Abstract
Crotalus durissus terrificus venom (Cdt) is toxic for a
variety of eukaryotic cells, especially at high concentrations.
However its effects on host immune cells are not well known. The
purpose of this study was to determine the effect of Cdt on
functional status and the mediators production in peritoneal
macrophages. The effects of Cdt were analyzed in vitro and were
detected using functional status of macrophages as
determined by the H2O2 release, spreading percentage,
phagocytic index, vacuole formation, and mediators production.
Several functional bioassays were employed: cytotoxicity was
determined by taking the lyses percentage and the presence of
hydrogen peroxide (H2O2) in macrophages, using the
horseradish peroxidase-dependent oxidation of phenol red and
nitric oxide (NO) in the supernatants of macrophages by the
Griess reaction. The tumor necrosis factor (TNF) activity was
detected by measuring its cytotoxic activity on L929 cells, and
the production the level of other cytokines was assayed
using enzyme-linked immunosorbent assay. In vitro studies revealed
that Cdt produced (a) a discrete increase in the release of
H2O2 and vacuole formation; (b) a decrease in spreading
percentage and in the phagocytic index; and (c) an increment in
the mediators production. More pronounced increments of IL-6 and
TNF were observed after 24 and 48 hours, respectively. Maximum
levels of IFN-