Fumonisin

The main target for fumonisins is the inhibition of the enzyme sphinganine (sphingosine) Due north-acyltransferase (or ceramide synthase), resulting in the accumulation of free sphingoid bases in serum, and in the target tissues, which in the rat are the liver and kidney.

From: Encyclopedia of Food Sciences and Nutrition (2d Edition) , 2003

Fumonisins

Kenneth A. Voss , ... Janee Gelineau-van Waes , in Reproductive and Developmental Toxicology (2d Edition), 2017

Abstruse

Fumonisins are fungal toxins institute in maize and maize-based foods. Fumonisins are toxic to animals but their bear on on man health is uncertain. Epidemiological evidence suggests that fumonisins are potential risk factors for neural tube defects (NTDs) and for growth retardation of young children living in areas where large amounts of fumonisin-contaminated corn are consumed on a regular ground. Fumonisin B 1 (FB1), the most common fumonisin, was not teratogenic in some animate being studies although adverse embryonic and fetal affects secondary to maternal toxicity were found. These included generalized growth damage and, at high doses, fetal death in utero. Other investigations have in contrast shown that FB1 induces NTDs in some mouse strains. The etiology of NTDs is complex and involves interactions between environmental, nutritional, and genetic factors. Reasons underlying differences in the sensitivity of mouse strains to NTD induction by fumonisins are not fully understood although they likely involve fumonisin-dependent disruption of sphingolipid biosynthesis and sphingolipid-dependent effects on folate utilization and uptake, diverse cell signaling pathways, and histone modification.

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Fumonisins

Kenneth A. Voss , ... Janee Gelineau-van Waes , in Reproductive and Developmental Toxicology, 2011

Reaction with reducing sugars

Fumonisins react with reducing sugars to form products ( Humpf and Voss, 2004) that exhibit reduced toxicity when fed to swine (Fernandez-Surumay et al., 2005) or rats (Liu et al., 2001). Binding of the saccharide to the main amine part of FB1 forms N-substituted compounds including N-(1-deoxyfructos-ane-yl) FBone (Poling et al., 2002) and N-carboxymethyl FBi (Howard et al., 2002), resulting in detoxification. Extrusion cooking combined with glucose supplementation has shown hope as a method for significantly reducing fumonisin concentrations (Bullerman et al., 2008) and toxicity (Voss et al., 2008, 2010). However, the chemic fate of all fumonisins in the uncooked cloth could not be deemed for later extrusion, suggesting that unknown decomposition or bounden products were formed.

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Hazards and Diseases

J.I. Pitt , in Encyclopedia of Food Safe, 2014

Abstract

Fumonisins are mycotoxins produced principally in maize past Fusarium verticillioides and the closely related Fusarium proliferatum. Recently information technology has been found that Aspergillus niger produces fumonisins in grapes, wines, and stale vine fruits, just simply at depression concentrations. Fumonisins crusade a range of diseases in animals, the most important beingness leukoencephalomalacia in horses and liver cancer in rats. In areas of high maize consumption, fumonisins may be responsible for esophageal cancer in adults and possibly spinal defects in neonates. Maize is a dietary staple in parts of Africa, South and Central America, and Cathay, and fumonisin consumption sometimes exceed acceptable levels in those areas. Milling has little outcome on fumonisin levels in flour or other fractions. Notwithstanding, nixtamalization, a traditional Central American procedure, reduces levels very effectively. Heating above 160   °C, which occurs in the manufacture of some extruded products, as well reduces fumonisin levels.

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MYCOTOXINS | Toxicology

J. Gil-Serna , ... B. Patiño , in Encyclopedia of Food Microbiology (Second Edition), 2014

Fumonisins

Fumonisins are a grouping of at to the lowest degree xv closely related mycotoxins included in 4 groups (A, B, C, and P). Fumonisin B 1 (FB1) is the most frequent representing 70–80% of the full fumonisin content in food products and, together with fumonisin B2 and B3, seems to exist the major fumonisin. Fumonisins are polyhydroxyl alkylamines esterified with two carbon acids and differ past the presence and position of the free hydroxyl groups. The A series of fumonisins are acetylated on the amino group, whereas the B series have a free amine (Effigy ii). The main fumonisin-producing species are Fusarium verticillioides, Fusarium proliferatum, Fusarium fujikuroi, Fusarium globosum, Fusarium nygamai, and Fusarium subglutinans, all included in the Gibberella fujikuroi species circuitous. Contempo studies take shown that some strains of A. niger, Fusarium oxysporum and Alternaria alternata are able to produce fumonisins.

Effigy 2. Structures of some important Fusarium toxins.

Fumonisins have a worldwide occurrence mainly in corn and other cereals, such as barley, wheat, sorghum, and rice, and all their derivative products (biscuits, flour, breakfast cereals).

Acute intoxication with fumonisins causes diarrhea and intestinal pain, and their chronic exposure is correlated with esophageal cancer in humans. Several studies have pointed out that loftier levels of FB1 in corn are related to a high incidence of esophageal cancer in the population of the same regions. Therefore, FB1 has been classified as a possible human carcinogen by the IARC. Additionally, chronic intoxication with fumonisins of pregnant women produces neural tube defects in the fetus.

Animal responses to fumonisin exposition are dependent on the species. For instance, the effect of fumonisin on pigs is pulmonary edema, horses can develop leukoencephalomalacia, and rabbits can suffer from encephalon hemorrhage. Laboratory rats and mice have been demonstrated to develop kidney and liver cancer when exposed to fumonisins.

The symptoms associated with fumonisins are due to disruption of sphingolipids' metabolism by inhibition of the enzyme ceramide synthase. This fact supposes an aggregating of sphinganine and sphingosine, which are mediators of fumonisin toxicity since they take been shown to induce oxidative stress and apoptosis in cellular lines.

Maximum limits for the total content of fumonisins have been established in the Eu in maize and maize-based products (EC   No. 1126/2007). Other countries have adopted similar limits for fumonisins, although in the majority of the international markets no limits for fumonisins accept been set.

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Mycotoxins: Toxicology

M. Mostrom , in Encyclopedia of Nutrient and Health, 2016

Fumonisins

Fumonisins are produced by Fusarium molds primarily on corn and absorbed from the alimentary canal and appear to be speedily excreted unmetabolized from the gut. Several studies accept linked fumonisin contagion of maize with esophageal cancer in humans in South Africa and China; however, a definitive link of fumonisin B1 to man cancer has non been determined. Fumonisin B1 is classified as possibly carcinogenic to humans (IARC group 2B) with inadequate testify of carcinogenicity in humans but sufficient prove for carcinogenicity in rodent livers. Fumonisin exposure and possible neural tube defects have been reported in animal studies and suggested to occur in human babies when mothers in early on pregnancy consume fumonisin-contaminated maize.

Fumonisins are somewhat unique in that markedly different clinical signs occur in unlike species with toxicity, although liver impairment appears to be mutual across species. Horses are very sensitive to fumonisins and develop liver toxicity and neurological signs of blindness, ataxia, and aimless circling that progresses to death; the lesion is leukoencephalomalacia or liquefactive necrosis of the white matter in cerebral hemispheres. At toxic levels of fumonisins, pigs develop open mouth animate, cyanosis of the skin and mucous membrane, high respiratory rate, inactivity, and expiry that is related to pulmonary edema. Poultry and adult cattle are relatively resistant to fumonisins and may develop liver damage and reduced feed intake at quite high concentrations of fumonisins in feed. Both the Usa FDA and European Marriage have recommended guidance levels of fumonisins in animal feeds.

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General Toxicologic Pathology

Wanda M. Haschek , ... Val R. Beasley , in Handbook of Toxicologic Pathology (Second Edition), 2002

A. SOURCE/OCCURRENCE

Fumonisins are mycotoxins produced past Fusarium verticillioides (= F. moniliforme), F. proliferatum, and a few other Fusarium species. Both fungi and fumonisins are found worldwide in corn as well as other cereals. Every bit an animal and human health threat, withal, fumonisins are associated with corn and corn-based foods. More than than 15 homologues accept been identified. Fumonisins B1 (FB1), Btwo (FBtwo), and B3 (FB3) are most mutual and are produced in an approximate ratio of 6:3:one. Other homologues, such as hydrolyzed fumonisins (also called aminopentols), may exist generated during nutrient preparation. Fumonisin concentrations vary geographically, oft differing betwixt nearby locations. Factors favoring fungal growth and toxin production include heat stress, insect damage, loftier humidity, and often a delay in harvest, as well every bit improper (moisture) storage. Insects that harm corn, such as the European corn borer, provide a means for the fungus to invade the plant. Resistance to the corn borer, equally found in some strains of genetically modified corn (GMO corn), due east.g. transgenic corn expressing Bacillus thuringiensis (Bt) toxin, decreases fungal invasion.

While fumonisins occur worldwide, especially high concentrations have been found in Communist china and southern Africa. Fumonisin concentrations in "home grown" corn from Linxiang, Cathay, and areas of the Transkei, southern Africa, are continuously high, and concentrations exceeding 100 ppm have been occasionally reported. Much lower concentrations of fumonisins, less than 1 to a few ppm, are generally institute in corn from the Us and South America, whereas corn from Canada is virtually complimentary of fumonisins. However, concentrations in excess of 10 ppm are not infrequently found, and concentrations ≥ 100 ppm occur given advisable climactic conditions such as the 1989 drought in the midwestern United States. Because fumonisin concentrations periodically can be high, there is a continuing possibility of episodic outbreaks of fumonisin-related diseases in susceptible animals such equally horses and pigs. Fumonisin concentrations in screenings and cracked, cleaved, or otherwise damaged kernels are generally higher. However, because the fungus is endophytic, normal-appearing corn may contain fumonisins.

Human being exposure to fumonisins is dietary, with the toxins found in a variety of commercial foods, including corn meal, corn flour, grits, masa, polenta, snack foods, and beer. In general, corn meal and blistering mixes take higher levels than more highly processed products. Sweet corn and popcorn take low fumonisin concentrations. Fumonisin residues in meat, milk, and eggs are negligible. Milling and distilling do not appreciably dethrone fumonisins. Fumonisins distribute unevenly in milling fractions with higher amounts found in bran, gluten, distiller grains, steep liquids, flour, meal, and grits. Corn starch, an important commercial product used in sweeteners, contains negligible amounts. The outcome of cooking on fumonisins is the discipline of ongoing enquiry. Some reports propose that fumonisins are resistant to thermal deposition at temperatures commonly used for cooking and blistering. However, other reports indicate that fumonisin concentrations are reduced in some products prepared by extrusion or in corn meal subsequently frying or autoclaving. Currently, there are no reliable methods for routinely assessing fumonisin exposures in humans.

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Mycotoxins: Classification

M. Mostrom , in Encyclopedia of Nutrient and Health, 2016

Fumonisins

Fumonisins are a grouping of heat-stable, h2o-soluble mycotoxins primarily produced in white and yellow corn in the field past Fuarsium verticillioides (syn. F. moniliforme) and F. proliferatum. Fumonisin contamination of other commodities is very express, although fumonisins can exist concentrated in coproducts of corn ethanol production in the distiller's grains. A period of drought during the growing season followed by wet, warm weather during pollination of corn favors development of fumonisins. Insect or bird impairment to corn provides a portal for mold invasion of the kernels, and oft fumonisins are plant in very loftier concentrations in corn screenings containing damaged kernels. Often, fumonisins are found to co-occur with other mycotoxins, particularly aflatoxin and tricothecenes, specifically deoxynivalenol (DON). Toxicity is associated with fumonisins Bi and B2, with fumonisin B2 usually occurring at virtually xxx% of fumonisin Bone concentration. Fumonisins FBiii, FB4, FAi, and FA2 occur at depression concentrations and practise not announced to be important toxicants at this fourth dimension. Fumonisins are chemically characterized as an aliphatic hydrocarbon with a terminal amine group and tricarboxylic acid side chains and are structurally similar to sphingolipids in cellular membranes. Horses (and rabbits) are the sensitive species. Fumonisins inhibit ceramide synthase enzyme involved with the conversion of sphinganine to sphingosine, which can increase sphinganine tissue concentrations and interfere with cellular growth, differentiation, and cell advice resulting in toxicity and carcinogenicity. Liver toxicity is often involved across species. Tissue and milk residues are not considered to exist a problem.

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Safety Assessment including Current and Emerging Problems in Toxicologic Pathology

Wanda M. Haschek , Kenneth A. Voss , in Haschek and Rousseaux's Handbook of Toxicologic Pathology (Third Edition), 2013

6.1 Source/Occurrence

Fumonisins are mycotoxins produced by Fusarium verticillioides (formerly Fusarium moniliforme Sheldon), Fusarium proliferatum, and a few other Fusarium species. Production past other species has also been reported, including Aspergillus niger and at least one Tolypocladium (Tolypocladium inflatum) species. Both the fungi and fumonisins are constitute worldwide in corn (Zea mays) also as other cereals. They have on occasion been plant in other crops, including cowpeas and asparagus. As an animal and human health threat, yet, fumonisins are associated with corn and corn-based foods. More than 30 homologs have been identified, and the number continues to grow. Fumonisins B1 (FBi), B2 (FB2), and B3 (FB3) are most mutual, and are produced in an guess ratio of 6   :   3   :   1. Fumonisin concentrations vary geographically, often differing between nearby locations.

Factors favoring fungal growth and toxin product include heat stress, insect damage, high humidity, and oft a delay in harvest, also as improper (wet) storage. Insects that damage corn, such as the European corn tapping, provide a means for the mucus to invade the plant. Resistance to the corn borer, as constitute in some strains of genetically modified corn (GMO), due east.g. transgenic corn expressing Bacillus thuringiensis kurstaki (Btk) toxin, decreases fungal invasion. Appropriately, fumonisin concentrations were found to exist lower in GMO corn than in unmodified cultivars that were grown under conditions favoring high amounts of insect damage.

While fumonisins occur worldwide, particularly high concentrations take been found in Communist china and southern Africa: fumonisin concentrations in "home grown" corn from Linxiang, China and areas of the Transkei, southern Africa exceeding 100   ppm have been occasionally reported. Much lower concentrations of fumonisins, less than 1 to a few ppm, are mostly found in corn from the USA and Southward America, while corn from Canada is virtually complimentary of fumonisins. Nevertheless, concentrations in excess of 10   ppm are not infrequently found and concentrations exceeding 100   ppm occur given appropriate climactic weather condition, such as the 1989 drought in the midwestern Us. Because fumonisin concentrations periodically can exist high, at that place is a continuing possibility of episodic outbreaks of fumonisin-related diseases in susceptible animals such as horses and pigs. Fumonisin concentrations in screenings and cracked, cleaved, or otherwise damaged kernels are generally higher than in whole grains. Notwithstanding, since the fungus is endophytic, normal-actualization corn may contain fumonisins.

Subconscious (masked) fumonisins are matrix-associated or matrix-spring forms present in corn or foods that are not detected by routine analytical methods. The contribution of hidden fumonisins to the full fumonisin content of corn or nutrient products is non firmly established, although some studies suggest that it might be considerable. The chemical nature of the mycotoxin–corn (or food)–matrix interactions, the prevalence of hidden fumonisins in corn or nutrient products, or their contribution to bioavailability and toxicity are not as even so established.

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Food Safety: Mycotoxins – Occurrence and Toxic Effects

J.D. Groopman , ... F. Wu , in Encyclopedia of Human Nutrition (Tertiary Edition), 2013

Toxicity

Fumonisin-contaminated corn has been associated with several brute diseases, including leukoencephalomalacia (LEM) in horses, pulmonary edema in swine, neurotoxicity, and feed refusal in multiple species, and hepatoxicity in horses, swine, and rats. Several studies have provided some possible insights into the mechanisms of toxicity. The fumonisins comport considerable structural similarity to the long-chain (sphingoid) base of operations backbones of sphingolipids. Information technology has been demonstrated that incubation of rat hepatocytes with fumonisins inhibited sphingolipid biosynthesis. FB one increased the amount of the biosynthetic intermediate sphinganine, which suggests that fumonisins inhibit the conversion of sphinganine to N-acyl-sphinganines. Information technology was later shown, using mouse cerebellar neurons in civilisation, that FB1 inhibited ceramide synthase in mouse brain microsomes with a competitive-like kinetic beliefs with respect to both sphinganine and stearoyl-CoA. Thus, disruption of the de novo pathway of sphingolipid biosynthesis may be a critical effect in the diseases that have been associated with consumption of fumonisins.

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Fungal Genomics

Jiujiang Yu , ... Thomas Due east. Cleveland , in Practical Mycology and Biotechnology, 2004

four.4 Fumonisins: Occurrence, Toxicity and Construction

Fumonisins are produced by F. verticillioides (teleomorph Gibberella moniliformis) and several related species. F. verticillioides is one of the about common ear and stalk rot pathogens of maize worldwide, and as a issue, fumonisins are frequent contaminants of maize (Munkvold and Desjardins 1997). Fumonisin Bone (FBane) is generally nowadays at the highest levels (seventy%) in naturally contaminated maize with the other B-series fumonisins (FB2, FB3 and FBiv) present at lower levels (5-20%) (Nelson et al. 1993). Consumption of fumonisin-contaminated feed can cause several fatal animal diseases, including cancer in rodents (Howard et al. 2001), and there are epidemiological correlations betwixt the consumption of F. verticillioides-rotted maize and man esophageal cancer in some regions of the world where maize is a dietary staple (Marasas 2001). Fumonisins are structurally similar to the sphingolipid intermediates sphinganine and sphingosine and disrupt sphingolipid metabolism by inhibiting the enzyme ceramide synthase (Wang et al. 1991). A causal relationship between the disruption of sphingolipid metabolism and fumonisin-associated diseases has non been established but seems likely given the multiple functions of sphingolipids in cells.

B-series fumonisins consist of a linear twenty-carbon backbone with an amine group at carbon 2 (C-two), a hydroxyl at C-3, methyl groups at C-12 and C-16, and half dozen-carbon tricarballylic esters at C-14 and C-15 (Fig. 4A) (Nelson et al. 1993). B-series fumonisins differ from i another by the presence or absence of hydroxyl groups at C-five and C-x.

Fig. 4. Chemic structure of Fumonisin B1. Chemic structure of Fumonisin B1 (A), and predicted biochemical steps and predicted functions of FUM proteins in fumonisin biosynthesis (B-F). (B), formation of the linear polyketide; (C) CoA activation, condensation with alanine, and carbonyl reduction of polyketide; (D) hydroxylation of backbone at C-10; (E) hydroxylation of backbone at C-5; (F) CoA activation of tricarboxylic acids (TCAs), and hydroxylation and TCA esterification of the fumonisin backbone at C-14 and C-15. The guild of most of the reactions following the formation of the linear polyketide is not known. Therefore the order of reactions indicated by the lettering of schemes B-F may not reflect the guild of reactions during fumonisin biosynthesis.

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