title: Chemopreventive Action by Ethanol-extracted Brazilian Green Propolis on Post-initiation Phase of Inflammation-associated Rat Colon Tumorigenesis.
abstract: Propolis has since long been utilized in numerous folk medicines with a variety of medicinal properties. In this study, the effects of ethanol-extracted (EEP) and water-extracted (WEP) Brazilian green propolis on the post-initiation phase of inflammation-associated rat colon tumorigenesis were directly compared.
  
  
  
  Male F344 rats at 6 weeks of age were subcutaneously injected with 1,2-dimethylhydrazine (DMH) at 40 mg/kg body weight twice during the first week, followed by 1% dextran sodium sulfate (DSS) in drinking water for one week. After a 1-week no-treatment period, animals were administered either basal Oriental MF powdered diet, or 1% EEP or 1% WEP in the basal diet until week 32.
  
  
  
  Post-initiation treatment with EEP significantly reduced the multiplicity of colorectal carcinomas compared to the control (0.40±0.13/rat vs. 2.29±0.84/rat, respectively, p<0.05), and EEP also reduced the tumor volume. Immunohistochemically, expression of inflammation-associated proteins inducible nitric oxide synthase, tumor necrotic factor alpha, nuclear factor kappa B and glutathione peroxidase-2 were significantly diminished in colorectal tumors from EEP-treated rats.
  
  
  
  Suppression of inflammation and oxidative stress, which had been triggered by DMH and promoted by DSS, was a primary mechanism by which EEP suppressed carcinogenesis.
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Doi
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujioka
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yui
authors.initials: Y
authors.lastname: Sokuza
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Ohnishi
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Min
authors.initials: M
authors.lastname: Gi
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Takeshita
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kumada
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Anna
authors.initials: A
authors.lastname: Kakehashi
authors.affiliation: Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan wani@med.osaka-cu.ac.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Wanibuchi
mesh_terms: D019813:1,2-Dimethylhydrazine; D000818:Animals; D002273:Carcinogens; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D003092:Colitis / Q000139:chemically induced / Q000517:prevention & control*; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D016264:Dextran Sulfate; D000431:Ethanol / Q000737:chemistry; D005979:Glutathione Peroxidase / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D011429:Propolis / Q000302:isolation & purification / Q000494:pharmacology*; D011916:Rats, Inbred F344; D013997:Time Factors; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D002273:Carcinogens; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D000431:Ethanol; D011429:Propolis; D016264:Dextran Sulfate; D005979:Glutathione Peroxidase; C525844:glutathione peroxidase 2, rat; D052247:Nitric Oxide Synthase Type II; D019813:1,2-Dimethylhydrazine
keywords: Ethanol-extracted propolis; colon cancer; dextran sodium sulfate; dimethylhydrazine; inflammation; oxidative stress; rat