Comparison of three methods for the extraction of aflatoxins from human serum in combination with a high-performance liquid chromatographic assay

Assessment of serum aflatoxin B1 levels in neonatal jaundice with glucose-6-phosphate dehydrogenase deficiency: a preliminary study

Aflatoxin (AF) contamination of food products is still a major health issue globally. Prior studies suggest that exposure to AFs during pregnancy has harmful fetal outcomes. This preliminary study was designed to assess serum AFB₁ levels in neonatal jaundice (NNJ) secondary to glucose-6-phosphate dehydrogenase (G6PD) deficiency. Twenty-four full-term neonates with hemolytic jaundice secondary to G6PD deficiency were enrolled in the study. Erythrocyte G6PD status was assessed colorimetrically, and serum aflatoxin B₁ (AFB₁) concentrations were measured by high-performance liquid chromatography. The results revealed that AFB₁ was detected in 58% (14/24) of the studied newborns while detected in 75% (18/24) of their mothers. AFB₁ positive cases had a highly significantly lower birthweight and G6PD activity (P = 0.001, each). Birthweight (r = - 0.574, P = 0.032) and G6PD activity (r = - 0.585, P = 0.028) negatively correlated with serum AFB₁ levels while serum alanine aminotransferase activity positively correlated with serum AFB₁ levels (r = 0.536, P = 0.048). Maternal AFB₁ exposure is associated with adverse birth outcomes as verified by the low birthweight and the evident decline in the activity of G6PD enzyme with the resultant hemolytic NNJ.

Toxicokinetics of aflatoxin in pregnant mice

Our objective was to study the toxicokinetics of aflatoxin (AF) in pregnant mice. Aflatoxin B1 (AFB1) was administered intraperitoneally (IP) to groups of pregnant mice in single doses of 20 mg/kg on gestation day (GD) 13 and orally at the same gestational age. Controls received (IP and oral) a proportionate volume of solvent only. Maternal blood was collected at 15, 30, 45, 60, 90, 120, and 150 minutes posttreatment. Their AFB1 contents were determined. Aflatoxin B1 concentrations following maternal exposure to AFB1 were highly correlated with time after exposure. The serum concentrations were predictable and the highest serum levels were seen immediately at 15 minutes in mice given AFs IP and at 30 minutes in those given it orally. The absorption was 5.0 microg/min and elimination was 3.0 microg/min. The toxicokinetics of AFB1 have been delineated. Aflatoxins are easily and rapidly absorbed both from the gastrointestinal tract (GI) tract and through the peritoneum.

Does aflatoxin as an environmental mycotoxin adversely affect the renal and hepatic functions of Egyptian lactating mothers and their infants? A preliminary report

BACKGROUNDS/AIMS

Aflatoxin as a mycotoxin constitutes a real human threat. Its presence in human milk was previously reported in different countries. This work is the first Egyptian report that aimed to assess the presence of aflatoxin in both mothers' milk and the infants' sera and studied its correlation with infants' kidney functions.

METHODS

Fifty healthy breast lactating mothers and their infants who were exclusively breast fed for at least 4 months were included. All of them were subjected to thorough laboratory evaluation including determination of aflatoxin concentration by high performance liquid chromatography.

RESULTS

Twenty-four mothers (48%) and their infants had been contaminated with aflatoxin with the following mean contamination levels (ng/ml); mothers' serum of 8.9+/-4.2, mothers' milk of 1.9+/-0.6 and infants' serum of 1.8+/-0.9. The presence of this contamination level is not associated with renal or hepatic dysfunction.

CONCLUSION

Mothers and their infants in our locality showed a relatively high aflatoxin contamination rate. We did not find a correlation of this contamination level and either renal or hepatic dysfunction.

Morbidity in neonates of mothers who have ingested aflatoxins

This study was undertaken to assess whether aflatoxin M(1) concentrations in newborn infants correlated with those of their mothers and to determine whether the presence of aflatoxin M(1) in cord blood was associated with an increase in morbidity in the newborn. There was a strong correlation (r =0.797, p <0.0001) between mothers' and cord blood levels of aflatoxin. There was also a strong negative correlation between aflatoxin levels and birthweight (r =-0.565, p <0.001) but there was no association between aflatoxin M(1) concentration in maternal or cord blood and rates of jaundice or infection.

Fetal exposure to aflatoxins in the United Arab Emirates

This is a prospective study in which aflatoxin levels were measured in umbilical cord blood from 201 women delivered consecutively in Tawam and Al Ain hospitals in order to determine whether the fetuses had been significantly exposed to the toxin. Aflatoxin B1, M1 and M2 were measured using high performance liquid chromatography. Aflatoxins were detected in 110 (54.7%) samples, 27 of which were positive for B1, 106 for M1 and 31 for M2. There was a significant negative correlation (p < 0.001) between birthweight and levels of aflatoxin. The high rate of detection of aflatoxins confirms that a significant number of infants in the UAE are exposed to these toxins which reflects maternal ingestion of aflatoxin-containing food. The presence of aflatoxin resulted in lower birthweights.

Oxidative degradation and detoxification of mycotoxins using a novel source of ozone

Practical methods to degrade mycotoxins using ozone gas (O3) have been limited due to low O3 production capabilities of conventional systems and their associated costs. Recent advances in electrochemistry (i.e. proton-exchange membrane and electrolysis technologies) have made available a novel and continuous source of O3 gas up to 20% by weight. It is possible that the rapid delivery of high concentrations of O3 will result in mycotoxin degradation in contaminated grains--with minimal destruction of nutrients. The major objectives of this study were to investigate the degradation and detoxification of common mycotoxins in the presence of high concentrations of O3. In this study, aqueous equimolar (32 microM) solutions of aflatoxins B1 (AfB1), B2 (AfB2), G1 (AfG1), G2 (AfG2), cyclopiazonic acid (CPA), fumonisin B1 (FB1), ochratoxin A (OA), patulin, secalonic acid D (SAD) and zearalenone (ZEN) were treated with 2, 10 and/or 20 weight% O3 over a period of 5.0 min and analysed by HPLC. Results indicated that AfB1 and AfG1 were rapidly degraded using 2% O3, while AfB2 and AfG2 were more resistant to oxidation and required higher levels of O3 (20%) for rapid degradation. In other studies, patulin, CPA, OA, SAD and ZEN were degraded at 15 sec, with no by-products detectable by HPLC. Additionally, the toxicity of these compounds (measured by a mycotoxin-sensitive bioassay) was significantly decreased following treatment with O3 for 15 sec. In another study, FB1 (following reaction with O3) was rapidly degraded at 15 sec, with the formation of new products. One of these appeared to be a 3-keto derivative of FB1. Importantly, degradation of FB1 did not correlate with detoxification, since FB1 solutions treated with O3 were still positive in two bioassay systems.

Aflatoxin: is it a neglected threat for formula-fed infants?

In the present study, the risk of exposure to aflatoxin in infants fed breast milk and formula was investigated. For this purpose, aflatoxin B1 (AFB1) was determined in the serum of both breast-fed and formula-fed infants. Serum AFB1 positivity was significantly higher in the formula-feeding (F) group than the breast-feeding (B) group (42.8 vs 8.5%, P < 0.01). The AFB1 concentration in different commercial formulas was also determined. Aflatoxin B1 was found in seven of the eight newly opened packages of different brands of formula. The concentrations showed a statistically significant increase at the 30th day after opening the packages (P < 0.01). Although AFB1 concentrations in the formulas were found to be within acceptable limits for most countries, still, its existence must be carefully evaluated because future influences of very small amounts of aflatoxin on the growing organism have not been fully elucidated. Therefore, it was again concluded that for infants, human milk is safer than commercial formulas because of the lower contamination risk of aflatoxin. Also, commercial formulas must be regularly examined by authorities for the possible risk of aflatoxin contamination.

Neonatal jaundice, aflatoxins and naphthols: report of a study in Ibadan, Nigeria

This study set out to investigate the prevalence of naphthols and aflatoxins in the sera of babies with neonatal jaundice and their mothers in order to determine whether they contribute to the occurrence of unexplained neonatal jaundice in Ibadan. Blood was obtained from 327 jaundiced neonates and 80 of their mothers, and 60 non-jaundiced controls and seven of their mothers admitted to hospital between April 1989 and April 1991. Blood group, bilirubin concentration, erythrocyte G6PD status, aflatoxin and naphthol concentrations in blood were measured. Altogether, 30.9% of the jaundiced neonates were G6PD-deficient, compared with 13.3% of controls (chi 2 = 6.88; p = 0.009). Aflatoxins were detected in 27.4% of jaundiced neonates, 17% of their mothers, 16.6% of controls and 14.4% of control mothers. Naphthols were detected in 7.2% of jaundiced babies, 6.3% of their mothers, 6.25% of control babies and 14.4% of their mothers. Analysis of the data revealed that either G6PD deficiency or the presence of any serum aflatoxin is a risk factor for neonatal jaundice; odds ratio were 2.97 (95%) confidence intervals (CI): 1.31-6.74) and 2.68 (CI: 1.18-6.10), respectively. This study demonstrates that G6PD deficiency and/or the presence of serum aflatoxins are risk factors for neonatal jaundice in Nigeria. Aflatoxins are an additional risk factor not previously reported.

Neonatal jaundice with reference to aflatoxins: an aetiological study in Zaria, northern Nigeria

Two prospective studies were undertaken to determine a possible relationship between perinatal aflatoxin exposure and neonatal jaundice. First, cord blood samples from 37 neonates who subsequently developed jaundice and from 40 non-jaundiced (control) babies were analysed for six major aflatoxins and aflatoxicol. Peripheral blood samples of both groups were also analysed postnatally for aflatoxins. In a second study, serum aflatoxin levels of 64 jaundiced neonates admitted from outside the hospital were compared with levels in 60 non-jaundiced control babies. Aflatoxins were detected in 14 (37.8%) cord blood samples of jaundiced neonates and in nine (22.5%) of the controls. The mean cord aflatoxin concentration was highest in jaundiced neonates with septicaemia, but the difference was not statistically significant. The frequency of detection of aflatoxins in peripheral blood was not significantly different in jaundiced and non-jaundiced babies. Aflatoxins were detected in the blood of over 50% of neonates with jaundice of 'unknown' aetiology. There was no correlation between severity of hyperbilirubinaemia and serum aflatoxin levels. Further studies are needed to determine the extent of pre- and postnatal exposure to aflatoxin in Nigerian infants and the effects of such exposure on fetal and neonatal health.

Aflatoxin, kwashiorkor, and morbidity

Children suffering from kwashiorkor could be grouped as those in whom aflatoxin was detectable in both serum and urine, and those in whom this mycotoxin was undetectable. Examination of the clinical records of the aflatoxin-positive and -negative children (58% and 42% of the sample, respectively) showed several other differences between the two groups. Compared with the aflatoxin-negative group, the children scored as aflatoxin-positive showed a significantly lower haemoglobin level (P = 0.02), a longer duration of oedema (P = 0.057), an increased number of infections (P = 0.037), and a longer duration of hospital stay (P = 0.008). The present findings suggest that the consumption of a staple food such as maize that is contaminated with the fungus Aspergillus flavus exposes susceptible kwashiorkor children to the metabolic hazards of aflatoxins, resulting in a greater risk of frequent infections.

Aflatoxins and kwashiorkor in Durban, South Africa

The present investigation has indicated that maize seeds stored under various simulated seasonal conditions show a spectrum of fungi that appear as a succession. The aflatoxin-producing fungus, Aspergillus flavus, is favoured by storage conditions of high temperature and humidity (summer and autumn seasons). This coincides with the more frequent admission of children suffering from kwashiorkor at King Edward VIII Hospital in Durban. Aflatoxin analysis was undertaken on 74 children diagnosed at King Edward VIII Hospital in Durban as cases of kwashiorkor, marasmus or underweight (Wellcome classification). The control group consisted of 35 age-matched patients with no symptoms of protein energy malnutrition. Aflatoxins were detected in serum and/or urine from all groups, including the controls. The serum/urine ratio was significantly higher in the kwashiorkor group than in the other groups. The control group, however, had a higher proportion of urine aflatoxins than the kwashiorkor group. These findings were interpreted in terms of impaired liver function in kwashiorkor. Aflatoxins may have a rôle in the pathogenesis of kwashiorkor, although the present findings do not indicate that they are a causal factor.

Chromatographic methods as tools in the field of mycotoxins

Achievements in the applications of chromatographic techniques in mycotoxicology are reviewed. Historically, column chromatography (CC) and paper chromatography (PC) were applied first, followed by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC). Although PC techniques are no longer used in the analysis of mycotoxins, selected applications of PC are included to underline historical continuity. The most important achievements published from 1980 onwards are described. They include clean-up methods, TLC, CC, HPLC and GC of mycotoxins in environmental samples, foods, feeds, body fluids and in studies on biosynthesis and biotransformations of mycotoxins. Advantages and disadvantages of chromatographic techniques used in mycotoxicology are also evaluated.

Foetal and neonatal exposure to aflatoxins

Studies on 125 primigravidae in rural Kenya revealed aflatoxins in the blood of 54 prenatally. At delivery re-examination of 34 showed aflatoxins in 12 previously negative. The overall detection rate was 53%. Blood from additional 59 women collected at delivery showed aflatoxins in 53%. Aflatoxins were detected in 37% of 101 cord bloods. There was no relationship between aflatoxins in maternal and cord bloods. The frequency of detection was significantly higher in maternal and cord bloods during the 'wet' than 'dry' months. The mean birth weights of females born to aflatoxin positive mothers was significantly lower (255 g) than those born to aflatoxin free mothers. Two stillbirths were recorded, in both cases maternal and cord blood showed aflatoxins. These findings and the adverse effects of prenatal aflatoxin exposure recorded in animal experiments indicate the need for further study of the effects of aflatoxins on the human foetus and newborn.