Comparison of the cytotoxicities ofFusarium metabolites andAlternaria metabolite AAL-toxin to cultured mammalian cell lines

Abstract

Four water-solubleFusarium metabolites (fumonisin B₁, fusaric acid, butenolide and moniliformin), water-insoluble pigment (8-O-methylbostrycoidin), and anAlternaria metabolite (AAL-toxin) were tested for relative cytotoxicity to five established mammalian cell lines. Butenolide was the most cytotoxic to all five cell lines. LC₅₀s were; 1 μg/ml to rat hepatoma (RH) (tumors derived from parenchymal cells), 7 μg/ml to baby hamster kidney (BHK-21) fibroblast cells, and 15 μg/ml to McCoy mouse (MM) fibroblast cells: LC₁₀₀s were 1 μg/ml to Chinese hamster ovary (CHO) fibroblast cells, and 5 μg/ml to dog kidney (MDCK) fibroblast cells. Fusaric acid was cytotoxic to the MDCK, MM, RH, and CHO cell lines; moniliformin was cytotoxic to the RH, CHO, and MDCK, cell lines. The pigment, however, was cytotoxic only to RH and CHO cell lines. Fumonisin B₁ and a related toxin, AAL-toxin, at a high dose level (100 μg/ml) were not cytotoxic to the RH, BHK, MM, CHO and MDCK cell lines. T-2 toxin was used as a positive control, and inhibited all cell lines at the nanogram level. The difference in response of these five cell lines to the toxic metabolites, that were noted in this study, was then used to evaluate nine HPLC fractions obtained from a methanol-water extract of anF. moniliforme culture. The results indicated that this type of cytotoxicity assay may be useful in following the isolation of metabolites from extracts ofFusarium culture, especiallyF. moniliforme.