Inhibition Of Cell Division Research Articles

Pengaruh Jenis Zat Pengatur Tumbuh terhadap Pertumbuhan Awal Bibit Sengon Laut (Paraserianthes falcataria)

Growth Regulatory Substances stimulate growth by signaling target cells to divide, grow or inhibit cell division or elongation. Plant response to ZPT application varies greatly depending on the stage of development. The growth of shoots and roots can be stimulated by immersing ZPT, because this method makes it easier for a part of the sengon plant, namely the seed, to absorb growth regulators. This study aims to determine the effect of the type of growth regulator on the initial growth of sea sengon seedlings. This research was conducted at the Jember State Polytechnic from June 2022 to September 2022. This study used a Non-factorial Randomized Block Design consisting of 4 levels, namely ZPT gibrelin acid (50 ppm), antonic (2 cc), coconut water 1 liters and finally water (control). Each treatment combination was repeated 6 times. The obtained data were analyzed using ANOVA at the 5% level. Has the result that the treatment of giving the type of growth regulator treatment on the initial growth of sea sengon seedlings has a significant effect on plant height (cm) and germination ability, and has no significant effect on stem diameter (mm), number of petioles, root length (cm), weight plant wet weight (grams), plant dry weight (grams), root wet weight (grams) and root dry weight (grams).

Expand and Sensitize: Guanidine‐Functionalized Exopolysaccharide Nanoparticles Cause Bacterial Cell Expansion and Antibiotic Sensitization

AbstractConventional antibacterial agents and mechanisms are frequently observed to be ineffective due to the evolution of bacteria to the strains with stronger antibiotic resistance, and hence developing alternative antibacterial materials and mechanisms is urgently needed. Here, guanidine‐functionalized exopolysaccharide (EPS) nanoparticles (termed EPGNs) with durable antibacterial and antibiofilm activities are developed. Very interestingly, the EPGNs obtained by the reaction of EPS, epichlorohydrin, and polyhexamethylene guanidine hydrochloride exhibit an unconventional antibacterial mechanism, i.e., they can induce substantial bacterial cell expansion by upregulating the SulA and DicB proteins that are responsible for cell division inhibition, along with the increase of reactive oxygen species production, bacterial cell surface disruption, and bacterial ribosomal RNA degradation. The transcriptome analysis reveals that EPGNs can hinder cell motility, induce loss of cell integrity, decrease the resistance of bacteria to oxidative stress, and finally lead to cell death. Moreover, EPGNs can effectively accelerate the bacteria‐infected wound healing. This work provides the first example that nanomaterials can cause bacterial cell expansion by affecting intracellular structures and inhibiting cell division, and it may inspire other researchers to investigate the effect of antibacterial materials on the change of bacterial volume and design unconventional antibacterial materials/strategies.

Fluorescence Lifetime Nanoscopy of Liposomal Irinotecan Onivyde: From Manufacturing to Intracellular Processing.

Onivyde was approved by the Food and Drug Administration (FDA) in 2015 for the treatment of solid tumors, including metastatic pancreatic cancer. It is designed to encapsulate irinotecan at high concentration, increase its blood-circulation lifetime, and deliver it to cells where it is enzymatically converted into SN-38, a metabolite with 100- to 1000-fold higher anticancer activity. Despite a rewarding clinical path, little is known about the physical state of encapsulated irinotecan within Onivyde and how this synthetic identity changes throughout the process from manufacturing to intracellular processing. Herein, we exploit irinotecan intrinsic fluorescence and fluorescence lifetime imaging microscopy (FLIM) to selectively probe the supramolecular organization of the drug. FLIM analysis on the manufacturer's formulation reveals the presence of two coexisting physical states within Onivyde liposomes: (i) gelated/precipitated irinotecan and (ii) liposome-membrane-associated irinotecan, the presence of which is not inferable from the manufacturer's indications. FLIM in combination with high-performance liquid chromatography (HPLC) and a membrane-impermeable dynamic quencher of irinotecan reveals rapid (within minutes) and complete chemical dissolution of the gelated/precipitated phase upon Onivyde dilution in standard cell-culturing medium with extensive leakage of the prodrug from liposomes. Indeed, confocal imaging and cell-proliferation assays show that encapsulated and nonencapsulated irinotecan formulations are similar in terms of cell-uptake mechanism and cell-division inhibition. Finally, 2-channel FLIM analysis discriminates the signature of irinotecan from that of its red-shifted SN-38 metabolite, demonstrating the appearance of the latter as a result of Onivyde intracellular processing. The findings presented in this study offer fresh insights into the synthetic identity of Onivyde and its transformation from production to in vitro administration. Moreover, these results serve as another validation of the effectiveness of FLIM analysis in elucidating the supramolecular organization of encapsulated fluorescent drugs. This research underscores the importance of leveraging advanced imaging techniques to deepen our understanding of drug formulations and optimize their performance in delivery applications.

Genotoxicity and acute toxicity of 2-amino-5-benzylthiazole in complex with polymeric nanocarrier in Allium bioassay

Background. The search for optimal methods of selective and integral determination of various cytotoxic compounds in biological fluids and tissues, which would have high sensitivity and allow for quick and reliable assessment and detection of potentially cytotoxic components of substances with biologically active action, remains relevant today. It is known that chemotherapeutic agents can be released into the environment (air, surface water, sediments and soil) and cause adverse consequences (impact on the stability of ecosystems due to reduced viability of species). The aim of this work was to investigate the effect of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl1-benzofuran-2-carboxamide (BF1) conjugated with PEG-based polymeric nanoparticles (PEG-PN – Th1) on genotoxicity and acute toxicity in allium bioassay. Materials and Methods. Allium cepa ana-telophase assay was applied to monitor genotoxicity of the studied compounds. The acute toxic effects such as inhibition of cell division, seed germination and growth of Allium roots were estimated. A. cepa seeds (15 per each point) were germinated on the studied solutions of BF1, Th1 and Th2 (10 μM) for 5 days at 22 °C. The root growth and the percentage of inhibition of seed germination were calculated. In order to establish cyto- and genotoxicity of the studied compounds, we have determined the mitotic index and the relative amount of chromosomal aberrations. Results. BF1 had a significant inhibitory effect on root growth and seed germination at a concentration of 10 μM. The effect was eliminated when it was influenced by BF1 complex with a polymeric carrier. The free polymer does not have a negative effect on the studied parameters either. A significant decrease in the mitotic index and increase in the percentage of chromosomal aberrations was observed under the action of BF1 at a concentration of 10 µM. There was no significant change in the value of mitoitic index and percentage of chromosomal aberrations under the action of Th2 comp­lex or polymeric carrier Th1. Conclusions. The thiazole derivative in complex with a polymeric carrier at a concentration of 10 µM did not show acute toxicity in Allium cepa bioassay. Polymer carrier based on polyethylene glycol neutralized the negative effect of BF1 on the mitotic and phase indices of Allium root meristem cells; it also decreased the percentage of chromosomal aberrations.

Cytogenetic changes in irradiated rats under influence of guaninium-zinc chloride complex

Aim. The main goal of this study was to study the anti-radiation effect of guaninium-zinc chloride complex on cytogenetic changes in irradiated rats. Methods. White rats of the Wistar line with an average weight of 110-125 grams served as the material for the detection of the anti-radiation effect of guaninium-zinc chloride complex. Animals were injected intraperitoneally with solutions of guaninium-zinc chloride complex at a concentration of 40 mg/kg 2 hours before irradiation and were subjected to general uniform gamma irradiation from a 60Co source in the Rukhund-20000 irradiation unit at a dose of 3 and 5 Gy. Results. Cytogenetic analysis of animals showed that with a single injection of guaninium-zinc chloride complex solutions before irradiation, the proportion of chromosomal abnormalities decreased markedly, and reached 2.93 %, and the amount of abnormal spermatozoa markedly decreased. Guaninium-zinc chloride complex softened the damaging effects of ionizing radiation. There was no suppression of cell division. Conclusions. It was found for the first time that, with the introduction of a solution of guaninium-zinc chloride complex in white Wistar rats before irradiation, it reduces the damaging effect of gamma irradiation. The obtained data gives grounds to assume that the guaninium-zinc chloride complex tested by us can be recommended as a promising anti-radiation agent.

Impact of aqueous extract of Viscum album on different organisms

The phytochemical and pharmacological potential of Viscum album extracts are widely used for the treatment of various diseases in many countries. The effect of aqueous extract from different mistletoe host trees (Abies alba, Acer saccharinum, Malus domestica, Pinus sylvestris) on model objects (Allium cepa and Drosophila milanogaster), bacteria (Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus), and fungi (Aspergillus niger, Heterobasidion annosum, Inonotus obliquus) was evaluated. The influence of mistletoe extracts on A. cepa, D. melanogaster and basidiomycetes species H. annosum and I. obliquus was demonstrated for the first time. The study findings revealed that the impact of mistletoe aqueous extract exhibits considerable variation, influenced by multiple factors. These factors include the specific tree from which mistletoe is obtained, the concentration used, and the organism targeted. Mistletoe extracts caused the appearance of cells with pathologies in the meristematic tissues of A. cepa at different stages of the plant cell cycle. A clear cytostatic effect on A. cepa and D. melanogaster was shown, with the highest effect of mistletoe extract obtained from A. saccharinum. The main action of the solution on cells is probably manifested in the inhibition of cell division according to the results of the cytotoxicity assessment of aqueous extracts of mistletoe. Antibacterial activity of concentated mistletoe extract obtained from A. saccharinum was found only against S. aureus with zone of growth inhibition 11.0 ± 0.1 mm. In the assay on agar plates the tested extracts stimulated the mycelial growth of A. niger 1.85 times higher compared to the control, but inhibited the growth of H. annosum, I. obliquus at 65.5% and 62.2%, respectively. However, the biomass production of H. annosum was strongly dependent on the host mistletoe tree of the aqueous extract, and both the inhibition of mycelial synthesis of the wood-destroying fungus and its stimulating effect on mycelial accumulation were found. A negative effect (1.46 times decrease in biomass ) of H. annosum was found in the case of application of mistletoe extract obtained from A. saccharinum. The highest stimulation effect on fungus (1.53 times increase in biomass) was established by using mistletoe extract prepared from A. alba. In this study the main effects on living organisms used were indirectly caused by the host trees of mistletoe extracts. The overall negative impact was associated with the host tree Acer saccharinum.

Cytokinin Promotes Jasmonic Acid Accumulation in the Control of Maize Leaf Growth.

Plant organ growth results from the combined activity of cell division and cell expansion. The co-ordination of these two processes depends on the interplay between multiple hormones that determine the final organ size. Using the semidominant Hairy Sheath Frayed1 (Hsf1) maize mutant that hypersignals the perception of cytokinin (CK), we show that CK can reduce leaf size and growth rate by decreasing cell division. Linked to CK hypersignaling, the Hsf1 mutant has an increased jasmonic acid (JA) content, a hormone that can inhibit cell division. The treatment of wild-type seedlings with exogenous JA reduces maize leaf size and growth rate, while JA-deficient maize mutants have increased leaf size and growth rate. Expression analysis revealed the increased transcript accumulation of several JA pathway genes in the Hsf1 leaf growth zone. A transient treatment of growing wild-type maize shoots with exogenous CK also induced the expression of JA biosynthetic genes, although this effect was blocked by the co-treatment with cycloheximide. Together, our results suggest that CK can promote JA accumulation, possibly through the increased expression of specific JA pathway genes.

Efficacy and potential use of vitamin D in the prevention and treatment of uterine fibroids

Introduction: Uterine fibroids (UFs) are the most common benign gynecological tumors. Pharmacological and/or surgical treatments are frequently required, depending on the woman's desire to preserve fertility. Due to side effects caused by pharmacological and surgical treatments, there is a growing interest in a safe approach for UFs. In recent years, hypovitaminosis D is believed to be a major risk factor in the development of a tumor. Studies proved vitamin D efficacy in inhibiting UFs growth by targeting pathways involved in the regulation of various biological processes, resulting in inhibition of tumor cell division and a significant reduction in its size. Vitamin D seems to be promising, effective, and low-cost method in the management of UFs and their clinical symptoms.
 Aim of the study: This article reviews the state of knowledge based on available studies. The aim of the study is to present the most important informations about effectiveness and potential usage of vitamin D in prevention and treatment of uterine fibroids.
 Material and methods: The authors created a paper summarizing review of currently available publications based on databases such as PubMed, Scopus and Google Scholar.

An enhancer trap system to track developmental dynamics in Marchantia polymorpha.

A combination of streamlined genetics, experimental tractability and relative morphological simplicity compared to vascular plants makes the liverwort Marchantia polymorpha an ideal model system for studying many aspects of plant biology. Here we describe a transformation vector combining a constitutive fluorescent membrane marker with a nuclear marker that is regulated by nearby enhancer elements and use this to produce a library of enhancer trap lines for Marchantia. Screening gemmae from these lines allowed the identification and characterization of novel marker lines, including markers for rhizoids and oil cells. The library allowed the identification of a margin tissue running around the thallus edge, highlighted during thallus development. The expression of this marker is correlated with auxin levels. We generated multiple markers for the meristematic apical notch region, which have different spatial expression patterns, reappear at different times during meristem regeneration following apical notch excision and have varying responses to auxin supplementation or inhibition. This reveals that there are proximodistal substructures within the apical notch that could not be observed otherwise. We employed our markers to study Marchantia sporeling development, observing meristem emergence as defining the protonema-to-prothallus stage transition, and subsequent production of margin tissue during the prothallus stage. Exogenous auxin treatment stalls meristem emergence at the protonema stage but does not inhibit cell division, resulting in callus-like sporelings with many rhizoids, whereas pharmacologically inhibiting auxin synthesis and transport does not prevent meristem emergence. This enhancer trap system presents a useful resource for the community and will contribute to future Marchantia research.

The structural basis of hyperpromiscuity in a core combinatorial network of type II toxin–antitoxin and related phage defense systems

Toxin-antitoxin (TA) systems are a large group of small genetic modules found in prokaryotes and their mobile genetic elements. Type II TAs are encoded as bicistronic (two-gene) operons that encode two proteins: a toxin and a neutralizing antitoxin. Using our tool NetFlax (standing for Network-FlaGs for toxins and antitoxins), we have performed a large-scale bioinformatic analysis of proteinaceous TAs, revealing interconnected clusters constituting a core network of TA-like gene pairs. To understand the structural basis of toxin neutralization by antitoxins, we have predicted the structures of 3,419 complexes with AlphaFold2. Together with mutagenesis and functional assays, our structural predictions provide insights into the neutralizing mechanism of the hyperpromiscuous Panacea antitoxin domain. In antitoxins composed of standalone Panacea, the domain mediates direct toxin neutralization, while in multidomain antitoxins the neutralization is mediated by other domains, such as PAD1, Phd-C, and ZFD. We hypothesize that Panacea acts as a sensor that regulates TA activation. We have experimentally validated 16 NetFlax TA systems and used domain annotations and metabolic labeling assays to predict their potential mechanisms of toxicity (such as membrane disruption, and inhibition of cell division or protein synthesis) as well as biological functions (such as antiphage defense). We have validated the antiphage activity of a RosmerTA system encoded by Gordonia phage Kita, and used fluorescence microscopy to confirm its predicted membrane-depolarizing activity. The interactive version of the NetFlax TA network that includes structural predictions can be accessed at http://netflax.webflags.se/.

Minichromosome maintenance proteins in lung adenocarcinoma: Clinical significance and therapeutic targets.

Lung cancer is the most common cause of cancer-related death worldwide, accounting for 1.8 million deaths annually. Analysis of The Cancer Genome Atlas data showed that all members of the minichromosome maintenance (MCM) family (hexamers involved in DNA replication: MCM2-MCM7) were upregulated in lung adenocarcinoma (LUAD) tissues. High expression of MCM4 (P = 0.0032), MCM5 (P = 0.0032), and MCM7 (P = 0.0110) significantly predicted 5-year survival rates in patients with LUAD. Simurosertib (TAK-931) significantly suppressed the proliferation of LUAD cells by inhibiting cell division cycle 7-mediated MCM2 phosphorylation. This finding suggested that MCM2 might be a therapeutic target for LUAD. Moreover, analysis of the epigenetic regulation of MCM2 showed that miR-139-3p, miR-378a-5p, and miR-2110 modulated MCM2 expression in LUAD cells. In patients with LUAD, understanding the role of these miRNAs may improve prognoses.

Therapeutic Potential of Methotrexate-Loaded Superparamagnetic Iron Oxide Nanoparticles Coated with Poly(lactic-co-glycolic acid) and Polyethylene Glycol against Breast Cancer: Development, Characterization, and Comprehensive In Vitro Investigation.

Novel superparamagnetic iron oxide nanoparticles (SPIONs) of Methotrexate (MTX) were developed using supercritical liquid technology and optimized with a Box-Behnken design in order to assess its potential as a candidate for the treatment of breast cancer. MTX-SPIONs coated with poly(lactic-co-glycolic acid)-polyethylene glycol 400 had an aggregate size of 500 nm and an encapsulation efficiency of 46.8 ± 3.9%. The Fourier-transformed infrared spectroscopy analysis revealed a shift in the main bands due to intermolecular hydrogen bonds, whereas the differential scanning calorimetry analysis revealed the absence of the MTX melting endotherm, indicating complete encapsulation with oxide nanoparticles. The zeta potential results indicated a value of 4.98 mV, whereas the in vitro release study revealed an initial burst release followed by a considerable release of 35.1 ± 2.78% after 12 h. Using flow cytometry, control, MTX, and MTX-SPIONs were evaluated for apoptosis, with MTX-SPIONs exhibiting greater apoptosis than the control group and MTX. In addition, MTX-SPIONs inhibited cell division and content organization while substantially increasing the proportion of cells in the G1 and G2 phases relative to the control group. MTX-SPIONs exhibited prolonged anticancer effects against MCF-7 cell lines compared to MTX alone, indicating that SPION-delivered chemotherapeutics may increase cytotoxicity. The medication was stable with low encapsulated drug loss, suggesting that the supercritical liquid technology-based method is a promising way for generating drug-polymer magnetic composite nanoparticles for cancer treatment.

Cellular toxicity and DNA damage induced by Newbouldia laevis used for male infertility treatment in prokaryotic and eukaryotic models.

Leaves of Newbouldia laevis have been extensively used in solving problems associated with infertility and childbirth in many African countries. Yet, information is very limited on the DNA damaging potential of this plant. This study evaluated the cytogenotoxic effect of the aqueous extract of N. laevis leaf using prokaryotic models (Ames Salmonella fluctuation test using TA100 and TA98 strains of Salmonella typhimurium and SOS Chromotest with Escherichia coli PQ37) and eukaryotic model (Allium cepa root cells). Identification of the volatile organic compounds (VOCs) and phytochemical screening of the plant extract were also performed. Onion bulbs were grown on each concentration (1 to 50%; v/v, extract/tap water) of the extract for chromosomal aberrations and root growth analyses. Results of the Ames test indicated that the extract is mutagenic while the SOS Chromotest results showed good complementation to the Ames test results, although the E. coli PQ37 system showed slightly higher sensitivity in the detection of mutagenicity and genotoxicity of the extract. The plant extract was cytotoxic when compared to the control, inducing a significant (p < 0.05) concentration-dependent inhibition of root growth from 5 to 50% concentrations. At 50% concentration, the extract completely inhibited cell division in the A. cepa. Also, chromosomal aberration increased significantly (p < 0.05) in exposed onions from 5 to 20% concentrations. The mutagenicity and cytogenotoxicity recorded in this report were believed to be caused by the presence of VOCs such as 1,2,3-benzene-triol, 1,2-benzenediol, and 5-hydroxymethylfurfural, and alkaloids in the extract an indication of the cytogenotoxicity of the aqueous extract of N. laevis leaf even at low concentration.

Structures of a FtsZ single protofilament and a double-helical tube in complex with a monobody

FtsZ polymerizes into protofilaments to form the Z-ring that acts as a scaffold for accessory proteins during cell division. Structures of FtsZ have been previously solved, but detailed mechanistic insights are lacking. Here, we determine the cryoEM structure of a single protofilament of FtsZ from Klebsiella pneumoniae (KpFtsZ) in a polymerization-preferred conformation. We also develop a monobody (Mb) that binds to KpFtsZ and FtsZ from Escherichia coli without affecting their GTPase activity. Crystal structures of the FtsZ–Mb complexes reveal the Mb binding mode, while addition of Mb in vivo inhibits cell division. A cryoEM structure of a double-helical tube of KpFtsZ–Mb at 2.7 Å resolution shows two parallel protofilaments. Our present study highlights the physiological roles of the conformational changes of FtsZ in treadmilling that regulate cell division.

Overexpression of Hsp104 by Causing Dissolution of the Prion Seeds Cures the Yeast [PSI+] Prion.

The yeast Sup35 protein misfolds into the infectious [PSI+] prion, which is then propagated by the severing activity of the molecular chaperone, Hsp104. Unlike other yeast prions, this prion is unique in that it is efficiently cured by the overexpression as well as the inactivation of Hsp104. However, it is controversial whether curing by overexpression is due to the dissolution of the prion seeds by the trimming activity of Hsp104 or the asymmetric segregation of the prion seeds between mother and daughter cells which requires cell division. To answer this question, we conducted experiments and found no difference in the extent of curing between mother and daughter cells when half of the cells were cured by Hsp104 overexpression in one generation. Furthermore, curing was not affected by the lack of Sir2 expression, which was reported to be required for asymmetric segregation of the [PSI+] seeds. More importantly, when either hydroxyurea or ethanol were used to inhibit cell division, the extent of curing by Hsp104 overexpression was not significantly reduced. Therefore, the curing of [PSI+] by Hsp104 overexpression is not due to asymmetric segregation of the prion seeds, but rather their dissolution by Hsp104.

A sensitive biosensor based on carbon nanohorn/rhodamine B for toxicity detection of polystyrene microplastics and typical pollutants

Microplastics have worldwide accumulated in water and coexisted with different toxic chemicals, which ultimately threaten human health. However, the combined cytotoxicity of microplastics and typical pollutants is still limited. Therefore, it is essential to evaluate the individual toxicity of microplastics and the combined toxicity with other contaminants rapidly and accurately. In this study, a sensitive electrochemical cell-based sensor based on a carbon nanohorn/rhodamine B modified electrode was proposed. Normal human liver (L-02) cells were used as the ideal model for toxicity evaluation. The sensor was used to detect the cytotoxicity of polystyrene microplastic (PS), bisphenol A (BPA), pentachlorophenol (PCP), and lead (Pb2+). The half inhibition concentration (IC50) values of PS, BPA, PCP, and Pb2+ to L-02 cells were 286.34 μg/mL, 78.85 μM, 67.87 μM, and 60.12 μM, respectively. The combined toxicity of PS and typical pollutants (BPA, PCP, Pb2+) revealed an additive effect. Moreover, the mechanism underlying the cytotoxicity of microplastics and three pollutants was investigated from the perspective of oxidative stress and cellular apoptosis. The toxic effects inhibited cell division and growth, with apparent oxidative stress damage and increased apoptosis. This study provideds a sensitive tool for toxicity detection of microplastics and typical pollutants, and reveals the possible mechanisms involved.

Rapid and universal quantification of viable bacteria with growth activity in raw milk using a fluorescent d-amino acid-flow cytometry (FDAA-FCM) method

The plate counting (PC) method is commonly used to determine the total bacterial count (TBC), which includes all viable bacterial cells displaying growth activity. However, this method is time-consuming and may not effectively identify all actively growing bacteria, and it remains largely unknown whether alternative methods can rapidly and universally quantify the TBC of growth-active bacteria. In this study, we investigated the use of fluorescent d-amino acid (FDAA)-based labeling, which universally targets viable bacteria, in conjunction with typical bacterial species found in milk. Furthermore, we established an antibiotic cocktail to impede cell division during the FDAA labeling process. We optimized the FDAA labeling and cell division inhibition conditions to integrate with flow cytometry (FCM), enabling the rapid quantification of viable bacteria with growth activity. Ultimately, we successfully demonstrated the universal quantification of viable bacteria in real milk samples with a TBC higher than 8.9 × 104 cells/mL within a timeframe of 2.5 h using the FDAA-FCM method. These findings suggest that the FDAA-FCM method holds great promise for quantifying TBC in complex biological samples, offering a rapid and universally applicable approach.

Immunological evaluation of herbal extracts commonly used for treatment of mental diseases during pregnancy

Nonpsychotic mental diseases (NMDs) affect approximately 15% of pregnant women in the US. Herbal preparations are perceived a safe alternative to placenta-crossing antidepressants or benzodiazepines in the treatment of nonpsychotic mental diseases. But are these drugs really safe for mother and foetus? This question is of great relevance to physicians and patients. Therefore, this study investigates the influence of St. John’s wort, valerian, hops, lavender, and California poppy and their compounds hyperforin and hypericin, protopine, valerenic acid, and valtrate, as well as linalool, on immune modulating effects in vitro. For this purpose a variety of methods was applied to assess the effects on viability and function of human primary lymphocytes. Viability was assessed via spectrometric assessment, flow cytometric detection of cell death markers and comet assay for possible genotoxicity. Functional assessment was conducted via flow cytometric assessment of proliferation, cell cycle and immunophenotyping. For California poppy, lavender, hops, and the compounds protopine and linalool, and valerenic acid, no effect was found on the viability, proliferation, and function of primary human lymphocytes. However, St. John’s wort and valerian inhibited the proliferation of primary human lymphocytes. Hyperforin, hypericin, and valtrate inhibited viability, induced apoptosis, and inhibited cell division. Calculated maximum concentration of compounds in the body fluid, as well as calculated concentrations based on pharmacokinetic data from the literature, were low and supported that the observed effects in vitro would probably have no relevance on patients. In-silico analyses comparing the structure of studied substances with the structure of relevant control substances and known immunosuppressants revealed structural similarities of hyperforin and valerenic acid to the glucocorticoids. Valtrate showed structural similarities to the T cells signaling modulating drugs.

Targeting Mycobacterium tuberculosis: Synthesis, in vitro and in silico evaluation of novel N1 -(benzo[d]oxazol-2-yl)-N4 -arylidine compounds.

The development of novel antimycobacterial agents is an urgent challenge to eradicate the increasing emergence and rapid spread of multidrug-resistant strains. Filamentous temperature-sensitive protein Z (FtsZ) is a crucial cell division protein. Alteration of FtsZ assembly leads to cell division inhibition and cell death. To find novel antimycobacterial agents, a series of N1 -(benzo[d]oxazol-2-yl)-N4 -arylidine compounds 5a-o were synthesized. The activity of the compounds was evaluated against drug-sensitive, multidrug-resistant, and extensive-drug-resistant Mycobacterium tuberculosis. Compounds 5b, 5c, 5l, 5m, and 5o showed promising antimycobacterial activity with minimum inhibitory concentrations (MIC) in the range of 0.48-1.85 µg/mL and with low cytotoxicity against human nontumorigenic lung fibroblast WI-38 cells. The activity of the compounds 5b, 5c, 5l, 5m, and 5o was evaluated against bronchitis causing-bacteria. They exhibited good activity against Streptococcus pneumoniae, Klebsiella pneumoniae, Mycoplasma pneumonia, and Bordetella pertussis. Molecular dynamics simulations of Mtb FtsZ protein-ligand complexes identified the interdomain site as the binding site and key interactions. ADME prediction indicated that the synthesized compounds have drug-likeness. The density function theory studies of 5c, 5l, and 5n were performed to investigate E/Z isomerization. Compounds 5c and 5l are present as E-isomers and 5n as an E/Z mixture. Our experimental outcomes provide an auspicious lead for the design of more selective and potent antimycobacterial drugs.

Cytosolic JNK-dependent microtubule reassembly protects Jurkat leukemia cells from selenite-induced apoptosis

BackgroundSelenite at high dosage exhibits great potential in curing tumors. It has been shown that selenite inhibits tumor growth through regulation of microtubule dynamics, however, the exact underlying mechanisms remained to be fully elucidated. Methods & resultsWestern blots were carried out to evaluate expression level of different molecules. Our current study discovered that selenite induced microtubule disassembly, cell cycle arrest and finally resulted in apoptosis in Jurkat leukemia cells, while during this process disassembled tubulins were re-organized after long-term exposure to selenite. Furthermore, JNK was activated in the cytoplasm of selenite-treated Jurkat cells, and inhibition of JNK activity successfully prevented the process of microtubule re-assembly. Moreover, inactivation of JNK further enhanced selenite-induced cell cycle arrest and apoptosis. According to the results from cell counting-8 assay, blockage of microtubule re-assembly by colchicine further inhibited Jurkat cell viability after exposure to selenite. Experiments in a xenograft model also proved that selenite could alter JNK activity, destroy microtubule structure and inhibit cell division in vivo. Moreover, TP53, MAPT and YWHAZ were identified to be three most confident interactors that link JNK to microtubule assembly using PPIs analysis. ConclusionOur study indicated that cytosolic JNK-dependent microtubule re-organization took a protective function during selenite-induced apoptosis, while inhibition of this process would finally enhance the anti-tumor effect of selenite.