@article {DOI187, author = {KENICHIRO DOI and MASAKI FUJIOKA and YUI SOKUZA and MARIKO OHNISHI and MIN GI and MASANORI TAKESHITA and KENJI KUMADA and ANNA KAKEHASHI and HIDEKI WANIBUCHI}, title = {Chemopreventive Action by Ethanol-extracted Brazilian Green Propolis on Post-initiation Phase of Inflammation-associated Rat Colon Tumorigenesis}, volume = {31}, number = {2}, pages = {187--197}, year = {2017}, publisher = {International Institute of Anticancer Research}, abstract = {Background/Aim: 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. Materials and Methods: 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. Results: Post-initiation treatment with EEP significantly reduced the multiplicity of colorectal carcinomas compared to the control (0.40{\textpm}0.13/rat vs. 2.29{\textpm}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. Conclusion: 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.}, issn = {0258-851X}, URL = {https://iv.iiarjournals.org/content/31/2/187}, eprint = {https://iv.iiarjournals.org/content/31/2/187.full.pdf}, journal = {In Vivo} }