Human Erythrocyte Cells Research Articles

Functional properties and safety traits of L. rhamnosus and L. reuteri postbiotic extracts

Postbiotics are the non-viable bacterial products or the low molecular weight metabolites produced by probiotics that have received considerable attention owing to their health promoting effects. The present study aimed to investigate the safety and antibacterial properties of postbiotic components of Lacticaseibacillus rhamnosus (Lra) and Limosilactobacillus reuteri (Lre) for their potential applications in food products. The freeze dried postbiotic metabolites (FD-P) from Lra and Lre were extensively analyzed for their physico-chemical properties and antibacterial actions against common food borne pathogens. Higher levels of total flavonoids (1971.79 ± 20 mg Qu/ g), total short-chain fatty acid (23 µg/g), sugar contents, CAT, and SOD anti-oxidative enzymes were detected in the Lra postbiotic, while GSH-px levels and riboflavin were higher in Lre postbiotics (P < 0.01). No significant differences were recorded in the total phenolic (2501 and 2518 mg GAE/ L) and crude protein contents (305. 58 and 296.23 µg/g) of the postbiotics (p ≥ 0.05), respectively. Both FD-P samples showed enhanced activities against Gram-Positive pathogens compared to Gram-Negative pathogens (p < 0.05), while combining the two postbiotics further potentiated the antibacterial actions. Both FD-P samples were non-hemolytic to human erythrocyte cells, and exhibited low cytotoxicity in MRC 5 and IPEC-J2 cell lines at the highest used concentrations (150 mg/ml). In summary, the postbiotics derived from Lra and Lre are safe bioactive ingredients with enhanced antibacterial and antioxidant capabilities, having potential applications as a natural preservatives in food system, potentially enhancing safety and extending the shelf life of food products.

Structure-Activity Relationship of Hydrazinylthiazole-5-Carbaldehydes as Potential Anti-Diabetic Agents.

Diabetes is an emerging threat to the world due to large number of deaths reported within the last decade. To overcome its spread and complications, herein, we reported synthesis and anti-diabetic potential of twelve novel 2-[(arylidenyl)methylidene]hydrazinyl-1,3-thiazole-5-carbaldehydes (3 a-l). All compounds have shown good to excellent α-amylase inhibitory activity, among them ortho substituted analogues, the compound 3 a (IC50=14.6 mM) and 3 l (IC50=17.9 mM) showed excellent inhibition potential due to the strong electron donating nature of the substituents attached at the aryl ring. The compounds 3 a-3 h (IC50=6.70-10.80 ppm) exhibited excellent anti-glycation potential as compared to standard amino-guanidine (IC50=11.92 ppm). Almost all the tested compounds are found biocompatible and very safe to the human erythrocyte cells at all tested concentrations. The molecular docking results have found that the binding energy score of all the tested compounds against human serum albumin protein (pdb: 1AO6) is between -5.1827 and -6.8661 kcal/mol which is far better than standard amino-guanidine (-4.234 kcal/mol).

Ratiometric paramagnetic probe based on ABTS•+ and Mn2+ for detection of glutathione and revelation of the mechanism for MnO2 nanosheet induced oxidation of ABTS

We designed a ratiometric paramagnetic probe based on electron spin resonance (ESR) signals of ABTS radical (ABTS•+) and Mn2+. Two ESR signals from different paramagnetic species (ABTS•+ and Mn2+) coexisting in the same solution were measured at the same time and were present in one spectrum. MnO2 nanosheets with oxidase-like properties were synthesized. The probe was used to investigate the oxidation mechanism of ABTS by MnO2 nanosheets. On one hand, MnO2 nanosheets catalyzed the generation of O2•− which oxidized ABTS to ABTS•+, and on the other hand, a small amount of ABTS was directly oxidized to ABTS•+ by MnO2 which was reduced to Mn2+. Glutathione (GSH) underwent a redox reaction with MnO2 nanosheets to yield Mn2+ with stable ESR signal. The concentration of MnO2 decreased in the presence of GSH, which inhibited the production of O2•− and ABTS•+. As a result, as the concentration of GSH increased, ESR signal of ABTS•+ descended and on the contrary ESR signal of Mn2+ ascended. Accordingly, the signal ratio of ABTS•+ to Mn2+ decreased with the increase of GSH concentration. The proposed ratiometric ESR probe could reduce the influence from background signal and improve the accuracy and sensitivity of the detection. We applied this strategy to the determination of GSH in human erythrocyte cells, and the results showed recoveries between 90.9 % and 92.6 %. With this method, simultaneously monitoring both nanozyme and its chromogenic substrate could be realized and thus a better understand of the mechanism for the function of MnO2 nanomaterial could be achieved.

Synergistic anti-virulence efficacy of citral and carvacrol against mixed vaginitis causing Candida albicans and Gardnerella vaginalis: An in vitro and in vivo study.

Mixed vaginitis due to bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) is the most prevalent form and presents a significant therapeutic challenge globally. Since, the administration of monotherapy leads to subsequent recurrent infections, synergistic therapy that completely eradicates both pathogens is of dire need to manage mixed vaginities scenario and to prevent its recurrence. The current investigation was focused on exploring the synergistic inhibitory efficacy of phytochemicals against the virulence traits of individual and mixed species of C. albicans and G. vaginalis in vitro and in vivo (Galleria mellonella). Out of five phytochemicals (carvacrol, thymol, cinnamaldehyde, eugenol, and borneol) screened for synergism with citral [(Ct) as the prime molecule owing to its myriad therapeutic potential], carvacrol (Ca) in combination with citral exhibited promising synergistic effect. Time-kill kinetics and one-minute contact-killing assays demonstrated the phenomenal microbicidal effect of Ct-Ca combination against both mono and dual-species within 30 min and one-minute time intervals, respectively. Furthermore, the sub-CMICs (synergistic combinatorial MIC) of Ct-Ca have significantly eradicated the mature biofilms and remarkably reduced the virulence attributes of both C. albicans and G. vaginalis (viz., yeast to hyphae transition, filamentation, protease production, and hydrophobicity index), in single and dual species states. The non-toxic nature of Ct-Ca combination was authenticated using in vitro (human erythrocyte cells) and in vivo (Galleria mellonella) models. In addition, the in vivo efficacy evaluation and subsequent histopathological investigation was done using the invertebrate model system G. mellonella, which further ascertained the effectiveness of Ct-Ca combination in fighting off the infection caused by individual and mixed species of C. albicans and G. vaginalis. Concomitantly, the current work is the first of its kind to delineate the in vitro interaction of C. albicans and G. vaginalis mixed species at their growth and biofilm states, together emphasizes the promising therapeutic potential of acclaimed phytochemicals as combinatorial synergistic therapy against mixed vaginitis.

Investigating the Antimicrobial Effects of a Novel Peptide Derived From Listeriolysin S on S aureus, E coli, and L plantarum: An In Silico and In Vitro Study.

The emergence of antibiotic resistance is one of the most significant issues today. Modifying antimicrobial peptides (AMPs) can improve their effects. In this study, the active region of Listeriolysin S (LLS) as a peptidic toxin has been recognized, and its antibacterial properties have been evaluated by modifying that region. After extracting the sequence, the structure of LLS was predicted by PEP-FOLD3. AntiBP and AMPA servers identified its antimicrobial active site. It was modified by adding arginine residue to its 3- and N-terminal regions. Its antimicrobial properties on Staphylococcus aureus, Escherichia coli, and Lactobacillus Plantarum were estimated. The results of AntiBP and AntiBP servers demonstrated that a region of 15 amino acids has the most antimicrobial properties (score = 1.696). After adding arginine to the chosen region, the physicochemical evaluation and antimicrobial properties revealed that the designed peptide is a stable AMP with a positive charge of 4, which is not toxic to human erythrocyte cells and has antigenic properties. The results of in vitro and colony counting indicated that at different hours, it caused a significant reduction in the count of S aureus, E coli, and L Plantarum compared with the control sample. Upcoming research implies that identifying and enhancing the active sites of natural peptides can help combat bacteria.

Phyto‐synthesis of silver nanoparticles from Tephrosia purpurea and its in‐vitro biogenic actions

Tephrosia purpurea silver nanoparticles (TP‐AgNPs) were synthesized with water‐based leaf extract of the plant T. purpurea. UV–Vis characterization had shown the maximum absorbance at 436 nm. The surface morphology was examined via electron microscopy (FE‐SEM) analysis (average size: ~100 nm, shape: spherical). The zeta potential (ZP) of TP‐AgNPs revealed values of −41.72 mV suggesting appropriate physical stability. Besides, an X‐ray crystallography (XRD) study had shown the crystalline size of 20 nm approximately having 2θ values of 32°, 38°, 44°, 64°, and 77° for the silver crystals. The energy dispersive (EDAX) study manifests the absorption peak at 2.983 keV for TP‐AgNPs. Infrared spectroscopy analysis (Fourier‐transform infrared spectroscopy) indicated the presence of alcoholic as well as aromatic groups in the extract that took part in the stability and silver reduction mechanisms. Biologically, TP‐AgNPs had shown prominent anti‐oxidant activities against 2,2‐diphenyl‐1‐picrylhydrazyl radicals (IC50 50 μg/mL) and H2O2 radicals (IC50 106 μg/mL). It had also inhibited the proliferation of breast cell lines (MCF 7) showing total growth inhibition (TGI) at 8.2 μg/mL with the LC50 of 44 μg/mL for TP‐AgNPs. Further, hemolysis analysis revealed that TP‐AgNPs are non‐toxic to human erythrocyte cells (RBCs) as they do not cause the breakdown of RBCs. Thus, TP‐AgNPs were found to be an effective agent to be studied further for chemotherapeutic mechanisms.

Optimization of Affinity Chromatography Based on Sepharose 4B- chitin for Rapid Purification of Urtica dioica Agglutinin.

Today, numerous antimicrobial and anticancer properties have been reported for plant lectins due to their ability to bind to carbohydrates. The Urtica dioica agglutinin (UDA lectin) is a monomeric, small, and low molecular weight glycoprotein. It has attracted the attention of many researchers for identification, treatment, and other clinical purposes. The aim of this study is the optimization of the chitin affinity chromatography based on Sepharose 4B (CNBr-activated Sepharose 4B) for the rapid purification of UDA lectin from Urtica dioica rhizome. The chitin ligands were dissolved in 40% Trichloroacetic acid and attached to Sepharose 4B according to the Amersham-Biosciences instructions. The attachment of the ligand to the Sepharose 4B beads was investigated by Fourier transform infrared (FTIR) spectroscopy. An acidic crude extract of nettle rhizome passes from chromatographic columns in two sizes with dimensions: 24 x 0.51 cm and 8.44 x 0.86 cm. Quantity and quality of purified lectin were calculated by the Bradford microplate method: SDS-PAGE gel electrophoresis and human erythrocyte cell (RBC) hemagglutination, respectively. The analysis of FTIR spectrograms showed that major changes were observed in the fingerprint regions. Besides, due to the dissolution of Sepharose 4B and chitin in the aqueous phase, this difference was not significant in the Imine and Nitrile regions. On the other hand, the comparative results of purification chromatograms showed that increasing the column length causes a smaller half-width and increases the length of the purified peak. Also, it leads to high-quality purified UDA lectin, with a molecular weight of almost 12.5 kDa in gel electrophoresis. Hemagglutination activity on trypsinized red blood cells was displayed, and agglutination of purified UDA lectin started at least at 300 μg.mL-1 concentration. According to our findings, we suggested that dissolving chitin in the polar solvent of Trichloroacetic acid, using Sepharose 4B as the beads of a matrix, and increasing the column length might lead to a decrease in the half-width of the peak. These can increase the purity and concentration of purified UDA lectin, and speed up the purification process. These findings could be used by researchers to accelerate the purification of UDA lectin in other studies, dealing with drug delivery systems, ELISA techniques, and cell growth.

Carbonic anhydrase inhibitory activities of novel proton transfer salts and their Cu(II) complexes

In this study, two new proton transfer salts of sulfonamide derivatives of maleic acid, namely (ClHabt)+(mabsmal)– (1) and (ClHabt)+(pabsmal)– (2), were obtained from 2-amino-6-chlorobenzo­thiazole (Clabt) and N-(3-sulfamoylphenyl)maleamide acid (Hmabsmal) and N-(4-sulfamoyl­phenyl)maleamide acid (Hpabsmal), respectively. Also, the Cu(II) complexes (3 and 4) of salts (1 and 2) and of Hmabsmal (5) were prepared. Compounds 1‒5 were characterized by elemental, NMR (1H and 13C), FTIR, and thermal analyses, as well as UV-Vis, magnetic moment, and molar conductivity measurements. Carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocyte cells by affinity chromatography. The effects of the synthesized compounds on the hydratase and esterase activities of CA isoenzymes were studied in vitro. The results reveal that the synthesized compounds inhibit both esterase and hydratase activities of hCA I and hCA II. The inhibition constants of the compounds (Ki) were determined according to the esterase activity measurements. Ki values of 1‒5 are in the range of 0.06 ± 0.003 µM and 4.25 ± 0.100 µM for hCA I, and of 0.02 ± 0.001 µM and 3.21 ± 0.200 µM for hCA II.

Cytotoxic effect of various solvent extracts of Acacia nilotica pods on human erythrocyte cells

Acacia nilotica is a multipurpose medicinal plant. Different parts of this plant are used to alleviate or treat various diseases. In the current study, an attempt was made to study the cytotoxicity of Acacia nilotica pod extracts towards normal human erythrocytes. The pods of A. nilotica were ground, then three different solvents were used in different ratios to prepare crude extracts, which were screened for in vitro hemolytic activity. UV-visible spectrophotometric method was used for the quantification of the hemolytic effect. The hemolysis percentages of the different extracts were found to be very minimal (Methanol extract: 4.65±0.24%; Ethanol extract: 3.77±0.48% and Aqueous extract: 2.69±0.51%), while Triton X-100 produced total hemolysis at the lowest concentration. These findings suggested that this plant could be considered as safe to human erythrocytes. However, further studies through in vivo toxicological tests should be considered in the future in order to best justify its safety.

Preliminary Data from the Phase I/II Study of TP-3654, a Selective Oral PIM1 Kinase Inhibitor, in Patients with Myelofibrosis Previously Treated with or Ineligible for JAK Inhibitor Therapy

Introduction: Myelofibrosis (MF) is characterized by bone marrow (BM) fibrosis, ineffective hematopoiesis, splenomegaly, and debilitating symptoms. Expression of PIM-1 is significantly upregulated in MF hematopoietic cells, supporting exploration of PIM-1 as a potential therapeutic target in MF. TP-3654 is a highly selective oral investigational PIM-1 kinase inhibitor. When administered alone and in combination with ruxolitinib, TP-3654 reduced spleen size and BM fibrosis in JAK2V617F and MPLW515L murine MF models (Dutta, 2021). In addition, TP-3654 decreased cytokine response genes and serum TGF-b in progenitor cells and JAK2V617F mice, respectively. TP-3654 showed less hematopoietic inhibition than Janus kinase (JAK) inhibitors (ruxolitinib, pacritinib and momelotinib) in in vitro human megakaryocyte and erythrocyte cell colony formation. Methods: This Phase I/II study evaluates the safety and efficacy of TP-3654 monotherapy in patients with MF (NCT04176198). Key eligibility criteria include primary or secondary MF; intermediate or high-risk MF per DIPSS; previously treated with or ineligible for JAK inhibitor treatment; grade ≥2 BM fibrosis; platelet count ≥25x109/L; absolute neutrophil count ≥1x109/L; splenomegaly; and ≥2 measurable symptoms. The study aims to identify the maximum tolerated dose and/or recommended Phase II dose using a Bayesian logistic regression model (BLRM) with overdose control, and to assess clinical activity (spleen volume reduction [SVR], total symptom score [TSS] improvement, and BM fibrosis reduction), safety, pharmacokinetic, and pharmacodynamic markers in peripheral blood and BM biopsies. Results: As of 11 July 2022, 8 patients were enrolled across 5 dose levels in the dose escalation phase. At baseline, median age was 70 years (range, 61 to 77), median spleen volume was 2370 cm3 (range, 1189 to 4407), median total symptom score was 19 (range, 4 to 62), median platelet count was 120 x109/L (range 68 to 237), median hemoglobin was 10.1 g/dL (range, 5.9 to 13.7), and two patients were transfusion-dependent. All patients had received prior treatment with at least one JAK inhibitor. Median duration of prior JAK inhibitor treatment was 35 weeks (range, 13 to 269). Six patients had JAK2V16F mutation, 2 patients had CALR mutation. The median duration of TP-3654 treatment was 21 weeks (range, 1 to 45). No dose-limiting toxicities occurred. Treatment-related adverse events (TRAEs) occurring in >20% of patients included mild to moderate nausea, vomiting, and diarrhea. Grade ≥ 3 TRAEs included only 1 case of vomiting. No hematological TRAEs were reported. No discontinuation due to AE occurred. SVR was observed in 5 out of 6 evaluable patients (median best change -14%, range -3.2% to -35%) (Figure 1). Symptom improvement was observed in 5 out of 6 evaluable patients (median best change -70%, range -32 to -100%). A panel of cytokines were evaluated in plasma samples obtained at baseline and during TP-3654 treatment. Reductions in cytokines (TGF-b, IL-18, VEGF, RANTES, MMP-9, and TIMP-1) were observed after TP-3654 treatment (Figure 2). Patients with higher cytokine reductions correlated with higher reduction in total symptom score. Enrollment is ongoing, updated data will be presented. Conclusions: The preliminary clinical data in dose escalation show: 1) encouraging signs of clinical activity in spleen volume reduction, symptom improvement, and cytokine reduction with TP-3654 monotherapy in patients previously treated with JAK inhibitors, 2) TP-3654 is well tolerated with limited myelosuppressive adverse events. The non-clinical findings and preliminary clinical safety/efficacy data support accelerated development and assessment of TP-3654 as the optimal partner for combination with JAK inhibitors. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Insights into the Antioxidant Mechanism of Newly Synthesized Benzoxazinic Nitrones: In Vitro and In Silico Studies with DPPH Model Radical.

Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases. In this context, increasing efforts are currently being made to the design and synthesis of new nitrone-based compounds with enhanced efficacy. The most researched nitrones are surely the ones related to α-phenyl-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) derivatives, which have shown to possess potent biological activity in many experimental animal models. However, more recently, nitrones with a benzoxazinic structure (3-aryl-2H-benzo[1,4]oxazin-N-oxides) have been demonstrated to have superior antioxidant activity compared to PBN. In this study, two new benzoxazinic nitrones bearing an electron-withdrawing methoxycarbonyl group on the benzo moiety (in para and meta positions respect to the nitronyl function) were synthesized. Their in vitro antioxidant activity was evaluated by two cellular-based assays (inhibition of AAPH-induced human erythrocyte hemolysis and cell death in human retinal pigmented epithelium (ARPE-19) cells) and a chemical approach by means of the α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay, using both electron paramagnetic resonance (EPR) spectroscopy and UV spectrophotometry. A computational approach was also used to investigate their potential primary mechanism of antioxidant action, as well as to rationalize the effect of functionalization on the nitrones reactivity toward DPPH, chosen as model radical in this study. Further insights were also gathered by exploring the nitrone electrochemical properties via cyclic voltammetry and by studying their kinetic behavior by means of EPR spectroscopy. Results showed that the introduction of an electron-withdrawing group in the phenyl moiety in the para position significantly increased the antioxidant capacity of benzoxazinic nitrones both in cell and cell-free systems. From the mechanistic point of view, the calculated results closely matched the experimental findings, strongly suggesting that the H-atom transfer (HAT) is likely to be the primary mechanism in the DPPH quenching.

S. boulardii Fails to Hold Its Cell Wall Integrity against Nonpathogenic E. coli: Are Probiotic Yeasts Losing the Battle?

Probiotic yeast Saccharomyces boulardii exerts direct probiotic action on pathogenic E. coli by trapping them on surfaces and inactivating toxic lipopolysaccharides. Using optical dark-field microscopy, we show that nonpathogenic E. coli cells also readily bind probiotic S. boulardii. More importantly, the adhered nonpathogenic E. coli progressively damage S. boulardii cell walls and lyse them. Co-cultured methylene blue-supplemented agar-plate assay indicates that rough lipopolysaccharides might be playing a key role in S. boulardii cell wall damage. When experiments are repeated with lipopolysaccharide-depleted E. coli and also lipopolysaccharide-deficient E. coli, adhesion decreases substantially. The co-cultured assay further reveals that free lipopolysaccharides, released from E. coli, are also causing damage to S. boulardii walls like adhered E. coli. These new findings contradict the known S. boulardii-E. coli interaction mechanisms. We confirm that E. coli cells do not bind or damage human erythrocyte cell walls; therefore, they have not developed pathogenicity. The combined results demonstrate the first example of nonpathogenic E. coli being harmful to probiotic yeast S. boulardii. This finding is important because gut microbial flora contain large numbers of nonpathogenic E. coli. If they bind or damage probiotic S. boulardii cell walls, then the probiotic efficiency toward pathogenic E. coli will be compromised.

The N-terminal amino-latch region of Hlg2 component of staphylococcal bi-component γ-haemolysin is dispensable for prestem release to form β-barrel pores.

The contribution of N-terminal regions of staphylococcal bi-component γ-haemolysin toxin components to haemolytic activity towards human erythrocyte cells was investigated in this study. A deletion construct of N-terminal amino acids 1-10 of Hlg2 (Hlg2 ΔN10), which is the S-component protein of γ-haemolysin, had little effect on its haemolytic activity, whereas N-terminal 1-11 amino acid deletion (Hlg2 ΔN11) significantly delayed haemolysis. Moreover, a deletion of N-terminal amino acids 1-17 of LukF, which is the F-component protein of γ-haemolysin, increased its haemolytic activity in combination with either the wild-type or Hlg2 ΔN10. Unlike the N-terminal amino-latch region of staphylococcal α-haemolysin, which is a single component β-barrel pore-forming toxin, the N-terminal regions present in γ-haemolysin components are dispensable for the haemolytic activity of the bi-component toxin. These results strengthen our recent proposal that staphylococcal bi-component γ-haemolysin toxin uses an N-terminal amino-latch independent molecular switch for prestem release during the formation of β-barrel pores.

Protein assisted one pot controlled synthesis of monodispersed and multifunctional colloidal silver‑gold alloy nanoparticles

Here, we prepared gold‑silver alloy nanoparticle (AgAuNPCS) of ~8.5 nm mean size via one-pot biogenic synthesis using casein as reducing as well as capping agent and explored its potential in various biomedical applications using curcumin (CUR) as a drug delivery agent. When we prepared the nanoconjugate with curcumin (AgAuNPCS-CUR) of 10.5 nm mean size via chemical activation followed by loading, it demonstrated excellent curcumin loading capacity (221.19 mg/g). Furthermore, AgAuNPCS-CUR exhibited pH driven CUR release up to a maximum of 85% at a pH 6.0. We also observed its significant storage stability up to 30 days at 4 °C. When applied in cancer cells, the nanoconjugate demonstrated higher cytotoxicity to multiple cancer cells (MCF-7, MDAMB231, HeLa and MG 63) than free CUR. However, such cytotoxicity was further enhanced by nearly ~8–10% using the folate receptor (FR)-based targeting. Furthermore, it demonstrated excellent antioxidant, as well as anti-inflammatory activity (NO assay) and such activity was found higher than that of free CUR. Both AgAuNPCS and AgAuNPCS-CUR also exhibited excellent cytocompatibility to human keratinocyte and erythrocyte cells. Hence, from the overall findings, we concluded that our biogenically synthesized AgAuNPCS alloy nanoparticle has, anti-inflammatory, anti-bacterial, anti-oxidant activity as well as potential for targeted therapy (in cancer) via controlled CUR delivery in biomedical applications.

ANTI-DENGUE TYPE 2 VIRUS ACTIVITIES OF ZINC (II) COMPLEX COMPOUNDS WITH 2-(2,4 -DIHYDROXYPHENYL)-3,5,7-TRIHYDROXYCROMEN-4-ONE LIGANDS IN VERO CELLS

Dengue virus (DENV) is a disease that is transmitted through Aedes aegypti and Aedes albopictus mosquitoes, and is spread in tropical and sub-tropical regions. Now, dengue or antiviral vaccines for humans do not yet exist, but there are great efforts to achieve this goal. Complex compounds are reported to fungicidal, bactericidal and antiviral activity. Antiviral activity against DENV is an important alternative to the characterization and development of drugs candidate. The purpose of this study was to study zinc(II) compounds with 2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxycromen-4-one ligand on DENV-2 replication in Vero cells. Vero cell lines (African green monkey kidney) was used in this study, maintained and propagated in Minimum Essential Eagle Medium containing 10% fetal bovine serum at 37°C in 5% CO2. The activity of dengue virus was carried out by enzyme-immunosorbent assay (ELISA) method and CellTiter96® Non-Radioactive Proliferation. The value of activity inhibition (IC50) of complex compounds with variations of mol metal: ligand 1:2, 1:3, and 1:4 against dengue virus type 2 (DENV2) was 2.44 μg/ml, 2.75 μg/ml, respectively and 2.00 μg/ml, also the toxicity value (CC50) of complex compounds with variation mol metal: ligand 1:4 for Vero cells is 3.59 μg/ml. The results of this study were indicate that these properties have been shown to inhibit anti-dengue type 2 virus (DENV-2), but are also toxic in Vero cells. Including previous study about complex compound interaction with dengue virus type 2 activity, Zn(II) more reactive compound then Cu(II), and Co(II). The comparison with Cu(II) complex compound, it has been revealed that Co(II) and Zn(II) is more toxic, was found to be nontoxic to human erythrocyte cells even at a concentration of 500 μg/ml.

Synthesis, characterization and unravelling the molecular interaction of new bioactive 4-hydroxycoumarin derivative with biopolymer: Insights from spectroscopic and theoretical aspect

In the progress of small molecule as drug candidates, 4-hydroxycoumarin based compounds bearing a crucial place as potent antibiotic agents with appreciable safety in drug invention. Being synthetically and easily obtainable, 4-hydroxycoumarin related compounds with planar structure have been promoted predominantly as DNA targeting agent. Nevertheless, here we elucidate the synthesis, characterization and theoretical study of bio-active small molecule 4-hydroxy-3,4′-bichromenyl-2,2′-dione (4HBD). Then we have illuminated the binding interactions of 4HBD with calf thymus DNA (ctDNA), which is particularly designed for biological application. Extensive investigations of the binding of 4HBD with ctDNA are provided by utilizing multi-spectroscopic and molecular docking approaches, including UV–vis absorbance, steady-state, time-resolved fluorescence spectroscopy and circular dichroism study. The calculated binding and quenching constant value from quantitative data analysis of absorption and emission spectroscopy shows that 4HBD binds to the ctDNA groove. Further confirmation of the same is found by comparative displacement and iodide quenching studies. Negative enthalpy, negative free energy and positive entropy change imply a hydrophobic force monitors the association of 4HBD with the biomacromolecule. Interestingly the small molecule (4HBD) shows potential anti-bacterial activity against the model pathogenic gram-negative (Escherichia coli and Pseudomonas aeruginosa) and gram-positive (Bacillus subtilis and Staphylococcus aureus) bacteria. The noncytotoxic nature of the 4HBD is demonstrated in vitro with the help of MTT assay by normal kidney epithelial (NKE), breast cancer cells (MCF-7) and human prostate cancer cell (PC3) lines. Hemolytic assay exhibits insignificant hemolysis of human erythrocyte cells at the minimum inhibitory concentration (MIC) of these tested bacteria. In this regard the present invention of 4-hydroxycoumarin based antimicrobial and noncytotoxic 4HBD molecule holds future promise in the development of new antibiotics.

Immunomodulatory, hemolytic and cytotoxic activity potentials of triterpenoid saponins from eight Cephalaria species

BackgroundSaponins isolated from a number of plants possess a broad spectrum of biological and pharmacological activities by using in vitro and in vivo bioassays. The recent investigations and findings in biological activity studies of saponins have mostly focused on immunomodulatory, hemolytic and cytotoxic properties. Hypothesis/purposeConsidering the great potential of saponins as bioactive agents, we investigated the cytotoxic, hemolytic and immunomodulatory activities of nineteen triterpenoid saponins from the aerial parts of eight Cephalaria species from Turkey. Study designThe isolated oleanane type saponins from Cephalaria species were tested for their hemolytic, cytotoxic and immunomodulatory activities through anin vitro cell based assay systems. MethodsHeLa, A549, and a normal cell line HEK293 were used for testing cytotoxicity using MTT method. Immunomodulatory activity was performed in stimulated whole blood cells by PMA plus ionomycin. Hemolytic activity was assessed on human erythrocytes. ResultsAristatoside C (3) and davisianoside B (16) displayed significant inhibitory effects on cancerous A549 and HeLa cells, and non-cancerous HEK293 cells with IC50 values of 3.52 ± 0.11, 35.69 ± 0.50, 8.96 ± 0.62 µM and 4.08 ± 0.06, 11.74 ± 0.82, 20.43 ± 3.21 µM, respectively. Thirteen saponins out of the nineteen tested increased IL-1β concentrations considerably, while six compounds changed IL-2 or IFN-γ levels slightly. Almost all of the saponins showed noticeable hemolysis in human erythrocyte cells based on the sugar units. ConclusionIn this study, almost all saponins with oleanolic acid as aglycones exhibited significant hemolysis, monodesmosidic saponins with hederagenin as aglycone were the most active compounds against lung cancer cells with greater activity than standard commercial chemotherapy drug doxorubicin and some of the hederagenin type saponins induced remarkable IL-1β secretion.

Amphiphilic Peptide-Based Supramolecular, Noncytotoxic, Stimuli-Responsive Hydrogels with Antibacterial Activity.

A series of peptides with a long fatty acyl chain covalently attached to the C-terminal part and a free amine (-NH2) group at the N-terminus have been designed so that these molecules can be assembled in aqueous medium by using various noncovalent interactions. Five different peptide amphiphiles with a general chemical formula [H2N-(CH2)nCONH-Phe-CONHC12 (n = 1-5, C12 = dodecylamine)] have been synthesized, characterized, and examined for self-assembly and hydrogelation. All of these molecules [P1 (n = 1), P2 (n = 2), P3 (n = 3), P4 (n = 4), P5 (n = 5)] form thermoresponsive hydrogels in water (pH 6.6) with a nanofibrillar network structure. Interestingly, the hydrogels obtained from compounds P4 and P5 exhibit potential antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli). Dose-dependent cell-viability studies using MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by taking human lung carcinoma (A549) cells vividly demonstrates the noncytotoxic nature of these gelator molecules in vitro. Hemolytic studies show nonsignificant or little hemolysis of human erythrocyte cells at the minimum inhibitory concentration (MIC) of these tested bacteria. Interestingly, it has been found that these antibacterial noncytotoxic hydrogels exhibit proteolytic resistance toward the enzymes proteinase K and chymotrypsin. Moreover, the gel strength and gel recovery time have been successfully modulated by varying the alkyl chain length of the N-terminally located amino acid residues. Similarly, the thermal stability of these hydrogels has been nicely tuned by altering the alkyl chain length of the N-terminally located amino acid residues. In the era of antibiotic-resistant strains of bacteria, the discovery of this new class of peptide-based antibacterial, proteolytically stable, injectable, and noncytotoxic soft materials holds future promise for the development of new antibiotics.

Synthesis, β-hematin inhibition studies and antimalarial evaluation of new dehydroxy isoquine derivatives against Plasmodium berghei: A promising antimalarial agent

Many people are affected by Malaria around the world, and the parasite is developing resistance against available drugs. Currently, isoquine and N-tert-butyl isoquine are some of the most promising antimalarial candidates that have already reached Phase I and II clinical trials, respectively. Nevertheless, pharmacodynamic studies have demonstrated that isoquine is highly sensitive to form O-glucuronide metabolite, which may affect its accumulation in tissues. To avoid the O-glucuronide formation and its negative influence in the accumulation process, a series of novel five dehydroxy isoquine derivatives were designed and prepared herein as potential antimalarial agents. By a simple three-step procedure, five dehydroxy isoquines were prepared and subsequently examined on the inhibition of haemozoin formation, the main target of the 4-aminoquinolines. Four derivatives displayed significant inhibitory activities at low IC50 values from 1.66 to 1.86 μM comparable to CQ. On the basis of the results, these four compounds were subsequently tested against Plasmodium berghei ANKA model in mice, showing to be as active as CQ with significant curative responses and parasitemia suppression in mice infected. On the other hand, these four compounds showed an acceptable non specific cytotoxicity on murine peritoneal macrophague and human erythrocyte cells. Thus, the presented data indicate that the dehydroxy isoquines 4b, 4c and 4e constitute promising cost-effective leads for the development of new antiplasmodial targeted at blood-stage malaria parasites.

Chemical constituents and biological activities of Dianthus elegans var. elegans

Chemical investigation of the aerial parts of Dianthus elegans var. elegans afforded two previously undescribed saponins, named dianosides M-N (1–2), together with four oleanane-type triterpenoid glycosides (3–6). Their structures were elucidated as 3-O-α-L-arabinofuranosyl-16α-hydroxyolean-12-ene-23α, 28β-dioic acid (1) and 3-O-α-L-arabinofuranosyl-(1 → 3)-β-D-glucopyranosyl 16α-hydroxyolean-12-ene-23α-oic acid, 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glycosyl ester (2) by chemical and extensive spectroscopic methods including IR, 1D, 2D NMR and HRESIMS. Both of the saponins were evaluated for their cytotoxicities against HEK-293, A-549 and HeLa human cancer cells using the MTT method. All compounds showed no substantial cytotoxic activity against tested cell lines. However, dianosides M-N and the n-butanol fraction exhibited considerable haemolysis in human erythrocyte cells. The immunomodulatory properties of dianosides M-N were also evaluated in activated whole blood cells by PMA plus ionomycin. Dianosides M-N increased IL-1β concentration significantly whereas the n-butanol fraction slightly augmented IL-1β secretion. All compounds did not change IL-2 and IFN-γ levels considerably.