[EFFECT OF FUCOIDANS ISOLATED FROM SEAWEEDS LAMINARIA DIGITATA AND FUCUS VESICULOSUS ON CELL LINES HELA G-63, ECV 304 AND PC 12].

The aim of the research was to investigate cytotoxicity of fucoidans on mammals cells. Three different samples of fucoidans were isolated from mechanically grounded brown algae Laminaria digitata and Fucus ve- siculosus. The sample F2 that differed from the others by higher sulfatation level and suppression of HeLa G-63 line culture growth was taken for further study in cell lines HeLa G-63, ECV 304 and PC 12. We have shown that fucoidan preparation F2 inhibits proliferation and induces cell death in a dose- and time-dependent manner for all investigated cell lines. Neuroendocrine tumor rat cell line PC 12 appeared to be the most sensitive to fucoidan treatment whereas endothelial human cells ECV 304 were the least sensitive.

[Assessing of the role superoxide, nitric oxide and redox metals in cytotoxic effect of the H2O2 and amyloid-beta-protein].

On the cells of neuroendocrine tumor of rats (line PC12) in culture was estimating of the governing mechanisms of the cytotoxicity of the oxidative stress and the role of the amyloids in increasing this stress. Using flowcytometric assessment of the cytotoxicity H2O2 and fragment beta-amyloid (Abeta) peptide (25-35) has been shown the dose-dependent increasing of the quote of the cells with DNA content < 2c. Isoeffective consentrations were 1 MM H2O2 and 5 MkappaM Abeta. The cytotoxicity H2O2 and A were accompanig with the increasing of the intracellular level of O2-. The treatment of the cells GSNO (donor of NO) and o-phenantrolin (chelators of Fe ions) significantly decreased the intracellular level of O2- as well as the cytotoxicity H2O2 and Abeta. Thus, in direct experiments has been shown of the part amyloids in the increasing of the oxidative stress and participation of the reactive oxide radicals in the cytotoxic effect of the Abeta. The addition argument which confirmed contribution of the oxidative stress in the cytotoxic effect of the Abeta was the similarity of the cellular response on the action of the oxidative agent - H2O2 and Abeta.

Changes in nitric oxide and superoxide levels in human endotheliocytes and carcinoma cells after exposure to low-dose ionizing radiation.

The exposure of HeLa G63 and ECV-304 cells to γ-rays of (137)Cs as well as ß-particles of (3)H(2)O and (3)H-thymidine induced changes in redox status of not only irradiated cells, but also their progeny. Increased intracellular levels of nitric oxide (NO) were observed only in HeLa G63 cells and persisted over three cell generations; ß-particles from (3)H(2)O were most efficient. Intracellular superoxide (O(2)(-)) level had similar dynamics in both cell lines. Intracellular O(2)(-) level decreased immediately after irradiation, but then increased and significantly surpassed the control level. These changes in the intracellular level of O(2)(-) were accompanied by decondensation of nuclear chromatin. Increased level of free radicals in the progeny of irradiated cells and changes in chromatin conformation and the absence of correlation between radiation-induced structural damage to chromosomes and intracellular level of free radicals suggest participation of epigenetic mechanisms of inheritance.

Modification of intracellular level of free radicals and apoptosis in cultured human endotheliocytes and carcinoma cells.

The intracellular levels of superoxide O(2)(-)and nitric oxide NO were directly measured under intravital conditions in cultured human endotheliocytes ECV 304 and carcinoma cells HeLa G-63. Comparative analysis of changes in the intracellular levels of superoxide and NO induced by ascorbic acid revealed a negative correlation between NO and O(2)(-)levels, whose strength depended on concentration of the acid. In pharmacological concentrations, ascorbic acid induced apoptotic death of carcinoma cells, but did not trigger apoptosis of endotheliocytes. The study demonstrated a possible way of cytotoxic action of ascorbic acid in pharmacological concentrations.