title: Effects of astaxanthin supplementation on chemically induced tumorigenesis in Wistar rats.
abstract: BACKGROUND
  Astaxanthin (ASTA) is a fat-soluble xanthophyll with powerful antioxidant functions. It is extracted from e.g. salmon, an important food source for certain human populations known to have a reduced risk of tumor development. It is possible that ASTA plays a role in cancer chemoprevention in such populations. The purpose of this study was to investigate the effects of dietary ASTA on chemically induced mammary tumorigenesis using N-methyl-N-nitroso-urea (MNU) in immature Wistar rats.
  
  
  METHODS
  Thirty-six 37 days old juvenile female Wistar rats were at random allocated to 4 groups of which Groups 1 and 2 received a single dose of 55 mg MNU/kg body weight. The effects of ASTA was evaluated by giving rats of Groups 2 and 4 a dose of 50 mg ASTA/kg/day for the entire duration of the study. Group 3 rats received feed added alimentary oil.Necropsy and histopathological examinations were carried out on each rat 14 months after the administration of MNU. Haematological values and antioxidative status were determined. Oxidative stress was evaluated by monitoring superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in hepatic tissue. Lipid peroxidation and carbonylation of proteins was determined in protein extracts from the liver.
  
  
  RESULTS
  Tumor development occurred only in rats of Groups 1 and 2, i.e. MNU exposed animals. Frequency of tumor development in general and average number of tumors per animal were insignificant between these two groups. Mammary gland tumors developed in equal frequencies in Group 1 and 2 rats, respectively. Although only rather few tumors were found in the mammary glands, a substantial number of other tumors were found in Group 1 and 2 rats, but at equal rates.Biochemical analyses showed significant higher levels of GPx, malondialdehyde and dinitrophenylhydrazine in Group 1 rats that for rats in all other groups thus indicating protective effects of ASTA on MNU induced hepatic oxidative stress.
  
  
  CONCLUSIONS
  Supplementation with ASTA did not reduce tumorigenesis induced by MNU in Wistar rats. However, supplementation with ASTA seemed to have anti-inflammatory effects.
authors.affiliation: Department of Pathologic Anatomy, Necropsy and Veterinary Forensic Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Calea Mănăstur, Cluj-Napoca, Romania. adrianfloringal@yahoo.com
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Gal
authors.forename: Sanda
authors.initials: S
authors.lastname: Andrei
authors.forename: Cristina
authors.initials: C
authors.lastname: Cernea
authors.forename: Marian
authors.initials: M
authors.lastname: Taulescu
authors.forename: Cornel
authors.initials: C
authors.lastname: Catoi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D019587:Dietary Supplements; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006403:Hematologic Tests / Q000662:veterinary; D015227:Lipid Peroxidation; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy*; D008770:Methylnitrosourea / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D024341:Xanthophylls / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D024341:Xanthophylls; D008770:Methylnitrosourea; C005948:astaxanthine; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase