• Title, Summary, Keyword: murine carcinogenesis model

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Suppressive Effects of Vitamin E on the Induction of Placental Glutathione S-transferase(GST-P) Positive foci and Antioxidant Enzyme Activity in Rat Hepatocarcinogenesis (비타민 E가 쥐간 세포의 암화과정에서 태반형 Glutathione S-transferase(GST-P) 양성 병소와 항산화요소계에 미치는 영향)

  • 최혜미
    • Journal of Nutrition and Health
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    • v.30 no.7
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    • pp.803-812
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    • 1997
  • The influences of dietary supplements of vitamin E on hepatocellular chemical carcinogenesis have been studied, Placental glutathione S-transferase(GST-P) positive foci area, antioxidant enzymes(superoxide dismutase(SOD), catalase, glutathione reductase, glutathione peroxidase, glutathione S-transferase(GST)), glucose 6-phosphatase(G6Pase) activities, and lipid peroxidation of mecrosomes(thiobarbituric acid reactive substances(TBARS) contents) were investigated. For is purpose , we used the murine chemical hepatocardinogenic procedure induced by modified Ito model, which consists of 200mg/kg body weight diethylinitrosamine (DEN) injection, 0.01% 2-acethlaminoflurene(2-AAF) feeding for 6 weeks, and partial hepatectomy on week 3. Weanling Sprague-Dawley male rats were fed pulverized Purina rat chow with 15, 000IU/kg diet vitamin E from initiation or promotion stages. We found that vitamin E supplement decreased the area of GST-P positive foci. Catalase, glutathione peroxidase, glutathione reductase. GST activities, and TBARS contents were decreased. On the other hand G6Pase activities were increased by vitamin E supplement. It seemed that vitamin E supplements helped endogenous defense systems against carcinogenesis by decreasing TBARS contents, $H_2O$$_2$ and organic peroxides. So, vitamin E seemed to protect cell from free radical damage in carcinogenesis. Anticarcinogenic effects of vitamin E were more effective at intiation that at promotion stage. These results suggest that vitamin E has suppressive effects on hepatocellular chemical carcinogenesis, probably through antioxidant effects against TBARS contents $H_2O$$_2$ and orgainc peroxides.

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Isolation of a Quinone-rich Fraction from Ardisia crispa Roots and its Attenuating Effects on Murine Skin Tumorigenesis

  • Yeong, Looi Ting;Hamid, Roslida Abdul;Yazan, Latifah Saiful;Khaza'ai, Huzwah
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2301-2305
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    • 2013
  • Ardisia crispa (Family: Myrsinaceae) is an evergreen, fruiting shrub that has been traditionally used as folklore medicine. Despite a scarcity of research publications, we have succeeded in showing suppressive effects on murine skin papillomagenesis. In extension, the present research was aimed at determining the effect of a quinone-rich fraction (QRF) isolated from the same root hexane extract on both initiation and promotion stages of carcinogenesis, at the selected dose of 30 mg/kg. Mice (groups I-IV) were initiated with a single dose of 7,12-dimethylbenz(${\alpha}$)anthracene (DMBA, $100{\mu}g/100{\mu}l$) followed by repeated promotion of croton oil (1%) twice weekly for 20 weeks. In addition, group I (anti-initiation) received QRF 7 days before and after DMBA; group II (anti-promotion) received QRF 30 minutes before each croton oil application; group III (anti-initiation/promotion) was treated with QRF as a combination of group I and II. A further two groups served as vehicle control (group V) and treated control (group VI). As carcinogen control, group IV showed the highest tumor volume ($8.79{\pm}5.44$) and tumor burden ($3.60{\pm}1.17$). Comparatively, group III revealed only 20% of tumor incidence, tumor burden ($3.00{\pm}1.00$) and tumor volume ($2.40{\pm}1.12$), which were significantly different from group IV. Group II also showed significant reduction of tumor volume (3.11), tumor burden (3.00) and tumor incidence (11.11%), along with prominent increase of latency period of tumor formation (week 12). Group I, nonetheless, demonstrated marked increment of tumor incidence by 40% with prompted latency period of tumor formation (week 7). No tumor formation was observed in groups V and VI. This study provided clear evidence of inhibitory effects of QRF during promotion period which was in agreement with our previous findings. The mechanism(s) underlying such effects have yet to be elucidated.

Inhibitory Effects of Low-Dose Aloe-Emodin on the Development of Colorectal Tumors in Min Mice

  • Shimpo, Kan;Chihara, Takeshi;Kaneko, Takaaki;Beppu, Hidehiko;Wakamatsu, Kazumasa;Shinzato, Masanori;Yukitake, Jun;Sonoda, Shigeru
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.14
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    • pp.5587-5592
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    • 2014
  • Aloe-emodin (AE), a natural anthraquinone compound, has been reported to exhibit anticancer activity in various cancer cell lines and anti-inflammatory effects in murine macrophages. In the present study, we investigated the cancer chemopreventive effects of AE in an Apc-deficient Min mouse model. In the first experiment, male Min mice were fed a basal diet or diets containing 5 ppm AE and 10 ppm AE for 12 weeks. The dietary administration of 5 ppm AE significantly reduced the number of colorectal tumors. In a second experiment, we investigated the effects of AE on colitis-related colon carcinogenesis in Min mouse treated with dextran sodium sulfate (DSS). Female Min mice were administered 1% DSS in their drinking water for 7 days. AE was given to mice in their diet at a dose of 5 or 50 ppm for 5 weeks. Feeding with AE significantly reduced the number of colorectal tumors. When proliferation of cells in normal-appearing colonic mucosa was assessed by monoclonal anti-rat Ki-67 antibody (MIB-5) immunohistochemistry in experiments 1 and 2, the AE treatment significantly decreased the mean MIB-5-labeling index. These results suggest that the dietary administration of low-dose AE may have chemopreventive effects against development of colorectal tumors in Min mice, possibly in part by reducing cell proliferation in colorectal mucosa.