The presence of“non-toxic” cyclic peptides planktopeptin BL1125, anabaenopeptin B and anabaenopeptin F, produced in bloom forming cyanobacteria, can provoke lysis of different non-axenic Microcystis aeruginosa cell lines via the induction of virus-like particles. This effect implies that a possible role of these peptides in the natural environment is the control of cyanobacterial population density. The process can be self-augmented with the release of cyclic peptides, starting a “forest fire effect” that ends in collapse of cyanobacterial blooms.
COBISS.SI-ID: 1798479
Xanthohumol is the major prenylated flavonoid present in the hop plant Humulus lupulus L. (Cannabinaceae) and a common ingredient of beer. The described results provided evidence that xanthohumol displays anti-genotoxic activity in metabolically competent human cells, such as HepG2 cells. When these were pre-treated with xanthohumol, they showed significantly reduced levels of t-BOOH-induced DNA strand breaks, indicating that its protective effect is mediated by induction of cellular defence mechanisms against oxidative stress.
COBISS.SI-ID: 1739855
The paper describes very selective peptidase inhibitory activities of the two main groups of cyclic peptides, depsipeptides and ureido linkage-containing peptides on serine peptidases. The planktopeptin BL1125 is a strong linear competitive tight-binding inhibitor of leukocyte and pancreatic elastase and also of chymotrypsin, whereas anabaenopeptins B and F show no inhibition of chymotrypsin, but inhibit both elastases. Relative selectivity and low cytotoxicity of the tested cyanopeptides suggests that they are potential candidates for therapy in inflammatory diseases and cancer.
COBISS.SI-ID: 21960743
Organophosphorous compounds (OPs) are commonly used pesticides. Although the primary mechanism of OP toxicity is the inhibition of acetylcholine esterase in the nervous system, this study aimed to reveal whether low concentrations of model OPs— methyl parathion (PT), methyl paraoxon (PO), and dimefox (DF) can induce DNA damage and/or affect cell proliferation in human hepatoma HepG2 cells. We found that PT and PO caused a reduction of cell proliferation and upregulated expression of DNA damage responsive genes, while DF increased cell proliferation and had no other effects.
COBISS.SI-ID: 1886287
Proteases play a key role in cancer progression, not only in invasion and metastasis, but also in early steps of carcinogenesis. This review article is summarising the efforts to efficiently prevent carcinogenesis and progression of cancer by inhibiting this system. In spite of certain not very successful clinical approaches to use protease inhibitors in the therapy of terminal cancer patents, we can conclude that this kind of therapy is still promising. However, certain basic problems should be solved before the protease inhibitors would be applied successfully in cancer therapy.
COBISS.SI-ID: 1612111