The inhibitory effect of zinc on cadmium-induced cell apoptosis and reactive oxygen species (ROS) production in cell cultures.

The prevention of apoptosis by Zn(2+) is a well-known phenomenon. Both in in vitro and in vivo Zn(2+) supplementation prevents apoptosis induced by a variety of agents, among them by cadmium ions. The target for protective action of Zn ions on cell apoptosis is still unknown. In this paper we have evaluated the effect of in vitro ZnCl(2) supplementation at a concentration corresponding to the physiological level (10 microM) and higher (50 microM), on apoptosis induced with different Cd concentrations in two cell types: HeLa human tumor cell line and bovine aorta endothelial cells (BAECs). We demonstrated that Zn supplementation, especially at 10 microM concentration, significantly inhibited apoptosis in both types of cells. To assess the mechanism involved in the Zn effect we examined the influence of Zn supplementation on Cd accumulation in cells, Cd-induced superoxide anion (O(2)(-)) and hydrogen peroxide (H(2)O(2)) production. Zn caused 1.2-2.0-fold inhibition of Cd accumulation, 1.2-2.0-fold inhibition of Cd-induced apoptotic cell death, 1.1-2.0-fold decrease in reactive oxygen species (ROS) production in HeLa cells and in BAECs. These results indicate that inhibition of Cd-induced apoptosis in cells by Zn might be due, not only by inhibition of Cd accumulation in cells but, at least in part, to inhibition of Cd-induced production of ROS, which in turn are known as strong inducers of apoptosis.

Antimitotic activity of aqueous extracts of Inonotus obliquus.

The cytotoxic effect of two aqueous extracts of Inonotus obliquus on human cervical uteri cancer cells (Hela S3) in vitro was evaluated. It was concluded that Inonotus extracts at a concentration of 10 micrograms/ml to 2000 micrograms/ml inhibited cancer cells growth. In cultures with extracts of the fungus a decrease of the cell proteins and mitotic index was observed. Moreover, the extracts disturbed mitoses by elevating the number of mitotic cells in metaphase. Aqueous extracts of Inonotus effected not only mitoses but also the 8/G phase of the cell cycle.

Effect of chronic vanadium administration in drinking water to rats.

Two-month old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) at a concentration of 0.01 or 0.05 mg V cm-3 (0.2 or 1.0 mM) for a period of 4 weeks. It was calculated that the animals took up doses of 1.5 and 5-6 mg V kg body weight-1 24 h-1, respectively. Food and AMV solution consumption in the experimental group was similar to food and water consumption in the control group. A statistically significant decrease of consumption of AMV solution at a concentration of 0.05 mg V cm-3 was noted only in males. Hematological examination demonstrated a decrease in the erythrocyte count, hemoglobin level and hematocrit index. This decrease in the erythrocyte count was associated with an increased percentage of reticulocytes in the peripheral blood of the animals drinking the solution with a higher vanadium content. Biochemical analyses demonstrated a decrease of L-ascorbic acid levels in the plasma and erythrocytes of animals drinking the AMV solutions. A distinct tendency for the malonyldialdehyde level to increase in the blood was also observed. Among the enzymes examined in the erythrocytes (catalase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and delta-aminolevulinic acid dehydratase [ALA-D]) only ALA-D activity was depressed.