In the study the genotoxic activity of MCLR on HepG2 cells and human peripheral blood lymphocytes was investigated using the comet assay. The induction of DNA strand breaks in HepG2 cells was dose and time dependent with the maximal DNA damage detected after 4 hours of exposure. In human lymphocytes higher concentrations of MCLR and longer exposure times were needed to induce DNA damage. The results showed that human hepatoma cells and human lymphocytes have different sensitivity towards cyanobacterial peptide MCLR.
COBISS.SI-ID: 2141519
In the article we explored the effect of MCLR on the expression of selected genes known to be involved in the cell response to DNA damage and apoptosis. We found a significantly elevated expression of tumour suppressor gene p53 and its downstream-regulated genes involved in DNA repair and cell cycle regulation (p21, gadd 45a, mdm2), as well as increased expression of the pro apoptotic gene bax, but no alterations of the anti-apoptotic bcl-2. Up-regulation of the expression of mdm2, p21 and gadd45a provides strong support for our previous suggestion that MCLR is a genotoxic carcinogen.
COBISS.SI-ID: 1820239
We have investigated the effect of noncytotoxic concentrations of MCLR on the generation of reactive oxygen species (ROS) and DNA damage in human colon adenocarcinoma CaCo2, astrocytoma IPDDC-A2 and B-lymphoblastoid NCNC cell lines. MCLR reduced viability of CaCo2 cells and increased ROS production in CaCo2 and IPDDC-A2. Using the comet assay, we showed that MCLR, at noncytotoxic concentrations, induced time and dose dependent increase of DNA damage in CaCo2 cells. These results indicate that, in addition to liver, colon cells should also be considered as a target for microcystin toxicity.
COBISS.SI-ID: 1889871
In the study we determined if MCYR influence apart of liver also other organs. Male Fisher F344 rats were exposed to sublethal dose (every second day 10 µg/kg b.w.; i.p) of MCYR for one month. The DNA damage in isolated cells was measured with the comet assay. An increase of DNA damage in MCYR-exposed animals observed in brain, liver, kidney and lung cells, while DNA from lymphocytes and spleen cells was not affected. We demonstrated that subchronic exposure to sublethal doses of MCs can induce systemic genotoxicity, and it affects not only the liver but also other organs.
COBISS.SI-ID: 1724751
The genotoxic activity of the extracts prepared from different strains of cultured cyanobacteria producing different quantities and spectrum of MCs was evaluated using differet bioassays (MTT assay, comet assay, micronucleus, MutaMouse). All the extracts induced DNA damage including those not containing MCs. These data indicate that besides MCs also other cyanobacterial metabolites are (produced by these cyanobacteria and are) genotoxic and represent environmental and human health risk.
COBISS.SI-ID: 1798223