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11, 25 dihydroxy vitamin D3, an active metabolite of vitamin­D3 has been reported to inhibit the growth of number neoplasms such as prostate, breast, colorectal, leukemia and skin cancers. Valproic acid, as a potent histone deacetylase inhibitor, also plays an important role in inhibition of proliferation of tumor cells. However, there are no reports so far on the cooperation between valproic acid and vitamin­ D3 for anti-leukemic effect. The goal of the present research was to evaluate whether low doses of vitamin D3 potentiate the toxicity of valproic acid and whether this toxic action is mediated via apoptotic mechanisms. In this study HL-60 cells were treated either with different concentrations of valproic acid and vitamin­ D3 alone and in combination with each other for 24 hours. Cell survival was determined by MTT assay and then Hoechst staining was used to determine the type of death cell. This present study indicates that vitamin ­D3 potentiates the antitumor effects of valproic acid. Also, the results of staining cells showed that valproic acid and vitamin ­D3 induced apoptosis in HL-60 cells. In total, the new combination of valproic acid and vitamin D3 showed synergistic anti-proliferative effect and induced apoptosis on HL-60 cancer cells.
                                                                       

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New properties of nano-materials have made nanotechnology the leading part of biology and medical sciences. Due to their various biomedical properties, iron-based magnetic nanoparticles (MNPs) have been highly considered by biological researchers. Nowadays, increasing resistance to antibiotics is a major problem in treating clinical infections. Finding new antibacterial agents is therefore essential for the treatment of resistant strains. In this study, the iron oxide MNPs were produced using culture-medium supernatant of a newly isolated bacterium to investigate the inhibitory effects of the NPs on strains with a major role in clinical infections. Biosynthesis of iron oxide MNPs were detected by UV-Vis spectroscopy and the average size of particles was estimated by dynamic light scattering technique. The anti-bacterial activity of these NPs against E. coli and S. aureus was investigated using methods for the calculation of bacterial sensitivity coefficient. In the presence of NPs, the highest sensitivity coefficient value was observed for E. coli in 1xMIC concentration. On the other hand, S. aureus showed the lowest value. The death rate of the two strains in contact with NPs followed the first order kinetic equation and the survival rate decreased with the increase of exposure time. The results of this study as well as the high functionality of iron oxide MNPs, make its application desirable in the prevention and treatment of clinical infections.

 

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The aim of this study was to evaluate the antibacterial activity of the water extracts of three species of Salvia (S. perspolitana, S. palaestina, S. bracteata) on Staphylococcus aureus, Escherichia coli and Pseudomonas aeroginosa. The antibacterial activity of water extracts of the studied species on the bacterial strains was examined using well diffusion method and minimum inhibitory concentration (MIC). Results showed that only S. bracteata formed growth inhibitory zone (9 mm) on Staphylococcus aureus. The extracts of all three plants formed growth inhibitory zone on E.coli and P. aeroginosa. The extract of S. bracteata was more effective than that of the other species. Results for MIC also showed that the extracts of S. perspolitana had the lowest effect on St. aureus and its MIC was observed in a concentration of 1024 µg/ml. The extracts of this species had the inhibitory effect in a concentration of 256 µg/ml. The uppermost inhibitory effect was provided by the extract of S. bracteata, since the minimum inhibitory concentration of this species for S. aureus was equal to 64 µg/ml; and for the other two bacteria, it was equal to 128 µg/ml. The extracts of S. palaestina had the lowest effect on S. aureus and its MIC was observed in a concentration of 1024 µg/ml. The extracts of this species had an MIC equal to 512 µg/ml for the other two bacteria. It was concluded that S. bracreata could be considered a suitable species with anti-bacterial activities in future researches.
 
 
 

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Plants have been used as medicines in the treatment of diseases from the past to present. In this research, the anti-microbial effects of aqueous and methanolic extracts of Erythrostemon gilliesii were studied. For this purpose, fresh flowers were ground and then macerated in methanol 100% and water overnight. After the evaporation of solvents, anti-microbial activities of the concentrated extracts were evaluated by the well-diffusion method on Klebsiella pneumoniae, Pseudomonas aeroginosa, Methicilin resistance, Staphylococcus aureus, Bacillus subtilis and Candida albicans. The results showed that the extracts were effective on different bacteria and yeasts. In order to determine the minimum inhibitory concentration (MIC) and minimum biocidal concentration (MBC), anti-microbial tests were performed in micro-plates. Subsequently, the results indicated that the extracts were stable at different temperatures. The aqueous and methanolic extracts of the flowers of E. gilliesii had exhibited anti-microbial effects against important infectious microbes and could be introduced as an excellent source for anti-microbial agents.
 
 

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Peroxidase catalyzes different oxidation of substrates using hydrogen peroxide, a reactive oxygen specie (ROS). ROS, at low concentrations, act as messenger to regulate intracellular signaling, whereas, at high concentrations, they can overcome the immune system by creating oxidative stress. Some common beverages such as coffee, tea and soft drinks contain high levels of xanthine alkaloids including theophylline and theobromine. In this study, the effect of theophylline and theobromine on peroxidase activity was kinetically studied by measuring the absorption of 4-aminoantipyrine, oxidized in the presence and absence of theophylline and theobromine at 510 nm for 3 minutes. The results showed that theobromine and theophylline acted as inhibitors with IC₅₀ of 0.50 and 0.55 mM, respectively. K_m and V_max values showed that both compounds are non-competitive inhibitors. The values of K_i were calculated as 0.03 and 0.045 mM for theobromine and theophylline, respectively. Lower values of K_i and IC₅₀ for theobromine compared to theophylline indicates that theobromine has a higher inhibition strength and binding tendency to the enzyme-substrate complex. Hence, it is concluded that theobromine has a stronger inhibitory effect on POD activity.
 
 

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It has been found that the second isoform of COX enzyme known as COX-2 plays an important role in inflammation and rheumatoid arthritis and osteoarthritis. Thus, designing COX-2 inhibitors to treat inflammation is among the most important goals of researchers. In this study, the inhibitory effect of 3 new imidazole derivatives on COX-2 was evaluated by in silico approach. Molecular docking was done using Autodock Vina and the best binding mode of inhibitors was used as input of molecular dynamics (MD) simulation. MD was performed using Gromacs software for 120 ns. Then, structural and thermodynamic analyzes (ΔG_binding) and prediction of physicochemical properties were performed. RMSD data showed the compounds reached a good equilibrium and had favorable stability during simulation. Also, the RMSF showed that due to binding of inhibitors, the fluctuations of complexes decreased and the active site residues had the lowest amount. Rg, SASA and DSSP analysis showed that the protein structure did not change significantly. It was also found that Ser530 and Tyr355 residues play a more effective role in hydrogen bond formation. Physicochemical parameters determined the good drug-likeness properties for all compounds. Structural and thermodynamic analyzes (MM-PBSA) and IC₅₀ data indicate the favorable inhibitory effect of compound 5b.