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Mauritianin is a rare flavonoid isolated from the overground parts of Astragalus monspessulanus subsp. monspessulanus. The aim was to investigate mauritianin in vivo for possible hepatoprotective, nephroprotective and neuroprotective activity in a model of carbon tetrachloride-induced liver damage. Thirty six Wistar rats were used and allocated to six experimental groups, treated orally: non-treated (control); treated with mauritianin alone (10 mg/kg); treated with silymarin alone (100 mg/kg); CCl4-treated; pre-treated with mauritianin for 7 days, then given CCl4 and subjected to curative treatment with mauritianin (10 mg/kg) for another 14 days; and treated with silymarin (100 mg/kg, 7 days), given CCl4, then for the next 14 days treated with silymarin (100 mg/kg). The reduced glutathione level (GSH), malonedialdehyde production (MDA), and the activity of ethylmorphine-N-demethylase (EMND) were measured in liver homogenate. A histopathological examination was performed on the livers, brains and kidneys of all animals. Administered alone, mauritianin had no toxicity. Both biochemical and pathoanatomical findings were similar to those in the silymarin-treated group. CCl4 caused severe organ damage - increased MDA production, decreased GSH and EMND levels, lipid accumulations in the liver, pericellular oedemas in the brain and interstitial haemorrhages, accompanied by necrotic changes in the kidneys. In animals pre-treated with mauritianin, exposed to CCl4 and treated 14 days more, minimal biochemical and pathological changes were found, compared to the latter group. A well-preserved histoarchitectonic was found, commensurable to observation of the organs of silymarin and CCl4 treated rats. [ABSTRACT FROM AUTHOR]

Neurodegenerative diseases such as Parkinson's and Alzheimer's continue to be some of the most significant challenges in modern medicine. Recent research related to the molecular mechanisms of parkinsonism has opened up new approaches to antiparkinsonian therapy. In response to this, we present the evaluation of the potential neuroprotective and MAOA/MAOB inhibitory effects of newly synthesized hydrazones, containing a pyrrole moiety in the carboxyl fragment of the structure. The substances were studied on different brain subcellular fractions, including rat brain synaptosomes, mitochondria, and microsomes. The single application of 50 µM of each compound to the subcellular fractions showed that all substances exhibit a weak neurotoxic effect, with 7b , 7d , and 8d being the least neurotoxic representatives. The corresponding neuroprotective and antioxidant effects were also evaluated in different injury models on subcellular fractions, single out 7b , 7d , and 8d as the most prominent derivatives. A 1 µM concentration of each molecule from the series was also studied for potential h MAOA/ h MAOB inhibitory effects. The results revealed a lack of h MAOA activity for all evaluated structures and the appearance of h MAOB effects, with compounds 7b , 7d , and 8d showing effects similar to those of selegiline. The best h MAOB selectivity index (>204) was determined for 7d and 8d , distinguishing these two representatives as the most promising molecules for further studies as potential selective MAOB inhibitors. The performed molecular docking simulations defined the appearance of selective MAOB inhibitory effects based on the interaction of the tested molecules with Tyr398, which is one of the components of the aromatic cage of MAOB and participated in π-π stabilization with the aromatic pyrrole ring. The preliminary PAMPA testing indicated that in relation to the blood-brain barrier (BBB) permeability, the tested pyrrole-based hydrazones may be considered as high permeable, except for 8a and 8e , which were established to be permeable in the medium range with -logP of 5.268 and 5.714, respectively, compared to the applied references.

Considering the complex pathogenesis of Alzheimer's disease (AD), the multi-target ligand strategy is expected to provide superior effects for the treatment of the neurological disease compared to the classic single target strategy. Thus, one novel pyrrole-based hydrazide ( vh0 ) and four corresponding hydrazide-hydrazones ( vh1-4 ) were synthesized by applying highly efficient MW-assisted synthetic protocols. The synthetic pathway provided excellent yields and reduced reaction times under microwave conditions compared to conventional heating. The biological assays indicated that most of the novel pyrroles are selective MAO-B inhibitors with IC 50 in the nanomolar range (665 nM) and moderate AChE inhibitors. The best dual-acting MAO-B/AChE inhibitor (IC 50 h MAOB-0.665 μM; IC 50 ee AChE-4.145 μM) was the unsubstituted pyrrole-based hydrazide ( vh0 ). Importantly, none of the novel molecules displayed h MAOA-blocking capacities. The radical-scavenging properties of the compounds were examined using DPPH and ABTS in vitro tests. Notably, the hydrazide vh0 demonstrated the best antioxidant activities. In addition, in silico simulations using molecular docking and MM/GBSA, targeting the AChE (PDB ID: 4EY6 ) and MAO-B (PDB: 2V5Z ), were utilized to obtain active conformations and to optimize the most prominent dual inhibitor ( vh0 ). The ADME and in vitro PAMPA studies demonstrated that vh0 could cross the blood-brain barrier, and it poses good lead-like properties. Moreover, the optimized molecular structures and the frontier molecular orbitals were examined via DFT studies at 6-311G basis set in the ground state.

In the current study, chromatographic and in silico techniques were applied to investigate the biotransformation of ethyl 5-(4-bromophenyl)-1-(2-(2-(2-hydroxybenzylidene) hydrazinyl)-2-oxoethyl)-2-methyl-1 H -pyrrole-3-carboxylate ( 11b ) in hepatocytic media. The initial chromatographic procedure was based on the employment of the conventional octadecyl stationary phase method for estimation of the chemical stability. Subsequently, a novel and rapid chromatographic approach based on a phenyl-hexyl column was developed, aiming to separate the possible metabolites. Both methods were performed on a Dionex 3000 ThermoScientific (ACM 2, Sofia, Bulgaria) device equipped with a diode array detector set up at 272 and 279 nm for analytes detection. An acetonitrile: phosphate buffer of pH 3.5: methanol (17:30:53 v / v / v ) was eluted isocratically as a mobile phase with a 1 mL/min flow rate. A preliminary purification from the biological media was achieved by protein precipitation with methanol. A validation procedure was carried out, where the method was found to correspond to all ICH (Q2) and M10 set criteria. Additionally, an in silico-based approach with the online server BioTransformer 3.0 was applied in an attempt to predict the possible metabolites of the title compound 11b . It was hypothesized that four CYP450 isoforms (1A2, 2C9, 3A4, and 2C8) were involved in the phase I metabolism, resulting in the formation of 12 metabolites. Moreover, docking studies were conducted to evaluate the formation of stable complexes between 11b and the aforementioned isoforms. The obtained data indicated three metabolites as the most probable products, two of which ( M9_11b and M10_11b ) were synthesized by a classical approach for verification. Finally, liquid chromatography with a mass detector was implemented for comprehensive and summarized analysis, and the obtained results revealed that the metabolism of the 11b proceeds possibly with the formation of glucuronide and glycine conjugate of M11_11b .

A series of ten new hydrazide-hydrazone derivatives bearing a pyrrole ring were synthesized and structurally elucidated through appropriate spectral characteristics. The target hydrazones were assessed for radical scavenging activity through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) tests, with ethyl 5-(4-bromophenyl)-1-(2-(2-(4-hydroxy-3,5-dimethoxybenzylidene)hydrazine-yl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate ( 7d ) and ethyl 5-(4-bromophenyl)-1-(3-(2-(4-hydroxy-3,5-dimethoxybenzylidene) hydra zine-yl)-3-oxopropyl)-2-methyl-1H-pyrrole-3-carboxylate ( 8d ) highlighted as the best radical scavengers from the series. Additional density functional theory (DFT) studies have indicated that the best radical scavenging ligands in the newly synthesized molecules are stable, do not decompose into elements, are less polarizable, and with a hard nature. The energy of the highest occupied molecular orbital (HOMO) revealed that both compounds possess good electron donation capacities. Overall, 7d and 8d can readily scavenge free radicals in biological systems via the donation of hydrogen atoms and single electron transfer. The performed in vitro assessment of the compound's protective activity on the H 2 O 2 -induced oxidative stress model on human neuroblastoma cell line SH-SY5Y determined 7d as the most perspective representative with the lowest cellular toxicity and the highest protection.

Astragalus glycyphyllos (Fabaceae) is used in the traditional medicine of many countries against hepatic and cardiac disorders. The plant contains mainly flavonoids and saponins. From a defatted methanol extract from its overground parts, a new triterpenoid saponin, 3- O -[ α -L-rhamnopyranosyl-(1→2)]- β -D-xylopyranosyl]-24- O - α -L-arabinopyranosyl-3 β ,6 α ,16 β ,24( R ),25-pentahydroxy-20 R -cycloartane, together with the rare saponin astrachrysoside A, were isolated using various chromatography methods. The compounds were identified via extensive high resolution electrospray ionisation mass spectrometry (HRESIMS) and NMR analyses. Both saponins were examined for their possible antioxidant and neuroprotective activity in three different in vitro models. Rat brain synaptosomes, mitochondria, and microsomes were isolated via centrifugation using Percoll gradient. They were treated with the compounds in three different concentrations alone, and in combination with 6-hydroxydopamine or tert -butyl hydroperoxide as toxic agents. It was found that the compounds had statistically significant dose-dependent in vitro protective activity on the sub-cellular fractions. The compounds exhibited a weak inhibitory effect on the enzyme activity of human recombinant monoamine oxidase type B (hMAO-B), compared to selegiline.

An in silico consensus molecular docking approach and in vitro evaluations were adopted in the present study to explore a dataset of FDA-approved drugs as novel multitarget MAO-B/AChE agents in the treatment of Alzheimer's disease (AD). GOLD 5.3 and Glide were employed in the virtual assessments and consensus superimpositions of the obtained poses were applied to increase the reliability of the docking protocols. Furthermore, the top ranked molecules were subjected to binding free energy calculations using MM/GBSA, Induced fit docking (IFD) simulations, and a literature review. Consequently, the top four multitarget drugs were examined for their in vitro MAO-B and AChE inhibition effects. The consensus molecular docking identified Dolutegravir, Rebamipide, Loracarbef and Diflunisal as potential multitarget drugs. The biological data demonstrated that most of the docking scores were in good correlation with the in vitro experiments, however the theoretical simulations in the active site of MAO-B identified two false-positives - Rebamipide and Diflunisal. Dolutegravir and Loracarbef were accessed as active MAO-B inhibitors, while Dolutegravir, Rebamapide and Diflunisal as potential AChE inhibitors. The antiretroviral agent Dolutegravir exhibited the most potent multitarget activity - 41% inhibition of MAO-B (1 μM) and 68% inhibition of AChE (10 μM). Visualizations of the intermolecular interactions of Dolutegravir in the active sites of MAO-B and AChE revealed the formation of several stable hydrogen bonds. Overall, Dolutegravir was identified as a potential anti-AD drug, however further in vivo evaluations should be considered., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

An in vitro/in vivo hepatotoxicity and hepatoprotection evaluation of a defatted extract and a phenolic fraction from Phlomis tuberosa , administered alone and in a carbon tetrachloride (CCl 4 )-induced metabolic bioactivation model, was performed. The extract and the phenolic fraction were analysed by high performance liquid chromatography (HPLC) to determine the total flavonoid content, to identify flavonoids and to quantify verbascoside. In addition, total polyphenolics in the samples were expressed as gallic acid equivalents. Applied alone, the extract and the fraction (5, 10 and 50 µg/mL) did not show a statistically significant hepatotoxic effect on isolated rat hepatocytes in vitro. In a CCl 4 -induced hepatotoxicity model, the samples exhibited a concentration-dependent, statistically significant hepatoprotective effect, which was most pronounced at 50 µg/mL for both. The phenolic fraction exhibited a more pronounced hepatoprotective effect compared to the extract. Data from the in vitro study on the effects of the extract were also confirmed in the in vivo experiment conducted in a CCl 4 -induced hepatotoxicity model in rats. A histopathological study showed that the animals treated with CCl 4 and the extract had an unaltered histoarchitecture of the liver. The effects of the extract were the same as those of silymarin.

Echinops ritro L. (Asteraceae) is traditionally used in the treatment of bacterial/fungal infections and respiratory and heart ailments. The aim of this study was to evaluate the potential of extracts from E. ritro leaves (ERLE) and flowering heads (ERFE) as antioxidant and hepatoprotective agents on diclofenac-induced lipid peroxidation and oxidative stress under in vitro and in vivo conditions. In isolated rat microsomes and hepatocytes, the extracts significantly alleviated oxidative stress by increasing cell viability and GSH levels and reducing LDH efflux and MDA production. During in vivo experiments, the administration of the ERFE alone or in combination with diclofenac resulted in a significant increase in cellular antioxidant protection and a decrease in lipid peroxidation witnessed by key markers and enzymes. A beneficial influence on the activity of the drug-metabolizing enzymes ethylmorphine-N-demetylase and aniline hydroxylase in liver tissue was found. In the acute toxicity test evaluation, the ERFE showed no toxicity. In the ultrahigh-performance liquid chromatography-high-resolution mass spectrometry analysis, 95 secondary metabolites were reported for the first time, including acylquinic acids, flavonoids, and coumarins. Protocatechuic acid O -hexoside, quinic, chlorogenic and 3, 5-dicaffeoylquinic acid, apigenin; apigenin 7- O -glucoside, hyperoside, jaceosidene, and cirsiliol dominated the profiles. The results suggest that both extracts should be designed for functional applications with antioxidant and hepatoprotective capacity.

Nanogels are attractive drug delivery systems that provide high loading capacity for drug molecules, improve their stability, and increase cellular uptake. Natural antioxidants, especially polyphenols such as resveratrol, are distinguished by low aqueous solubility, which hinders therapeutic activity. Thus, in the present study, resveratrol was incorporated into nanogel particles, aiming to improve its protective effects in vitro. The nanogel was prepared from natural substances via esterification of citric acid and pentane-1,2,5-triol. High encapsulation efficiency (94.5%) was achieved by applying the solvent evaporation method. Dynamic light scattering, atomic force microscopy, and transmission electron microscopy revealed that the resveratrol-loaded nanogel particles were spherical in shape with nanoscopic dimensions (220 nm). In vitro release tests showed that a complete release of resveratrol was achieved for 24 h, whereas at the same time the non-encapsulated drug was poorly dissolved. The protective effect of the encapsulated resveratrol against oxidative stress in fibroblast and neuroblastoma cells was significantly stronger compared to the non-encapsulated drug. Similarly, the protection in a model of iron/ascorbic acid-induced lipid peroxidation on rat liver and brain microsomes was higher with the encapsulated resveratrol. In conclusion, embedding resveratrol in this newly developed nanogel improved its biopharmaceutical properties and protective effects in oxidative stress models.

In light of the known neuroprotective properties of indole compounds and the promising potential of hydrazone derivatives, two series of aldehyde-heterocyclic hybrids combining those pharmacophores were synthesized as new multifunctional neuroprotectors. The obtained derivatives of indole-3-propionic acid (IPA) and 5-methoxy-indole carboxylic acid (5MICA) had good safety profiles: Hemolytic effects < 5% (200 μM) and IC 50 > 150 µM were found in the majority of the SH-SY5Y and bEnd3 cell lines. The 2,3-dihydroxy, 2-hydroxy-4-methoxy, and syringaldehyde derivatives of 5MICA exhibited the strongest neuroprotection against H 2 O 2 -induced oxidative stress in SH-SY5Y cells and 6-OHDA-induced neurotoxicity in rat-brain synaptosomes. All the compounds suppressed the iron-induced lipid peroxidation. The hydroxyl derivatives were also the most active in terms of deoxyribose-degradation inhibition, whereas the 3,4-dihydroxy derivatives were able to decrease the superoxide-anion generation. Both series of compounds showed an increased inhibition of hMAO-B, with greater expression detected in the 5MICA hybrids. The in vitro BBB model with the bEnd3 cell line showed that some compounds increased the permeability of the endothelial monolayer while maintaining the tight junctions. The combined results demonstrated that the derivatives of IPA and 5MICA showed strong neuroprotective, antioxidant, MAO-B inhibitory activity and could be considered as prospective multifunctional compounds for the treatment of neurodegenerative disorders.

Oxidative stress is one of the key factors responsible for many diseases-neurodegenerative (Parkinson and Alzheimer) diseases, diabetes, atherosclerosis, etc. Creatine, a natural amino acid derivative, is capable of exerting mild, direct antioxidant activity in cultured mammalian cells acutely injured with an array of different reactive oxygen species (ROS) generating compounds. The aim of the study was in vitro (on isolated rat brain sub-cellular fractions-synaptosomes, mitochondria and microsomes) evaluation of newly synthetized creatine derivatives for possible antioxidant and neuroprotective activity. The synaptosomes and mitochondria were obtained by multiple centrifugations with Percoll, while microsomes-only by multiple centrifugations. Varying models of oxidative stress were used to study the possible antioxidant and neuroprotective effects of the respective compounds: on synaptosomes-6-hydroxydopamine; on mitochondria-tert-butyl hydroperoxide; and on microsomes-iron/ascorbate (non-enzyme-induced lipid peroxidation). Administered alone, creatine derivatives and creatine (at concentration 38 µM) revealed neurotoxic and pro-oxidant effects on isolated rat brain subcellular fractions (synaptosomes, mitochondria and microsomes). In models of 6-hydroxydopamine (on synaptosomes), tert-butyl hydroperoxide (on mitochondria) and iron/ascorbate (on microsomes)-induced oxidative stress, the derivatives showed neuroprotective and antioxidant effects. These effects may be due to the preservation of the reduced glutathione level, ROS scavenging and membranes' stabilizers against free radicals. Thus, they play a role in the antioxidative defense system and have a promising potential as therapeutic neuroprotective agents for the treatment of neurodegenerative disorders, connected with oxidative stress, such as Parkinson's disease.

Novel, rapid and precise RP-HPLC-DAD method was developed, validated and successfully applied for determination of metabolic changes of ethyl 5-(4-bromophenyl)-1-(3-(2-(2-hydroxybenzylidene)hydrazinyl)-3-oxopropyl)-2-methyl-1 H -pyrrole-3-carboxylate ( 12b ) in isolated rat hepatocytes. The analytes were detected by a simple DAD detector at 279 nm wavelength. A single-step extraction method was implemented to enable fast purification and extraction from cellular culture, resulting in a complete recovery. Thereafter, the method was adequately transferred to a LC-MS system for identification of unknown products. Additionally, network metabolism evaluation was performed to predict the structures of major metabolites with their isotope mass through BioTransformer 3.0. The data from the LC-MS analysis and the online server were compared for comprehensive identification. The results indicated formation of four metabolic products, obtained through processes of hydrolysis ( 12 and b ), hydroxylation in the structure 12b ( M1 ) and O-dealkylation ( M2 )., Competing Interests: Competing interestsThe authors declare no competing interests.Competing interestThe authors have no relevant financial or non-financial interests to disclose., (© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Background: The significant increase in patients suffering from different types of cancer, guides scientists to take prompt measures in the development of novel and effective antiproliferative agents, where the intercalation of heterocyclic fragments in the designed molecules has proven to be a useful practice., Objective: The newly synthesized compounds were obtained from the corresponding 1,4-dicarbonyl derivative through multicomponent reactions to produce biologically active target molecules and assessed by in silico and in vitro assays for their possible antitumor activity., Methods: The pharmacological bioassay was conducted in the panel of human tumor cell lines (i) SKW-3 (ACC 53) - human T-cell leukemia and (ii) HL-60 (ACC 3) - human acute myeloid leukemia (AML). The statistical processing of MTT data included the paired Student's t-test with p ≤ 0.05 set as significance level., Results: All evaluated structures displayed a higher cytotoxic effect against the acute myeloid leukemia HL-60 with 11o and 11p as the most active compared to the activity against SKW-3 cell line. Throughout the cytotoxicity screening two molecules, 11l and 12o, displayed comparable chemosensitivity on both cell lines. The corresponding hepatotoxicity on isolated rat hepatocytes and microsomes was also established, identifying 11, 12 and 12a as the least toxic and 11x, 11d, 12x and 12d as the most toxic derivatives., Conclusion: As the most promising compound is underlined ethyl 1-(2-(2-((1-acetyl-1H-indol-3-yl)methylene)hydrazinyl)-2- oxoethyl)-5-(4-bromophenyl)-2-methyl-1H-pyrrole-3-carboxylate (11l) demonstrating highest activity on both evaluated tumor cell lines, decreased hepatotoxicity on all evaluated parameters and docking score of -7.517 kcal/mol., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The current study is focused on investigation and quantitation of seven commercially available on the Bulgarian market food supplements, containing multivitamin mixtures of water-soluble and fat-soluble vitamins. In addition, a second fermentation brewer's yeast is also analyzed. The analytical procedures are performed on a RP-HPLC/DAD using Purospher STAR C18 (Merck Millipore, Germany) 5 μm, 25 × 0.46 cm column, conditioned at 25 °C in a column oven. Dionex UltiMate 3000 high performance liquid chromatograph was carried out in diode array detector, set up at 270 nm for water-soluble vitamins, except for vitamin B 5 , where 210 nm was applied as analytical wavelength. The fat-soluble vitamins were detected at 325 nm and 265 nm for vitamin A and vitamin E, respectively. Two general methods were developed where Method 1 was based on gradient elution and Method 2 was based on isocratic elution. Both methods identified stated by the manufacturer labeled amounts. The developed methods are applicable for routine analysis of vitamin contents both in multivitamin preparations and in brewer's yeast from secondary fermentation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)

Parkinson's disease is a huge burden in modern medicinal practice. A serious drawback of current antiparkinsonian therapy is its symptomatic nature. This directed our investigations in the search for new more potent derivatives, affecting not only the loss of dopaminergic neurons but also the oxidative damage of neuronal cells. Thus in vitro neurotoxicity and neuroprotective analysis on a group of N -pyrrolyl hydrazide-hydrazones were performed. The neurotoxicity of the target derivatives was determined on a subcellular level in isolated rat synaptosomes, mitochondria and microsomes determining their effect on cellular vitality, GSH depletion and MDA production. The neuroprotective effects of the evaluated hydrazones were measured in three models of induced oxidative stress: 6-OHDA, t -BuOOH and Fe 2+ /AA-induced lipid peroxidation. Molecular docking simulations along with in vitro evaluation of MAO-B inhibitory potential of the target molecules were also performed. The results identified the ethyl 5-(4-bromophenyl)-1-(3-hydrazinyl-3-oxopropyl)-2-methyl-1 H -pyrrole-3-carboxylate ( 12 ) as the most promising compound with the lowest neurotoxicity and highest neuroprotection on all evaluated parameters and inhibiting the h MAOB enzyme by 50%, comparable with the activity of the reference, Selegiline. The compatibility of the in silico and in vitro evaluations is a good prerequisite for these methods to be applied in future assessment of pyrrole-based compounds as anti-Parkinson agents.

The neurotoxic, neuroprotective and MAO-B inhibitory effects of series N '-substituted 3-(1,3,7-trimethyl-xanthin-8-ylthio)propanehydrazides are evaluated. The results indicate compounds N '-(2,3-dimethoxybenzylidene)-3-(1,3,7-trimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1 H -purin-8-ylthio)propanehydrazide ( 6k ) and N '-(2-hydroxybenzylidene)-3-(1,3,7-trimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1 H -purin-8-ylthio)propanehydrazide ( 6l ) as most perspective. The performed QSTR analysis identified that the decreased lipophilicity and smaller dipole moments of the molecules are the structural features ensuring lower neurotoxicity. The obtained results may be used as initial information in the further design of (xanthinyl-8-ylthio)propanhydrazides with potential h MAOB inhibitory effect and pronounced neuroprotection.

Oxidative stress is a key contributing factor in the complex degenerating cascade in Parkinson's disease. The inhibition of MAO-B affords higher dopamine bioavailability and stops ROS formation. The incorporation of hydroxy and methoxy groups in the arylhydrazone moiety of a new series of 1,3-disubstituted benzimidazole-2-thiones could increase the neuroprotective activity. In vitro safety evaluation on SH-SY5Y cells and rat brain synaptosomes showed a strong safety profile. Antioxidant and neuroprotective effects were evaluated in H 2 O 2 -induced oxidative stress on SH-SY5Y cells and in a model of 6-OHDA-induced neurotoxicity in rat brain synaptosomes, where the dihydroxy compounds 3h and 3i demonstrated the most robust neuroprotective and antioxidant activity, more pronounced than the reference melatonin and rasagiline. Statistically significant MAO-B inhibitory effects were exerted by some of the compounds where again the catecholic compound 3h was the most potent inhibitor similar to selegiline and rasagiline. The most potent antioxidant effect in the ferrous iron induced lipid peroxidation assay was observed for the three catechols- 3h and 3j , 3q . The catecholic compound 3h showed scavenging capability against superoxide radicals and antioxidant effect in the iron/deoxyribose system. The study outlines a perspective multifunctional compound with the best safety profile, neuroprotective, antioxidant and MAO-B inhibiting properties.

Sdox is a hydrogen sulfide (H 2 S)-releasing doxorubicin effective in P-glycoprotein-overexpressing/doxorubicin-resistant tumor models and not cytotoxic, as the parental drug, in H9c2 cardiomyocytes. The aim of this study was the assessment of Sdox drug-like features and its absorption, distribution, metabolism, and excretion (ADME)/toxicity properties, by a multi- and transdisciplinary in silico , in vitro , and in vivo approach. Doxorubicin was used as the reference compound. The in silico profiling suggested that Sdox possesses higher lipophilicity and lower solubility compared to doxorubicin, and the off-targets prediction revealed relevant differences between Dox and Sdox towards several cancer targets, suggesting different toxicological profiles. In vitro data showed that Sdox is a substrate with lower affinity for P-glycoprotein, less hepatotoxic, and causes less oxidative damage than doxorubicin. Both anthracyclines inhibited CYP3A4, but not hERG currents. Unlike doxorubicin, the percentage of zebrafish live embryos at 72 hpf was not affected by Sdox treatment. In conclusion, these findings demonstrate that Sdox displays a more favorable drug-like ADME/toxicity profile than doxorubicin, different selectivity towards cancer targets, along with a greater preclinical efficacy in resistant tumors. Therefore, Sdox represents a prototype of innovative anthracyclines, worthy of further investigations in clinical settings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Alov, Al Sharif, Aluani, Chegaev, Dinic, Divac Rankov, Fernandes, Fusi, García-Sosa, Juvonen, Kondeva-Burdina, Padrón, Pajeva, Pencheva, Puerta, Raunio, Riganti, Tsakovska, Tzankova, Yordanov and Saponara.)

Nine glycosides of patuletin, 6-methoxykaempferol and spinacetin from Good King Henry ( Chenopodium bonus-henricus L.) were investigated for neuroprotective, anti- α -glucosidase and lipase activities. All tested flavonoids (100 µM) showed statistically significant neuroprotective activities on isolated rat brain synaptosomes using 6-hydroxydopamine in vitro model. They preserved synaptosome viability as well as the reduced glutathione level. 6-Methoxykaempferol glycoside 9 possessed the most prominent neuroprotective and antioxidant effects, within the same range as silibinin (100 µM). Anti- α -glucosidase and lipase activities of the tested compounds were established by measuring the levels of the released 4-nitrophenol using LC-MS here for the first time. Patuletin glycosides 2 and 7 possessed similar activity to acarbose with IC 50 210, 249 and 206 µM, respectively. All flavonoids exhibited prolipase activity and could be used in the treatment of cachexia. The most active were flavonoids, which contain esterified ferulic acid.

Neuroprotective drugs and selective monoamine oxidase inhibitors can slow down the progression and improve symptoms of Parkinson's disease (PD). Since there is an implication of oxidative stress in the pathophysiological mechanisms of the disease, the compounds possessing an ability to reduce the oxidative stress are prime candidates for neuroprotection. Thereby our current study is focused on the development of new multi-target PD drugs capable of inhibiting the activity of monoamine oxidase-B while exerting neuroprotective and antioxidant properties. A small series of benzimidazole derivatives containing hydroxy and methoxy arylhydrazone fragments has been synthesized and the neurotoxicity of the compounds has been evaluated in vitro on neuroblastoma SH-SY5Y cells and on isolated rat brain synaptosomes by measuring the cell viability and the levels of reduced glutathione and a good safety profile has been shown. The 2-hydroxy-4-methoxy substituted arylhydrazone 7 was the least toxic on neuronal SH-SY5Y cells and showed the lowest neurotoxicity in rat brain synaptosomes. The neuroprotective properties of the test compounds were further assessed using two models: H 2 O 2 -induced oxidative stress on SH-SY5Y cells and 6-hydroxydopamine-induced neurotoxicity in rat brain synaptosomes. Compound 7 showed more pronounced neuroprotective activity on SH-SY5Y cells, compared to the referent melatonin and rasagiline. It also preserved the synaptosomal viability and the reduced glutathione levels; the effects were stronger than those of rasagiline and comparable to melatonin. All the tested compounds were capable to inhibit human monoamine oxidase-B enzyme to a significant extent, however, compound 7 exerted the most prominent inhibitory activity, similar to selegiline and rasagiline. The carried out molecular docking studies revealed that the activity is related to the appropriate molecular structure enabling the ligand to enter deeper in the narrow and highly lipophylic active site pocket of the human monoamine oxidase-B and has a favoring interaction with the key amino acid residues Tyr326 and Cys172. Since much scientific evidence points out the implication of iron dyshomeostasis in PD, the compounds were tested to reduce the ferrous iron induced oxidative molecular damage on biologically important molecules in an in vitro lecithin containing model system. All the investigated compounds denoted protection effect, stronger than the one of the referent melatonin. In order to support the assignments of the significant neuroprotective and antioxidant pharmacological activities, the radical-scavenging mechanisms of the most promising compound 7 were evaluated using DFT methods. It was found that the most probable free radicals scavenging mechanism in nonpolar phase is the hydrogen atom transfer from the amide group of compound 7, while in polar medium the process is expected to occur by a proton transfer. The current study outlines a perspective leading structure, bearing the potential for a new anti-PD drug. All performed procedures were approved by the Institutional Animal Care Committee of the Medical University of Sofia (Bulgarian Agency for Food Safety with Permission № 190, approved on February 6, 2020)., Competing Interests: None

Ethnopharmacological Relevance: Astragalus glycyphyllos L. has been extensively used in Bulgarian folk medicine as an antihypertensive, diuretic, anti-inflammatory, anti-tumour, in cases of cardiac insufficiency, renal inflammation, calculosis, etc. AIM OF THE STUDY: To evaluate the possible in vitro/in vivo anti-proliferative/anti-tumour activity of a purified saponins' mixture (PSM) obtained from the plant., Materials and Methods: Viability and proliferative activity of the Graffi myeloid tumour cells was assessed by MTT test. The morphological alterations were visualized and analysed by fluorescent microscopy after intravital double staining. An in vivo model of Graffi tumour bearing hamsters was used to examine the influence of PSM on transplantability, tumour growth, survival and mortality as well as to observe pathomorphological changes., Results: Graffi tumour cells were sensitive to purified saponins' mixture after 24 and 48 h treatment. The treatment induced a statistically significant decrease of the viability/proliferation of the Graffi tumour cells. These effects were concentration- and time-dependent. Fluorescent microscopy studies showed that these antiproliferative effects were connected to the induction of apoptosis. The in vivo study showed the presence of a stromal component, single mononuclear cells in the stroma. Multiple incorrect mitotic figures were observed in the tumour tissue from the control group. Well-formed stroma with accumulation of mononuclear cells and mitotic cells were found in the group, treated with PSM. The tumour weight was decreased in the group, treated with PMS., Conclusion: The results indicate that PSM exhibited in vitro/in vivo antiproliferative/anti-tumour effects., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Selective monoamine oxidase type B (MAO-B) inhibitors are currently used as coadjuvants for treating early motor symptoms of Parkinson's disease. Aiming at the elucidation of MAO-B inhibitors with 1,3,4-oxadiazole scaffolds, we make a comprehensive update on the new and old chemical methods employed for the synthesis of the unsymmetrical oxadiazole derivatives that lead to high yield compounds. We summarize a state of the selective MAO-B inhibitors with oxadiazole scaffold, describing the results, structures, structure-activity relationships (SARs) and medicinal chemistry strategies over the years. The analysis of the recent papers would facilitate tracking the increasing number of oxadiazole derivatives as new chemical spaces with MAO-B inhibitory potential designed to ensure the safe use of the compounds and elimination of the unwanted drug-drug interactions., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

An ultra-high-performance liquid chromatography - high-resolution mass spectrometry profiling method was used for a comprehensive study of flavonoid and saponin-rich fractions from the aerial parts of wild spinach ( Chenopodium bonus-henricus L.). Thirty-six compounds, respectively, 22 saponins of eight sapogenins (phytolaccagenin, bayogenin, medicagenic acid, 2 β -hydroxygypsogenin, 2 β -hydroxyoleanoic acid, 2-hydroxy-30-nor-gypsogenin, 2-hydroxyakebonic acid, and akebonic acid) together with 12  flavonoid glycosides of 6-methoxykaempferol, isorhamnetin, patuletin, spinacetin as well as two ecdysteroids (20-hydroxyecdysone and polypodine B) were detected. The occurrence of sapogenins 2-hydroxy-30-nor-gypsogenin, 2-hydroxyakebonic acid, and akebonic acid in the Chenopodium genus is reported here for the first time. The flavonoid and saponin-rich fractions showed in vitro hepatoprotective and antioxidant activity comparable to those of flavonoid complex silymarin (60 μg/mL) in a model of metabolic bioactivation, induced by CCl 4 . All tested fractions, compared to silymarin, significantly reduced the cellular damage caused by CCl 4 in rat hepatocytes, preserved cell viability and GSH level, decreased LDH leakage, and reduced lipid damage. The results showed that saponin-rich fractions F3A and F3B possessed better hepatoprotective activity than flavonoid-rich fractions (F2A and F2B). The most active was fraction F3B and this is probably due to the synergism between the saponins and some acylated flavonol glycosides found there., (© 2020 Walter de Gruyter GmbH, Berlin/Boston.)

Background: Many neurodegenerative disorders include oxidative stress-mediated pathology. Melatonin and its metabolites act as endogenous reactive oxygen species (ROS) scavengers and antioxidants. N,N'-Disubstituted benzimidazole-2-thiones with extended side chains could exert antioxidant and neuroprotective properties due to structural similarities to melatonin., Methods: The toxicological potential of the compounds was evaluated by monitoring the synaptosomal viability and the levels of reduced glutathione (GSH) in isolated rat brain synaptosomes. The neuroprotective effects were assessed in vitro in a model of 6-hydroxydopamine (6-OHDA)-induced neurotoxicity. The capability to decrease superoxide anion radical and hypochlorite was evaluated by luminol-dependent chemiluminescent assays., Results: Compounds 5-7 containing residues of veratraldehyde, vanillin, and syringaldehyde at concentration 250 μM, preserved at the highest degree the synaptosomal viability and GSH levels. Further screening of compounds 5-7 at lower concentrations of 100 μM, 10 μM, and 1 μM, respectively, demonstrated that 6 and 7 do not show any toxicity within this concentration range. In the model of 6-OHDA-induced oxidative stress, 6 revealed concentration-dependent, neuroprotective, and antioxidant activities similar to melatonin. All the three compounds demonstrated ability to decrease the chemiluminescent scavenging index (CL-SI) in the hypochlorite containing system. In the superoxide system, the hydrazones exhibited different effects on the signal., Conclusions: Our studies suggest that the benzimidazole-aldehyde hybrids act as direct ROS scavengers and membranes' stabilizers against free radicals. Thus, they play a role in the antioxidative defense system and have a promising potential as therapeutic neuroprotective agents for the treatment of neurodegenerative disorders.

A new tetracyclic saponin, 17( R ),20( R )-3 β ,6 α ,16 β -trihydroxycycloartanyl-23-carboxylic acid 16-lactone 3-O- β -D-glucopyranoside ( 1 ) together with one known flavonoid, camelliaside A ( 2 ) were isolated from the aerial parts of Astragalus glycyphyllos L. Their structures were determined by chemical, HRESIMS and NMR methods. On 6-hydroxydopamine in vitro model on isolated rat brain synaptosomes, compounds 1 - 2 had statistically significant neuroprotective activity similar to that of Silibinin, tested at 100 μM. Saponin 1 possessed the most prominent neuroprotective and antioxidant effects in this in vitro model. On human recombinant monoamine oxidase type B enzyme compound 1 displayed strong inhibiting activity, compared to Selegiline (1 μM). It could be concluded that the new epoxycycloartane saponin 1 could be a promising leading structure in respect of neurodegenerative diseases.

Objective: The syntheses and biological activities of 8-thiosubstituted-1,3,7- trimethylxanthine derivatives bearing an aromatic hydrazide-hydrazone fragment in the side chain at C8 are described., Methods: The chemical structures of the synthesized compounds 6a-m were confirmed based on their MS, FTIR, 1H NMR and 13C NMR analyses., Results: The in vitro investigations of neuroprotective effects manifested on cellular (human neuroblastoma cell line SH-SY5Y) and sub-cellular (isolated rat brain synaptosomes) levels show that compounds 6g and 6i demonstrate statistically significant activity. The performed monoamine oxidase B (MAO-B) inhibition study in vitro show that compounds 6g and 6i possess a significant MAO-B inhibition activity close to L-deprenyl., Conclusion: These results suggest that such compounds may be utilized for the development of new candidate MAO-B inhibitors for the treatment of Parkinson's disease., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Parkinson's Disease (PD) is a neurodegenerative and debilitating disease that affects 1% of the elderly population. Patient's motor disability results in extreme difficulty to deal with daily activities. Conventional treatment is limited to dopamine replacement therapy, which fails to delay disease's progression and is often associated with a number of adverse reactions. Recent progress in understanding the mechanisms involved in PD has revealed new molecular targets for therapeutic approaches. Among them, caffeine and xanthine derivatives are promising drug candidates, because of the possible symptomatic benefits in PD. In fact, consumption of coffee correlates with a reduced risk of PD. Over the last decades, a lot of efforts have been made to uncover the therapeutic potential of xanthine structures. The substituted xanthine molecule is used as a scaffold for the synthesis of new compounds with protective effects in neurodegenerative diseases, including PD, asthma, cancer and others. The administration of the xanthines has been proposed as a non-dopaminergic strategy for neuroprotection in PD and the mechanisms of protection have been associated with antagonism of adenosine A2A receptors and Monoamine Oxidase type B (MAO-B) inhibition. The current review summarizes frequently suspected non-dopaminergic neuroprotective mechanisms and the possible beneficial effects of the xanthine derivatives in PD, along with some synthetic approaches to produce perspective xanthine derivatives as non-dopaminergic agents in PD treatment., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

An ultra-high-performance liquid chromatography-high-resolution mass spectrometry based profiling of a purified MeOH extract (PME) from the roots of Chenopodium bonus-henricus L. (Amaranthaceae) tentatively identified 15 saponins of six sapogenins. The PME exerts hepatoprotective and antioxidant activities comparable to those of flavonoid complex silymarin in in vitro (1 and 10 μg/mL) and in vivo (200 mg/kg/daily for 7 days) models of hepatotoxicity, induced by CCl4. The main constituents of PME, respectively saponins bonushenricoside A (1), 3-O-β-D-glucuronopyranosyl-bayogenin-28-O-β-D-glucopyranosyl ester (2), 3-O-β-D-glucuronopyranosyl-medicagenic acid-28-O-β-D-xylopyranosyl (1→4)-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl ester (3), 3-O-β-D-glucuronopyranosyl-2β-hydroxygypsogenin-28-O-β-D-glucopyranosyl ester (4), 3-O-α-L-rabinopyranosyl-bayogenin-28-O-β-D-glucopyranosyl ester (6) and bonushenricoside B (8) (3 μg/mL each), compared to silymarin (5 and 50 μg/mL), significantly reduced the cellular damage caused by CCl4 in rat hepatocytes, preserved cell viability and glutathione level, decreased lactate dehydrogenase leakage and reduced lipid damage. The experimental data suggest that the glycosides of phytolaccagenin, bayogenin, medicagenic acid, 2β-hydroxygypsogenin, 2β-hydroxyoleanoic acid and oleanoic acid are a promising and safe class of hepatoprotective agents.

Muscimol is the main compound found in Amanita muscaria. Several studies have proven that muscimol has suppressive effects on essential tremor, without impairing speech and coordination. The effects of muscimol in Parkinson-affected patients is also described in a number of studies. These studies describe the free radical scavenging and antioxidant activity of the mushroom extract. We have evaluated the possible neuroprotective effects of a standardized extract from A. muscaria, containing high amounts of muscimol, on different models of neurotoxicity in rat brain microsomes, mitochondria, synaptosomes as well as on neuroblastoma cell line SH-SY5Y. The possible inhibitory effect on human recombinant monoaminoxidase-B (hMAOB) enzyme was also studied. The extract revealed statistically significant neuroprotective effects on the in vitro neurotoxicity models and no inhibitory activity on hMAOB., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A number of novel melatonin derivatives, containing aroylhydrazone moieties, were synthesized and explored in vivo for anticonvulsant activity, neurotoxicity in ICR mice as well as in-vitro for cytoxicity and oxidative stress in rats. The structures and configurations were confirmed by NMR, FTIR, HRMS and crystal X-ray diffraction method. For selection of potent structures for synthesis a pharmacophore model was used. Two compounds 3e, with a 2-furyl moiety fragment and 3f with 2-thienyl fragment, showed a potency in maximal electroshock (MES) test (ED 50  = 50.98 mg kg -1 , PI > 5.88 and ED 50  = 108.7 mg kg -1 ; PI > 2.76), respectively, higher than melatonin (ED 50  = 160.3 mg kg -1 , PI > 1.87). The compounds 3c, 3e, 3f and 3i suppressed psychomotor seizures in the 6 Hz test and 3c was the most potent with higher ED 50  = 13.98 mg kg -1 and PI of > 21.46 compared to that of melatonin (ED 50  = 49.76 mg kg -1 and PI of > 6.03) in mice. None of the compounds displayed neurotoxicity in the rota-rod test. The novel melatonin derivatives exerted weak cytotoxic effects while 3f showed the lowest hepatoxic effects comparable to that of the positive control melatonin in rats. The high affinities to the elucidated pharmacophore model of the novel melatonin compounds derived from the inclusion of aroylhydrazone moiety in the indole scaffold yielded suitable candidates with anticonvulsant activity in the MES and 6 Hz test of psychomotor seizures., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Competing Interests: None

The aim of the current study was to evaluate the effect of a defatted extract (EAS) and three flavonoids, isolated from Astragalus spruneri Boiss. (Fabaceae) using in vitro/in vivo models of liver injury. The EAS was characterized by HPLC and flavonoids (14 mg/g dw) and saponins (8 mg/g dw) were proved. The flavonoids (ASF1, ASF3 and ASF5) were isolated from the same extract and partially identified by LC-MS. In in vitro models of non-enzyme induced (Fe 2+ /AA) lipid peroxidation in isolated liver microsomes and CCl 4 -induced metabolic bioactivation and t-BuOOH-induced oxidative stress in isolated rat hepatocytes, both EAS and the flavonoids exerted similar to silybin (positive control) an antioxidant and cytoprotective activity, discerned by decreased MDA production in the microsomes and by preserved cell viability and GSH levels as well as by decreased LDH activity and MDA quantity in isolated rat hepatocytes. The antioxidant and hepatoprotective effect of EAS has been confirmed in vivo against CCl 4 -induced liver injury in rats. EAS restored the GSH levels and the activity of the antioxidant enzymes CAT and SOD, affected by CCl 4 administration, as well as decreased the production of MDA. The effect of EAS was commensurable with those of silymarin., (Copyright © 2017 Elsevier Ltd. All rights reserved.)