A comparative study of in vitro cytotoxic, antioxidant, and antimicrobial activity of Pt(II), Zn(II), Cu(II), and Co(III) complexes with N-heteroaromatic Schiff base (E)-2-[N'-(1-pyridin-2-yl-ethylidene)hydrazino]acetate.

In search for novel biologically active metal based compounds, an evaluation of in vitro cytotoxic, antioxidant, and antimicrobial activity of new Pt(II) complex and its Zn(II), Cu(II), and Co(III) analogues, with NNO tridentately coordinated N-heteroaromatic Schiff base ligand (E)-2-[N'-(1-pyridin-2-yl-ethylidene)hydrazino]acetate, was performed. Investigation of antioxidative properties showed that all of the compounds have strong radical scavenging potencies. The Zn(II) complex showed potent inhibition of DNA cleavage by hydroxyl radical. A cytotoxic action of investigated compounds was evaluated on cultures of human promyelocitic leukaemia (HL-60), human glioma (U251), rat glioma (C6), and mouse melanoma (B16) cell lines. It was shown that binuclear pentacoordinated Zn(II) complex possesses a strong dose-dependent cytotoxic activity, of the same order of magnitude as cisplatin on B16, C6, and U251 cells. Furthermore, Zn(II) complex causes oxidative stress-induced apoptotic death of HL-60 leukemic cells, associated with caspase activation, phosphatidylserine externalization, and DNA fragmentation.

A Search for the Optimum Selenium Source to Obtain Mushroom-Derived Chemopreventive Preparations.

The objective of this research was to test whether selenium-yeast (Se-yeast) is a better source of selenium than sodium selenite for accumulation in mycelia and immunoactive cell wall polysaccharides. Culture media were enriched in selenium to a concentration of 20 µg/mL. Selenium was added to the medium either in the form of sodium selenite or in form of Se-yeast (Sel-Plex; Alltech Inc., Lexington, KY). The total selenium concentrations in the mycelium biomass and in the isolated crude polysaccharides were determined using atomic absorption spectroscopy. We found that selenium accumulated more efficiently in cultures enriched with Se-yeast. A higher concentration of selenium was also found in the crude polysaccharide fractions isolated from the mycelium grown in Se-yeast-enriched media. With the use of the needle trap gas chromatography-mass spectrometry method, we found that there are significant differences in the composition of the volatile aroma and flavor compounds secreted by the mycelia cultivated in different media.