD). This panel of representative miRNAs can be further explored to develop a non-invasive diagnostic test for BOO. The age-related discrepancy in the urinary miRNA content observed in this study points to the importance of selecting appropriate, age-matched controls

Neonicotinoids and bees: A large scale field study investigating residues and effects on honeybees, bumblebees and solitary bees in oilseed rape grown from clothianidin-treated seed

In 2013, the European Food Safety Authority (EFSA) has highlighted several data gaps regarding the exposure and risk of pesticides to honeybees, bumblebees and solitary bees, including the risks from exposure to contaminated nectar and pollen. This study aims to contribute data, results and conclusions to obtain more information on exposure and risks of flowering oilseed rape seed treated with the neonicotinoid clothianidin, to pollinators. Semi-field and field trials were conducted at five different locations across Germany, using the Western honeybee (Apis mellifera L.), the buff-tailed bumblebee (Bombus terrestris L.) and the red mason bee (Osmia bicornis L.) as study organisms.Highest amounts of clothianidin residues were measured in single samples of mud cell walls (7.2 μg kg-1) and pollen (5.9 μg kg-1) from solitary bee nests. Residues in nectar from honey sacs, honeybee combs and bumblebee nests (2.2, 2.9, and 3.0 μg kg-1 respectively) showed no clear differences in the amount of residues, neither did residues in pollen (1.5, 1.8, and 1.3 μg kg-1 respectively). These results suggest differences in the risk profiles of those three bee species. Keywords: clothianidin, residues, honeybees, bumblebees, solitary bees, field, semi-fiel

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570