Oxidative stress and its relationship to fertility and reproduction is a topic of interest in medicine, especially in the context of the effects of trace elements and micronutrients. Oxidative stress occurs when there is an excess of free radicals in the body, which can lead to cell and tissue damage. Free radicals are reactive oxygen species (ROS) that can be formed as a result of normal metabolic processes, as well as under the influence of external factors such as environmental pollution, UV radiation, and diet. Oxidative stress has a significant impact on fertility. In men, it can lead to DNA damage in sperm, which can result in reduced semen quality, reduced sperm motility and increased numbers of defective sperm, and free radical damage to sperm cell membranes causing a reduction in the number of available sperm. In women, oxidative stress can affect the quality of female reproductive cells, which can lead to problems with their maturation and with embryo implantation in the uterus and can also affect ovarian function and disrupt hormonal regulation of the menstrual cycle. A proper balance of trace elements and micronutrients is key to protecting against oxidative stress and maintaining reproductive health. Supplementation with appropriate elements such as zinc, selenium, copper, manganese, chromium, and iron can help reduce oxidative stress and improve fertility. This work discusses the effects of selected elements on oxidative stress parameters specifically in terms of fertility and reproduction.

Complexes of Co(II), Ni(II) and Cu(II) with 2-(3,5-dimethyl-1H-pyrazole-1-yl)-4-phenyl-1,3-thiazole (a) and 3,5-dimethyl-1H-pyrazole-1-carbothioamide (b) ligands were synthesized. The crystal and molecular structures of four of them were determined by the X-ray diffraction method. In the complexes with ligand a the metal atom was bound via two nitrogen atoms, whereas ligand b interacted through the nitrogen and sulfur atoms. Comparing the coordination modes observed for both studied ligands, the thiocarbamoyl sulfur atom can participate in metal binding and in bridge formation, whereas the thiazole (aromatic) sulfur atom is not involved in the coordination. This effect seems to enhance (at least partially) conformational flexibility. Hydrogen bonds played a principal role in the crystal network formation of the analyzed compounds. The cytotoxic activity of the complexes against HL-60 and NALM-6 leukemia cells and the WM-115 melanoma cell line was also measured. The copper(II) complex with the thiosemicarbazone ligand (7b) exhibited relatively high cytotoxicity towards all tested tumor cells. The cytotoxicity of copper(II) complexes 7b and 9b against the melanoma WM-115 cells was over three times higher than that of cisplatin.

Antibiotic resistance acquired by various bacterial fungal and viral pathogens poses therapeutic problems of increasing severity. Among the infections that are very difficult to treat, biofilm-associated cases are one of the most hazardous. Complex structure of a biofilm and unique physiology of the biofilm cells contribute to their extremely high resistance to environmental conditions, antimicrobial agents and the mechanisms of host immune response. Therefore, the biofilm formation, especially by multidrugresistant pathogens, is a serious medical problem, playing a pivotal role in the development of chronic and recurrent infections. These factors create a limitation for using traditional chemiotherapeutics and contribute to a request for development of new approaches for treatment of infectious diseases. Therefore, early reports on antimicrobial activity of several complexes of metal ions, bearing thiosemicarbazide or thiosemicarbazones as the ligands, gave a boost to worldwide search for new, more efficient compounds of this class, to be used as alternatives to commonly known drugs. In general, depending on the presence of other heteroatoms, these ligands may function in a di-, tri- or tetradentate forms (e.g., of N,S,-, N,N,S-, N,N,N,S-, N,N,S,S-, or N,S,O-type), which impose different coordination geometries to the resultant complexes. In the first part of this review, we describe the ways of synthesis and the structures of the ligands based on the thiosemicarbazone motif, while the second part deals with the antimicrobial activity of their complexes with selected metal ions.

Copper(II), cobalt(II) and nickel (II) complexes (1–6) of 1-[amino(thioxo)methyl]-5-hydroxy-3-methyl-1H-pyrazole have been synthesized and characterized by IR, UV-Vis, NMR, ESI-MS and elemental analysis. Ligand and metal(II) complexes have been screened for their toxic effect on HeLa and K562 cancer cell lines, as well as on normal HUVEC cells. Cytotoxic effectiveness of copper(II) complexes (1 and 4) (IC₅₀ 2–5 μM after 48 h) was 4–50 times higher than that of other complexes and cisplatin. These complexes were non-toxic to primary human endothelial cells. For these complexes, induction of cell apoptosis by the caspase 3/7 assay has been measured. The interactions with DNA by the enzymatic method have also been investigated.