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Pure, Ni-doped, and Ni/Co–co-doped magnetite nanoparticles at different Co concentrations (1%, 2%, and 3%) and a constant concentration value of Ni were fabricated by the hydrothermal method. The nanoparticles were investigated by X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, a vibrating sample magnetometer, Fourier-transform infrared spectroscopy, and UV–visible spectroscopy. The X-ray diffraction showed that pure Fe3O4, Ni-Fe3O4, and 3%Ni-3%Co-Fe3O4 have cubic inverse-spinel structures, while the samples co-doped with Ni:Co (1%, 2%) revealed orthorhombic structure. The doping resulted in a reduction of the average crystalline size values from 47.755 to 9.927 nm. The morphology of all the samples was spherical, with a mean diameter in the range of 75–120 nm. The presence of Ni, Co, Fe, and O in a lattice of Ni/Co–co-doped Fe3O4 was confirmed by energy dispersive X-ray spectroscopy (EDS) analysis. The FTIR spectrum displayed two bands at 400–50 cm−1 and 520–480 cm−1, which were present in all samples. These vibration bands correlate to the ferrite spinel lattice vibration. The UV–visible absorption spectra of doped and co-doped samples showed a blue shift in the absorption edge as compared to undoped (pure) magnetite nanoparticles. The energy gap increased with doping and co-doping, from 1.5 to 2.6 eV. The measurement of the magnetic characteristics of pure Fe3O4 (Ms = 82.7 emu g−1, Mr = 8.4 emu g−1, and HC = 60 Oe). While in the case of Ni-doped and Ni/Co–co-doped samples, all the extracted magnetic parameters declined in comparison to pure Fe3O4. Furthermore, the hemolysis assay of all samples with concentrations ranging between 100 and 800 µg/ml was used in this study. After completing the study of hemolytic activity for all samples, the results revealed that the activity was concentration-dependent. [ABSTRACT FROM AUTHOR]

Objective: In this work, in order to optimize the structure of histidine-containing antifungal peptides with a "linear" type of amphipathicity (LTA), we carried out the synthesis and comparative screening of the antifungal activity of a series of histidine-containing SAMPs (F2H7, F2H10, F2H13, F2H16, H10, H10F2) with a "linear" type of amphipathicity that we constructed de novo. We also aimed to study their hemolytic properties, to assess their therapeutic index, and to compare the obtained results with similar data for the antifungal histidine-rich 12-mer peptide P113 (AKRHHGYKRKFH), a drug candidate known as PAC-113, one of the shortest and most active analogues of the natural antifungal histidine-rich peptide Hst 5. Methods: Peptides were synthesized by a solid phase method using a Fmoc-based strategy. To determine the antifungal activity of the peptides, we used the opportunistic fungus strain Candida albicans EMTK 34. The number of microorganisms (titer) in the suspension was determined by optical density at a wavelength of 595 nm. To determine the antifungal activity of the peptides, cell cultures were co-incubated with the studied peptides in 96-well plates. The cells were incubated with the drug for 24 h at 37°C. To assess the antifungal activity of the studied peptides, their minimum inhibitory concentrations (MIC50) were determined, i.e. such peptide concentration at which the growth of microorganisms was suppressed by 50%. To assess the toxicity of the peptides, their hemolytic activity was determined, which was tested against fresh human erythrocytes using a photometric method. To assess the selectivity of the action of peptides, the values of the minimum hemolytic concentration (MHC) of the peptides were determined and the values of their therapeutic index (TI) were calculated as the ratio of the minimum hemolytic concentration (MHC) to the MIC50 value. Results and Discussion: It was shown that the antifungal activity of the studied SAMPLTA increases with an increase in the number of histidine residues in their composition, reaching the maximum value for the histidine-containing peptide F2H16 (MIC50 = 1.0 µM). It has been shown that as the chain length of peptides increases, their hemolytic toxicity also increases. The TI values for these peptides were 233, 247, 79, and 60, respectively. It has been shown that, against C. albicans, histidine-containing SAMP-LTA derivatives with phenylalanine residues at the N-terminus of the peptide (F2H10) are less effective compared to similar peptides (H10F2) containing phenylalanine residues at the C-terminus. Among the studied peptides, the most active was the H10 peptide (MIC50 = 0.7 µM), which does not contain phenylalanine residues, which in its antifungal activity is not only more effective than all other histidine-containing peptides, including the F2H16 peptide with 16 histidine residues, but also 4– 5 times more effective than the antifungal peptide P113 (MIC50 = 3.4 µM), a short active fragment of natural Hst 5, well known from the literature. Among all the studied peptides, H10 and P113 have minimal (almost zero) values of hemolytic activity. However, due to its higher antifungal activity, the selectivity of the H10 peptide (TI > 1400) exceeds the selectivity of the P113 peptide (TI > 340) by more than 4 times. Conclusions: Thus, peptide H10, due to its high antifungal activity, low hemolytic toxicity and, accordingly, high therapeutic significance, can be used as a promising antifungal peptide drug. [ABSTRACT FROM AUTHOR]

The present study focused on evaluating the antibacterial properties, radical scavenging, and photocatalytic activities of Centaurea behen-mediated silver nanoparticles (Cb-AgNPs). The formation of Cb-AgNPs was approved by UV–Vis spectrometry, Fourier-transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction. The results showed that the obtained AgNPs have a maximum absorbance peak at 450 nm with spherical morphology and an average size of 13.03 ± 5.8 nm. The catalytic activity of the Cb-AgNPs was investigated using Safranin O (SO) solution as a cationic dye model. The Cb-AgNPs performed well in the removal of SO. The coupled physical adsorption/photocatalysis reaction calculated about 68% and 98% degradation of SO dye under solar irradiation. The Cb-AgNPs inhibited the growth of gram-negative or positive bacteria strains and had excellent DPPH radicals scavenging ability (100% in a concentration of 200 µg/ml) as well as a good effect on reducing coagulation time (at concentrations of 200 and 500 µg/mL reduced clotting time up to 3 min). Considering the fact that green synthesized Cb-AgNPs have antioxidant and antibacterial properties and have a good ability to reduce coagulation time, they can be used in wound dressings. As well as these NPs with good photocatalytic activity can be a suitable option for degrading organic pollutants. [ABSTRACT FROM AUTHOR]

Lipophilicity is a physicochemical parameter well known as a decisive factor for predicting the successful development of a drug. Thus, a balance between potency and physicochemical properties during medicinal chemistry optimization is needed. In this study, the lipophilicity of isoindole-1,3(2H)-dione derivatives designed as phosphodiesterase 10A (PDE10A) inhibitors was determined by chromatographic [reversed-phase thin-layer chromatography (RP-TLC) and ultra-performance liquid chromatography/mass spectrometry (UPLC/MS)] and in silico methods. To assess the correlation between the obtained lipophilicity parameters, principal component analysis (PCA) was performed. logP values obtained by chromatographic (logPRP-TLC and logPUPLC/MS) and in silico methods were compared using the PCA method. The results of PCA revealed that logPUPLC/MS and in silico clogP provided by the ChemDraw program were highly correlated. Compounds' drug likeness was screened, and the pharmacokinetic properties were predicted. All the investigated compounds displayed drug-likeness properties, and they met the criteria of Lipinski's rule of five, which predicted the oral bioavailability of drug candidates. Analysis of the influence of physicochemical properties on the biological activity showed that the compounds with increased potency on PDE10A had significantly higher topological polar surface area (TPSA) values. The blood‒brain barrier permeability and the hemolytic activity of model compound 18 were examined. The model compound 18 displayed no toxicity effect on erythrocytes in the hemolytic assay and good parallel artificial membrane permeability. The results showed that phthalimide compounds with benzimidazole moiety are a source of compound-targeted inhibition of PDE10A with balanced physicochemical and drug-likeness properties. [ABSTRACT FROM AUTHOR]

The present investigation evaluated the toxic effect and bioactive potential of marine macro algae Caulerpa scalpelliformis. The crude methanolic extract was fractionated in diethylaminoethyl (DEAE) cellulose column chromatography using NaCl (0.1–10 M). The fractions were dialyzed and freeze-dried. The active fractions (F1, F2, and F3) were obtained using TLC chromatography. The crude methanolic extract and fractions showed strong hemolytic activity of 129.55, 73.73, 43.47, and 37.73 HT/mg in chicken blood, respectively, the human blood group (AB and O) showed considerable hemolytic activity of 73.73, 43.47, and 37.73 HT/mg, respectively, and the fraction (F3) had no activity. The acute toxic effect of the crude methanolic extract and fractions (F1, F2, and F3) showed the lethal dose (LD50) at 176, 121.5, 138, and 152 mg/kg body weight. The crude methanolic extract and fractions indicated strong analgesic activity at the ratio of 0.26, 0.37, 0.11, and 0.10 using the tail flick test in mice at 12.5 mg/kg body weight. These results suggest that the methanolic extract and its fractions from C. scalpelliformis may be potential pharmacological agents. [ABSTRACT FROM AUTHOR]

The selection of effective antibiotics is becoming increasingly limited due to the emergence of bacterial resistance. Designing and developing nanoscale antibacterials is a strategy for effectively addressing the antibiotic crisis. In this work, AgNPs@AMP nanoparticles were synthesized to take advantage of the synergistic antibacterial activity of the (LLRR)3 antimicrobial peptide (AMP) and silver nanoparticles (AgNPs). Based on morphological structure characterization and biocompatibility analysis, the inhibitory properties of AgNPs@AMP on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated. The results demonstrated that AMP and AgNPs were physically bound to form AgNPs@AMP nanoparticles, which had better solution stability, improved nanomaterial properties, and overcame the hemolytic activity of AMP and the cytotoxicity of AgNPs. The inhibitory activity of AgNPs@AMP against E. coli and S. aureus was significantly higher than that of AMP and AgNPs. It was capable of disrupting the morphology and internal structure of cells, damaging the cell membrane, and inhibiting the activity of enzymes related to the material-energy metabolism of the tricarboxylic acid cycle. Compared to AMP and AgNPs, AgNPs@AMP were found to effectively inhibit the infection of mouse wounds and promote their healing. Therefore, AMP-modified AgNPs can enhance their biocompatibility and antibacterial activity, and they can be further developed as a potential antimicrobial agent. [ABSTRACT FROM AUTHOR]

The combination scattering spectroscopy method investigated strains of the epidermal staphylococcus with hemolytic activity and without hemolytic activity. The main spectral differences of the studied groups are established. Complex analysis was used to estimate hemolytic activity using combined scattering (SR) spectroscopy and mathematical approaches. [ABSTRACT FROM AUTHOR]

Magnetic Beta zeolite was synthesized under hydrothermal conditions by doping aluminosilicate gel with magnetite nanoparticles. The strength of Fe3O4 nanoparticle fixation in the composite synthesized under hydrothermal conditions was evaluated in comparison with the samples prepared by coprecipitation. The efficiency of the adsorption and desorption of 5-fluorouracil antitumor drug on samples of Beta zeolite and Beta–Fe3O4 magnetic nanocomposite was studied. The kinetics of the 5-fluorouracil release from the composite was described using the Higuchi model. The physicochemical properties of the samples were characterized. The hemolytic activity of the initial Beta zeolite and magnetic composite based on it toward human blood cells and the ability for biodegradation in a synthetic biological medium were studied with the aim of ensuring safe use of the materials as drug carriers. The results of the study allow conclusions on the possibility of using the magnetic nanocomposites in vivo. [ABSTRACT FROM AUTHOR]

The study investigates the physicochemical, porous/textural, and adsorptive properties, as well as the biological activity of BEA, RHO, PAU, and FAU(Y) synthetic zeolites. The adsorption capacity of the zeolites for oxytocin, lysozyme, and albumin—markers of low- and medium-molecular-weight pathological proteins—was measured. The concentration-dependent effects of the zeolites on the viability of human endothelial cells (Ea.hy926) were evaluated. At concentrations of 2.5 to 10 mg/mL, the Y zeolite was found to exhibit no pronounced cytotoxicity. In the presence of the BEA, the cell viability decreased to 80% even at 2.5 mg/mL. The RHO and PAU were shown to have the highest cytotoxicity and significantly inhibit the growth of human cells (down to 23–35%). The study demonstrated that only BEA and Y, among the synthetic zeolites tested, have good biomedical potential due to their high adsorption capacity, low hemolytic activity, and low cytotoxicity. [ABSTRACT FROM AUTHOR]

The ubiquity of pathogenic E. coli isolate possessing antimicrobial resistance was investigated in seafood samples procured from major seafood supply chain markets established for export and domestic consumption along Tuticorin coast. Out of 63 seafood samples examined, 29 (46%) were found to be contaminated by pathogenic E. coli harbouring one or more genes of virulent potential. Based on virulome profiling, 9.55% of isolates belonged to enterotoxigenic E. coli (ETEC), 8.08% to enteroaggregative E. coli (EAEC), 7.35% to enterohemorrhagic E. coli (EHEC), 2.20% to enteropathogenic E. coli (EPEC), and 2.20% to uropathogenic E. coli (UPEC). All the 34 virulome positive and haemolytic pathogenic E. coli have been serogrouped as O119, O76, O18, O134, O149, O120, O114, O25, O55, O127, O6, O78, O83, O17 and clinically significant O111, O121, O84, O26, O103, and O104 (non-O157 STEC) serotypes in this study. Multi-drug resistance (MDR) (≥ 3 antibiotic classes/sub-classes) was exhibited in 38.23% of the pathogenic E. coli, and 17.64% were extensive drug resistant (XDR). Extended spectrum of β-lactamase (ESBL) genotypes were confirmed in 32.35% isolates and 20.63% isolates harboured ampC gene. One sample (Penaeus semisulcatus) collected from landing centre (L1) harboured all ESBL genotypes blaCTX-M, blaSHV, blaTEM, and ampC genes. Hierarchical clustering of isolates revealed the separation of ESBL isolates into three clusters and non-ESBL isolates into three clusters based on phenotypic and genotypic variations. Based on dendrogram analysis on antibiotic efficacy pattern, carbapenems and β-lactam inhibitor drugs are the best available treatment for ESBL and non-ESBL infections. This study emphasizes the significance of comprehensive surveillance of pathogenic E. coli serogroups that pose serious threat to public health and compliance of AMR antimicrobial resistant genes in seafood that hinder seafood supply chain. [ABSTRACT FROM AUTHOR]

The global increase in antimicrobial drug resistance has dramatically reduced the effectiveness of traditional antibiotics. Structurally diverse antibiotics are urgently needed to combat multiple-resistant bacterial infections. As part of innate immunity, antimicrobial peptides have been recognized as the most promising candidates because they comprise diverse sequences and mechanisms of action and have a relatively low induction rate of resistance. However, because of their low chemical stability, susceptibility to proteases, and high hemolytic effect, their usage is subject to many restrictions. Chemical modifications such as D-amino acid substitution, cyclization, and unnatural amino acid modification have been used to improve the stability of antimicrobial peptides for decades. Among them, a side-chain covalent bridge modification, the so-called stapled peptide, has attracted much attention. The stapled side-chain bridge stabilizes the secondary structure, induces protease resistance, and increases cell penetration and biological activity. Recent progress in computer-aided drug design and artificial intelligence methods has also been used in the design of stapled antimicrobial peptides and has led to the successful discovery of many prospective peptides. This article reviews the possible structure–activity relationships of stapled antimicrobial peptides, the physicochemical properties that influence their activity (such as net charge, hydrophobicity, helicity, and dipole moment), and computer-aided methods of stapled peptide design. Antimicrobial peptides under clinical trial: Pexiganan (NCT01594762, 2012–05–07). Omiganan (NCT02576847, 2015–10–13). [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) are believed to have health-promoting properties to the host and can be used in therapeutics interventions; intriguingly, they have the property to produce bio-preservatives substances. Therefore, this study aimed to mine probiotics and evaluate their safety, functional properties, and cholesterol-lowering capability. Seven potential probiotic strains were compared from 56 LAB strains isolated from traditional Chinese fermented milk. The results showed that all tested strains are tolerant to gastric acidity (45.5–83.26) and bile salts (11.92–92.91%) and have antibacterial activity against Staphylococcus aureus ATCC25923 and Escherichia coli ATCC25922. Likewise, it lowered the cholesterol levels in vitro by live cells (26.57–45.76%) and dead cells (29.53–50.97%) with remarkable aggregation ability (13.8–43.71%). Antioxidant properties and produce short chain fatty acids (SCFAs) were strain-dependent features. Upon assessment of the safety, Enterococcus faecium NWAFU-BIO-AS14 exhibited virulence factors genes (VFs) of (mur-2ed, odc, and tet(K)) and + hemolysis activity. While Enterococcus faecium NWAFU-BIO-A-B24 and Limosilactobacillus fermentum NWAFU-BIO-B-S6 have VFs of (odc, vanC2, and ant(6)-Ia). Limosilactobacillus fermentum NWAFU-BIO-D-B2 has only (odc). Thus, they are not considered as safe probiotics. In contrast, Lactiplantibacillus plantarum NWAFU-BIO-BS29, Companilactobacillus crustorum NWAFU-BIO-AS16, and Lactobacillus gallinarum NWAFU-BIO-D-S7 are the safest and best strains, respectively, due to the absence of 16 VFs and their sensitivity to antibiotics such as kanamycin, erythromycin, tetracycline, gentamycin, vancomycin, streptomycin, chloramphenicol, and ampicillin. Accordingly, these strains have a high potentiality to be used as starter cultures or safely applied as perfect probiotics in functionals food and feed. [ABSTRACT FROM AUTHOR]

Blooms of Phaeocystis globosa have been reported accountable for massive fish mortality worldwide. The toxigenic mechanisms of P. globosa, however, remain largely unclear due to the multiple structures and/or synergistic or antagonistic effects of hemolytic compounds. External stressors could lead to the regulation of photoprotective or antioxidative defense system, as well as the potential hemolytic activity. Therefore, the light-induced photosynthetic system, including the accessory photosynthetic growth, the relative electron transfer rate (ETR), photosynthetic efficiency (Fv/Fm), quantum yield of photosystem II (Yield), together with the hemolytic activity of P. globosa were investigated under variable environmental conditions in the present study. Results confirmed that hemolytic activity of P. globosa was initiated by the light, but inhibited by low temperature (16 °C), high light intensity (>100 µmol/(m2·s)), and iron-limited conditions. Interestingly, the hemolytic activity was not impacted by photosynthetic electron inhibitors (Diuron, atrazine, paraquat, and dibromothymoquinone), which significantly inhibited the photosynthetic activity of P. globosa. The correlated response of hemolytic and photosynthetic activity of P. globosa under those environmental factors suggested that the hemolytic compounds of P. globosa would be involved in the photosynthetic process but not in the electron transfer chain of P. globosa. [ABSTRACT FROM AUTHOR]

The antimicrobial and hemolytic activities of synthetic antimicrobial peptides (SAMP) XFXXFFXXFF (X5F5) with a 'circular' (helical or cyclic) type of amphipathicity (CTA) has been studied. The studied peptides contain cationic amino acid residues of arginine, lysine, or histidine (X = Arg, Lys, or His). These peptides have been shown to exhibit more than eight times higher antibacterial and ~2 times lower antifungal activity as compared with SAMP XXXXXXXXXFF (X9F2) with a 'linear' type of amphipathicity (LTA). It has been found that the peptides that contain the cationic arginine residues have the highest antibacterial activity, and the histidine-containing peptides have the lowest antibacterial activity. On the contrary, the histidine-containing peptides have the highest fungicidal activity against fungal cultures of Candida albicans. The X5F5 peptides, regardless of their cationic composition, exhibit increased hemolytic activity (20–60% hemolysis at 500-µM peptide concentration in the medium) compared to the X9F2 peptides with a linear type of amphipathicity (no more than 4% hemolysis at the same peptide concentrations). Despite their relatively high hemolytic activity, the average bacterial selectivity of the X5F5 peptides remains quite high; their average geometric therapeutic index (AG TI) is ~10, except for histidine-containing peptides H5F5 (AG TI = 0.5). At the same time, the selectivity of the histidine-containing peptide H5F5 to fungal cells (TI = 2.7) is five times higher than that to bacterial cells but 200 times lower than the fungicidal selectivity of the histidine-containing peptide H9F2 with a 'linear' amphipathic type (TI = 571.4). The arginine- and lysine-containing peptides with a circular type of amphipathicity (R5F5 and K5F5) and histidine-containing peptides with a linear type of amphipathicity (Н9F2) can be recommended to create antibacterial and antifungal drugs, respectively. [ABSTRACT FROM AUTHOR]

Naturally occurring frog skin peptides are one of largest sources of antimicrobial peptides that have many advantages including high potency, broad spectrum of targets and low susceptibility to multiple drug-resistance bacteria. However, they also have disadvantages such as hemolytic activity, low stability and high production costs. For these reasons, various strategies have been applied to overcome these drawbacks restricting their use in clinical trials. Previously reported brevinin-1GHa (BR-1GHa) is a 24 amino acid long antimicrobial peptide isolated from Hylarana guentheri with hemolytic activity. To enhance the antimicrobial activity of this peptide and to reduce its hemolytic activity, we designed five new temporin like analogues and examined their bioactivities. Temporins are another class of frog skin peptides without hemolytic activity and shorter than brevinins. When the antimicrobial activities of new analogues were examined against a panel of microorganisms, BR-1GHa-3, in which two alanine residues in the truncated version of BR-1GHa were replaced with leucine, exhibited significantly improved antimicrobial activity against Gram-positive bacterial strains (e.g., S. aureus ATCC 29213 and E. casseliflavus ATCC 700327) with lower hemolytic activity compared to the BR-1GHa peptide. Furthermore, BR-1GHa-4 analogue, in which Gly3 was replaced with Pro, did not show any hemolytic activity except for highest (128 µM) concentration tested and have a strong antimicrobial effect on Gram-positive bacteria (e.g., E. faecalis ATCC 51299 and B. cereus ATCC 13061). [ABSTRACT FROM AUTHOR]

Camellia sinensis (green tea leaves) which acts as a reducing agent was used for the reduction of graphene oxide (GO) to obtain reduced graphene oxide (RGO). Anionic surfactant SDS was used to enhance the stability of synthesized reduced graphene oxide nanoparticles. Characterized reduced graphene oxide nanoparticle grain size was calculated to be 3.92 nm from the X-ray diffraction method, whereas zeta potential was measured − 35.23 ± 5.45 mV at room temperature. Antioxidant and cell cytotoxicity against A-549 lung carcinoma cells were also studied. Phytochemical content of Camellia sinensis imparts feasible DPPH activity of 85.98 ± 2.49% against RGO, whereas ABTS scavenging activity was found to be 88.87 ± 1.74% followed by measurement of the total phenolic content of 842 ± 13.33 µg/gm. RGO at concentration 400 µg/ml showed an optimum level of hemolysis at pH 7.4 (4.92 ± 1.20%) than pH 5.6 (11.15 ± 0.03%). Cytotoxicity activity studied by MTT assay of RGO on A-549 lung carcinomas cells was compared with drug doxorubicin. The bandgap energy of RGO was calculated to be 3.97 eV from absorption data, hence reveals the generation of oxidative stress in the A-549 lung cancer cell line. Thus, the surfactant and phytochemicals found in Camellia sinensis enhanced the stability of RGO, thereby providing enough energy to destabilize the target cells without affecting healthy cells, hence suggests its role in therapeutics application. [ABSTRACT FROM AUTHOR]

Ancylostoma ceylanicum is a common zoonotic nematode that inhabits the small intestine of humans, dogs, and cats. Saposin-like proteins (SLPs) have hemolytic and antibacterial activities and could be used as diagnostic or vaccine candidates. To explore the biological functions of Ancylostoma ceylanicum SLP (Ace-SLP-1), cDNA-encoding Ace-SLP-1 mature peptide was cloned into prokaryotic expression vector pET-28a and transformed into Escherichia coli BL21 (DE3) to induce expression. After incubation of canine red blood cell suspension with different concentrations of recombinant Ace-SLP-1, the supernatant was separated to measure OD value and calculate the hemolysis rate. The different concentrations of recombinant protein were co-cultured with E. coli and Enterococcus faecalis, and colony-forming units (CFU) were determined by the plate counting method. Peripheral blood mononuclear cells (PBMCs) from healthy dogs were incubated with different concentrations of recombinant Ace-SLP-1, and the cytokine expression was evaluated by relative quantitative PCR. Our results showed that the hemolytic activity of Ace-SLP-1 increased with the increase in protein concentration from 25 to 100 μg/mL. The recombinant protein had no antibacterial activity against the two kinds of bacteria but could stimulate the secretion of cytokines (IL-4, IL-10, IL-12, and IL-13) in canine PBMCs. These data suggest that Ace-SLP-1 is involved in hookworm blood-feeding and survival and has good immunogenicity, supporting its potential as a diagnostic and vaccine target molecule. [ABSTRACT FROM AUTHOR]

Some new derivatives based on 2,6-diisobornylphenol and containing amine moieties of the pinane structure at the para-position relative to the phenolic hydroxy group were synthesized. The antioxidant properties of the obtained compounds were estimated using various in vitro models. The introduction of diamine moiety into a starting molecule led to a significant increase in the radical scavenging activity and the ability to chelate Fe2+ ions. [ABSTRACT FROM AUTHOR]

The silver oxide nanoparticle was successfully synthesized using floral waste by simple one pot, cost effective method. The complete formation of silver oxide nanoparticles was characterized by UV-spec, FT-IR, powder XRD. The morphological structure of synthesized Ag2O NPs was confirmation by FE-SEM. The biofilm inhibition and biofilm metabolic assay results were confirmed that the synthesized Ag2O NPs very effective against biofilm formation. In addition, exopolysaccharide and hydrophobicity degradation assays were supported to biofilm inhibition at 250 µg/mL concentration. In addition, the architectural and extracellular damages of K. pneumoniae were proved by CLSM and SEM. Finally, the reported hemolytic activity effect of synthesized Ag2O NPs shown at very low compared with CLSI guidelines, this might be due to the presence of the polyphenols of floral waste extract. Conclusively, the synthesized Ag2O NPs was eco-friendly nature and promising anti-biofilm agent against K. pneumoniae [ABSTRACT FROM AUTHOR]

Synthesis of heterocyclic compounds encompassing multiple functionalities and their biological screening is the most adapted strategy in the world for pharmacological evaluation of future drug candidates. The undertaken research was initiated by esterification 2-(1H-indol-3-yl)acetic acid (1) with catalytic amount of sulfuric acid in ethanol to ethyl 2-(1H-indol-3-yl)acetate (2), which was then reacted with hydrazine hydrate in methanol to achieve 2-(1H-indol-3-yl)acetohydrazide (3). The corresponding hydrazide 3 was reacted with a variety of arylsulfonyl chlorides (4a-j) in sodium carbonate solution (pH 9-10) to afford N-[2-(1H-indol-3-yl)acetyl]arylsulfonohydrazides (5a-j). The structural characterization of synthesized compounds was done by 1H-NMR, 13C-NMR, IR and EI-MS spectral data. Moreover, these derivatives were evaluated for anti-bacterial potentials along with their % age hemolytic and enzyme inhibitory activities. It was found that compounds 5a, 5b, 5d and 5h revealed good anti-bacterial against all the bacterial strains used in this study, while 5d, 5g and 5h exhibited good enzyme inhibition potentials against BChE which were close to the reference standard eserine. These compounds also revealed low values of % hemolytic activity. Results of computational docking were also found in agreement with the enzyme inhibition data. [ABSTRACT FROM AUTHOR]

Activated carbon has been reported to act as a catalyst for condensation reactions between glucose molecules. The present study describes the use of activated carbon as a new catalyst for the synthesis of branched cyclodextrins (CDs). Two main methods have been used to synthesize branched CDs: a method using an enzymatic condensation or transfer reaction, and a method using a chemical reaction. However, these methods have problems such as a limited number of the types of branched CDs that can be synthesized that depend on the characteristics of the enzyme, the long reaction time required (several days or more), difficulty in synthesizing branched CD with a high degree of substitution (DS), the need for large quantities of environmentally harmful solvents, and a complicated and costly reaction. Using activated carbon as a catalyst, branched CDs with a high DS could be synthesized within a relatively short time (a few hours), regardless of the type of saccharide in the branched portion. Furthermore, since the reaction was conducted under solvent-free conditions using activated carbon, the amount of solvent used in the production of branched CD could be reduced. The branched β-CDs prepared using the activated carbon catalyst showed high solubility, high solubilization capacity, and low hemolytic activity, similar to the 2-hydroxypropyl-β-CD used for pharmaceuticals. These results indicate that activated carbon is an industrially and environmentally useful catalyst for branched CD syntheses. [ABSTRACT FROM AUTHOR]

We have studied the antimicrobial and hemolytic activity of synthetic antimicrobial peptides (SAMPs), i.e., Arg9Phe2 (P1-Arg), Lys9Phe2 (P2-Lys), and His9Phe2 (P3-His), which have a "linear" type of amphipathicity and contain the cationic amino acid residues of arginine, lysine, or histidine. In this study, we have used various pathogenic microorganism strains of gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica), gram-positive bacteria (Staphylococcus aureus), and the conditionally pathogenic yeast fungus (Candida albicans). It has been shown that the replacement of the arginine residues by lysine or histidine residues in the tested SAMPs significantly degrades their antibacterial properties in the series: P1-Arg > P2-Lys P3-His. The cationic analog of SAMP, P1-Arg, has the highest antibacterial activity (MIC50 = 43–76 μM), while peptide P3-His does not exhibit this activity (MIC50 > 100 μM). The P1-Arg and P2-Lys peptides were 6–10 times more active against the opportunistic fungus C. albicans (MIC50 6.7 and 10.9 μM, respectively) and the P3-His peptide has 100-times increased antimycotic activity (MIC50 0.6 μM) compared with their effect on bacterial cells. All of the tested peptides with the linear type of amphipathicity and low hydrophobicity, i.e., P1-Arg, P2-Lys, and P3-His, that contain only two Phe residues regardless of the presence of cationic amino acids (Arg, Lys, or His) exhibit a relatively low hemolytic activity (not more than 4% hemolysis at 1000 μM peptide concentration). Thus, considering the same synthesis efficiency (56–63%) and approximately the same low toxicity of the tested SAMPs with a linear type of amphipathicity, it is recommended to use those that contain the cationic arginine or histidine residues to create antibacterial or antifungal peptide agents, respectively. [ABSTRACT FROM AUTHOR]

The indenture of the green approach in synthesizing metal oxide nanoparticles has resulted in greater stoutness and favorable dimensions of nanoparticles since they are synthesized using a single step process. In this study, using algae extract of Tetraselmis indica as precursor, Zinc acetate was reduced to obtain ZnO nanoparticles using green synthesis approach. Synthesized ZnO nanoparticles (ZnONPs) were characterized using UV spectrometer (UV-vis spec), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX), and Fourier transform infrared (FTIR) spectroscopy. The biomedical application of ZnONPs was further studied in understanding with antibacterial, antioxidant, and hemolytic assays. UV visible spectrophotometry at wavelength of 372 nm confirmed the synthesis of ZnONPs. The results from X-ray diffractometer (XRD) studies approve the crystalline spherical structure of nanoparticle and the mean size of the ZnONPs was calculated to be ± 27 nm by using Scherrer formula. Fourier transform infrared spectroscopy (FTIR) analysis distinguished the presence of the various functional groups at different peak range, and the absorption peak at 470 cm−1 exhibits the presence of ZnO nanoparticle. Scanning electron microscopy (SEM) images identified the zinc oxide nanoparticles ranging in size from 20 to 40 nm. Results of EDAX (energy dispersive analysis of X-ray) represented the elemental configuration of the zinc oxide (ZnO) nanoparticles. The biosynthesized ZnONPs had potential antibacterial property against pathogenic strains of bacteria which was confirmed by performing "Agar well diffusion method." Out of selected bacterial strains, the gram-positive organism S. aureus with the maximum zone (18.4 ± 0.5 mm) and the gram-negative organism E. coli with the minimum zone (12.3 ± 0.3 mm) were the most sensitive and resistant organisms. The hemolysis assay performed with horse blood exhibited the less toxicity of the nanoparticles with the erythrocytes. The free radical scavenging activity of the ZnO nanoparticles was studied using DPPH assay and it was observed to have high reduction property in high concentration (100 mg ml−1) which is directly proportional. Therefore, the findings observed not only indicate the possible use of ZnO nanoparticles but also provide an alternative source, i.e., algae, for the cost-effective synthesis of ZnO nanoparticles by means of green synthesis, demonstrating their potential applications in the field of biomedical, textile, cosmetic, and food packaging applications. [ABSTRACT FROM AUTHOR]

Development of highly improved or reinforced Graphene oxide nanosheets were synthesized by converting it into a whole green GO nanofiber material and by infusing the aqueous seed extracts of Sesamum indicum (SI), along with the fiber generation process of GO. The synthesized GO nanofibers (NF) and GO/SI NF were characterized for structural, morphological, elemental and functional group analysis. The antimicrobial and biocompatible nature of GO/SI NF was evaluated in comparison with GO NF. The results showed the non-toxic nature of both the nanofibers (GO NF and GO/SI NF) on gram-negative bacteria (Klebsiella oxytoca) and gram-positive bacteria (Staphylococcus aureus). Both the nanofibers were hemo-/biocompatible toward human red blood cells and human epithelial cell lines (TH 1); however, the hemo-/biocompatibility was further increased after the addition of SI into GO NF, and therefore, GO/SI NF can be a potent green nanofiber material for the biomedical applications. [ABSTRACT FROM AUTHOR]

Four benzamide derivatives (5a, 5b, 8a, 8b) bearing heterocyclic furan and piperazine ring have been synthesized and evaluated for enzyme inhibition and hemolytic activity. Initial 4-(chloromethyl)benzoyl chloride (1) and 3-(chloromethyl)benzoyl chloride (6) were stirred with benzyl amine (2a) and cyclohexyl amine (2b), respectively, in aqueous medium at pH 9 – 10 maintained by aqueous sodium carbonate. The resulting benzamides (3a, 3b, 7a, 7b) were refluxed with 1-(2-furoyl)piperazine (4) in the presence of K2CO3 and CH3CN to acquire target compounds (5a, 5b, 8a, 8b). The spectroscopic techniques including 13C NMR, 1H NMR, IR and EI-MS corroborated the proposed molecular structures of final compounds. Among these, two compounds (5b, 8b) proved to be considerable inhibitors of butyrylcholinesterase enzyme. Study of the hemolytic activity potential revealed low toxicity level of compound 5b. [ABSTRACT FROM AUTHOR]

C60 fullerenes have proved their therapeutic effects and efficacy by the results of countless experiments. For further usage of these nanoparticles, the systematic toxicological investigations are required. Blood compatibility should be studied for C60 fullerenes due to the potential blood contact. Currently, available data is not systematic and has not provided insights into possible side effects of C60 fullerenes on blood components. In this study, water-soluble pristine C60 fullerenes were tested in vitro to assess their biocompatibility in rabbit. The blood compatibility has been evaluated looking at the impact of C60 fullerenes on erythrocyte integrity, platelet aggregation, and some blood factors involved in coagulation. Our results revealed that C60 fullerenes cannot elicit hemolysis at studied concentrations and did not show any effect on coagulation process. C60 fullerenes in concentration-dependent manner increased ADP-dependent platelet aggregation and changed the key kinetic parameters of these processes. C60 fullerenes inhibited thrombin amidolytic activity but did not affect the activities of other studied coagulation factors. The prothrombotic property of C60 fullerenes could be the potential risk factor that leads to enhancement of vascular thrombosis. The ability of fullerene to inhibit thrombin activity is important for the pharmacological use of these carbon nanoparticles as anticoagulant agents. [ABSTRACT FROM AUTHOR]

The work is devoted to studying the influence of synthesis conditions on the hydrothermal crystallization of zeolite nanoparticles with a Beta structure and studying their properties. The experimentally optimal conditions for the preparation of Beta zeolite nanoparticles of various sizes are determined by varying the temperature and time parameters of the process. The synthesized samples are characterized by X-ray diffraction analysis, scanning electron microscopy, and low-temperature nitrogen adsorption. The sorption ability of zeolite samples of different sizes with respect to inorganic cations (for example, lead ions) and organic molecules (for example, thiamine hydrochloride), as well as their hemolytic activity in relation to human red blood cells, is studied. It is found that the sorption ability of the samples decreases with increasing particle size. For the first time, the results of the dependence of the hemolytic activity of nanoparticles on their size are obtained. Based on the results obtained, conclusions are drawn about the possibility of using nanozeolites in medicine. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO NPs) have emerged as a good anticancer and antibacterial activity, which are involved with their strong ability to trigger excess reactive oxygen species (ROS) production, release zinc ions and induce cell apoptosis. The present study aims to synthesize ZnO nanoparticles from zinc acetate (chemical co-precipitation method), and green synthesis (Sesbania grandiflora leaf extract) method evaluated their antibacterial and hemolytic activities. The prepared ZnO NPs were characterized by various techniques such as UV-visible absorption spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscope (HR-TEM) and Fourier transform infrared spectroscopy (FTIR). FE-SEM study reveals that the morphology of the crystal is spherical and flakes-shaped and the estimated sizes were 70–150 nm. The analysis of EDAX has shown the presence of zinc and oxygen. The HR-TEM analysis of zinc oxide nanoparticles with different magnifications consists of spherical shape and it is well distributed without any aggregation. The FTIR study has shown the presence of Zn–O bond, C–O bond, C–H bond, OH groups, =C–H and C=O bond. Powder XRD studies indicated the formation of pure wurtzite hexagonal structure with particle sizes of 32 and 45 nm. UV-visible spectrophotometer showed absorbance peak in range of 375–378 nm. The antibacterial activity of the ZnO nanoparticles showed antibacterial activities against both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonasaeruginosa) microorganisms by disc diffusion method and also determined that the cytotoxicity was assessed by hemolytic activity. Our results have revealed that zinc oxide nanoparticles could elicit hemolysis and severely impact the proliferation of lymphocytes at all investigated concentrations (25, 50, 75, 100 μg/mL). [ABSTRACT FROM AUTHOR]

Marine organisms and their associated microorganisms contain a wide range of novel bioactive natural compounds that are widely used in the field of anti-microbial, anti-tumor, and anti-cancer drug discovery research. Hence, much focus has been given to isolate the bioactive compounds from marine sources. Sea anemone, one such marine resource, is used in recent years to extract bioactive compounds. It belongs to the phylum Cnidaria. The distinguishing feature of cnidarians is nematocysts, specialized venomous organs that the animals use mainly for capturing prey and protecting themselves from predators. There are over one thousand species of sea anemone reported worldwide and of which 40 species belonging to 17 families are found in India. Out of 40 species, 24 are marine, 13 are estuarine and 3 are common to both habitats. We present an overview of some of the potential marine bioactive compounds from a curative point of view isolated from sea anemone. Among the Order Actiniaria, Family Actiniidae exhibits by far the highest number of species yielding promising compounds, followed by Family Stichodactylidae. Haemolytic activity has been the major area of interest in the screening of actinarian compounds. [ABSTRACT FROM AUTHOR]

The antimicrobial and hemolytic activities of R9F2С2 (P1ss), (KFF)3KС2 (P2ss), and (RAhaR)4AhaβAС2 (P3ss) (where Aha is 6-aminohexanoic acid and βA is beta-alanine) synthetic antimicrobial peptides (SAMP) with different amphipathic properties and containing the cysteine residues with free sulfhydryl groups were studied. The introduction of cysteine residues into the composition of SAMP was shown to increase their antimicrobial activity 3–7 times, while their hemolytic activity increased 2–12 times in relation to human erythrocytes for different peptides in different ways, which determined their different selectivity. The P1ss peptide with a linear type of amphipathicity showed the highest antimicrobial activity and high selectivity against the fungus Candida albicans and bacterium Staphylococcus aureus (MIC 0.5 μM; TI 52 μM). The P1ss peptide possessed not only greater antimicrobial activity against pathogenic fungus C. albicans in comparison to the P2ss peptide (MIC 3.9 μM) with the classical helical amphipathicity, but also more than three times lower hemolytic activity (MHC 26 and 8 μM, respectively). Therefore, TI for the P2ss peptide (TI 2.1) turned out to be more than 20 times lower than that for the P1ss peptide. Thus, the P1ss peptide is the most promising antimicrobial preparation among the studied SAMP. [ABSTRACT FROM AUTHOR]

Natural jute fiber can be used as a good source of biocomposite for application in biomedical field. Here microcrystalline jute cellulose (MCJC) particles were first prepared by the hydrolysis of bleached jute pulp with H2SO4 and the effect of acid strength was examined. A maximum crystallinity index of 89% was found for MCJC particles prepared by hydrolysis with 30% H2SO4. The surface of MCJC particles possessing the highest crystallinity index was then modified with various synthetic polymers like poly(2-hydroxyethyl methacrylate) (PHEMA), poly(glycidyl methacrylate) (PGMA), and poly(lauryl methacrylate-methyl methacrylate) P(LMA-MMA) via in situ seeded free radical polymerization. The values of crystallinity index decreased to 74, 66 and 76% in MCJC/PHEMA, MCJC/PGMA and MCJC/P(LMA-MMA) composite particles respectively. The adsorption magnitudes of biomolecules on composites were relatively high compared to those on MCJC particles. Lower hemolytic activities (< 1.0%) confirmed the biocompatible nature of composite particles, a requisite property for any composite desired for efficient biorelated applications. [ABSTRACT FROM AUTHOR]

Worldwide, antibacterial resistance has increased dramatically in the past years. Antimicrobial peptides are a group of immune-related peptides/proteins that protect the host from microbial infections, and were identified broad activity against pathogenic microorganism and not easy to generate insecticide resistance. It appears that antimicrobial peptides possess great potential for developing into a new ideal antimicrobial drug. Bombyx mori Gloverin A2 (BMGlvA2) was an antimicrobial peptide of B. mori, however, directly extracted and purified BMGlvA2 was difficult and uneconomic. In this study, BMGlvA2 gene was successfully cloned from B. mori and heterologous expression with vector pET28a (+) by E. coli Rosetta (DE3). The selected E. coli Rosetta (DE3)-BMGlvA2 strain yielded 241 µg/ml recombinant BMGlvA2 (rBMGlvA2) protein after 9 h inducted by 1.0 mM IPTG (isopropyl-β-d-thiogalactoside) at 28 °C. rBMGlvA2 protein was identified by western blot and MALDI-TOF. MALDI-TOF analysis indicated that its amino acid sequence is consistent with naturally secreted proteins by B. mori (sequence coverage 78.71%). Importantly, inhibition zone assay shown that rBMGlvA2 efficiently inhibited the growth of several Gram-negative bacteria, including E. coli DH5α, E. coli Rosetta, E. coli K88, S. typhimurium and several Gram-positive bacteria, including S. aureus and B. subtilis. Furthermore, The MIC of rBMGlvA2 showed antimicrobial activity against E. coli DH5α. Meaningfully, rBMGlvA2 did not display hemolytic activity against pig red blood cells. In conclusions, the antimicrobial activity and hemolytic of rBMGlvA2 suggested that it could be one of potential alternatives to conventional antibiotics against Gram-negative and Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

The glycerol monolaurate (GML) is a surfactant used in the food industry and has potent antimicrobial activity against many microorganisms; however, the use of GML is not expanded due its high melting point and poor solubility in water. The aim of the study was to produce, characterize, and evaluate in vitro the cytotoxicity of GML and GML nanocapsules. The GML nanocapsules were produced and characterized by a mean diameter, zeta potential, and polydispersity index. The cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) release, thiobarbituric acid reactive substances (TBARS), and hemolytic activity. The genotoxicity was verified by comet assay. The physicochemical parameters showed a mean diameter of 192.5 ± 2.8 nm, a polydispersity index of 0.061 ± 0.018, and a zeta potential about − 21.9 ± 1 mV. The viability test demonstrated the protector effect of GML nanocapsule compared with the GML on peripheral blood mononuclear cells (PBMC) and VERO cells (isolated from kidney epithelial cells extracted from an African green monkey). A reduction in lipid peroxidation and lactate dehydrogenase release in GML nanocapsule–exposed cells compared with GML treated cells was observed. The damage on erythrocytes was addressed in treatment with GML, while the treatment with GML nanocapsules did not cause an effect. Moreover, the comet assay showed that the GML-caused genotoxicity and GML nanocapsules do not demonstrate damage. The study showed the reduction of toxicity of GML nanocapsules by many methods used in antimicrobial therapy. [ABSTRACT FROM AUTHOR]

The aim of the present study was to synthesize safe and economical cobalt nanoparticles by using secondary metabolites from Celosia argentea plant extract and to further evaluate their antioxidant, antibacterial and hemolytic activities. Catalytic activity of these green synthesized nanoparticles was evaluated for the degradation studies of cationic methylene dye in the presence and absence of anionic surfactant (sodium dodecyl sulfate). Different parameters affecting the dye degradation procedure were investigated and optimized. Fourier transform infrared spectroscopy studies identified the functional groups present in bioactive compounds which were responsible for the reduction and stabilization of the cobalt nanoparticles. The green synthesized cobalt nanoparticles were characterized by X-ray diffraction, scanning electron microscope and energy-dispersive X-ray spectroscopy. Cobalt nanoparticles (CoNPs) exhibited good antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl radical, and its scavenging power was found to be increased with increasing concentration. CoNPs also displayed good antimicrobial activity against tested microbes. Moreover, they showed very less toxicity and efficient activity toward dye degradation. [ABSTRACT FROM AUTHOR]

Interactions of tributyltin (TBTA) and triphenyltin (TPhTA) 2-[4 (dimethylamino)phenylazo]benzoates, showing promising cytostatic activity against tumor cells, with erythrocytes and with erythrocyte membranes and model lipid membranes have been investigated. The effect of TBTA and TPhTA on the erythrocyte and its model membrane was investigated by the microscopic and spectroscopic methods. Interaction of tin complexes with the membrane was determined on the basis of hemolytic activity, changes induced in the shape of erythrocytes, as well as physicochemical parameters of the membrane, such as fluidity. The studies showed that the compounds in higher concentration induce hemolysis; however, TBTA is more toxic than TPhTA. Both TBTA and TPhTA induce morphological alterations in red blood cells-from discocytes to spherocytes and from discocytes to echinocytes. The results suggest that investigated complexes interact with the erythrocyte membrane, change its properties, and probably locate themselves in the hydrophilic part of the membrane, which agrees with conclusions drawn from investigation of erythrocyte membranes and model lipid membranes with the help of fluorescence and infrared spectroscopy. [ABSTRACT FROM AUTHOR]

Two species of jellyfish, Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye, have occurred offcoastal areas of the northeastern China Sea, Yellow Sea, and Bohai Sea in recent years. They influence marine ecosystem safety and fishery production, and also pose a risk to human health. The current study examined the hemolytic and cytotoxic activities of crude venoms extracted from the nematocysts of C. nozakii and N. nomurai. The results showed that there were more nematocysts on tentacles from C. nozakii than on tentacles of the same length from N. nomurai. The protein concentration per nematocyst extracted from N. nomurai was higher than that from C. nozakii. Both nematocyst venoms showed dose- and timedependent hemolytic activity on erythrocytes from chicken, pigeon, and sheep, with sheep erythrocytes being the most sensitive, with EC50 values of 69.69 and 63.62 μg/mL over a 30-min exposure with N. nomurai and C. nozakii nematocyst venoms, respectively. A cytotoxic assay of both jellyfish venoms on A431 human epidermal carcinoma cells resulted in IC50 values of 68.6 and 40.9 μg/mL after 24-h incubation, respectively, with venom from C. nozakii showing stronger cytotoxic activity than that from N. nomurai. The results of current study indicate that nematocyst venom from C. nozakii had stronger hemolytic and cytotoxic activities than that from N. nomurai and, thus, C. nozakii might be more harmful to the health of humans and other species than are N. nomurai when they appear in coastal waters. [ABSTRACT FROM AUTHOR]

Bacillus sp. strain MA04 a plant growth-promoting rhizobacteria (PGPR) showed hemolytic activity on blood agar plates, and the supernatant from liquid culture in nutrient broth at 24 h exhibited emulsification activity, suggesting the production of biosurfactants. In antagonist assays, the supernatant showed antifungal activity against phytopathogenic fungi such as Penicillium expansum, Fusarium stilboides, Sclerotium rolfsii y Rhizoctonia solani, finding a reduction of mycelial growth of all fungi tested, ranging from 35 to 69%, this activity was increased with time of culture, accomplishing percentages of inhibition up to 85% with supernatants obtained at 72 h. Then, the crude biorsurfactant (CB) was isolated from the supernatant in order to assay its antagonistic effect on the phytopathogens previously tested, finding an increase in the inhibition up to 97% at 500 mg/L of CB. The composition of CB was determined by infrared spectroscopy, identifying various functional groups related to lipopeptides, which were purified by high-performance liquid chromatography and analyzed by MALDI-TOF/TOF-MS, revealing a mixture of fengycins A and B whose high antifungal activity is been widely recognized. These results show that PGPR Bacillus sp. MA04 could also contribute to plant health status through the production of metabolites with antimicrobial activity. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate probiotic properties of antimicrobial Lactobacillus plantarum VJC38 in vitro. L. plantarum VJC38 was isolated from the crop of broiler chicken and characterized using dnaK gene sequence. The inhibitory activities of L. plantarum VJC38 against bacterial and fungal pathogens were evaluated. Antifungal compounds secreted by the strain VJC38 were identified using Gas Chromatography and Mass Spectrometry (GC-MS). The strain was evaluated for its tolerance to low pH, resistance to bile salts, auto-aggregation, co-aggregation with pathogenic Escherichia coli, cell surface hydrophobicity, cholesterol lowering activity, β-galactosidase production, adhesion ability to Caco-2 cells, mucin degradation, hemolytic activity and biogenic amine production. Phylogenetic analysis of dnaK gene of bacterial strain VJC38 showed 99% sequence similarity to Lactobacillus plantarum var. plantarum. It showed effective inhibition against food spoiling and pathogenic organisms like Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, Aspergillus niger, Penicillium expansum and Eurotium species. The antifungal compound phenol- 2,4-bis(1,1-dimethylethyl) (PD) was identified in the culture filtrate of L. plantarum VJC38 and reported to have inhibition against Aspergillus species. L. plantarum VJC38 exhibited tolerance to low pH, resistance to bile salts, bile salt hydrolase activity, auto-aggregation (87.5%), co-aggregation with Escherichia coli (55.7%), cholesterol lowering activity (64%), β-galactosidase production (1206 MU), adherence to Caco-2 cells (11%), negative for mucin degradation, hemolytic activity and biogenic amine production. L. plantarum VJC38 could be a good candidate for further investigation in vivo to elucidate its health benefits and to evaluate its technological properties as a bio-protective strain. [ABSTRACT FROM AUTHOR]

Candida albicans is one of the most common pathogens of opportunistic infections and has a lot of hydrolytic enzymes important for pathogenesis of candidiasis, such as protease, phospholipase, and others. The genome of C. albicans contains seven phospholipase genes C (pla, plb1 plb2, plc1, plc2, plc3, and pld1), only four of which are well studied and well described (plb1 plb2, plc, and pld1); the role of others in the pathogenesis of candidiasis remains unclear. In this paper, the effect of iron on the hemolytic activity (HA) and gene expression of phospholipase C—plc, plb1, and plb2 by C. albicans in a nutrient broth and serum is studied. It is established that the addition of iron in the broth and serum induces a hemolytic activity and gene expression plb1 and plb2 of phospholipase C by C. albicans. In the serum, the highest dependence on the iron concentration ([Fe2+]) was observed for the expression of the plb2 gene and plc phospholipase C. Comparative characteristics of the presented results showed that in the serum, the expression level of the phospholipase C genes is lower than in the Saburo broth. The highest iron dependence is observed for the plb2 gene. It can be demonstrated according to the research that the nature of the hemolytic activity of C. albicans is due to the expression of the phospholipase gene plb2; the value of other genes in the expression of HA substantially depends on the medium of cultivation. Thus, any changes of iron homeostasis in the direction of an overloaded iron induce the activity of phospholipase C PLB2 and PLС by Candida spp. making iron from hemoglobin available for uptake, which is important for the pathogenesis of candidiasis. [ABSTRACT FROM AUTHOR]

By acid-catalyzed reaction of substituted isatins with Girard's reagent T, new water-soluble isatin-3-acylhydrazones were obtained with high yields. Their antimicrobial activity was evaluated. Selective activity against Gram-positive bacteria ( S. aureus 209p and B. cereus 8035) and yeast-like fungus Candida albicans 855- 653 along with low hematoxicity was established. Graphical abstract: [ABSTRACT FROM AUTHOR]

Actinoporins constitute a unique class of pore-forming toxins found in sea anemones that are able to bind and oligomerize in membranes, leading to cell swelling, impairment of ionic gradients and, eventually, to cell death. In this review we summarize the knowledge generated from the combination of biochemical and biophysical approaches to the study of sticholysins I and II (Sts, StI/II), two actinoporins largely characterized by the Center of Protein Studies at the University of Havana during the last 20 years. These approaches include strategies for understanding the toxin structure-function relationship, the protein-membrane association process leading to pore formation and the interaction of toxin with cells. The rational combination of experimental and theoretical tools have allowed unraveling, at least partially, of the complex mechanisms involved in toxin-membrane interaction and of the molecular pathways triggered upon this interaction. The study of actinoporins is important not only to gain an understanding of their biological roles in anemone venom but also to investigate basic molecular mechanisms of protein insertion into membranes, protein-lipid interactions and the modulation of protein conformation by lipid binding. A deeper knowledge of the basic molecular mechanisms involved in Sts-cell interaction, as described in this review, will support the current investigations conducted by our group which focus on the design of immunotoxins against tumor cells and antigen-releasing systems to cell cytosol as Sts-based vaccine platforms. [ABSTRACT FROM AUTHOR]

Compounds [Cu (benz)(Hbenz)] ( 1) and [Cu(ppa)(HO)] (2), where benz = benzoate and ppa = 3-pyridinepropionic acid, were synthesized and studied for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the inhibition of enzymes such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), lipoxygenase (LOX), urease, chymotrypsin and α-glucosidase. The synthesized compounds were also studied by hemolytic method for their cytotoxicity and found to be low-toxicity substances. For AChE inhibition, compound 2 showed IC = 31.22 ± 0.45 μM, as compared to compound 1with IC = 36.52 ± 0.44 μM. Both compounds showed comparably low activity against BChE and were also active against urease, but compound 1 exhibited selective anti-urease activity. The anti-α-glucosidase activity of both compounds was comparable with that of standard drug used. [ABSTRACT FROM AUTHOR]

Vegetative insecticidal proteins produced by some Bacillus thuringiensis strains are specifically toxic to different agricultural pests such as the polyphagous Spodoptera and several other Lepidopteran insects, but one of the major problems found in the use of these biopesticides was the lack of an easy and credible method of quantification of such secreted toxins. Heterologous expression of B. thuringiensis Vip3Aa16 toxin was performed in Escherichia coli then the protein was purified by chromatography. Using blood agar as well as blood agar overlay (zymogram assay), we reported, for the first time, the capacity of Vip3Aa16 to induce hemolysis. The hemolytic activity of this protein was shown to be relatively stable after treatment at 40 °C and at a range of pH between 6.5 and 9. Moreover, a linear relationship was shown between hemolysis levels and Vip3Aa16 concentrations. The model established in the present study could quantify Vip3A toxin as a function of hemolytic activity and the assay proposed showed to be a simple and low-cost method to readily assess Vip3A toxins in liquid cultures and facilitate the use of this kind of bioinsecticides in pest management programs. [ABSTRACT FROM AUTHOR]

In the present study, the effects of an environmental friendly natural reagent coumarin, on the growth and potential virulence factors, as well as its ability to interfere the infection of Vibrio splendidus (Vs), were determined. Coumarin showed no effects on the maximal growth of Vs, and biofilm formation of Vs, while it significantly decreased protease activity and hemolytic activity by 43 and 80%, respectively. Correspondingly, coumarin exhibited an obviously protective effect, with a relative percent survival of 60% upon Apostichopus japonicus from infection by Vs. To preliminarily investigate the mechanism underlining the inhibitory effects, regulation of genes Vsm and Vsh respectively related to protease activity and hemolytic activity by supernatant and supernatant extract containing acyl-homoserine lactones (AHLs) and coumarin was determined. Cell-free supernatant from higher density and its ethyl acetate extract containing AHL signal molecules could respectively upregulate the mRNA level of Vsm by 17.4- and 2.3-fold and Vsh by 7.2- and 5.0-fold, when Vs was at lower cell density. However, coumarin could reduce the stimulatory effects of both the supernatant and its ethyl acetate extract. Combining all the results in our study, it was suggested that coumarin could be considered as an alternative to be used for controlling infection of Vs, downregulating the expression of potential virulence factors through interfering the AHL-mediated pathways. [ABSTRACT FROM AUTHOR]

Diabetes is embracing the human population in logarithmic fashion both in developed as well as developing countries. Aldose reductase is one of the important enzymes of polyol pathway of sugar metabolism in humans. Aldose reductase inhibition has been identified as one of the important target for developing novel antidiabetic agents. In this report, we present an effective synthesis of 7-(substituted phenyl) chromeno-pyrano [2,3-d]pyrimidine-6,8,10-( 7H,9H,11H)-trione derivatives and demonstrate their aldose reductase inhibition potential in order to identify novel schemes for finding putative aldose reductase inhibitors. The antioxidant activity of all the synthesized compounds with negligible toxicity demonstrates the biological efficacy of the synthesized compounds. The in silico molecular docking and structural analysis of docked poses conducted in the current investigation sheds light on the structural rationale of the observed aldose reductase inhibition by all the newly synthesized compounds. [ABSTRACT FROM AUTHOR]

Traditional fermented sap beverages from two provinces of Mexico were studied for the isolation of pathogenic bacteria from these beverages. Eight strains of hemolytic Gram positive bacteria, identified as Bacillus pumilus ( B. pumilus), were isolated. They showed different antibiotic resistance profiles and tolerances to the simulated gastrointestinal conditions. All the B. pumilus isolated were resistant to at least one antibiotic tested. Regarding the simulated gastrointestinal conditions, strains S1 and S3 were able to tolerate all the conditions. Hemolytic activity has been associated with a health risk and is often considered as a virulence determinant associated with pathogenicity. Therefore, the hemolytic activity along with the ability to tolerate gastrointestinal conditions and the resistance to antibiotics exhibited by B. pumilus strains S1 and S3 could be associated with a health risk for pulque consumers. [ABSTRACT FROM AUTHOR]

The antimicrobial activity and cytotoxicity of novel 1,3-bis(alkyl)-6-methyluracil derivatives containing 1,2,3- and 1,2,4-triazolium fragments in alkyl chains have been studied. The compounds have been tested for the antimicrobial activity toward some gram-positive and gram-negative bacteria and fungal cultures. The cytotoxic action has been estimated toward mammalian cells. It has been found that the basic structural factor that affects the antimicrobial activity is the nature of alkyl radicals at triazole fragments. [ABSTRACT FROM AUTHOR]

In the present investigation, probiotic potential (antagonistic activity, enzyme production, hemolytic activity, biosafety, antibiotic sensitivity and bile tolerance level) of Bacillus subtilis LR1 was evaluated. Bacteriocin produced by the bacterial strain B. subtilis LR1 isolated from the gastrointestinal tract of Labeo rohita was purified and characterized. The molecular weight of the purified bacteriocin was ~50 kDa in 12 % Native PAGE and showed inhibitory activity against four fish pathogens such as Bacillus mycoides, Aeromonas salmonicida, Pseudomonas fluorescens and Aeromonas hydrophila. The purified bacteriocin was maximally active at temperature 40 °C and pH 7.0, while none of the tested surfactants affect the bacteriocin activity. Extracellular enzyme activity of the selected bacterial strain was also evaluated. Amylase activity was estimated to be highest (38.23 ± 1.15 µg of maltose liberated mg protein ml of culture filtrate) followed by cellulase and protease activity. The selected bacterium was sensitive to most of the antibiotics used in this experiment, can tolerate 0.25 % bile salt and non-hemolytic in nature. Finally, the efficiency of the proposed probiotic candidate was evaluated in in vivo condition. It was detected that the bacterial strain can effectively reduce bacterial pathogenicity in Indian major carps. [ABSTRACT FROM AUTHOR]

We evaluated the hemolytic activity of 41 commercially available triterpenoid saponins and sapogenins derived from three types of structural skeletons. Structure-activity relationships were established by comparing the structural characteristics of both the aglycone and sugar moieties among the tested compounds. The majority of oleanane-type sapogenins had stronger hemolytic effects than those of the ursane and dammarane types. The presence of polar regions on sapogenins, such as a carboxyl (COOH) at position 28, an α-hydroxyl (α-OH) at position 16, and/or a β-hydroxyl (β-OH) at position 2, significantly enhanced hemolysis. Meanwhile, the introduction of an α-OH at position 2 or a methyl hydroxyl (CHOH) at positions 23 or 24 was closely associated with reduced activity. Our findings suggest that not only the complexity of sugar moieties but also the types and stereochemical configurations of functional groups at different positions, as well as the skeleton types, are important structural features affecting hemolytic potential. Our results provide a baseline in terms of the toxicity of saponins and sapogenins to erythrocytes, which holds promise for drug development. [ABSTRACT FROM AUTHOR]

Chromogranin A (CGA)-N46, a derived peptide of human chromogranin A, has antifungal activity. To further research the active domain of CGA-N46, a series of derivatives were designed by successively deleting amino acid from both terminus of CGA-N46, and the amino acid sequence of each derivative was analyzed by bioinformatic software. Based on the predicted physicochemical properties of the peptides, including half-life time in mammalian reticulocytes (in vitro), yeast (in vivo) and E. coli (in vivo), instability index, aliphatic index and grand average of hydropathicity (GRAVY), the secondary structure, net charge, the distribution of hydrophobic residues and hydrophilic residues, the final derivatives CGA-N15, CGA-N16, CGA-N12 and CGA-N8 were synthesized by solid-phase peptide synthesis. The results of bioinformatic analysis showed that CGA-N46 and its derivatives were α-helix, neutral or weak positive charge, hydrophilic, and CGA-N12 and CGA-N8 were more stable than the other derivatives. The results of circular dichroism confirmed that CGA-N46 and its derived peptides displayed α-helical structure in an aqueous solution and 30 mM sodium dodecylsulfate, but α-helical contents decreased in hydrophobic lipid vesicles. CGA-N15, CGA-N16, CGA-N12 and CGA-N8 had higher antifungal activities than their mother peptide CGA-N46. Among of the derived peptides, CGA-N12 showed the least hemolytic activity. In conclusion, we have successfully identified the active domain of CGA-N46 with strong antifungal activity and weak hemolytic activity, which provides the possibility to develop a new class of antibiotics. [ABSTRACT FROM AUTHOR]