Fumonisin production and toxic capacity in airborne black Aspergilli

Abstract

This study presents the distribution of fumonisin (FB)-producing and non-producing airborne Aspergilli (Nigri) in apartments (AP), basements (BS) and a grain mill (GM) in Croatia, and their cytotoxic, immunomodulation and genotoxic potency in comparison with FB1 and FB2. Concentration of black Aspergilli was 260-fold higher in GM than in living environment with domination of A. tubingensis and A. welwitschiae. FB2- but not FB1- was confirmed via HPLC-MS and detection of fum1 and fum8 genes for one isolate of A. niger (0.015 μg/mL) and 8/15 isolates of A. welwitschiae (0.128–13.467 μg/mL). After 24 h, both FB1 and FB2 were weakly cytotoxic (MTT assay) to human lung A549 cells and THP-1 macrophage-like cells. In THP-1 cells FB1 but not FB2 provoked a higher increase of IL-8, TNF-α and IL-1β (ELISA). In A549 cells DNA damaging effect of FB1 was slightly higher than that of FB2 (Comet assay). In THP-1 macrophage-like cells A. tubingensis and A. piperis evoked immunomodulatory effects which corresponded to their cytotoxicity (IC50 = 0.228–0.323 mg/mL); A. welwitschiae, A. tubingensis and A. piperis exerted cytotoxic (IC50 = 0.214–0.460 mg/mL) and genotoxic effects in A549 cells. Presumably, secondary metabolites other than FB2 may have contributed to the toxicity of black Aspergilli.