Formulating Ternary Inclusion Complex of Sorafenib Tosylate Using ß-Cyclodextrin and Hydrophilic Polymers: Physicochemical Characterization and In Vitro Assessment.

Sorafenib tosylate (SFNT) is the first-line drug for hepatocellular carcinoma. It exhibits poor solubility leading to low oral bioavailability subsequently requiring intake of large quantities of drug to exhibit desired efficacy. The present investigation was aimed at enhancing the solubility and dissolution rate of SFNT using complexation method. The binary inclusion complex was prepared with ß-cyclodextrin (ß-CD). The molecular docking studies confirmed the hosting of SFNT into hydrophobic cavity of ß-CD, while the phase solubility studies revealed the stoichiometry of complexation with a stability constant of 735.8 M-1. The ternary complex was prepared by combining the SFNT-ß-CD complex with PEG-6000 and HPMC polymers. The results from ATR-IR studies revealed no interaction between drug and excipients. The decreased intensities in ATR-IR peaks and changes in chemical shifts from NMR of SFNT in complexes indicate the possibility of SFNT hosting into the hydrophobic cavity of ß-CD. The disappearance of SFNT peak in DSC and XRD studies revealed the amorphization upon complexation. The ternary complexes exhibited improved in vitro solubility (17.54 µg/mL) compared to pure SFNT (0.19 µg/mL) and binary inclusion complex (1.52 µg/mL). The dissolution profile of ternary inclusion complex in 0.1 N HCl was significantly higher compared to binary inclusion complex and pure drug. In cytotoxicity studies, the ternary inclusion complex has shown remarkable effect than the binary inclusion complex and pure drug on HepG2 cell lines.

Modeling the immune response to Salmonella during typhoid.

Several facets of the host immune response to Salmonella infection have been studied independently at great depths to understand the progress and pathogenesis of Salmonella infection. The circumstances under which a Salmonella-infected individual succumbs to an active disease, evolves as a persister or clears the infection are not understood in detail. We have adopted a system-level approach to develop a continuous-time mechanistic model. We considered key interactions of the immune system state variables with Salmonella in the mesenteric lymph node to determine the final disease outcome deterministically and exclusively temporally. The model accurately predicts the disease outcomes and immune response trajectories operational during typhoid. The results of the simulation confirm the role of anti-inflammatory (M2) macrophages as a site for persistence and relapsing infection. Global sensitivity analysis highlights the importance of both bacterial and host attributes in influencing the disease outcome. It also illustrates the importance of robust phagocytic and anti-microbial potential of M1 macrophages and dendritic cells (DCs) in controlling the disease. Finally, we propose therapeutic strategies for both antibiotic-sensitive and antibiotic-resistant strains (such as IFN-γ therapy, DC transfer and phagocytic potential stimulation). We also suggest prevention strategies such as improving the humoral response and macrophage carrying capacity, which could complement current vaccination schemes for enhanced efficiency.

Curcumin Reduces the Motility of Salmonella enterica Serovar Typhimurium by Binding to the Flagella, Thereby Leading to Flagellar Fragility and Shedding.

UNLABELLED: One of the important virulence properties of the pathogen is its ability to travel to a favorable environment, cross the viscous mucus barrier (intestinal barrier for enteric pathogens), and reach the epithelia to initiate pathogenesis with the help of an appendage, like flagella. Nonetheless, flagella can act as an "Achilles heel," revealing the pathogen's presence to the host through the stimulation of innate and adaptive immune responses. We assessed whether curcumin, a dietary polyphenol, could alter the motility of Salmonella, a foodborne pathogen. It reduced the motility of Salmonella enterica serovar Typhimurium by shortening the length of the flagellar filament (from ∼8 µm to ∼5 µm) and decreasing its density (4 or 5 flagella/bacterium instead of 8 or 9 flagella/bacterium). Upon curcumin treatment, the percentage of flagellated bacteria declined from ∼84% to 59%. However, no change was detected in the expression of the flagellin gene and protein. A fluorescence binding assay demonstrated binding of curcumin to the flagellar filament. This might make the filament fragile, breaking it into smaller fragments. Computational analysis predicted the binding of curcumin, its analogues, and its degraded products to a flagellin molecule at an interface between domains D1 and D2. Site-directed mutagenesis and a fluorescence binding assay confirmed the binding of curcumin to flagellin at residues ASN120, ASP123, ASN163, SER164, ASN173, and GLN175. IMPORTANCE: This work, to our knowledge the first report of its kind, examines how curcumin targets flagellar density and affects the pathogenesis of bacteria. We found that curcumin does not affect any of the flagellar synthesis genes. Instead, it binds to the flagellum and makes it fragile. It increases the torsional stress on the flagellar filament that then breaks, leaving fewer flagella around the bacteria. Flagella, which are crucial ligands for Toll-like receptor 5, are some of the most important appendages of Salmonella Curcumin is an important component of turmeric, which is a major spice used in Asian cooking. The loss of flagella can, in turn, change the pathogenesis of bacteria, making them more robust and fit in the host.

Effectors of Salmonella pathogenicity island 2: An island crucial to the life of Salmonella.

The tug of war between a pathogen and its host has been one of the most amazing stories in the field of microbial pathogenesis for ages. The strongest known species of all living organisms is the Homo sapiens and yet it is incredible how a pathogen of the size of few microns is smart enough to defeat this mightiest group of survivors. It is of utmost interest to understand the mechanisms behind the successful habitation of a pathogen inside the ever-resisting and complicate human body. Numerous examples of diseases caused by such pathogens exist which intrigues us to venture in the world of host-pathogen interactions.