• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.595-600
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• 2015

Background: Accumulating evidence suggests that metformin possesses anticarcinogenic properties, and its use is associated with favorable outcomes in several cancers. However, it remains unclear whether metformin influences prognosis in prostate cancer (PCa) with concurrent type 2 diabetes (T2D). Materials and Methods: We searched PubMed, EMBASE, and the Cochrane Library from database inception to April 16, 2014 without language restrictions to identify studies investigating the effect of metformin treatment on outcomes of PCa with concurrent T2D. We conducted a meta-analysis to quantify the risk of recurrence, progression, cancer-specific mortality, and all-cause mortality. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated. Publication bias was assessed by Begg's rank correlation test. Results: A total of eight studies fulfilled the eligibility criteria. We found that diabetic PCa patients who did not use metformin were at increased risk of cancer recurrence (RR, 1.20; 95%CI, 1.00-1.44), compared with those who used metformin. A similar trend was observed for other outcomes, but their relationships did not reach statistical significance. Funnel plot asymmetry was not observed among studies reporting recurrence (p=0.086). Conclusions: Our results suggest that metformin may improve outcomes in PCa patients with concurrent T2D. Well-designed large studies and collaborative basic research are warranted.

• Preventive Nutrition and Food Science
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• 제7권4호
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• pp.358-366
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• 2002

To search for novel cancer preventive agents, we assessed the quinone reductase (QR)-inducing activities of medicinal herb extracts in cultured murine hepatoma cells (hepalclc7 cells). Among 216 herb extracts tested in this study, 8 kinds of herbal extracts were found to induce QR activity in hepalclc7 cells by more than 2-fold when used at the concentration of 25 $\mu\textrm{g}$/$m\ell$. The methanol extracts of Aster koraiensis NK and Pulsatilla koreana Nakai induced QR by 252 and 223 % , respectively, at the concentration of 25 $\mu\textrm{g}$/$m\ell$. Most of the herbal extracts with QR inducing-activity increased the enzyme activity in a typical dose-dependent manner. The QR activity in BP$^{r}$ cl cells was induced move than 50 % by the extracts of Pulsatilla koreana Nakai, Inula helenium, Physalis alkekengi var, francheti (Masters) Makino, Chrysanthemum zawadskii var. latilobum Kitamuva, Auemisia keiskeana Miquel, Chfsanthemum boreale Makino. In conclusion, hlsatilla koreana Nakai, Aster koraiensis N.K, and Chfsanthemum zawadskii var. iatilobum Kitamura, which showed relatively high QR induction, merit further animal study to evaluate their potential as cancer preventive agents.

• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.283-290
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• 2011

The recent increase of colon, breast, and prostate cancer incidence in Korea has been attributed to a diet pattern change to a more Western style, in which the foods eaten are higher in protein and fat. Whether high protein intake itself stimulates tumor cell growth and exacerbates disease status has been investigated, however, many epidemiological studies have inconsistent results between meat intake and the risk of certain cancers. These inconsistent results are partly because of the difficulty of studying the effects of just the meat intake. Other factors, such as overall meal context, could not be completely excluded in the study. To address the question of whether high protein itself is independently associated with carcinogenesis, we initiated ICR mice with 200 nmol ($50{\mu}g$) 7,12-dimethylbenz[a]anthracene (DMBA) and fed animals either a normal diet (ND, 14% casein) or a high protein diet (HPD, 50% casein) for 15 weeks with 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion in two-stage skin carcinogenesis protocol. There was no significant difference between ND and HPD group in food intake and body weight throughout the experiment. However, tumor multiplicity of the HPD group was decreased by 75.5% compared to that of the ND group. In addition, HPD inhibited skin hyperplasia and epidermal cell proliferation. Western analyses with whole skin lysates showed that HPD inhibited TPA-induced Akt (S473), S6K (T389), 4E-BP1 (Thr 37/46) and Erk1/2 (Thr202/Tyr204) phosphorylation as well as COX-2 expression. Taken together, these data suggest that a high protein diet has an anticarcinogenic effect by inhibiting the TPA-induced Akt signaling pathway.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 국제심포지움
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• pp.59-72
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• 2002

The anticarcinogenic effects of epicatechin(EC) and ginsenoside Rb2(Rb2), which are major components of green tea and Korea ginsen, respectively, were investigated using a model system of gap junctional intercellular communication (GJIC) in WB-F344 rat liver epithelial cells. 12-O-Tetradecanoylphorbol-13-accetate (TPA) and hydrogen preoxide, known as cancer promoters, inhibited GJIC in the epithelial cells as determined by the scrape loading/dye transfer assay, fluorescence redistribution assay after photobleaching, and immunofluorescent staining of connexin 43 using a laser confocal microscope. The inhibition of GJIC by TPA and H2O2 was prevented with treatment of Rb2 or Ec. The effect of EC on GJIC was stronger in TPA-treated cells than in H2O2-treated cells, while the effect of Rb2 was opoosite to that of EC. EC, at the concentration of 27.8$\mu$g/ml, prevented the TPA-induced GJIC inhibition by about 60%. Rb2, at the concentration of 277$\mu$g/ml, recovered the H2O2-induced GJIC inhibition by about 60%. These results suggest that Rb2 and EC may prevent human cancers by preventing the down-regulation of GJIC during the cancer promotion phase and that the anticancer effect of green tea and Korea ginseng may come from the major respective conponents, EC and Rb2.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1611-1616
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• 2014

Spirogyra neglecta, a freshwater green alga, is a local food in the northern and northeastern parts of Thailand. This investigation explored the anticarcinogenicity of S neglecta and its possible cancer chemopreventive mechanisms in rats divided into 14 groups. Groups 1 and 10 served as positive and negative control groups, respectively. Groups 1-9 were intraperitoneally injected with diethylnitrosamine (DEN) once a week for 3 weeks. Groups 10-14 received normal saline instead. One week after the last DEN injection, groups 2-5 were administered for 9 consecutive weeks various doses of S neglecta extract (SNE) and dried S neglecta (SND), mixed with basal diet. Groups 6-9 and 11-14 similarly were administered various doses of SNE and SND starting from the first week of the experiment. Administration of SNE and SND was not associated with formation of glutathione-Stransferase placental form (GST-P) positive foci in rat liver. SNE and SND during initiation phase significantly reduced the number of GST-P positive foci in rats injected with DEN. The number of GST-P also diminished in groups treated with SNE and SND after injection with DEN, except for the low dose extract group. SNE showed stronger anticarcinogenic potency than SND. Furthermore, SNE also decreased the number of Ki-67 positive cells. However, the numbers of TUNEL-positive cells in the liver of the SNE-treated groups were not statistically different from the controls. The GST activity in 50 mg/kg bw of SNE and 1% of SND groups was significantly increased as compared to the positive control. In conclusion, Spirogyra neglecta (Hassall) K$\ddot{u}$tzing showed cancer chemopreventive properties at the early stages of diethylnitrosamine-induced hepatocarcinogenesis in rats. Possible inhibitory mechanisms include enhancement of the activities of some detoxifying enzymes and/or suppression of precancerous cells.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.271-271
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• 2017

Tartary buckwheat is known for its high rutin (quercetin 3-rutinoside) content which has antioxidant, anti-inflammatory, and anticarcinogenic effects. The buckwheat tea which is popular in Korea, is dependent on the quality of applied processing methods (steaming, dehuling, and roasting). This study focused on the evaluation of changes in rutin and anti-oxidant contents during the processing of tartary buckwheat tea. Raw tartary buckwheat seeds contains the highest quantities of rutin (2,212 mg/100 g D.W.). Soaking in water and steaming the whole seeds of tartary buckwheat significantly decreased its rutin and quercetin contents. Whereas the contents of rutin and quercetin in dehulled groats increased after steaming. The process of roasting with $70-80^{\circ}C$ for 2-3 min significantly decreased the contents of rutin (992 mg/100 g D.W.) and quercetin (12.8 mg/100 g D.W.). In the processing of tartary buckwheat tea, rutin content dropped about 45% in comparison with raw whole seeds.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3473-3477
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• 2015

Plants and their by-products offer a diverse mixture of chemical constituents like natural antioxidants. Date-pits are rich in phenolic compounds that have antioxidant potential. The main objective of this study was to investigate the protective effect of a date-pit extract (DPE) against AOM-induced colonic carcinogenicity and oxidative stress. Thirty-two weanling male Sprauge-Dawley rats were randomly divided into four groups (eight rats in each group). All rats were fed basic diet and water ad libitum, and randomly distributed per treatment groups as follows: negative controls injected with normal saline once a week for two weeks, a cancer group injected intra-peritoneally with azoxymethane (15mg/kg body weight) for two consecutive weeks, and DPE treated groups receiving the extract via the oral route (1.5ml/day) for the entire experiment in the presence or absence of AOM injection. Results showed that DPE contained phytonutrients that were capable of inhibiting chemically-induced oxidative stress in the rat colonic cells. In those animals that consumed DPE, a protective effect was observed against AOM-induced oxidative stress in rat colonic cells as evident by a significant decrease in MDA and oxidized DCF formation in AOM injected and DPE fed groups. It is concluded that DPE has potential antioxidant and anticarcinogenic properties.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3123-3129
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• 2013

Background: The search for naturally occurring agents in routinely consumed foods that may inhibit cancer development is of high priority. [6]-Paradol is a pungent phenolic bioactive component from ginger with welldocumented health promoting antioxidant, antimutagenic, antigenotoxic and anti-inflammatory properties. However, anticarcinogenic effects have yet to be fully explored. The objectives of the present study were therefore to assess protective effects against 7,12-dimethylbenz(a)anthracene (DMBA) induced buccal pouch carcinogenesis in male golden Syrian hamsters. Methods: Oral squamous cell carcinomas developed in the left buccal pouch of hamsters on painting with 0.5% of DMBA, three times in a week. To assess the apoptotic associated gene expressing potential of [6]-paradol, it was orally administered to DMBA treated hamsters on alternate days from DMBA painting for 14 weeks. Results: We observed 100% tumor formation with marked levels of neoplastic changes and altered the expression of apoptotic associated gene (p53, bcl-2, caspase-3 and TNF-${\alpha}$) was observed in the DMBA alone painted hamsters as compared to control hamsters. Oral administration of [6]-paradol at a dose of 30 mg/kg b.wt to DMBA treated animals on alternative days for 14 weeks significantly reduced the neoplastic changes and improved the status of apoptosis associated gene expression. Conclusion: These observations confirmed that [6]-paradol acts as a tumor suppressing agent against DMBA induced oral carcinogenesis. We also conclude that [6]-paradol also effectively enhances apoptosis- associated gene expression in DMBA treated animals.

• Preventive Nutrition and Food Science
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• 제10권4호
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• pp.340-343
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• 2005

Induction of NAD(P)H:(quinone-acceptor) oxidoreductase (QR) which promotes obligatory two electron reduction of quinones and prevents their participation in oxidative cycling and thereby the depletion of intracellular glutathione, has been used as a marker for chemopreventive agents. Induction of phase II enzyme is considered to be an important mechanism of cancer prevention. In our previous study, we assessed the quinone reductase QR-inducing activities of 216 kinds of medicinal herb extracts in cultured murine hepatoma cells, BPRc1 and hepalc1c7 cells. Among the 216 herbal extracts tested in that study, extracts from Chrysanthemum zawadskii showed significant induction of QR. In this study, we examined QR-inducing activity of solvent fractions of the herbal extract. The dichloromethane fraction of the herb showed the highest QR induction among the samples fractionated with four kinds of solvents with different polarity. The fraction also significantly induced the activity of glutathione S-transferase (GST), one of the major detoxifying enzymes, at $4{\mu}g/mL\;and\;2{\mu}g/mL$ in hepalc1c7 and BPRc1 cells, respectively. In conclusion, dichloromethane-soluble fraction of Chrysanthemum zawadskii which showed relatively strong induction of detoxifying enzymes merits further study to identify active components and evaluate their potential as cancer preventive agents.

• Journal of Nutrition and Health
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• 제31권6호
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• pp.1014-1023
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• 1998

The influences of fish oil and different levels of vitamin I supplement on hepatocellular chemical carcinogenesis have been studied. Male Sprague-Dawley rats received diethylnitrosamine (DEN)(200mg/kg body weight) and were subjected to two-thirds partial hepatectomy to induce murine chemical hepatocarcinogenic procedure. Placental glutathione S-transferase(GST-P) positive foci area, antioxidant enzymes(Cu/Zn-superoxide dismutase(SOD), catalase, glutathione reductase (GR), total- glutathione peroxidase (TGPx), glutathione S -transferase (GST)), glucose 6-phosphatase (G6Pase) activities, and lipid peroxidation of microsomes(thiobarbituric acid reactive substances (TBARS)) were measured. Experimental animals were fed 15% corn or fish oil with 0, 40, 1,000, 10,000IU vitamin E /kg diet for 8 weeks. Vitamin E supplements decreased the area of GST-P positive foci in both groups. The higher the vitamin E levels, the smaller the area of GST-P positive foci were noticed. Compared to 0 IU vitamin E, 40 IU in corn oil and 1,000 IU in fish oil groups were effective in decreasing G57-P positive foci area. Fish oil groups tended to have smaller area of GST-P positive foci. fish oil groups showed lower body weight, lower activities of Cu/Zn-SOD and TGPx, higher TBARS contents, higher activities of GST, catalase, G6Pase, GR and higher liver/body ratio than corn oil groups. As the level of vitamin I increased, GST-P positive foci count, catalase activities, and TBARS tended to decrease. G6Pase activities tended to increase in both groups. At higher vitamin E levels, GST activities tended to decrease in fish oil groups. These results suggest that vitamin I has suppressive offects on hepatocellular chemical carcinogenesis probably through antioxidant eH:cts decreasing TBARS contents, $H_2O$$_2$, and organic peroxides. fish oil tended to have greated suppressive offects than corn oil on hepatocellular carcinogenesis. (Korean J Nutrition 31(6) : 1014-1023, 1998)