Bioavailability enhancement of coenzyme Q10: An update of novel approaches

Coenzyme Q10 (CoQ10) is an essential, lipid-soluble vitamin involved in electron transport in the oxidoreductive reactions of the mitochondrial respiratory chain. Structurally, the quinone ring is connected to an isoprenoid moiety, which has a high molecular weight. Over the years, coenzyme Q10 has become relevant in the treatment of several diseases, like neurodegenerative disorders, coronary diseases, diabetes, hypercholesterolemia, cancer, and others. According to studies, CoQ10 supplementation might be beneficial in the treatment of CoQ10 deficiencies and disorders associated with oxidative stress. However, the water-insoluble nature of CoQ10 is a major hindrance to successful supplementation. So far, many advancements in CoQ10 bioavailability enhancement have been developed using novel drug carriers such as solid dispersion, liposomes, micelles, nanoparticles, nanoemulsions, self-emulsifying drug systems, or various innovative approaches (CoQ10 complexation with proteins). This article aims to provide an update on methods to improve CoQ10 solubility and bioavailability.

EACVI survey on radiation exposure in interventional echocardiography

AIMS

The European Association of Cardiovascular Imaging (EACVI) Scientific Initiatives Committee performed a global survey on radiation exposure in interventional echocardiography. The survey aimed to collect data on local practices for radioprotection in interventional echocardiography and to assess the awareness of echocardiography operators about radiation-related risks.

METHODS AND RESULTS

A total of 258 interventional echocardiographers from 52 different countries (48% European) responded to the survey. One hundred twenty-two (47%) participants were women. Two-thirds (76%) of interventional echocardiographers worked in tertiary care/university hospitals. Interventional echocardiography was the main clinical activity for 34% of the survey participants. The median time spent in the cath-lab for the echocardiographic monitoring of structural heart procedures was 10 (5-20) hours/month. Despite this, only 28% of interventional echocardiographers received periodic training and certification in radioprotection and 72% of them did not know their annual radiation dose. The main adopted personal protection devices were lead aprons and thyroid collars (95% and 92% of use, respectively). Dedicated architectural protective shielding was not available for 33% of interventional echocardiographers. Nearly two-thirds of responders thought that the radiation exposure of interventional echocardiographers was higher than that of interventional cardiologists and 72% claimed for an improvement in the radioprotection measures.

CONCLUSION

Radioprotection measures for interventional echocardiographers are widely variable across centres. Radioprotection devices are often underused by interventional echocardiographers, portending an increased radiation-related risk. International scientific societies working in the field should collaborate to endorse radioprotection training, promote reliable radiation dose assessment, and support the adoption of radioprotection shielding dedicated to interventional echocardiographers.

What Do We Know So Far About Ventricular Arrhythmias and Sudden Cardiac Death Prediction in the Mitral Valve Prolapse Population? Could Biomarkers Help Us Predict Their Occurrence?

PURPOSE OF THE REVIEW

To summarize currently available data on the topic of mitral valve prolapse (MVP) and its correlation to the occurrence of atrial and ventricular arrhythmias. To assess the prognostic value of several diagnostic methods such as transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance, cardiac computed tomography, electrocardiography, and electrophysiology concerning arrhythmic episodes. To explore intra and extracellular biochemistry of the cardiovascular system and its biomarkers as diagnostic tools to predict rhythm disturbances in the MVP population.

RECENT FINDINGS

MVP is a common and mainly benign valvular disorder. It affects 2-3% of the general population. MVP is a heterogeneous and highly variable phenomenon with three structural phenotypes: myxomatous degeneration, fibroelastic deficiency, and forme fruste. Exercise intolerance, supraventricular tachycardia, and chest discomfort are the symptoms that are often paired with psychosomatic components. Though MVP is thought to be benign, the association between isolated MVP without mitral regurgitation (MR) or left ventricle dysfunction, with ventricular arrhythmia (VA) and sudden cardiac death (SCD) has been observed. The incidence of SCD in the MVP population is around 0.6% per year, which is 6 times higher than the occurrence of SCD in the general population. Often asymptomatic MVP population poses a challenge to screen for VA and prevent SCD. Therefore, it is crucial to carefully assess the risk of VA and SCD in patients with MVP with the use of various tools such as diagnostic imaging and biochemical and genetic screening.

Neighbour-stranger discrimination in an African wood dove inhabiting equatorial rainforest

We investigated within- and between-individual song variation and song-based neighbour-stranger discrimination in a non-learning bird species, the blue-headed wood-dove (Turtur brehmeri), which inhabits lowland rainforests of West and Central Africa. We found that songs of this species are individually specific and have a high potential for use in individual recognition based on the time-frequency pattern of note distribution within song phrases. To test whether these differences affect behaviour, we conducted playback experiments with 19 territorial males. Each male was tested twice, once with the songs of a familiar neighbour and once with the songs of an unfamiliar stranger. We observed that males responded more aggressively to playback of a stranger's songs: they quickly approached close to the speaker and spent more time near it. However, no significant differences between treatments were observed in the vocal responses. In addition, we explored whether responses differed based on the song frequency of the focal male and/or that of the simulated intruder (i.e., playback), as this song parameter is inversely related to body size and could potentially affect males' decisions to respond to other birds. Song frequency parameters (of either the focal male or the simulated intruder) had no effect on the approaching response during playback. However, we found that the pattern of response after playback was significantly affected by the song frequency of the focal male: males with lower-frequency songs stayed closer to the simulated intruder for a longer period of time without singing, while males with higher-frequency songs returned more quickly to their initial song posts and resumed singing. Together, these results depict a consistently strong response to strangers during and after playback that is dependent on a male's self-assessment rather than assessment of a rival's strength based on his song frequency. This work provides the first experimental evidence that doves (Columbidae) can use songs for neighbour-stranger discrimination and respond according to a "dear enemy" scheme that keeps the cost of territory defence at a reasonable level.

Evaluation of Knowledge and Self-Awareness of Polish Soldiers Regarding Exposure to Chemical and Physical Factors in Their Place of Service/Work

INTRODUCTION

Soldiers constitute a professional group carrying out their duties in variable, often challenging environmental conditions, including harmful and burdensome ones.

MATERIALS AND METHODS

This study was conducted on a nationwide sample of 1331 soldiers. The research tool was an anonymous questionnaire comprising 48 questions. Descriptive statistics were used to describe the characteristics of the studied group. The chi-square test was employed to examine the relationship between variables. A 95% confidence interval was adopted, with a significance level of p = 0.05.

RESULTS

One in four soldiers work with low and one in five with moderate exposure to harmful chemical factors. Almost 10% of respondents lack knowledge about the types of chemical factors present during their service. One in five soldiers work with low and one in eight with moderate exposure to ionizing radiation. Approximately 5% of survey participants lack knowledge about the types of physical factors. One in three soldiers are unaware of the carcinogenic and mutagenic effects of the aforementioned factors.

CONCLUSIONS

The systematic enhancement of knowledge and awareness among army members will help minimize the consequences of exposure to harmful conditions.

Detection ranges of forest bird vocalisations: guidelines for passive acoustic monitoring

Passive acoustic monitoring has proven to have many advantages for monitoring efforts and research activities. However, there are considerations to be taken into account regarding the placement of autonomous sound recorders. Detection ranges differ among species and in response to variable conditions such as weather or the location of vocalising animals. It is thus important to the success of a research project to understand, with a certain degree of confidence, the distances at which birds might be detected. In two types of forests in Poland, we played back the vocalisations of 31 species of European forest birds exemplifying different singing characteristics. Based on recordings obtained along a 500-m transect, we estimated the probability of detection and maximum detection distance of each vocalisation. We broadcasted the recording at three heights of singing and repeated playbacks three times during the breeding season to evaluate the effect of vegetation growth. Our results revealed that environmental and meteorological factors had a significant influence on both detection probability and maximum detection distances. This work provides comprehensive measurements of detection distance for 31 bird species and can be used to plan passive acoustic monitoring research in Europe, taking into account species traits and individual characteristics of the study area.

New cyclopentaquinoline and 3,5-dichlorobenzoic acid hybrids with neuroprotection against oxidative stress for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative brain disease. Thus, drugs including donepezil, rivastigmine, and galantamine are not entirely effective in the treatment of this multifactorial disease. The present study evaluates eight derivatives (3a-3h) as candidates with stronger anti-AD potential but with less side effects. Reactive oxygen species (ROS) assays were used to assess oxidative stress which involve in the neurodegeneration. The neuroprotective properties of 3e against oxidative stress were done in three experiments using MTT test. The anti-AD potential was determined based on their anticholinesterase inhibition ability, determined using Ellman's method, Aβ aggregation potential according to thioflavin (Th) fluorescence assay, and their antioxidative and anti-inflammatory activities. Compound 3e exhibited moderate cholinesterase inhibition activity (AChE, IC₅₀ = 0.131 µM; BuChE, IC₅₀ = 0.116 µM; SI = 1.13), significant inhibition of Aβ(1-42) aggregation (55.7%, at 5 µM) and acceptable neuroprotective activity. Extensive analysis of in vitro and in vivo assays indicates that new cyclopentaquinoline derivatives offer promise as candidates for new anti-AD drugs.

The Influence of Selected Laser Engraving Parameters on Surface Conditions of Hybrid Metal Matrix Composites

Hybrid metal matrix composites (HMMCs) are a special type of material, possessing combined properties that belong to alloys and metals according to market demands. Therefore, they are used in different areas of industry and the properties of this type of material are useful in engineering applications, e.g., in aircraft engines and electrotechnical parts. The structure of the material requires a number of scientific studies to develop an appropriate processing technology. The paper presents the susceptibility of material from the HMMCs group with the EN AC-44300 (AISi12(Fe)) aluminum alloy matrix with a two-component reinforcement made of alumina particles (AP) and aluminosilicate fibers (AF) to thermal treatment with a laser beam. During this process, laser engraving of the researched material with variable beam power Pav and variable speed of the laser head vl were carried out. A metallographic analysis of the material was carried out. After laser engraving, surface structural changes of the material were determined. The properties of the surface geometric structure of processed material were also examined. Presented studies concern laser engraving on the surface of composite from the HMMC group, which was made by vacuum infiltration. Thanks to this method, it is possible both to produce shaped and precise composite castings with saturated reinforcement and to consequently minimize machining losses. Metal-ceramic composites from the HMMC group are hard-to-machine materials which create problems during machining. The aim of these studies was to develop a laser engraving technology with Al matrix composite with the addition of Al2O3 particles and aluminosilicate fibers, which constitute the reinforcement. The focus was on the selection of engraving parameters (beam power and speed of movement of the laser head). Clear examples of engraving, suitable for macro-assessment, were obtained with minimal change in the initial surface structure of the composite.

Response of forest Turtur doves to conspecific and congeneric songs in sympatry and allopatry

Birds have a diverse acoustic communication system, and the ability to recognise their own species' song from a distance facilitates complex behaviours related to mate attraction and rival deterrence. However, certain species, including doves, do not learn songs and their vocal repertoires are much simpler than those of better-studied songbirds. In these so-called non-learning birds, relatively little is known about the role that bird song plays in intra- and interspecific interactions, and how such behaviours might be acquired (inherited or learned from experience). To investigate this question, we focused on two species of African wood doves whose long-range songs are used in a territorial context. Specifically, we examined the responses of sympatric and allopatric populations of male blue-headed wood-doves (Turtur brehmeri) and tambourine doves (Turtur tympanistria) to different types of simulated territorial intrusions, i.e. playback of conspecific, congeneric, and control songs. We aimed to assess (i) whether these species, which have similar songs, respond only to their own species' song or exhibit interspecific territoriality, and (ii) if the response pattern is affected by the presence or absence of congeners in the general area. We found that both species responded strongly to playback of their own species in both sympatric and allopatric populations. In allopatry, though, male tambourine doves misdirected their response and also approached the playback of congeneric songs. Our results indicate that, in areas where the studied Turtur doves live in sympatry, they do not exhibit consistent interspecific territoriality. However, we cannot exclude the possibility that the smaller tambourine dove avoids its larger congener during the process of territory establishment. The difference in tambourine doves' response toward the song of present (sympatric) or absent (allopatric) congeners suggests that the ability to discriminate between songs of similarly singing potential competitors is acquired through earlier interactions and learning. This plasticity in response supports the misdirected aggression hypothesis, which argues that interspecific territorialism emerges as a maladaptive by-product of signal similarity. However, on an evolutionary timescale, such an ability could be considered an adaptive cognitive tool useful for resolving competing interests with congeners.

Determination of Saturation Conditions of the Aluminum Metal Matrix Composites Reinforced with Al2O3 Sinter

Aluminum metal matrix composites (Al MMCs) are a class of materials characterized by being light in weight and high hardness. Due to these properties, Al MMCs have various applications in the automobile, aeronautical and marine industries. Ceramic-reinforced Al MMCs in the form of sinters are known for having excellent abrasive properties, which makes them an attractive material in certain fields of technology. The biggest problem in their production process is their low ability to infiltrate ceramics with alloys and consequently the difficulty of filling a ceramic preform. The castability of such composites has not yet been researched in detail. The aim of this study was to create aluminum metal matrix composite castings based on aluminum alloys (AlSi11) reinforced with an Al2O3 sinter preform using a Castability Trials spiral mold, and then to determine the degree of saturation with the liquid metal of the produced ceramic shaped body (Castability Trials spiral). For the selected AlSi11 alloy, the liquidus (Tl) and solidus (Ts) temperatures were determined by performing thermal-derivation analysis during cooling, which is Tl-579.3 °C and Ts-573.9 °C. The resultant pressure necessary for the infiltration process was estimated for the reinforcement capillaries with the following dimensions: 10, 15, 20, 25, 30 and 35 microns. The following values were used to determine the capillary pressure (Pk): surface tension of the alloy-σ = 840 mN/m; the extreme wetting angle of the reinforcement by the metal-θ = 136°. It has been experimentally confirmed that for the vacuum saturation process, the estimated resultant pressure enables saturation of reinforcement with capillaries larger than 25 microns, provided that the alloy temperature does not drop lower than the infiltration temperature. After the experiment, the time and route of the liquid metal flow in the spiral were determined. On the basis of the obtained values, a simulation was developed and initial assumptions such as saturation time, alloy temperature, reinforcement and mold temperature were verified. The energy balance showed that the saturation limit temperature was Tk = 580.7 °C for the reinforcement temperature of 575 °C. In contrast to the above, the assumption that the temperature of the metal after equalizing the temperature of the composite components must be higher than the liquidus temperature (Tliq = 579.3 °C) for the aluminum alloy used must be fulfilled. After the experiment, the time and path of the liquid metal flow in the spiral were determined. Then, on the basis of the obtained values, a simulation was developed, and the initial assumptions (saturation time and temperature) were verified.

Comparison of reorganized versus unaltered cardiology departments during the COVID-19 era: a subanalysis of the COV-HF-SIRIO 6 study

BACKGROUND

Since the beginning of the coronavirus disease-2019 (COVID-19) pandemic, numerous cardiology departments were reorganized to provide care for COVID-19 patients. We aimed to compare the impact of the COVID-19 pandemic on hospital admissions and in-hospital mortality in reorganized vs. unaltered cardiology departments.

METHODS

The present subanalysis is a multicenter retrospective COV-HF-SIRIO 6 study that includes all patients (n = 101,433) hospitalized in 24 cardiology departments in Poland between January 1, 2019 and December 31, 2020, with a focus on patients with acute heart failure (AHF).

RESULTS

Reduction of all-cause hospitalizations was 50.6% vs. 21.3% for reorganized vs. unaltered cardiology departments in 2020 vs. 2019, respectively (p < 0.0001). Considering AHF alone respective reductions by 46.5% and 15.2% were registered (p < 0.0001). A higher percentage of patients was brought in by ambulance to reorganized vs. unaltered cardiology departments (51.7% vs. 34.6%; p < 0.0001) alongside with a lower rate of self-referrals (45.7% vs. 58.4%; p < 0.0001). The rate of all-cause in-hospital mortality in AHF patients was higher in reorganized than unaltered cardiology departments (10.9% vs. 6.4%; p < 0.0001). After the exclusion of patients with concomitant COVID-19, the mortality rates did not differ significantly (6.9% vs. 6.4%; p = 0.55).

CONCLUSIONS

In cardiology departments reorganized to provide care for COVID-19 patients vs. unaltered ones, observed: i) a greater reduction in hospital admissions in 2020 vs. 2019; ii) higher rates of patients brought by ambulance and lower rates of self-referrals; and iii) higher all-cause in-hospital mortality for AHF due to COVID-19 related deaths.

Analysis of the risk factors for perioperative morbidity after laparoscopic revisional bariatric procedures: results from the multicenter Polish Revision Obesity Surgery Study

BACKGROUND

The growing number of primary bariatric operations has led to an increase in demand for revision surgeries. Higher numbers of revisional operations are also observed in Poland, yet their safety and efficacy remain controversial because of a lack of current recommendations and guidelines.

OBJECTIVE

To review risk factors influencing perioperative morbidity.

METHODS

A retrospective study was conducted to analyze the results of surgical treatment among 12 Polish bariatric centers. Inclusion criteria were laparoscopic revisional bariatric surgeries and patients ≥18 years of age. The study included 795 patients, of whom 621 were female; the mean age was 47 years (range: 40-55 years).

RESULTS

Perioperative morbidity occurred in 92 patients (11.6%) enrolled in the study, including 76 women (82.6%). The median age was 45 years (range: 39-54 years). Statistically significant risk factors in univariate logistic regression models for perioperative complications were the duration of obesity, revisional surgery after Roux-en-Y gastric bypass (RYGB) or adjustable gastric band (AGB), difference in body mass index before revisional surgery and the lowest achieved after primary surgery, and postoperative morbidity of the primary surgery as the cause for revisional bariatric surgery. These factors were included in the multivariate regression model. Revisional surgery after AGB (odds ratio [OR] = 2.18; 95% confidence interval [CI]: 1.28-3.69; P = .004), revisional surgery performed after RYGB (OR = 6.52; 95% CI: 1.98-21.49; P = .002), and revisions due to complication of the primary surgery (OR = 1.89; 95% CI: 1.06-3.34; P = .030) remained independent risk factors for perioperative morbidity.

CONCLUSION

Revisional operations after RYGB or AGB and those performed because of postoperative morbidity after primary surgery as the main cause for revisional surgery were associated with a significantly increased risk of postoperative morbidity.

Tool Wear and Surface Roughness in Turning of Metal Matrix Composite Built of Al2O3 Sinter Saturated by Aluminum Alloy in Vacuum Condition

Metal matrix composites (MMCs) are a special class of materials carrying combined properties that belongs to alloys and metals according to market demands. Therefore, they are used in different areas of industry, and the properties of this type of material are useful in engineering applications. Machining of such composites is of great importance to finalize the fabrication process with improved part quality. However, the process implies several challenges due to the complexity of the cutting processes and random material structure. The current study aims to examine machinability characteristics. Effects of turning a metal matrix composite built of Al₂O₃ sinter, saturated with an EN AC-44000 AC-AlSi₁₁ alloy, are presented in this paper. In the present study, a turning process of new metal matrix composites was carried out to determine the state-of-the-art material for various engineering applications. During the turning process, the cutting forces, a tool's wear, and surface roughness were investigated. Further, the SEM (scanning electron microscope) analysis of cutting inserts was performed. The influence of MMC structure on the machining process and surface roughness was studied. The Al₂O₃ reinforcements were used in different graininess. Effects of conventional turning of the metal matrix composite with Al₂O₃ sinter of FEPA (Federation of European Producers of Abrasives) 046 and FEPA 100 grade were compared. Results analysis of these tests showed the necessity of continuing research on turning metal matrix composites built of an AlSi alloy and Al₂O₃ ceramic reinforcement. The study showed the properties of MMCs that influenced machinability. In this paper, the influence of feed rate's value on surface roughness was carried out. The significant tool wear during the turning of the MMC was proved.

In Silico ADME and Toxicity Prediction of Benzimidazole Derivatives and Its Cobalt Coordination Compounds. Synthesis, Characterization and Crystal Structure

As a result of the synthesis, three new solids, cobalt (II) coordination compounds with benzimidazole derivatives, and chlorides were obtained. The ligands that were used in the synthesis were specially synthesized and were commercially unavailable. During the synthesis, a single crystal of the complex with the L1 ligand was obtained and the crystal structure was refined. All coordination compounds were characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analysis. All the obtained data allowed one to determine the formulas of the new compounds, as well as to determine the method of metal-ligand coordination. Thermal analysis allowed to know the temperature stability of the compounds, solids intermediate and final products of pyrolysis. Additionally, volatile decomposition and fragmentation products have been identified. The toxicity of the compounds and their bioavailability were determined using in silico methods. By predicting activity on cell lines, the potential use of compounds as chemotherapeutic agents has been specified. The blood-brain barrier crossing and the gastrointestinal absorption were defined. Pharmaceutical biodistribution was also simulated.

Synthesis and Biological Studies of Novel Aminophosphonates and Their Metal Carbonyl Complexes (Fe, Ru)

The quest to find new inhibitors of biologically relevant targets is considered an important strategy to introduce new drug candidates for the treatment of neurodegenerative diseases. A series of (aminomethyl)benzylphosphonates 8a–c and their metallocarbonyl iron 9a–c and ruthenium 10a–c complexes were designed, synthesized, and evaluated for their inhibitory potentials against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) by determination of IC₅₀. Metallocarbonyl derivatives, in general, did not show significant inhibition activity against these enzymes, the most potent inhibitor was the (aminomethyl)benzylphosphonate 8a (IC₅₀ = 1.215 µM against AChE). Molecular docking analysis of AChE and (aminomethyl)benzylphosphonates 8a–c showed the strongest interactions of 8a and AChE compared to isomers 8b and 8c. Cytotoxicity studies of synthesized compounds towards the V79 cell line were also performed and discussed.

Impact of COVID-19 pandemic on acute heart failure admissions and mortality: a multicentre study (COV-HF-SIRIO 6 study)

Aims

The coronavirus disease‐2019 (COVID‐19) pandemic has changed the landscape of medical care delivery worldwide. We aimed to assess the influence of COVID‐19 pandemic on hospital admissions and in‐hospital mortality rate in patients with acute heart failure (AHF) in a retrospective, multicentre study.

Methods and results

From 1 January 2019 to 31 December 2020, a total of 101 433 patients were hospitalized in 24 Cardiology Departments in Poland. The number of patients admitted due to AHF decreased by 23.4% from 9853 in 2019 to 7546 in 2020 (P < 0.001). We noted a significant reduction of self‐referrals in the times of COVID‐19 pandemic accounting 27.8% (P < 0.001), with increased number of AHF patients brought by an ambulance by 15.9% (P < 0.001). The length of hospital stay was overall similar (7.7 ± 2.8 vs. 8.2 ± 3.7 days; P = not significant). The in‐hospital all‐cause mortality in AHF patients was 444 (5.2%) in 2019 vs. 406 (6.5%) in 2020 (P < 0.001). A total number of AHF patients with concomitant COVID‐19 was 239 (3.2% of AHF patients hospitalized in 2020). The rate of in‐hospital deaths in AHF patients with COVID‐19 was extremely high accounting 31.4%, reaching up to 44.1% in the peak of the pandemic in November 2020.

Conclusions

Our study indicates that the COVID‐19 pandemic led to (i) reduced hospital admissions for AHF; (ii) decreased number of self‐referred AHF patients and increased number of AHF patients brought by an ambulance; and (iii) increased in‐hospital mortality for AHF with very high mortality rate for concomitant AHF and COVID‐19.

Song type and song type matching are important for joint territorial defense in a duetting songbird

Birds have a diverse acoustic communication system, with species-specific repertoires facilitating more complex behaviors in terms of both within- and between-pair communications. Certain song types are produced for specific functions, such as aggressive encounters. In addition, song matching behaviors, whereby neighboring individuals match song types, can be used in aggressive interactions as a sophisticated acoustic behavior. In this study, we examined the functions of song types, in a duet context, of male yellow-breasted boubous (Laniarius atroflavus), an Afromontane bush-shrike with a vocal sexual dimorphism. We aimed at assessing whether, structurally, certain song types elicited a heightened reaction than others and also whether song matching affected response behavior. A dual speaker playback procedure was performed for 18 pairs of boubous, each pair being exposed to duets with three different male song types. We found differences in response toward the different duet types but these differences resulted from the amount at which males matched different song types. Pairs responded stronger when a focal male matched the playback type, and matching was significantly more often found in cases where the rarest type of male song was used. We found no sex differences in terms of response strength to playback type. Our results indicate a two-level way of coding aggression toward intruding pairs. The yellow-breasted boubous utilize their repertoires, linking matching with structure in order to show aggression in terms of territory defense and sexual conflict. This study also confirms joint territorial defense as a main function of duets in this species.

Improved clinical investigation and evaluation of high-risk medical devices: the rationale and objectives of CORE-MD (Coordinating Research and Evidence for Medical Devices)

In the European Union (EU) the delivery of health services is a national responsibility but there are concerted actions between member states to protect public health. Approval of pharmaceutical products is the responsibility of the European Medicines Agency, while authorising the placing on the market of medical devices is decentralised to independent 'conformity asssessment' organisations called notified bodies. The first legal basis for an EU system of evaluating medical devices and approving their market access was the medical device directives, from the 1990s. Uncertainties about clinical evidence requirements, among other reasons, led to the EU Medical Device Regulation (2017/745) that has applied since May 2021. It provides general principles for clinical investigations but few methodological details ‒ which challenges responsible authorities to set appropriate balances between regulation and innovation, pre- and post-market studies, and clinical trials and real-world evidence. Scientific experts should advise on methods and standards for assessing and approving new high-risk devices, and safety, efficacy, and transparency of evidence should be paramount. The European Commission recently awarded a Horizon 2020 grant to a consortium led by the European Society of Cardiology and the European Federation of National Associations of Orthopaedics and Traumatology, that will review methodologies of clinical investigations, advise on study designs, and develop recommendations for aggregating clinical data from registries and other real-world sources. The CORE‒MD project (Coordination of Research and Evidence for Medical Devices) will run until March 2024; here we describe how it may contribute to the development of regulatory science in Europe.

Thin-Layer Chromatography Gradient Optimization Strategy for Wet Load Adsorption Flash Chromatography

Chromatography is one of the most popular methods for the separation of compounds in modern pharmaceutical industry and science. Despite the extensive use of the reversed phase chromatography in analytical and preparative applications, the normal phase adsorption chromatography has a special place in purifying post-reaction mixtures or the separation of natural extracts, especially in wet load mode, because of simplicity and high velocity of preparation. Complex mixtures, more difficult to separate, require gradient methods to obtain better results of separations. These methods can be developed by external software, but the automatic methods are often not very accurate and the negative impact of wet load application on separation quality is considerable in them. Therefore, we present the thin-layer chromatography (TLC) gradient optimization strategy for wet load separations to obtain repeatable results of separations for different compounds without worrying about negative impact of wet loading on separation quality. The strategy provides information about an elution model of desired compound, which is used to develop the gradient method. The strategy also allows to standardize the separation length, because gradient methods performed by the TLC gradient optimization strategy have a very similar duration time in column volumes. The method can also be simply scaled because of using the column volume as a base unit in calculations.

Cytotoxic Activity against A549 Human Lung Cancer Cells and ADMET Analysis of New Pyrazole Derivatives

Two new pyrazole derivatives, namely compound 1 and compound 2, have been synthesized, and their biological activity has been evaluated. Monocrystals of the obtained compounds were thoroughly investigated using single-crystal X-ray diffraction analysis, FTIR spectroscopy, and NMR spectroscopy. The results gathered from all three techniques are in good agreement, provide complete information about the structures of 1 and 2, and confirm their high purity. Thermal properties were studied using thermogravimetric analysis; both 1 and 2 are stable at room temperature. In order to better characterize 1 and 2, some physicochemical and biological properties have been evaluated using ADMET analysis. The cytotoxic activity of both compounds was determined using the MTT assay on the A549 cell line in comparison with etoposide. It was determined that compound 2 was effective in the inhibition of human lung adenocarcinoma cell growth and may be a promising compound for the treatment of lung cancer.

A review of the mechanisms underlying selected comorbidities in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the central nervous system (CNS) leading to mental deterioration and devastation, and eventually a fatal outcome. AD affects mostly the elderly. AD is frequently accompanied by hypercholesterolemia, hypertension, atherosclerosis, and diabetes mellitus, and these are significant risk factors of AD. Other conditions triggered by the progression of AD include psychosis, sleep disorders, epilepsy, and depression. One important comorbidity is Down’s syndrome, which directly contributes to the severity and rapid progression of AD. The development of new therapeutic strategies for AD includes the repurposing of drugs currently used for the treatment of comorbidities. A better understanding of the influence of comorbidities on the pathogenesis of AD, and the medications used in its treatment, might allow better control of disease progression, and more effective pharmacotherapy.

Effects of a Unique Combination of the Whole-Body Low Dose Radiotherapy with Inactivation of Two Immune Checkpoints and/or a Heat Shock Protein on the Transplantable Lung Cancer in Mice

Non-small cell lung cancer (NSCLC) continues to be the leading cause of cancer death worldwide. Recently, targeting molecules whose functions are associated with tumorigenesis has become a game changing adjunct to standard anti-cancer therapy. As evidenced by the results of preclinical and clinical investigations, whole-body irradiations (WBI) with X-rays at less than 0.1-0.2 Gy per fraction can induce remissions of various neoplasms without inciting adverse side effects of conventional chemo- and radiotherapy. In the present study, a murine model of human NSCLC was employed to evaluate for the first time the anti-neoplastic efficacy of WBI combined with inactivation of CTLA-4, PD-1, and/or HSP90. The results indicate that WBI alone and in conjunction with the inhibition of the function of the cytotoxic T-lymphocyte antigen-4 (CTLA-4) and the programmed death-1 (PD-1) receptor immune checkpoints (ICs) and/or heat shock protein 90 (HSP90) markedly reduced tumorigenesis in mice implanted by three different routes with the syngeneic Lewis lung cancer cells and suppressed clonogenic potential of Lewis lung carcinoma (LLC1) cells in vitro. These results were associated with the relevant changes in the profile of pro- and anti-neoplastic immune cells recruited to the growing tumors and the circulating anti- and pro-inflammatory cytokines. In contrast, inhibition of the tested molecular targets used either separately or in combination with each other did not exert notable anti-neoplastic effects. Moreover, no significant synergistic effects were detected when the inhibitors were applied concurrently with WBI. The obtained results supplemented with further mechanistic explanations provided by future investigations will help design the effective strategies of treatment of lung and other cancers based on inactivation of the immune checkpoint and/or heat shock molecules combined with low-dose radiotherapy.

Aspartame-True or False? Narrative Review of Safety Analysis of General Use in Products

Aspartame is a sweetener introduced to replace the commonly used sucrose. It was discovered by James M. Schlatter in 1965. Being 180-200 times sweeter than sucrose, its intake was expected to reduce obesity rates in developing countries and help those struggling with diabetes. It is mainly used as a sweetener for soft drinks, confectionery, and medicines. Despite its widespread use, its safety remains controversial. This narrative review investigates the existing literature on the use of aspartame and its possible effects on the human body to refine current knowledge. Taking to account that aspartame is a widely used artificial sweetener, it seems appropriate to continue research on safety. Studies mentioned in this article have produced very interesting results overall, the current review highlights the social problem of providing visible and detailed information about the presence of aspartame in products. The studies involving the impact of aspartame on obesity, diabetes mellitus, children and fetus, autism, neurodegeneration, phenylketonuria, allergies and skin problems, its cancer properties and its genotoxicity were analyzed. Further research should be conducted to ensure clear information about the impact of aspartame on health.

Characterization of Metal-Bound Benzimidazole Derivatives, Effects on Tumor Cells of Lung Cancer

Four new ligands and four new copper (II) coordination compounds were prepared and characterized by chemical, elemental analysis, cytotoxicity, and FTIR spectroscopy (Fourier transform infrared spectroscopy). The nature of metal-ligand coordination was investigated. The thermal properties of complexes in the solid state were studied using TG-MS techniques (thermogravimetric analysis coupled with mass spectrometry) under dynamic flowing air atmosphere to analyze the principal volatile thermal decomposition and fragmentation products that evolved during thermolysis. The intermediate and final solid thermolysis products were also determined. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) assay was used to evaluate active metabolic cells as an IC50 (half maximal inhibitory concentration). The relationship between antitumor activity and the position of nitrogen atoms in the organic ligand has been shown.

Promising results in development of male contraception

Nowadays, conscious planning of the family is very important for many people. The possibility of using protective measures against unplanned pregnancy is a great comfort. Most forms of contraceptives are intended for women, although their use can be ruled out in various health conditions. Scientists have been trying to develop a different type of method for men for many years. More and more research is being done and there have been promising results. It is hoped that soon both genders will have a similar range of contraceptive options to enable responsible family planning.

Biological evaluation and molecular docking of novel 1,3,4-thiadiazole-resorcinol conjugates as multifunctional cholinesterases inhibitors

Two series of novel 1,3,4-thiadiazole-resorcinol conjugates were efficiently synthesized and evaluated as cholinesterases inhibitors. N-Butyl- and N-chlorophenyl-5-amino-1,3,4-thiadiazol-2-yl)benzene-1,3-diols were identified as the most promising compounds of low nanomolar activity against AChE (IC₅₀ = 29-76 nM) and moderate activity against BuChE. The inhibition mechanism studies proved that the compounds are mixed type inhibitors. The docking simulations showed great affinity of the compounds for both enzymes. The modelled amine derivatives exhibited a similar arrangement in the catalytic anionic site of AChE similar to that of tacrine. The thiadiazole ring interacted with Trp84 and the phenyl groups created π-π stacking interactions with the residue - Phe330. The compounds showed better inhibition of the in vitro self-induced Aβ (1-42) aggregation than that compared with curcumin as well as antioxidant properties similar to those of quercetin. They exhibited metal ion chelating properties, acceptable cytotoxicity in vitro and favourable ADMET profile determined in silico.

Identification and investigation of mechanically separated meat (MSM) with an innovative ultrasonic method

An innovative analytical ultrasonic method for identification and investigation of Mechanically Separated Meat (MSM) samples is presented. To this end, the ultrasonic wave velocity (f=5MHz) in the investigated meat samples was measured. The measured ultrasonic velocity ranged from 1553.4 to 1589.9 m/s. The investigations were performed for: 1) minced hand deboned chicken fillets, 2) low pressure MSM from chicken carcasses, 3) low pressure MSM from chicken collarbones, 4) high pressure MSM from chicken carcasses and 5) high pressure MSM from chicken collarbones. Statistically significant (p<0.001) differences in the ultrasonic velocity were observed for each of investigated kinds of meat. High significant correlations were found between the ultrasonic velocity and the content of protein, fat, sodium and density of the investigated meat. The applicability of the developed ultrasonic method for identifying various kinds of meat and to determine the content of protein, fat, sodium and density was demonstrated.

Radiolabeled Peptides and Antibodies in Medicine

Radiolabeled peptides are a relatively new, very specific radiotracer group, which is still expanding. This group is very diverse in terms of peptide size. It contains very small structures containing several amino acids and whole antibodies. Moreover, radiolabeled peptides are diverse in terms of the binding aim and therapeutic or diagnostic applications. The majority of this class of radiotracers is utilized in oncology, where the same structure can be used in therapy and diagnostic imaging by varying the radionuclide. In this study, we collected new reports of radiolabeled peptide applications in diagnosis and therapy in oncology and other fields of medicine. Radiolabeled peptides are also increasingly being used in rheumatology, cardiac imaging, or neurology. The studies collected in this review concern new therapeutic and diagnostic procedures in humans and new structures tested on animals. We also performed an analysis of clinical trials, which concerns application of radiolabeled peptides and antibodies that were reported in the clinicaltrials.gov database between 2008 and 2018.

Structure and functions of Yellow-breasted Boubou (Laniarius atroflavus) solos and duets

Background

Birds have extremely well-developed acoustic communication and have become popular in bioacoustics research. The majority of studies on bird song have been conducted in the temperate zones where usually males of birds sing to attract females and defend territories. In over 360 bird species mostly inhabiting the tropics both males and females sing together in duets. Avian duets are usually formed when a male and female coordinate their songs. We focused on a species with relatively weakly coordinated duets, with male solo as the prevailing vocalisation type.

Methods

Instead of analysing a set of recordings spread over a long time, we analysed whole day microphone-array recordings of the Yellow-breasted Boubou (Laniarius atroflavus), a species endemic to West African montane rainforests. We described the structure of the solo and duet vocalisations and temporal characteristics of daily activity based on 5,934 vocal bouts of 18 focal pairs and their neighbours.

Results

Birds had small, sex specific repertoires. All males shared three types of loud whistles functioning as song type repertoires in both solos and duets. Females vocalised with five types of harsh, atonal notes with a more variable and usually lower amplitude. Three of them were produced both as solos and in duets, while two seem to function as alarm and excitement calls given almost exclusively as a solo. Solos were the most common vocalisation mode (75.4%), with males being more vocally active than females. Duets accounted for 24.6% of all vocalisations and in most cases were initiated by males (81%). The majority of duets were simple (85.1%) consisting of a single male and female song type, but altogether 38 unique duet combinations were described. Males usually initiated singing at dawn and for this used one particular song type more often than expected by chance. Male solo and duet activities peaked around dawn, while female solos were produced evenly throughout the day.

Discussion

Yellow-breasted Boubou is a duetting species in which males are much more vocal than females and duetting is not a dominating type of vocal activity. Duet structure, context and timing of daily production support the joint resource defence hypothesis and mate guarding/prevention hypotheses, however maintaining pair contact also seems to be important. This study provides for the first time the basic quantitative data describing calls, solos and duet songs in the Yellow-breasted Boubou.

New hybrids of tacrine and indomethacin as multifunctional acetylcholinesterase inhibitors

A new series of hybrid compounds were designed, consisting of anti-AChE and BuChE activity components with an anti-inflammatory component. A series of 9-amino-1,2,3,4-tetrahydroacridine and indomethacin derivatives were synthesized. All compounds were created using alkyldiamine with different chain lengths as a linker. Various biological activities were evaluated, including inhibitory activity against AChE and BuChE. The tested compounds showed high inhibitory activities against cholinesterases. The IC50 values for all compounds ranging from 10 nM to 7 µM. The potency of inhibition was much higher than well-known AChE and BuChE inhibitors (tacrine and donepezil). Compound 3h had the strongest inhibitory activity; kinetic studies showed it to have a mixed-type of acetylcholinesterase inhibition properties. The cytotoxicity of the newly-synthesized compounds against HepG2 (hepatocarcinoma cells) and EA.hy96 (human vein endothelial cells) cell lines was determined using the MTT and MTS tests. All investigated compounds presented similar cytotoxic activity against HepG2 and EA.hy926 cell line, ranged in micromolar values. Compounds with longer linkers showed higher antioxidant activity. The most active compound was 3h. Docking studies confirmed interactions with important regions of AChE and BuChE. Its multifunctional properties, i.e. high activity against AChE and BuChE, antioxidant activity and low cytotoxicity, highlight 3h as a promising agent for the treatment of AD.

New Tetrahydroacridine Hybrids with Dichlorobenzoic Acid Moiety Demonstrating Multifunctional Potential for the Treatment of Alzheimer's Disease

A series of new tetrahydroacridine and 3,5-dichlorobenzoic acid hybrids with different spacers were designed, synthesized, and evaluated for their ability to inhibit both cholinesterase enzymes. Compounds 3a, 3b, 3f, and 3g exhibited selective butyrylcholinesterase (EqBuChE) inhibition with IC₅₀ values ranging from 24 to 607 nM. Among them, compound 3b was the most active (IC₅₀ = 24 nM). Additionally, 3c (IC₅₀ for EeAChE = 25 nM and IC₅₀ for EqBuChE = 123 nM) displayed dual cholinesterase inhibitory activity and was the most active compound against acetylcholinesterase (AChE). Active compound 3c was also tested for the ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated using ACD Labs Percepta and Chemaxon. A Lineweaver–Burk plot and docking study showed that 3c targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, 3c appears to possess neuroprotective activity and could be considered a free-radical scavenger. In addition, 3c did not cause DNA damage and was found to be less toxic than tacrine after oral administration; it also demonstrated little inhibitory activity towards hyaluronidase (HYAL), which may indicate that it possesses anti-inflammatory properties. The screening for new in vivo interactions between 3c and known receptors was realized by yeast three-hybrid technology (Y3H).

Biological assessment of new tetrahydroacridine derivatives with fluorobenzoic moiety in vitro on A549 and HT-29 cell lines and in vivo on animal model

A new series of tetrahydroacridine derivatives with the fluorobenzoyl moiety was synthesized and evaluated for cytotoxic activity against lung cancer cell lines A549 and colorectal cancer HT29. The cytotoxic activity of the compounds was compared on the somatic cell line-EAhy926. Compounds showed high cytotoxic activity on A549 cells (IC₅₀ 183.26-68.07 μM) and HT29 cells (IC₅₀ 68.41-19.70 μM), higher than controls-etoposide (IC₅₀ 451.47 μM) toward A549 and 5-fluorouracil (IC₅₀ 1626.85 μM) against HT29. Derivative 4 was the most cytotoxic to A549, whereas for the cell lines HT29 compound 6. Selected compounds showed similar cytotoxicity to the EAhy926 cell line (IC₅₀ about 50 μM). In the hyaluronidase inhibition assay, all compounds exhibited anti-inflammatory activity, including 4 exhibiting the best inhibitory activity-IC₅₀ of 52.27 μM when the IC₅₀ heparin was 56.41 μM. Mathematical modeling was performed to determine LD₅₀ after intraperitoneal, oral, intravenous and subcutaneous administration and to predict potential mutagenicity and carcinogenicity of the compounds analyzed. Obtained results showed that tested derivatives are slightly toxic compounds, and LD₅₀ values (mg/kg) ranged from 680 to 1200 (oral rat model), the analyzed compounds have low mutagenic potential, and differences between derivatives are insignificant and very low probability of carcinogenicity. To confirm mathematical calculations, an in vivo test was carried out on a laboratory mouse model for two selected compounds. It allowed to qualify compounds: 6 to category 4 of the GHS scale, and 4 to category 3 of the GHS scale.

Biological Evaluation, Molecular Docking, and SAR Studies of Novel 2-(2,4-Dihydroxyphenyl)-1H- Benzimidazole Analogues

In the present study, new 4-(1H-benzimidazol-2-yl)-benzene-1,3-diols, modified in both rings, have been synthesized and their efficacies as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors have been determined. The modified Ellman’s spectrophotometric method was applied for the biological evaluation. The compounds showed strong (IC₅₀ 80–90 nM) AChE and moderate (IC₅₀ 5–0.2 µM) BuChE inhibition in vitro. Some compounds were effective toward AChE/BuChE, exhibiting high selectivity ratios versus BuChE, while the other compounds were active against both enzymes. The structure–activity relationships were discussed. The compounds inhibited also in vitro self-induced Aβ(1–42) aggregation and exhibited antioxidant properties. The docking simulations showed that the benzimidazoles under consideration interact mainly with the catalytic site of AChE and mimic the binding mode of tacrine.

Novel tetrahydroacridine derivatives with iodobenzoic moieties induce G0/G1 cell cycle arrest and apoptosis in A549 non-small lung cancer and HT-29 colorectal cancer cells

A series of nine tetrahydroacridine derivatives with iodobenzoic moiety were synthesized and evaluated for their cytotoxic activity against cancer cell lines—A549 (human lung adenocarcinoma), HT-29 (human colorectal adenocarcinoma) and somatic cell line—EA.hy926 (human umbilical vein cell line). All compounds displayed high cytotoxicity activity against A549 (IC₅₀ 59.12–14.87 µM) and HT-29 (IC₅₀ 17.32–5.90 µM) cell lines, higher than control agents—etoposide and 5-fluorouracil. Structure–activity relationship showed that the position of iodine in the substituent in the para position and longer linker most strongly enhanced the cytotoxic effect. Among derivatives, 1i turned out to be the most cytotoxic and displayed IC₅₀ values of 14.87 µM against A549 and 5.90 µM against HT-29 cell lines. In hyaluronidase inhibition assay, all compounds presented anti-inflammatory activity, however, slightly lower than reference compound. ADMET prediction showed that almost all compounds had good pharmacokinetic profiles. 1b, 1c and 1f compounds turned out to act against chemoresistance in cisplatin-resistant 253J B-V cells. Compounds intercalated into DNA and inhibited cell cycle in G0/G1 phase—the strongest inhibition was observed for 1i in A549 and 1c in HT-29. Among compounds, the highest apoptotic effect in both cell lines was observed after treatment with 1i. Compounds caused DNA damage and H2AX phosphorylation, which was detected in A549 and HT-29 cells. All research confirmed anticancer properties of novel tetrahydroacridine derivatives and explained a few pathways of their mechanism of cytotoxic action.

Discovery of New Cyclopentaquinoline Analogues as Multifunctional Agents for the Treatment of Alzheimer's Disease

Here we report the two-step synthesis of 8 new cyclopentaquinoline derivatives as modifications of the tetrahydroacridine structure. Next, the biological assessment of each of them was performed. Based on the obtained results we identified 6-chloro-N-[2-(2,3-dihydro-1H-cyclopenta[b]quinolin-9-ylamino)-hexyl]]-nicotinamide hydrochloride (3e) as the most promising compound with inhibitory potencies against EeAChE and EqBuChE in the low nanomolar level 67 and 153 nM, respectively. Moreover, 3e compound is non-hepatotoxic, able to inhibit amyloid beta aggregation, and shows a mix-type of cholinesterase's inhibition. The mixed type of inhibition of the compound was confirmed by molecular modeling. Then, yeast three-hybrid (Y3H) technology was used to confirm the known ligand-receptor interactions. New derivatives do not show antioxidant activity (confirmed by the use of two different tests). A pKa assay method was developed to identify the basic physicochemical properties of 3e compound. A LogP assay confirmed that 3e compound fulfills Lipinsky's rule of five.

Investigation of the photolysis and TiO2, SrTiO3, H2O2-mediated photocatalysis of an antipsychotic drug loxapine - Evaluation of kinetics, identification of photoproducts, and in silico estimation of properties

The photolytic and photocatalytic transformation of loxapine with the use of H₂O₂, TiO₂ and SrTiO₃ under the simulated solar radiation was studied. A micro-scale method for simultaneous irradiation of multiple samples in photostability chamber was applied. RP-UHPLC-DAD coupled with ESI-Q-TOF mass spectrometer was used for the quantitative and qualitative analysis of the processes. Influence of catalysts concentration on kinetic parameters of loxapine photodecomposition was evaluated, and TiO₂ at medium concentration (100 mg L^-1) turned out to be the most effective. Sixteen transformation products were detected and their structures were elucidated. On the basis of the elucidated structures, computational evaluation of toxicity, bioconcentration and bioaccumulation factors as well as biodegradability of transformation products were conducted. The multivariate chemometric method (principal component analysis) was used to compare the calculated properties as well as the applied methods. Most of the transformation products were generally less toxic and more biodegradable than the parent compound.

New cyclopentaquinoline hybrids with multifunctional capacities for the treatment of Alzheimer's disease

Alzheimer’s disease (AD) is the most common progressive form of brain neurodegeneration and the most prevailing cause of dementia. Unfortunately, the aetiology of AD is not completely studied but different factors are associated with the development of AD such as among others low level of acetylcholine, aggregation of β-amyloid (Aβ), hyperphosphorylated tau protein, oxidative stress, and inflammation. The study encompass organic syntheses of 2,3-dihydro-1H-cyclopenta[b]quinoline with 5,6-dichloronicotinic acid and suitable linkers derivatives as multifunctional agents for AD treatment. Afterwards self-induced amyloid beta aggregation, inhibition studies of acetylcholinesterase and butyrylcholinesterase and molecular docking studies were performed. The results showed that 3b compound exhibited the best acetylcholinesterase inhibitory activity, with IC₅₀ value of 0.052 µM which is lower compared to references. Besides, all synthesised compounds showed good butyrylcholinesterase inhibitory activity with IC₅₀ values from 0.071 to 0.797 µM. Compound 3b exhibited strong Aβ_1–42 aggregation inhibitory effect with 25.7% at 5 µM to 92.8% at 100 µM as well as good anti-inflammatory effect. Thus, new compounds could create new perspectives for further development as a multi-target-directed agent for AD treatment.

Novel tetrahydroacridine derivatives with iodobenzoic acid moiety as multifunctional acetylcholinesterase inhibitors

New synthesized series of 9-amino-1,2,3,4-tetrahydroacridine derivatives with iodobenzoic acid moiety were studied for their inhibitory activity toward cholinesterase and against β-amyloid aggregation. All novel molecules 3a-3i interacted with both cholinesterases-acetylcholinesterase and butyrylcholinesterase-delivered nanomolar IC₅₀ values. The structure-activity relationship showed that N-butyl moiety derivatives are stronger inhibitors toward AChE and BuChE than N-ethyl and N-propyl moieties compounds. The most potent compound toward acetylcholinesterase was inhibitor 3f (IC₅₀  = 31.2 nm), and it was more active than reference drug, tacrine (IC₅₀  = 100.2 nm). Compound 3f showed strong inhibition of butyrylcholinesterase (IC₅₀  = 8.0 nm), also higher than tacrine (IC₅₀  = 16.3 nm). In the kinetic studies, compound 3f revealed mixed type of acetylcholinesterase inhibition. The computer modeling was carried out. The most active compound 3f was confirmed as peripheral anionic site inhibitor of acetylcholinesterase. Moreover, molecule 3f inhibited β-amyloid aggregation (at the concentration 10 μm-24.96% of inhibition, 25 μm-72%, 50 μm-78.44%, and 100 μm-84.92%). Therefore, among all examined, compound 3f is the most promising molecule for further, more detailed research of novel multifunctional agents in the therapy of Alzheimer's disease.

Novel tetrahydroacridine and cyclopentaquinoline derivatives with fluorobenzoic acid moiety induce cell cycle arrest and apoptosis in lung cancer cells by activation of DNA damage signaling

Lung cancer is still the leading cause of cancer-related death worldwide, indicating a necessity to develop more effective therapy. Acridine derivatives are potential anticancer agents due to their ability to intercalate DNA as well as inhibit enzymes involved in replication and transcription. Recently, we have evaluated anticancer activity of 32 novel acridine-based compounds. We found that the most effective were tetrahydroacridine and cyclopentaquinoline derivatives with fluorobenzoic acid containing eight and nine carbon atoms in the aliphatic chain. The aim of this study was to determine the molecular mechanisms of compounds-induced cell cycle arrest and apoptosis in human lung adenocarcinoma cells. All compounds activated Ataxia telangiectasia mutated kinase and phosphorylated histone H2A.X at Ser139 indicating DNA damage. Treatment of cells with the compounds increased phosphorylation and accumulation of p53 that regulate cell cycle as well as apoptosis. All compounds induced G0/1 cell cycle arrest by phosphorylation of cyclin-dependent kinase 2 at Tyr15 resulting in attenuation of the kinase activity. In addition, cyclopentaquinoline derivatives induced expression of cyclin-dependent kinase 2 inhibitor, p21; however, tetrahydroacridine derivatives had no significant effect on p21. Moreover, all compounds decreased the mitochondrial membrane potential accompanied by increased expression of Bax and down-regulation of Bcl-2, suggesting activation of the mitochondrial pathway. All compounds also significantly attenuated the migration rates of lung cancer cells. Collectively, our findings suggest a central role of activation of DNA damage signaling in response to new acridine derivatives treatment to induce cell cycle arrest and apoptosis in cancer cells and provide support for their further development as potential drug candidates.