Fumonisin B1 affects viability and alters nitric oxide production of a murine macrophage cell line.

Fumonisin B1 (FB1), the major toxin produced by Fusarium verticillioides contaminating corn, is known to elicit many organ- and species-specific toxicities in animals. In the present study, exposure to FB1 decreased viability of a murine macrophage cell line (RAW264.7) in a dose-dependent manner (1-100 microM). Further, when cells exposed to FB1 were stimulated with lipopolysaccharide (LPS), a dose-dependent increase in production of nitric oxide (NO) was observed, but only at FB1 concentrations (10-50 microM) that induced significant cytotoxicity. Stimulation of cells with phorbol myristate acetate (PMA) resulted in increased NO production at 50 microM FB1, but induced a variable NO response at 1-10 microM FB1. Results suggest that FB1 affected cell viability and altered inducible NO production by RAW macrophages in a manner that was dependent on the pathway of stimulation.