Ratio-dependent effects of photoactivated hypericin and manumycin A on their genotoxic and mutagenic potential.

Natural compounds originated from plants and microorganisms and their combinations are currently being investigated as a possible treatment for several diseases including cancer. Hypericin (photodynamically-active pigment from Hypericum perforatum L.) and manumycin A (inhibitor of farnesyltransferase from Streptomyces parvulus) belong to the chemicals potentially applicable in clinical practice. In this study we evaluated potential cytotoxic (via trypan blue exclusion test), genotoxic (via DNA-topology and comet assays), and mutagenic effects (via bacterial reverse mutation test) of these compounds and their combinations considering the molecular mechanism of their action in cell-free and cellular systems. Our results did not reveal neither cytotoxic nor mutagenic activities of tested compounds and their combinations. Regarding the genotoxic potential, no damage of plasmid DNA in cell-free system was detected. On the other hand, photoactivated hypericin and manumycin A were able to induce primary DNA damage in human lymphocytes analyzed by comet assay. The possible antagonistic interactions between these two metabolites were estimated using SynergyFinder software analysis and experimental data obtained from comet assay. Our findings indicate that not only the presence of substances, but also their ratio plays an important role in resulting effects of the combined treatment in cellular system.

Exceptional Properties of Lepidium sativum L. Extract and Its Impact on Cell Viability, Ros Production, Steroidogenesis, and Intracellular Communication in Mice Leydig Cells In Vitro.

The prevalence of reproductive dysfunction in males has risen in the last few years, and alternative therapies are gradually gaining in popularity. Our in vitro study aimed to evaluate the potential impact of Lepidium sativum L. on mice TM3 Leydig cells, concerning basal parameters such as cell viability, cell membrane integrity, and lysosomal activity, after 24 h and 48 h exposure. Moreover, reactive oxygens species generation, sex-steroid hormone secretion, and intercellular communication were quantified. In the present study, the microgreen extract from Lepidium was rich in ferulic acid, 4-OH benzoic acid, and resveratrol, with a significant antioxidant activity. The results showed that lower experimental doses (62.5-250 µg/mL) could positively affect the observed parameters, with significant differences at 250 µg/mL after 24 h and 48 h, respectively. Potential risks could be associated with higher concentrations, starting at 500 µg/mL, 1000 µg/mL, and 2000 µg/mL of Lepidium. Nevertheless, biochemical quantification indicated a significant antioxidant potential and a rich content of biologically active molecules at the applied doses, and time determined the intracellular response of the cultured model.

Comparison of Cytotoxic, Genotoxic, and DNA-Protective Effects of Skyrin on Cancerous vs. Non-Cancerous Human Cells.

Secondary metabolites as a potential source of anticancer therapeutics have been the subject of many studies. Since hypericin, a metabolite isolated from Hypericum perforatum L., shows several biomedical properties applicable in oncology, the aim of our study was to investigate its potential precursor skyrin in terms of genotoxic and DNA-protective effects. These skyrin effects were analyzed by cell-free methods, and cytotoxicity was estimated by an MTT assay and by a trypan blue exclusion test, while the genotoxic/antigenotoxic potential was examined by comet assay using non-cancerous human lymphocytes and the HepG2 cancer cell line. Skyrin did not show DNA-damaging effects but rather exhibited DNA-protectivity using a DNA-topology assay. However, we observed only weak antioxidant and chelating skyrin properties in other cell-free methods. Regarding the cytotoxic activity of skyrin, HepG2 cells were more prone to skyrin-induced death in comparison to human lymphocytes. Skyrin in non-cytotoxic concentrations did not exhibit elevated genotoxicity in both cell types. On the other hand, skyrin displayed moderate DNA-protective effects that were more noticeable in the case of non-cancerous human lymphocytes. The potential genotoxic effects of skyrin were not observed, and its DNA-protective capacity was more prominent in non-cancerous cells. Therefore, skyrin might be a promising agent used in anticancer therapy.

Reconstruction of human genome evolution in yeast: an educational primer for use with "systematic humanization of the yeast cytoskeleton discerns functionally replaceable from divergent human genes".

The evolution of eukaryotic organisms starting with the last eukaryotic common ancestor was accompanied by lineage-specific expansion of gene families. A paper by Garge et al. provides an excellent opportunity to have students explore how expansion of gene families via gene duplication results in protein specialization, in this case in the context of eukaryotic cytoskeletal organization . The authors tested hypotheses about conserved protein function by systematic "humanization" of the yeast cytoskeletal components while employing a wide variety of methodological approaches. We outline several exercises to promote students' ability to explore the genomic databases, perform bioinformatic analyses, design experiments for functional analysis of human genes in yeast and critically interpret results to address both specific and general questions.