title: Effects of iron-unsaturated human lactoferrin on hydrogen peroxide-induced oxidative damage in intestinal epithelial cells.
abstract: Human milk (HM) contains various bioactive antioxidants. Lactoferrin (Lf) has been assumed to be one of the major antioxidants in HM. We examined the antioxidative properties of iron-unsaturated human Lf (apo-hLf, the major form of Lf in HM) in two intestinal epithelial cell lines: (1) An intestinal epithelial cell line (IEC-6) were preincubated for 24 h with either 50 microg/mL of apo-hLf, iron-saturated human Lf (holo-hLf), iron-unsaturated bovine transferrin (apo-bTf), or 800 ng/mL of the iron-chelating compound deferoxamine (DFX), followed by hydrogen peroxide (H2O2) challenge to induce oxidative stress. Survival rates were significantly higher in the cells preincubated with apo-hLf and DFX than those preincubated with holo-hLf. (2) Caco-2 cells were preincubated with or without apo-hLf for 24 h, followed by an H2O2 challenge. Intracellular oxidative stress was assessed by a fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA). Fluorescent intensity of cell images and cell homogenates was significantly lower in the cells preincubated with apo-hLF than those preincubated without apo-hLF. Our study indicates that apo-hLf alleviates H2O2-induced oxidative damage in intestinal cells due to the iron-chelating capacity. Therefore, Lf in HM may act as an antioxidant in the gastrointestinal tract (GIT).
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University School of Medicine, 113-0033 Tokyo, Japan. hiromichi.shoji@nifty.ne.jp
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Shoji
authors.forename: Satoshi
authors.initials: S
authors.lastname: Oguchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Shinohara
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shimizu
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamashiro
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D007781:Lactoferrin / Q000502:physiology*; D008895:Milk, Human / Q000502:physiology; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats
chemical_list: D016877:Oxidants; D006861:Hydrogen Peroxide; D007501:Iron; D007781:Lactoferrin