ABSTRACT
Most zinc studies show its benefits or changes that coincide with its deficiency, but some have reported damages by supplements. In this work, the effects of zinc in different cell lines (U-937, human monocytes, and murine bone marrow cells) were analyzed. The cells were put in their specific culture medium either alone or with a stimulant [1-phorbol 12-myristate 13-acetate (PMA) for U-937 and monocytes, granulocyte macrophage colony stimulating factor (GM-CSF) for bone marrow cells]. These preparations, with or without zinc (0.05 to 1.0 mM), were incubated and microscopically analyzed on days 3, 9, and 11. The viability of all cells cultivated with 0.05 and 0.1 mM of zinc was similar to that of the controls without zinc (90%). With 1.0 mM of zinc, the viability diminished (p < 0.005) to 80% in U-937 and to 50% in monocytes and bone marrow cells; the number of cells increased in the three lines, but there was no differentiation. We conclude that the effects observed with different doses of zinc vary not only among the different species but also according to the time the cells were exposed to the metal. The same doses of zinc can have either a stimulatory or an inhibitory effect.
Subject(s)
Cell Differentiation/drug effects , Cell Survival/drug effects , Zinc/pharmacology , Animals , Bone Marrow Cells/drug effects , Humans , Mice , Monocytes/drug effects , U937 CellsABSTRACT
The present study analyzes the effects of zinc on Entamoeba histolytica activity and on its pathogenicity. Metal activity was evaluated in vitro with regard to the parasite's viability, replication, and adhesion to epithelial cells and in vivo with regard to its pathogenicity. The results obtained in vitro show that zinc at 1.0 mM concentration does not affect amebic viability; however, it does decrease amebic replication and adhesion (P < 0.001). In vivo studies performed on a model of experimental liver abscess in the hamster indicate that the intraperitoneal administration of a single dose of zinc at 48 h after the intrahepatic inoculation of amebic trophozoites significantly inhibits (P < 0.001) abscess development. The results indicate that zinc alters the functionality of the ameba in vitro as reflected by a decrease in replication and adhesion and in vivo as manifested by inhibition of amebic pathogenicity.
Subject(s)
Entamoeba histolytica/pathogenicity , Liver Abscess, Amebic/drug therapy , Zinc/therapeutic use , Animals , Cell Adhesion/drug effects , Cell Division/drug effects , Cells, Cultured , Cricetinae , Injections, Intraperitoneal , Liver Abscess, Amebic/pathology , Mesocricetus , Virulence/drug effects , Zinc/pharmacologyABSTRACT
Patients with alcoholic hepatic cirrhosis have a higher predisposition to acquiring infections than healthy individuals, suggesting an alteration in the immune system. They also exhibit an important decrease in certain plasmatic constituents such as zinc, albumin, and transferrin which are involved in the normal immune response. The blastoid transformation of lymphocytes stimulated in vitro with phytohemagglutinin M and P in patients with alcoholic hepatic cirrhosis was studied and the results were correlated with the plasmatic constituents aforementioned. The rate of blastoid transformation was significantly lower (p < .001) in these patients when compared to the control group, but did not correlate directly with the concentration of zinc, albumin, transferrin or circulating globulins. Patients' plasma significantly inhibited the response of normal cells to stimulation with phytohemagglutinin and Concanavalin A; nevertheless, the blastoid transformation of lymphocytes in these patients was not restored to normal levels when incubated with control plasma.
