title: High bioavailability iron maize (Zea mays L.) developed through molecular breeding provides more absorbable iron in vitro (Caco-2 model) and in vivo (Gallus gallus).
abstract: BACKGROUND
  Iron (Fe) deficiency is the most common micronutrient deficiency worldwide. Iron biofortification is a preventative strategy that alleviates Fe deficiency by improving the amount of absorbable Fe in crops. In the present study, we used an in vitro digestion/Caco 2 cell culture model as the guiding tool for breeding and development of two maize (Zea mays L.) lines with contrasting Fe bioavailability (ie. Low and High). Our objective was to confirm and validate the in vitro results and approach. Also, to compare the capacities of our two maize hybrid varieties to deliver Fe for hemoglobin (Hb) synthesis and to improve the Fe status of Fe deficient broiler chickens.
  
  
  METHODS
  We compared the Fe-bioavailability between these two maize varieties with the presence or absence of added Fe in the maize based-diets. Diets were made with 75% (w/w) maize of either low or high Fe-bioavailability maize, with or without Fe (ferric citrate). Chicks (Gallus gallus) were fed the diets for 6 wk. Hb, liver ferritin and Fe related transporter/enzyme gene-expression were measured. Hemoglobin maintenance efficiency (HME) and total body Hb Fe values were used to estimate Fe bioavailability from the diets.
  
  
  RESULTS
  DMT-1, DcytB and ferroportin expressions were higher (P<0.05) in the "Low Fe" group than in the "High Fe" group (no added Fe), indicating lower Fe status and adaptation to less Fe-bioavailability. At times, Hb concentrations (d 21,28,35), HME (d 21), Hb-Fe (as from d 14) and liver ferritin were higher in the "High Fe" than in the "Low Fe" groups (P<0.05), indicating greater Fe absorption from the diet and improved Fe status.
  
  
  CONCLUSIONS
  We conclude that the High Fe-bioavailability maize contains more bioavailable Fe than the Low Fe-bioavailability maize, presumably due to a more favorable matrix for absorption. Maize shows promise for Fe biofortification; therefore, human trials should be conducted to determine the efficacy of consuming the high bioavailable Fe maize to reduce Fe deficiency.
authors.affiliation: USDA-ARS Robert W, Holley Center for Agriculture and Health, 538 Tower Road, Cornell University, Ithaca, NY 14853, USA. et79@cornell.edu
authors.forename: Elad
authors.initials: E
authors.lastname: Tako
authors.forename: Owen A
authors.initials: OA
authors.lastname: Hoekenga
authors.forename: Leon V
authors.initials: LV
authors.lastname: Kochian
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Glahn
mesh_terms: D018798:Anemia, Iron-Deficiency; D000818:Animals; D001682:Biological Availability; D018938:Caco-2 Cells; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D003573:Cytochrome b Group / Q000235:genetics / Q000378:metabolism; D032621:DNA Shuffling; D004032:Diet; D005290:Ferric Compounds / Q000493:pharmacokinetics; D005527:Food, Fortified; D015870:Gene Expression; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D019266:Iron, Dietary / Q000493:pharmacokinetics*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010833:Phytic Acid / Q000008:administration & dosage / Q000032:analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry* / Q000235:genetics; D000098742:Ferroportin; D000099236:Solute Carrier Family 11, Member 2
chemical_list: D027682:Cation Transport Proteins; D003573:Cytochrome b Group; D005290:Ferric Compounds; D006454:Hemoglobins; D019266:Iron, Dietary; D010088:Oxidoreductases; D010833:Phytic Acid; D012333:RNA, Messenger; D000098742:Ferroportin; D000099236:Solute Carrier Family 11, Member 2; C025314:ferric citrate; C422926:CYBRD1 protein, human