Direct and microsomal activated aflatoxin B 1 exposure and its effects on Turkey peritoneal macrophage functions in vitro

Abstract

Sephadex-elicited turkey peritoneal exudate cells were used to establish adherent macrophage monolayers on glass coverslips in order to determine the effects of aflatoxin B 1 (AFB 1) on macrophages. Adherent macrophage monolayers were exposed to increasing doses of AFB 1 (5, 10, 20, and 40 μg), either directly, or to 0.01, 0.1, 0.5, 1, and 5 μg of AFB 1 in the presence of a chicken microsomal mixed function oxidase system (MFO). Cultures were incubated with the appropriate treatments for 1 hr, then washed and allowed to recover in fresh growth medium for 2 hr. Direct exposure of macrophages to AFB 1 had no detrimental effect on macrophage adherence, percentage damaged, percentage phagocytic, and the number of antibody-coated or uncoated sheep red blood cells internalized per phagocytic macrophage when compared with the sham or solvent treated cultures. However, the addition of MFOs to the cultures treated with much lower doses of AFB 1 resulted in significantly higher morphological alterations along with a reduction in cell adherence and phagocytic potential. Addition of piperonyl butoxide (a P450 inhibitor) abrogated AFB 1-MFO induced alterations. Data collected in this study suggest that turkey macrophages are resistant to the direct exposure of AFB 1 and that AFB 1 induced alterations in macrophage effector functions are due to metabolic activation of AFB 1 by MFOs.