title: Antioxidant enzyme activities of iron-saturated bovine lactoferrin (Fe-bLf) in human gut epithelial cells under oxidative stress.
abstract: Chemoprevention by dietary constituents in the form of functional food has emerged as a novel approach to control inflammatory diseases and cancers. Recently we reported for the first time that iron content is a critical determinant in the anti-tumour activity of bovine milk lactoferrin (bLf). We therefore wanted to evaluate the chemo-preventative efficacy of Apo-bLF and 100% iron-saturated bLF (Fe-bLF) on hydrogen peroxide (H2O2)-induced colon carcinogenesis, and their influence on antioxidant enzyme activities within colon carcinogenesis. This was undertaken through observing how oxidative stress induced by H2O2 alters antioxidant enzyme activity within HT29 colon cancer cells, and then observing changes in this activity by treatments with the different antioxidants ascorbic acid (AA), Apo-bLF and Fe-bLF. All antioxidant enzymes (catalase, glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-s-transferase (GsT) and superoxide dismutase (SOD)) appeared to be increased within HT29 cells, even prior to H2O2 exposure, and all enzymes showed significant decreased activity when cells were treated with the antioxidants AA, Apo-bLF or Fe-bLF, with or without H2O2 exposure. The results indicate that all three antioxidants have the ability to scavenge ROS, lower antioxidant enzyme activities within already excited states, and possibly allow colon cancer cells to be overcome by oxidative stress that would normally be prevented, perhaps leading to damage and potential apoptosis of the cancer cells. In conclusion, the anti-oxidative effects of Apo-bLF and Fe-bLf studied for the first time, show dynamic changes that may allow for necessary protection from imbalanced oxidative conditions, and potential at reducing the ability of cancer cells to protect themselves from oxidative stress states.
authors.affiliation: Laboratory of Immunology and Molecular Biomedical Research (LIMBR), Centre for Biotechnology and Interdisciplinary Biosciences (BioDeakin), Institute for Technology Research and Innovation (ITRI), Deakin University, Waurn Ponds, Victoria, Australia.
authors.forename: Hannah
authors.initials: H
authors.lastname: Burrow
authors.forename: Rupinder K
authors.initials: RK
authors.lastname: Kanwar
authors.forename: Jagat R
authors.initials: JR
authors.lastname: Kanwar
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002374:Catalase / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D004847:Epithelial Cells / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D007781:Lactoferrin / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D013329:Structure-Activity Relationship; D013482:Superoxide Dismutase / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D006861:Hydrogen Peroxide; D007501:Iron; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D007781:Lactoferrin