COMPARATIVE SUBCHRONIC TOXICITY STUDIES OF NIXTAMALIZED AND WATER-EXTRACTED FUSARIUM-MONILIFORME CULTURE MATERIAL

Fumonisins are mycotoxins produced by Fusarium moniliforme, F. prolife ratum and other Fusarium species, which are commonly found on corn, ca use a variety of species-specific toxicoses, and have been linked to h uman oesophageal cancer in areas of southern Africa and China where co rn is a dietary staple. The effect of nixtamalization, the process by which masa flour is produced by alkaline hydrolysis of corn, on the or gan-specific toxicity of F. moniliforme culture material containing fu monisin B-1 (FB1) was studied and the effectiveness of nixtamalization and water extraction for detoxifying culture material was compared. M ale rats (n = 10/group) were fed diets containing 5% culture material equivalent weights of nixtamalized culture material (NX diet) providin g 58 ppm hydrolysed FB1 but no FB1, water-extracted culture material ( WE diet) providing 8 ppm FB1, or untreated culture material (CM diet) providing 71 ppm FB1 for 4 wk. An additional control group was fed a d iet containing sound seed corn. Serum chemical and histopathological f indings confirmed that the nixtamalized culture material was hepatotox ic and nephrotoxic. Hepatopathy was found in all rats fed the NX or CM diets. The lesions were qualitatively similar in these two groups, bu t were noticeably less severe in rats fed the NX diet. In contrast, on ly one rat fed the WE diet exhibited mild hepatopathy. Mild-to-moderat e nephropathy resembling that induced by FB1 was found in all rats fed the NX, WE or CM diet. Thus, the organ-specific effects of nixtamaliz ed culture material, containing no detectable FB1, were similar to tho se of the FB1-containing diet prepared from untreated culture material . Furthermore, nixtamalization was not as effective as water extractio n as a detoxification method. Copyright (C) 1996 Published by Elsevier Science Ltd.