Doi Kenichiro, Fujioka Masaki, Sokuza Yui, Ohnishi Mariko, Gi Min, Takeshita Masanori, Kumada Kenji, Kakehashi Anna, Wanibuchi Hideki
Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
Department of Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan
In Vivo. 2017 Mar-Apr;31(2):187-197. doi: 10.21873/invivo.11044.
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.
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.
背景/目的：长期以来，蜂胶已被用于多种民间药物，具有多种药用特性。在本研究中，直接比较了乙醇提取物（EEP）和水提取物（WEP）巴西绿蜂胶对炎症相关大鼠结肠肿瘤发生起始后阶段的影响。
6周龄雄性F344大鼠在第一周内皮下注射两次1,2 - 二甲基肼（DMH），剂量为40 mg/kg体重，随后在饮用水中加入1%葡聚糖硫酸钠（DSS），持续一周。经过1周的无处理期后，动物分别给予基础东方MF粉状饲料，或在基础饲料中添加1% EEP或1% WEP，直至第32周。
与对照组相比，EEP起始后治疗显著降低了结直肠癌的多发性（分别为0.40±0.13/只大鼠 vs. 2.29±0.84/只大鼠，p<0.05），EEP还减小了肿瘤体积。免疫组织化学分析显示，EEP处理大鼠的结肠肿瘤中，炎症相关蛋白诱导型一氧化氮合酶、肿瘤坏死因子α、核因子κB和谷胱甘肽过氧化物酶-2的表达显著降低。
抑制由DMH引发并由DSS促进的炎症和氧化应激是EEP抑制致癌作用的主要机制。
