Search results for "Mace"

Synthesis and cytotoxic activity of new artemisinin hybrid molecules against human leukemia cells

2017

A series of new artemisinin-derived hybrids which incorporate cholic acid moieties have been synthesized and evaluated for their antileukemic activity against sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 cells. The new hybrids 20-28 showed IC50 values in the range of 0.019µM-0.192µM against CCRF-CEM cells and between 0.345µM and 7.159µM against CEM/ADR5000 cells. Amide hybrid 25 proved the most active compound against both CCRF-CEM and CEM/ADR5000 cells with IC50 value of 0.019±0.001µM and 0.345±0.031µM, respectively. A relatively low cross resistance to hybrids 20-28 in the range of 5.7-fold to 46.1-fold was measured. CEM/ADR5000 cells showed higher resistance than CCRF-CEM to al…

A putative antiviral role of plant cytidine deaminases

2014

[Background]: A mechanism of innate antiviral immunity operating against viruses infecting mammalian cells has been described during the last decade. Host cytidine deaminases (e.g., APOBEC3 proteins) edit viral genomes, giving rise to hypermutated nonfunctional viruses; consequently, viral fitness is reduced through lethal mutagenesis. By contrast, sub-lethal hypermutagenesis may contribute to virus evolvability by increasing population diversity. To prevent genome editing, some viruses have evolved proteins that mediate APOBEC3 degradation. The model plant Arabidopsis thaliana genome encodes nine cytidine deaminases ( AtCDAs), raising the question of whether deamination is an antiviral mec…

S2k guidelines for the use of topical preparations on the skin

2018

The present guidelines are aimed at dermatology residents and board-certified dermatologists as well as policymakers and insurance companies. Developed by dermatologists in collaboration with pharmacists using a formal consensus process (S2k), they include general aspects with respect to pharmacokinetics and regulatory terminology. Recommendations are provided on the various indications for extemporaneous preparations and their quality assurance. The importance of pharmaceutical vehicles and problems associated with substituting one vehicle for another are discussed. The guidelines include criteria for choosing a suitable pharmaceutical vehicle and for specific aspects in terms of treatment…

Effect of Calcium Ions on the Disintegration of Enteric-Coated Solid Dosage Forms.

2015

To investigate the effect of calcium ions on the disintegration of enteric-coated dosage forms, disintegration testing was performed on enteric-coated aspirin tablets in the presence and absence of calcium in the test media. The results show that the presence of calcium ions retards the disintegration of enteric-coated dosage forms. This finding, which has not been reported in scientific literature, sheds light on the importance of conducting well-designed detailed investigations into the potential of calcium from dietary sources, calcium supplements, antacids, and/or phosphate binders affecting the absorption of drugs formulated into enteric-coated dosage forms. Moreover, it shows the nece…

2021

The biological activities of shancigusin C (1) and bletistrin G (2), natural products isolated from orchids, are reported along with their first total syntheses. The total synthesis of shancigusin C (1) was conducted by employing the Perkin reaction to forge the central stilbene core, whereas the synthesis of bletistrin G (2) was achieved by the Wittig olefination followed by several regioselective aromatic substitution reactions. Both syntheses were completed by applying only renewable starting materials according to the principles of xylochemistry. The cytotoxic properties of shancigusin C (1) and bletistrin G (2) against tumor cells suggest suitability as a starting point for further str…

Cutting-edge progress and challenges in stimuli responsive hydrogel microenvironment for success in tissue engineering today.

2020

The field of tissue engineering has numerous potential for modified therapeutic results and has been inspired by enhancements in bioengineering at the recent decades. The techniques of regenerating tissues and assembling functional paradigms that are responsible for repairing, maintaining, and revitalizing lost organs and tissues have affected the entire spectrum of health care studies. Strategies to combine bioactive molecules, biocompatible materials and cells are important for progressing the renewal of damaged tissues. Hydrogels have been utilized as one of the most popular cell substrate/carrier in tissue engineering since previous decades, respect to their potential to retain a 3D str…

2020

The term “amyloid” refers to proteinaceous deposits of peptides that might be generated from larger precursor proteins e.g., by proteolysis. Common to these peptides is a stable cross-β dominated secondary structure which allows self-assembly, leading to insoluble oligomers and lastly to fibrils. These highly ordered protein aggregates have been, for a long time, mainly associated with human neurodegenerative diseases such as Alzheimer’s disease (Amyloid-β peptides). However, they also exert physiological functions such as in release of deposited hormones in human beings. In the light of the rediscovery of our microbial commensals as important companions in health and disease, the fact that…

Mechanistic understanding of underperforming enteric coated products: Opportunities to add clinical relevance to the dissolution test.

2020

Over the last 70 years several cases of in vivo failure of enteric coated (EC) formulations have been reported. The observed failures seem to be due to the slower than expected in vivo performance of EC products. Upon reaching the intestinal lumen, the dosage form is exposed to a bicarbonate buffered environment at much lower interfacial buffering capacity compared to those applied in compendial phosphate buffers. Hence, there is an urgent need to understand the behavior of EC products in bicarbonate buffer (BCB) and to revaluate the current dissolution methods used for such products. The current pilot study mechanistically investigated the performance of five EC products available in the C…

2020

Nature is an indispensable source of new drugs, providing unique bioactive lead structures for drug discovery. In the present study, secalonic acid F (SAF), a naturally occurring ergochrome pigment, was studied for its cytotoxicity against various leukemia and multiple myeloma cells by the resazurin assay. SAF exhibited cytotoxic activity on both leukemia and multiple myeloma cells. Generally, multiple myeloma cells were more sensitive to SAF than leukemia cells. NCI-H929 cells were the most affected cells among the tested panel of multiple myeloma cell lines and were taken for further studies to assess the mode of action of SAF on those cells. Cell cycle analysis revealed that SAF induced …

Ligand density on nanoparticles: A parameter with critical impact on nanomedicine

2019

Nanoparticles modified with ligands for specific targeting towards receptors expressed on the surface of target cells are discussed in literature towards improved delivery strategies. In such concepts the ligand density on the surface of the nanoparticles plays an important role. How many ligands per nanoparticle are best for the most efficient delivery? Importantly, this number may be different for in vitro and in vivo scenarios. In this review first viruses as "biological" nanoparticles are analyzed towards their ligand density, which is then compared to the ligand density of engineered nanoparticles. Then, experiments are reviewed in which in vitro and in vivo nanoparticle delivery has b…