• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3343-3352
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• 2014

Chemoprevention is an attempt to use nontoxic natural and synthetic substances or their mixtures to intervene the relatively early stages of carcinogenesis, before invasive characteristics are manifested. The consumption of fruits is well known to reduce the risk of human cancers. Although most fruits are available only on a seasonal basis, recent advances in food processing technologies have made it possible to extend the shelf life of fruits and fruit-products. Fruits can be preserved by applying different drying processes to reduce the moisture content. Different varieties of dried fruits are now sold in supermarkets, thereby making them readily accessible to consumers. Since oxidative stress and chronic inflammation play important roles in cancer development, dried fruits with antioxidative and anti-inflammatory properties hold promise for cancer chemoprevention. The antioxidant, anti-inflammatory and chemopreventive activities of dried fruits are largely attributed to their polyphenols and vitamins. Dried fruits contain adequate amounts of bioactive principles, such as anthocyanins, acetogenins, catechins, coumarins, phenolic acids, terpenes, xanthones, and others. Since numerous health beneficial phytochemicals in fruits are conserved even after processing, regular intake of dried fruits can help prevent cancer. This review addresses the chemopreventive potential of representative dried fruits and their active constituents.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.183-187
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• 2005

Abstract The cancer chemopreventive potential of chitosanoligosaccharides was investigated by measuring the induction of quinone reductase and glutathione S-transferase activities and inhibition of cytochrome P450 1A1, 2B1, and 2E1 activities. Chitosanoligosaccharide I (1-${\kappa}$Da${\kappa}$Da) significantly induced glutathione S-transferase activity with a maximal 1.5-fold increase at 500 ${\mu}$g/ml, while chitosanoligosaccharide II (3-${\kappa}$Da${\kappa}$Da) (500 ${\mu}$g/ml) strongly induced quinone reductase (p<0.01) and glutathione S-transferase (p<0.005) activities. The in vitro incubation of rat liver microsomes with chitosanoligosaccharides I and II (2.5, 5, 50, and 500 ${\mu}$g/ml) showed a dose-dependent inhibiton of cytochrome P450 1A1, 2B1, and 2E1 activities. Chitosanoligosaccharide II was a more potent inhibitor of cytochrome P450 2B1 activity than chitosanoligosaccharide I. Accordingly, these findings suggest that chitosanoligosaccharides are potential chemopreventive agents.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1546-1549
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• 2007

Chitosan oligosaccharide (COS, 3 kDa

• Toxicological Research
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• v.23 no.3
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• pp.207-214
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• 2007

Chronic oxidative stress produced by exposure to environmental chemicals or pathophysiological states can lead animals to aging, carcinogenesis and degenerative diseases. Indirect antioxidative mechanisms, in which natural or synthetic agents are used to coordinately induce the expression of cellular antioxidant capacity, have been shown to protect cells and organisms from oxidative damages. Electrophile and free radical detoxifying enzymes, which were originally identified as the products of genes induced by cancer chemopreventive agents, are members of this protective system. The NFE2 family transcription factor Nrf2 was found to govern expression of these detoxifying enzymes, and screening for Nrf2-regulated genes has identified many gene categories involved in maintaining cellular redox potential and protection from oxidative damage as Nrf2 downstream genes. Further, studies using Nrf2-deficient mice revealed that these mutant mice showed more susceptible phenotypes towards exposure to environmental chemicals/carcinogens and in oxidative stress related disease models. With the finding that cancer chemopreventive efficacy of indirect antioxidants (enzyme inducers) is lost in the absence of Nrf2, a central role of Nrf2 in the antioxidative protective system has been firmly established. Promising results from cancer prevention clinical trials using enzyme inducers propose that pharmacological interventions that modulate Nrf2 can be an effective strategy to protect tissues from oxidative damage.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2000.09a
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• pp.26-26
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• 2000

The consumption of cruciferous vegetables such as cabbage and broccoli have been shown to have a chemopreventive effect in human and in experimental animals. Indole-3-carbinol (I3C), one component of cruciferous vegetables, has been shown to exert its chemopreventive effect in liver, colon and mammary tissue before or concurrent exposure of carcinogen, but in some reports, there have been several evidence that consumption of I3C after carcinogen treatment induced tumor promotion in some tissues. There have been no reports about the effect of I3C after carcinogen exposure in N-Nitroso-N-methylurea (MNU)-induced mammary tumor model of rats. (omitted)

• Korean Journal of Acupuncture
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• v.19 no.2
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• pp.51-56
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• 2002

Induction of phase II enzymes such as quinone reductase (QR) and glutathione S-transferase (GST) is considered a major mechanism of protection against initiation of carcinogenesis. The present study was performed to evaluate the chemopreventive activity of Acori Graminei Rhizoma aqua-acupuncture solution (AGRAS) and Acori Graminei Rhizoma water-extracted solution (AGRWS) by measuring the induction of phase II enzymes. AGRAS and AGRWS are potent inducers of quinone reductase activity in murine hepatoma Hepa1c1c7 cells. The levels of GSH and GST was increased sightly with AGRAS and AGRWS. These results suggest that AGRAS and AGRWS may act as blocking agents against carcinogenesis by induction of phase II enzymes.

• Archives of Pharmacal Research
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• v.24 no.4
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• pp.349-354
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• 2001

Curcumin, a dietary pigment in turmeric, posseses anti-carcinogenic and anti-metastatic properties. The present study was conducted to study in vitro chemopreventive effects of curcumin in transformed breast cells. Here, we show that curcumin inhibits H-ras-induced invasive phenotype in MCF10A human breast epithelial cells (H-ras MCF10A) and downregulates matrix metalloproteinase (MMP)-2 dose-dependently. Curcumin exerted cytotoxic effect on H-ras MCF10A cells in a concentration-dependent manner. Curcumin-induced cell death was mainly due to apoptosis in which a prominent downregulation of Bcl-2 and upregulation of Bax were involved. We also suggest a possible involvement of caspase-3 in curcumin-induced apoptosis. Curcumin treatment resulted in the production of reactive oxygen species (ROS) in H-ras MCF10A cells. Apoptotic event by curcumin was significantly inhibited by pretreatment of an antioxidant N-acetyl-$_L$-cysteine (NAC), suggesting redox signaling as a mechanism responsible for curcumin-induced apoptosis in H-ras MCF10A cells. Taken together, our results demonstrate that curcumin inhibits invasion and induces apoptosis, proving the chemopreventive potential of curcumin .

• YAKHAK HOEJI
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• v.54 no.1
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• pp.32-38
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• 2010

The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1572-1575
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• 2006

Water extract from Cnidii Rhizoma (CRW) was tested for colon cancer chemopreventive activity by measuring the induction of phase II detoxification enzyme activity [quinone reductase (QR) and glutathione S-transferase (GST)] and glutathion (GSH) levels and ornithine decarboxylase (ODC) activity in cultured human colorectal adenocarcinoma HT-29 cells. CRW inhibited cell proliferation in cultured HT-29 cells. CRW induced QR activity in a dose-dependent manner in a concentration range of 0.1${\sim}$5.0 $mg/m{\ell}$. GST activity was also induced with the treatment of CRW in HT-29 cells. In addition GSH levels was increased with CRW. CRW inhibited ODC activity, a key enzyme of polyamine biosynthesis, which is enhanced in tumor promotion. These results suggest that CRW has colon cancer chemopreventive activity by increasing phase II enzyme activity and GSH levels and inhibiting ODC activity in vitro.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.287-292
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• 2002

To find new inhibitory effects from oriental drugs, Albizziae root was extracted in methanol and the extracted was stepwisely fractionated by hexane, chloroform, ethylacetate, butanol and water. In cytotoxic effect of Albizziae root fractions against cancer cell lines including human hepatoma cells(HepG2) were investigated. Expecially the butanol fraction exhibited a inhibition effects on the growth of human hepatoma cells(HepG2). It inhibited of HepG2 cells with the value of IC50. The activities of qutathione after B(a)P treatment were markedly decreased than control, but those levels were increased by the treatment of Albizziae root methanol fraction. The activity of glutathione-S-transferase after B(a)P treatment were markedly decreased than control, but those levels were increased by the treatment of Albizziae root methanol traction. Induction of phase II enzymes is a major mechanism of chemoprevention. The induction levels of quinone reductase(QR) activity in cultured murine hepatoma(Hepa IcIc7)cell by methanol extract of Albizziae root were measured. Among the tested tractions, the extracts of butanol were found to induce QR activities over 2.8 fold than control. These results suggest that Albizziae root has chemopreventive Potential by inducing QR activities and GST levels and increasing GSH