Chronic Fumonisin Intake Induces Erythrocyte Osmotic Fragility

Abstract

Fumonisin B1 (FB1) is a mycotoxin that appears as a frequent maize and maize-based foods contaminant in Argentina. It has an inhibitory effect of ceramide synthetase, a key enzyme in the biosynthesis of sphingolipids, it can affect cells in different ways since sphingomyelin is required for the stability of cells membranes. In Argentina, has been reported a high percentage of contamination in freshly harvested and stored maize. The aim of this work was to determine the effects of FB1 on human erythrocytes “in vitro” and to evaluate the effect of a chronic intake of fumonisin on erythrocyte function and on hematological and hepatic parameters in rats. Male 1-month Wistar rats were separated into two groups of 5 rats. The control group was given saline solution while the other group received orally for 60 days 1mg/kg/day of FB1 from a culture of Fusarium proliferatum. On day 60, blood was collected in EDTA tubes for haematological or heparin for hepatic parameters and osmotic fragility. The osmotic fragility study was performed by two tests: immediate erythrocyte osmotic resistance (ROE i), where the erythrocytes from control or treated rats were placed in solutions of different concentrations of ClNa between 0 and 0.9 g/% and other ROE 24 hs, where the erythrocytes were preincubated 24 hrs at 37° C and then placed in hypotonic ClNa solution (0.4 g%). Hematological parameters showed a significant decrease of treated vs. control rats in the number of platelets (393.3 ± 70.6 x 103/mm3 vs 926.0 ± 23.5 x 103/mm3, in hemoglobin and hematocrit: 12.9 ± 0, 4 g% vs 14.1 ± 1.1 g% and 38.2 ± 0.0% vs 40.7 ± 3.1% and liver damage parameters showed significant differences between treated vs controls for phosphatase alkaline (1144±89 vs 608.3.3±96.4). In the studies of osmotic resistance, sodium chloride concentrations of 0.5 g% and 0.4 g% showed differences in the values of percentage of hemolysis in treated vs controls (97% vs 9.8%, 0.5g% ClNa and 100 vs. 74%, 0.4g% ClNa) with ROEi values of 0.53 g% for the treated and 0.41 g% for the controls; while for 24 hs ROE, the differences were for sodium chloride concentration 0.4g% (77 vs 47%). “In vitro” experiments, human erythrocytes incubated with FB1 during 24 hs showed an altered morphology; while no significant differences were observed in % of hemolysis between controls and treated erythrocytes. The results show that the chronic intake of fumonisin in rats leads to alterations in erythrocytes in either their shape or size, which manifests itself in the increase of their osmotic fragility. Differences were observed in hemoglobin concentrations although it was not reflected in the mean corpuscular volume (MCV) between both groups. Further investigations should be done to clarify the effect of fumonisins on erythrocyte cellular membrane and their function.