Abstract
The effects of Spirulina platensis (Sp) extract exposure on chicken macrophages were examined. Sephadex-elicited abdominal exudate macrophage monolayers were exposed to varying concentrations (10 to 40 μg/ml) of Sp for 1 to 16 hours. Spirulina-treated macrophages exhibited phenotypic changes in terms of increased spreading and vacuolization with minimal cytotoxicity. Percentage of phagocytic macrophages for unopsonized sheep red blood cells (SRBC) and average number of internalized SRBC was significantly higher in Sp-treated macrophages as compared to the sham-treated controls. However, phagocytosis of opsonized SRBC was not affected by Sp-treatment. Macrophage cultures exposed to Sp produced a factor in their culture supernatant with tumoricidal potential which was similar in reactivity to the one produced by macrophages after exposure to lipopolysaccharide. The ability of splenic natural killer cells to kill tumor cell targets was not affected by Sp treatment. These findings suggest that Spirulina exposure enhances selected effector functions of cells of the chicken immune system after in vitro exposure.