In Vitro Antitumor Activity of Endophytic and Rhizosphere Gram-Positive Bacteria from Ibervillea sonorae (S. Watson) Greene against L5178Y-R Lymphoma Cells

Plant-associated microorganisms represent a potential source of new antitumor compounds. The aim of the present study was to isolate endophytic and rhizosphere Gram-positive bacteria from Ibervillea sonorae and produce extracts with antitumor activity. Methanol and ethyl acetate extracts were obtained from 28 d bacterial fermentation, after which murine L5178Y-R lymphoma cells growth inhibition was evaluated at concentrations ranging from 15.62 µg/mL to 500 µg/mL by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide reduction colorimetric assay. IC50 and the selectivity index (SI) were calculated and compared with healthy control human peripheral blood mononuclear cells (PBMC). Identification of the isolated strains was performed using the 16S ribosomal gene and by MALDI-TOF MS mass spectrometry. The endophytic and rhizosphere bacterial extracts from strains ISE-B22, ISE-B26, ISE-B27, ISS-A01, ISS-A06, and ISS-A16 showed significant (p < 0.05) L5178Y-R cell growth inhibition, compared with an untreated control. The rhizosphere Micromonospora echinospora isolate ISS-A16 showed the highest (90.48%) percentage of lymphoma cells growth inhibition and SI (19.1) for PBMC, whereas the Bacillus subtilis ISE-B26 isolate caused significant (p < 0.01) growth inhibition (84.32%) and a SI of 5.2. Taken together, results of the present study evidenced antitumor effects by I. sonorae endophytic and rhizosphere bacteria culture extracts. Further research will involve the elucidation of the compounds that exert the antitumor activity and their evaluation in pre-clinical studies.

Molecular docking study on columbin isolated from Tinospora cordifolia as a cholinesterase inhibitor

Purpose: To investigate the acetylcholinesterase (AChE) inhibitory potential of columbin and also to assess its binding affinity against AChE protein. Methods: Crystals of columbin were isolated from the ethyl acetate fraction of Tinospora cordifolia using column chromatography and its structure was determined using x-ray crystallography. Ellman colorimetric assay was used to determine the AChE inhibitory effect in vitro while molecular docking was performed using the MOE 2015.010 software. The selected protein data bank (PDB) was modeled using PDB ID: 10CE (pacific electric ray). Results: The crystal and structure refinement data of columbin were: C20H22O6, Orthorhombic, P212121, a = 7.4951(2) Å (α = 90°), b = 11.6451(3) Å (β = 90°), c = 19.5882(5) Å (γ = 90°), V=1709.68(8) Å3, Z = 4, Density (calculated) = 1.392 Mg/m3, absorption coefficient = 0.851 mm-1, goodness-of-fit on F2 =1.091, T = 100(2) K. Columbin demonstrated good AChE inhibitory effect with half-maximal inhibitory concentration (IC50) of 1.2993 ± 0.17 mg/mL. Molecular docking data revealed that it exhibited hydrophobic and hydrogen bonding interactions with the surrounding residues, and this accelerated complexation between the ligands and the active site of the enzyme. Conclusion: Columbin may be useful in the management of neurodegenerative conditions such as Alzheimer’s disease.

Eugenyl-2-Hydroxypropyl Methacrylate-Incorporated Experimental Dental Composite: Degree of Polymerization and In Vitro Cytotoxicity Evaluation

The aim of this study was to evaluate the properties of new dental formulations containing eugenyl-2-hydroxypropyl methacrylate (EgGMA) monomer, as restorative dental material, in terms of their degree of photopolymerization and cytotoxicity. The target model composites (TBEg0, TBEg2.5, and TBEg5) were prepared by mixing 35% organic matrix (TEGDMA/BisGMA (50/50 wt%) of which 0, 2.5, and 5 wt%, respectively, were replaced with EgGMA monomer) with 65% filler (silanized hydroxyapatite (HA)/zinc oxide (ZnO2), 4:3 by weight). The vinylic double-bond conversion (DC) after light-curing was studied using Fourier transform infrared technique whereas cell viability was in vitro tested using primary human gingival fibroblasts cells over 7 days by means of AlamarBlue colorimetric assay. The obtained data were statistically analyzed using ANOVA and Tukey post-hoc tests. The results revealed no significant difference in DC between TBEg2.5 (66.49%) and control (TBEg0; 68.74%), whereas both differ significantly with TBEg5, likely due to the inhibitory effect of eugenol moiety at high concentration. The cell viability test indicated that all the composites are biocompatible. No significant difference was counted between TBEg2.5 and TBEg5, however, both differed significantly from the control (TBEg0). Thus, even though its apparent negative effect on polymerization, EgGMA is potentially safer than bisphenol-derived monomers. Such potential properties may encourage further investigations on term of EgGMA amount optimization, compatibility with other dental resins, and antimicrobial activity.

In Situ Detection of Hydrogen Sulfide in 3D-Cultured, Live Prostate Cancer Cells Using a Paper-Integrated Analytical Device

In this study, a paper-integrated analytical device that combined a paper-based colorimetric assay with a paper-based cell culture platform was developed for the in situ detection of hydrogen sulfide (H2S) in three-dimensional (3D)-cultured, live prostate cancer cells. Two kinds of paper substrates were fabricated using a simple wax-printing methodology to form the cell culture and detection zones, respectively. LNCaP cells were seeded directly on the paper substrate and grown in the paper-integrated analytical device. The cell viability and H2S production of LNCaP cells were assessed using a simple water-soluble tetrazolium salt colorimetric assay and H2S-sensing paper, respectively. The H2S-sensing paper showed good sensitivity (sensitivity: 6.12 blue channel intensity/μM H2S, R2 = 0.994) and a limit of quantification of 1.08 μM. As a result, we successfully measured changes in endogenous H2S production in 3D-cultured, live LNCaP cells within the paper-integrated analytical device while varying the duration of incubation and substrate concentration (L-cysteine). This paper-integrated analytical device can provide a simple and effective method to investigate H2S signaling pathways and drug screening in a 3D culture model.

Colorimetric assay based on iron (III) ion triggering the aggregation of poly(tannic acid) coated Au nanocomposite for protein detection

Herein, several components including mesoporous silica nanoparticles (MSNs) as a reservoir, iron (III) ion to trigger color change, gold nanoparticle (AuNP) as an imaging agent and tannic acid (TA) to...

Benefits of Usage of Immobilized Silver Nanoparticles as Pseudomonas aeruginosa Antibiofilm Factors

The aim of this study was to assess the beneficial inhibitory effect of silver nanoparticles immobilized on SiO2 or TiO2 on biofilm formation by Pseudomonas aeruginosa—one of the most dangerous pathogens isolated from urine and bronchoalveolar lavage fluid of patients hospitalized in intensive care units. Pure and silver doped nanoparticles of SiO2 and TiO2 were prepared using a novel modified sol-gel method. Ten clinical strains of P. aeruginosa and the reference PAO1 strain were used. The minimal inhibitory concentration (MIC) was determined by the broth microdilution method. The minimal biofilm inhibitory concentration (MBIC) and biofilm formation were assessed by colorimetric assay. Bacterial enumeration was used to assess the viability of bacteria in the biofilm. Silver nanoparticles immobilized on the SiO2 and TiO2 indicated high antibacterial efficacy against P. aeruginosa planktonic and biofilm cultures. TiO2/Ag0 showed a better bactericidal effect than SiO2/Ag0. Our results indicate that the inorganic compounds (SiO2, TiO2) after nanotechnological modification may be successfully used as antibacterial agents against multidrug-resistant P. aeruginosa strains.