title: Vitamin E content in fish oil emulsion does not prevent lipoperoxidative effects on human colorectal tumors.
abstract: OBJECTIVE
  The anticancer action exerted by polyunsaturated fatty acid peroxidation may not be reproduced by commercially available lipid emulsions rich in vitamin E. Therefore, we evaluated the effects of fish oil (FO) emulsion containing α-tocopherol 0.19 g/L on human colorectal adenocarcinoma cells and tumors.
  
  
  METHODS
  HT-29 cell growth, survival, apoptosis, and lipid peroxidation were analyzed after a 24-h incubation with FO 18 to 80 mg/L. Soybean oil (SO) emulsion was used as an isocaloric and isolipidic control. In vivo, nude mice bearing HT-29 tumors were sacrificed 7 d after an 11-d treatment with intravenous injections of FO or SO 0.2 g ∙ kg(-1) ∙ d(-1) FO or SO to evaluate tumor growth, necrosis, and lipid peroxidation.
  
  
  RESULTS
  The FO inhibited cell viability and clonogenicity in a dose-dependent manner, whereas SO showed no significant effect compared with untreated controls. Lipid peroxidation and cell apoptosis after treatment with FO 45 mg/L were increased 2.0-fold (P < 0.01) and 1.6-fold (P = 0.04), respectively. In vivo, FO treatment did not significantly affect tumor growth. However, immunohistochemical analyses of tumor tissue sections showed a decrease of 0.6-fold (P < 0.01) in the cell proliferation marker Ki-67 and an increase of 2.3-fold (P = 0.03) in the necrotic area, whereas malondialdehyde and total peroxides were increased by 1.9-fold (P = 0.09) and 7.0-fold (P < 0.01), respectively, in tumors of FO-treated compared with untreated mice.
  
  
  CONCLUSIONS
  These results suggest that FO but not SO has an antitumor effect that can be correlated with lipid peroxidation, despite its vitamin E content.
authors.affiliation: Nutrition, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Fang
authors.initials: F
authors.lastname: Cai
authors.forename: Virginie
authors.initials: V
authors.lastname: Granci
authors.forename: Olivier
authors.initials: O
authors.lastname: Sorg
authors.forename: Franz
authors.initials: F
authors.lastname: Buchegger
authors.forename: Claude
authors.initials: C
authors.lastname: Pichard
authors.forename: Yves Marc
authors.initials: YM
authors.lastname: Dupertuis
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000473:pathology; D004655:Emulsions / Q000032:analysis / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage* / Q000737:chemistry; D019073:HT29 Cells; D006801:Humans; D007150:Immunohistochemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D051379:Mice; D013024:Soybean Oil / Q000008:administration & dosage / Q000737:chemistry; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D000970:Antineoplastic Agents; D004655:Emulsions; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D014810:Vitamin E; D013024:Soybean Oil