ABSTRACT
Drug-loaded nanoparticles (NPs) allow specific accumulation and controlled release of drugs to infected tissues with minimal cytotoxicity. In this study, gemifloxacin conjugated silver nanoparticles (Gemi-AgNPs) were synthesized, and the amplification of their antibacterial potential against the human pathogen as well as their stability was monitored under physiological conditions. Fourier transform infrared spectroscopy (FTIR) analysis demonstrated the interaction between -NH2 and -OH functional moiety and the metal surface. The morphological analyses via transmission electron microscopy revealed that Gemi-AgNPs has a round oval shape and average particle size of 22.23 ± 2 nm. The antibacterial and antibiofilm activities of these NPS showed that Gemi-AgNPs exhibit excellent antimicrobial and biofilm inhibition activity against human pathogens, namely, Proteus mirabilis (P. mirabilis) and methicillin-resistant Staphylococcus aureus (MRSA). A significant increase in the antibiofilm activity of Gemi-AgNPs was confirmed by crystal violet, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining, and microscopic analysis. Gemi-AgNPs exhibited the ability to inhibit urease with an IC50 value of 57.4 ± 0.72 µg/mL. The changes in the bacterial cell morphology were analyzed via TEM, which revealed that cell membranes disrupted and completely destroyed the cell morphology by the treatment of Gemi-AgNPs.
Subject(s)
Metal Nanoparticles , Methicillin-Resistant Staphylococcus aureus , Anti-Bacterial Agents/chemistry , Gemifloxacin , Humans , Metal Nanoparticles/chemistry , Microbial Sensitivity Tests , Plant Extracts/chemistry , Silver/chemistry , Silver/pharmacology , Spectroscopy, Fourier Transform InfraredABSTRACT
The antipyretic potential of viscosine, a natural product isolated from the medicinal plant Dodonaea viscosa, was investigated using yeast-induced pyrexia rat model, and its structure-activity relationship was investigated through molecular docking analyses with the target enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1). The in vivo antipyretic experiments showed a progressive dose-dependent reduction in body temperatures of the hyperthermic test animals when injected with viscosine. Comparison of docking analyses with target enzymes showed strongest bonding interactions (binding energy -17.34 kcal/mol) of viscosine with the active-site pocket of mPGES-1. These findings suggest that viscosine shows antipyretic properties by reducing the concentration of prostaglandin E2 in brain through its mPGES-1 inhibitory action and make it a potential lead compound for developing effective and safer antipyretic drugs for treating fever and related pathological conditions.
ABSTRACT
Selenium (Se)-fortified broccoli (Brassica oleracea var. italica) has been proposed as a functional food for cancer prevention, based on its high glucosinolate (GSL) content and capacity for Se accumulation. However, as selenate and sulphate share the initial assimilation route, Se fertilization could interfere with sulphur metabolism and plant growth. Consequently, GSL accumulation could be compromised. To evaluate these potentially adverse effects of Se fertilization, we performed a comprehensive study on sand-grown young broccoli plants (weekly selenate applications of 0.8 µmol plant(-1) via the root) and field-grown adult broccoli plants during head formation (single foliar selenate application: 25.3 or 253 µmol plant(-1) ). The results show that under these conditions, Se application does not affect plant growth, contents of cysteine, glutathione, total GSL, glucoraphanin (major aliphatic GSL) or the expression of BoMYB28 (encoding a functionally confirmed master regulator for aliphatic GSL biosynthesis). Conversely, due to the changed expression of sulphate transporters (BoSULTR1;1, 1;2, 2;1, and 2;2), sulphate and total S contents increased in the shoot of young plants while decreasing in the root. We conclude that broccoli can be fertilized with Se without reduction in GSL content, even with Se accumulation exceeding the level recommended for human consumption.