RESUMO
SCOPE: Fumonisin (FB) occurs in maize and is an inhibitor of ceramide synthase (CerS). We determined the urinary FB1 (UFB1 ) and sphingoid base 1-phosphate levels in blood from women consuming maize in high and low FB exposure communities in Guatemala. METHODS AND RESULTS: FB1 intake was estimated using the UFB1 . Sphinganine 1-phosphate (Sa 1-P), sphingosine 1-phosphate (So 1-P), and the Sa 1-P/So 1-P ratio were determined in blood spots collected on absorbent paper at the same time as urine collection. In the first study, blood spots and urine were collected every 3 months (March 2011 to February 2012) from women living in low (Chimaltenango and Escuintla) and high (Jutiapa) FB exposure communities (1240 total recruits). The UFB1 , Sa 1-P/So 1-P ratio, and Sa 1-P/mL in blood spots were significantly higher in the high FB1 intake community compared to the low FB1 intake communities. The results were confirmed in a follow-up study (February 2013) involving 299 women living in low (Sacatepéquez) and high (Santa Rosa and Chiquimula) FB exposure communities. CONCLUSIONS: High levels of FB1 intake are correlated with changes in Sa 1-P and the Sa 1-P/So 1-P ratio in human blood in a manner consistent with FB1 inhibition of CerS.
Assuntos
Inibidores Enzimáticos/farmacologia , Fumonisinas/toxicidade , Oxirredutases/antagonistas & inibidores , Zea mays/microbiologia , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Eritrócitos/química , Feminino , Fumonisinas/urina , Humanos , Lisofosfolipídeos/sangue , Pessoa de Meia-Idade , Esfingosina/análogos & derivados , Esfingosina/sangueRESUMO
SCOPE: Fumonisin (FB) intake can be high when maize is a dietary staple. We determined (i) urinary FB (UFB) in women consuming maize in high- and low-exposure communities in Guatemala, (ii) the FB levels in maize, (iii) the relationship between UFB and FB intake, and (iv) the relative excretion of UFB1 , UFB2 , and UFB3 . METHODS AND RESULTS: Urine and maize were analyzed for FB for 1 year in three departments. Maize consumption was estimated by an interview questionnaire. Fumonisin B1 , B2 , and B3 (FB1 , FB2 and FB3 ), were detected in 100% of maize samples. FB1 in maize and urine was significantly higher in Jutiapa compared to Chimaltenango or Escuintla. The FB intake paralleled UFB1 in a dose-dependent manner but UFB1 was present in much higher levels than UFB2 or UFB3 compared to maize. CONCLUSION: In Jutiapa, agroecological conditions favored FB production. UFB1 mirrored the estimated FB intake. UFB1 > 0.1 ng/mL resulted in a dose-dependent increase in the risk of exceeding FB intake of 2 µg/kg b.w./day compared to women with no detectable UFB1 . More than 50% exceeded 2 µg/kg b.w./day when UFB1 was >0.5 ng/mL. UFB2 and UFB3 were rarely detected confirming that FB1 is either absorbed better or preferentially excreted in urine.
Assuntos
Fumonisinas/administração & dosagem , Fumonisinas/urina , Adulto , Feminino , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Guatemala , Humanos , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem , Zea mays/química , Zea mays/microbiologiaRESUMO
SCOPE: Fumonisins (FB) are mycotoxins found in maize. The purpose of this study was to (i) determine the relationship between FB(1) , FB(2) , and FB(3) intake and urinary excretion in humans, (ii) validate a method to isolate urinary FB on C(18) -SPE cartridges for international shipment, and (iii) test the method using samples from Guatemala. METHODS AND RESULTS: Volunteers (n = 10) consumed 206 grams/day of tortillas and biscuits prepared from masa flour and a product containing maize flour. Volunteers estimated their daily urine output and samples were analyzed for FB(1) , FB(2) , and FB(3) and hydrolyzed FB(1) . Only FB(1) was detected in urine suggesting lower absorption of FB(2) and FB(3) . Excretion was highly variable peaking soon after consumption began and decreasing rapidly after consumption stopped. Within 5 days after consumption ended, FB(1) was not detected in urine. In a study with eight volunteers, the average total urinary FB(1) was 0.5% of the intake. FB(1) was detected in 61% (107/177) of the samples collected in Guatemala. CONCLUSION: The results support the use of urinary FB(1) to assess ongoing exposure in population-based studies. However, relating the FB(1) concentration in urine to dietary intake of FB by individual subjects will be complicated due to interindividual variability and the rapidity of clearance.