Plants are known as a source of different biologically active compounds, which are uncommon for other kingdoms of life. Among them are different amino acid analogues, which are synthesized and accumulated in certain plants as a passive defense mechanism against herbivorous insects and grazing mammals. As a rule, cell protein synthesis machinery of herbivores cannot effectively differentiate between standard proteinogenic amino acids and their specific plant analogues, resulting in misincorporation of the latter into nascent proteins and their malfunctioning, which constitutes a mechanism of plant defense. Examples of such amino acids are analogues of arginine (canavanine, indospicine), proline (azetidine-2-carboxylic acid), and cysteine/lysine (thialyasine). This review summarizes existing knowledge on these and other related amino acids as potential antibacterial and antifungal agents, including their possible targets and known resistance mechanisms. We also discuss the possibility of using amino acid analogues as sole antimicrobial agents or in combination with known antibacterials and antifungals. We also propose a strategy of enhancing the antimicrobial activity of amino acid analogue by concomitant starvation for the corresponding standard amino acid, which has been proven efficient in anticancer studies. Such an approach might potentially help to overcome, at least partially, microbial resistance to known antibiotics, especially when such resistance relies on increased protein synthesis in pathogen cells.

MCF-7 human breast cancer cells sensitive and resistant to cisplatin and doxorubicin were used in experiments. Various cultivation times of these cells in the presence of iron nanoparticles were used...

The review covers different aspects of structural and functional features of magnetic nanoparticles. Especially those which are associated with their interaction with cells and cause development of oxidative stress, apoptosis disruption of DNA structure and cytoskeleton, changes in intracellular signal cascades etc. It is suggested that use of iron oxide nanoparticles for magnet-driven drug delivery in cancer therapy might be safe and promising because it can enhance antitumor effects of known cytostatic drugs.

Metabolic anticancer therapy based on enzymatic arginine (Arg) deprivation (ADT) is currently being evaluated in clinical trials. The combination of ADT with low doses of the plant cytotoxic analogs of Arg, canavanine (Cav) or indospicine (Isp), have been proposed as being more efficient and selective against malignant cells. The leguminous plant Indigofera spicata contains one of the highest known amounts of Isp. Here we demonstrate for the first time that the Isp-containing ethanolic extract from I. spicata is growth-inhibiting and toxic for cultured human colorectal and ovarian carcinoma cells. The extract reduces the viability of colorectal carcinoma cells two-fold under Arg-deficient conditions and entirely abrogates their residual proliferative potential (growth recovery) after the treatment. Pre-exposure of the extract to recombinant human arginase I (rhARGI) as a therapeutic Arg-depleting agent did not impact the extract’s efficacy. Further development of Isp as a component of combinatorial anticancer metabolic targeting strategies is discussed.

Modern views on interaction of static magnetic field with cells and cellular structures, as well as the data on their possible biotropic effects have been reviewed. The emphasis was made on the results of those studies that used moderate (0.1 - 1 T) static magnetic fields, as the fields with such characteristics are used for targeted delivery of magnetically sensitive nanocomposites in targeted therapy of malignant neoplasms. Based on the available data, it has been concluded that the primary cause of the changes in cells induced by external static magnetic field is disruption of free radical metabolism and elevation of their concentration. It results in oxidative stress, dysfunction of ion channels, changes in cell morphology, expression of some genes and proteins, and changes in apoptosis and proliferation.