An Antibody Specific for the Dog Leukocyte Antigen DR (DLA-DR) and Its Novel Methotrexate Conjugate Inhibit the Growth of Canine B Cell Lymphoma

Thymine-Modified Nanocarrier for Doxorubicin Delivery in Glioblastoma Cells

Brain tumor glioblastoma is one of the worst types of cancer. The blood-brain barrier prevents drugs from reaching brain cells and shields glioblastoma from treatment. The creation of nanocarriers to improve drug delivery and internalization effectiveness may be the solution to this issue. In this paper, we report on a new nanocarrier that was developed to deliver the anticancer drug doxorubicin to glioblastoma cells. The nanocarrier was obtained by nanoemulsion polymerization of diallyl disulfide with 1-allylthymine. Diallyl disulfide is a redox-sensitive molecule involved in redox cell activities, and thymine is a uracil derivative and one of the well-known bioactive compounds that can enhance the pharmacological activity of doxorubicin. Doxorubicin was successfully introduced into the nanocarrier with a load capacity of about 4.6%. Biological studies showed that the doxorubicin nanocarrier composition is far more cytotoxic to glioblastoma cells (T98G) than it is to cancer cells (M-HeLa) and healthy cells (Chang liver). The nanocarrier improves the penetration of doxorubicin into T98G cells and accelerates the cells' demise, as is evident from flow cytometry and fluorescence microscopy data. The obtained nanocarrier, in our opinion, is a promising candidate for further research in glioblastoma therapy.

Synthesis of Morpholine-, Piperidine-, and N-Substituted Piperazine-Coupled 2-(Benzimidazol-2-yl)-3-arylquinoxalines as Novel Potent Antitumor Agents

A novel series of 2-(benzimidazol-2-yl)quinoxalines with three types of pharmacophore groups, namely, piperazine, piperidine, and morpholine moieties, which are part of known antitumor drugs, was designed and synthesized. The compounds have been characterized by NMR and IR spectroscopy, high- and low-resolution mass spectrometry, and X-ray crystallography. 2-(Benzimidazol-2-yl)quinoxalines with N-methylpiperazine substituents showed promising activity against a wide range of cancer lines, without causing hemolysis and showing little cytotoxicity against normal human Wi-38 cells (human fetal lung). A mixture of regioisomers 2-(benzimidazol-2-yl)-3-(4-fluorophenyl)-6(and 7)-(4-methylpiperazin-1-yl)quinoxalines (mri BIQ 13da/14da) showed a highly selective cytotoxic effect against human lung adenocarcinoma (cell line A549) with a half-maximal inhibitory concentration at the level of doxorubicin with a selectivity index of 12. The data obtained by flow cytometry, fluorescence microscopy, and multiparametric fluorescence analysis suggested that the mechanism of the cytotoxic effect of the mri BIQ 13da/14da on A549 cells may be associated with the stopping of the cell cycle in phase S and inhibition of DNA synthesis as well as with the induction of mithochondrial apoptosis. Thus, mri BIQ 13da/14da can be considered as a leading compound deserving further study, optimization, and development as a new anticancer agent.

Synthesis and Biological Evaluation of Taurine-Derived Diarylmethane and Dibenzoxanthene Derivatives as Possible Cytotoxic and Antimicrobial Agents

The series of novel taurine-derived diarylmethanes and dibenzoxanthenes was synthesized starting from simple commercially available precursors via modular three-stage approach. All the newly synthesized compounds were screened for in vitro antibacterial and antifungal activity, as well as cytotoxicity towards normal and cancer cell lines. Some of the synthesized compounds exhibited 2-4-fold higher activity against S. aureus, E. faecalis and B. cereus compared with Chloramphenicol. In contrast to Chloramphenicol, the tested compounds also showed bactericidal, rather than bacteriostatic effect, which makes them promising candidates for further studies.

Self-Assembling Metallocomplexes of the Amphiphilic 1,4-Diazabicyclo[2.2.2]octane Derivative as a Platform for the Development of Nonplatinum Anticancer Drugs

New 1-cetyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide complexes with copper(II) bromide and lanthanum(III) nitrate were characterized using dynamic light scattering and transmission electron microscopy, with self-assembly and the morphological behavior elucidated. For the lanthanum(III) nitrate complex, the 3D crystal structure was characterized using X-ray diffractometry. These metallosurfactants were tested as antitumor agents, and a high cytotoxic effect comparable with doxorubicin was revealed against the M-HeLa and A-549 cell lines. Both complexes were 2 times more active toward the MCF-7 cell line than the breast cancer drug tamoxifen. The cytotoxic mechanism of complexes is assumed to be related to the induction of apoptosis through the mitochondrial pathway.

A glutathione responsive nanocarrier based on viologen resorcinarene cavitand and 1-allylthymine

A glutathione-sensitive nanocarrier for doxorubicin to improve cellular penetration and selective cytotoxic effects on T98G human glioblastoma cells.

Antimicrobial and cytotoxic effects of ammonium derivatives of diterpenoids steviol and isosteviol

Antimicrobial and cytotoxic activities of several ammonium derivatives of diterpenoids steviol and isosteviol have been investigated in vitro. The results have showed that these compounds possess high antibacterial activity against MRSA strains and cytotoxic effect against cancer cell lines MCF-7, M-HeLa, A-549, PC3, HepG2, T98G. Lead compounds 4 and 5 were detected, which, in the case of the MCF-7 cell line (human breast adenocarcinoma), showed IC₅₀ at the doxorubicin level with a selectivity index of 5.0-5.2. Flow cytometry and laser confocal microscopy analysis demonstrated that the mechanism of cytotoxic effects of the tested compounds on MCF-7 cells could be associated with the induction of apoptosis along the mitochondrial pathway. At the same time, they did not cause hemolysis and showed only slight cytotoxicity with respect to normal human cells of embryonic lung (Wi-38). The obtained results allow us to consider the studied compounds as promising scaffolds for the design of new effective antibacterial drugs and anticancer agents targeting mitochondria.

The structure - Activity correlation in the family of dicationic imidazolium surfactants: Antimicrobial properties and cytotoxic effect

BACKGROUND

The development of new effective microbicide surfactants and the search for the structure-biological activity relationship is an important and promising problem. Surfactants containing imidazolium fragment attract attention of researchers in the field of chemotherapy, because these compounds often exhibit high antimicrobial activity. The aim of this work is to identify the newly synthesized surfactants from the viewpoint of their potential usefulness in pharmacology and medicine. For this purpose, a detailed study of antimicrobial, hemolytic and cytotoxic activity of dicationic alkylimidazolium surfactants of the m-s-m (Im) series with a variable length of a hydrocarbon tail (m = 10, 12) and a spacer fragment (s = 2, 3, 4) was carried out.

METHODS

Aggregation of surfactants in solutions was estimated by tensiometry and conductivity. Antimicrobial activity was determined by the serial dilution technique. Cytotoxic effects of the test compounds on human cancer and normal cells were estimated by means of the multifunctional Cytell Cell Imaging system. Cell Apoptosis Analysis was made by flow cytometry.

RESULTS

The test compounds show high antimicrobial activity against a wide range of test microorganisms and do not possess high hemolytic activity. Importantly, some of them display a bactericidal activity comparable to ciprofloxacin fluoroquinolone antibiotic against Gram-positive bacteria, including methicillin-resistant strains of S. aureus (MRSA). The cytotoxicity of the compounds against normal and tumor human cell lines has been tested as well, with cytotoxic effect and selectivity strongly controlled by structural factor and kind of cell line. Superior results were revealed for compound 10-4-10 (Im) in the case of HuTu 80 cell line (duodenal adenocarcinoma), for which IC₅₀ value at the level of doxorubicin and a markedly higher selectivity index (SI 7.5) were demonstrated. Flow cytometry assay shows apoptosis-inducing effect of this compound on HuTu 80 cells, through significant changes in the potential of mitochondrial membrane.

MAJOR CONCLUSIONS

Antibacterial properties are shown to be controlled by alkyl chain length, with the highest activity demonstrated by surfactants with decyl tail, with the length of the spacer fragment showing practically no effect. The results indicate that the mechanism of cytotoxic effect of the compounds can be associated with the induction of apoptosis via the mitochondrial pathway.

GENERAL SIGNIFICANCE

Selectivity against pathogenic microorganisms and low toxicity against eukaryotic cells allow considering dicationic imidazolium surfactants as new effective antimicrobial agents. At the same time, high selectivity against some cancer cell lines indicates the prospect of their using as components of new anticancer drugs.