• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.525-528
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• 1999

Mutagenic activities of extracts from the filtrate of the cultured broth (PI-I), mycelia (pI-II), and the fruiting bodies (PI-III) of Phellinus igniarius were examined by Ames/Salmonella tests. No mutagenic activity was found in Salmonella typhimurium strains TA98 and TA100, either with or without S9 activation. In contrast, PI-I, PI-II, and PI-III showed inhibitory effects on the mutagenic activities by the directly-acting mutagens, 4-nitro-ο-phenylenediamine(NPD) and sodium azide ($NaN_3$), and also by the indirectly-acting mutagens, 2-aminofluorene (2-AF) and benzo[a]pyrene (B[a]P). These results suggest that P. igniarius possesses some antimutagenic activity and may contain some chemopreventive agents.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.122-124
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• 1999

Induction of NAD(P)H : (quinone-acceptor) oxidoreductase (QR) which 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. We postulated that vitamin E, an antioxidant, which induces QR as the gene of QR was reported to contain antioxidant reponsive element in the 5'-flanking region. Vitamin E resulted in significant induction of QR in both hepalclc7 cells and mouse tissues. QR induction was observed; to be maximal at 25uM vitamin E for hepalclc7 cells while it was maximal in the level of 2.5∼5 μmoles vitamin E/㎏ BW for mouse tissues. Thus the cancer-preventive effect of vitamin E may be exerted by it induction of intracellular detoxifying enzymes.

• Advances in Traditional Medicine
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• v.6 no.2
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• pp.69-78
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• 2006

The isoflavonoids comprise a group of phyto-oestrogens that have useful biological activities including oestrogenic, antioxidant and anticancer. As dietary components for humans, they are bioavailable from leguminous vegetables (such as genistein from soybean), and have been well-documented to have numerous health benefits. A wide range of epidemiological studies in humans and limited studies in animals have identified isoflavonoids as potential chemopreventive agents against hormone-dependent cancers. Therefore, an attempt has been made through this review to summarise the information in the mechanisms aspect of isoflavonoid phyto-oestrogens in inhibiting cancer in vitro and in vivo in the models of human cancers.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.256-267
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• 2012

Tamoxifen is a central component of the treatment of estrogen receptor (ER)-positive breast cancer as a partial agonist of ER. It has been clinically used for the last 30 years and is currently available as a chemopreventive agent in women with high risk for breast cancer. The most challenging issue with tamoxifen use is the development of resistance in an initially responsive breast tumor. This review summarizes the roles of ER as the therapeutic target of tamoxifen in cancer treatment, clinical values and issues of tamoxifen use, and molecular mechanisms of tamoxifen resistance. Emerging knowledge on the molecular mechanisms of tamoxifen resistance will provide insight into the design of regimens to overcome tamoxifen resistance and discovery of novel therapeutic agents with a decreased chance of developing resistance as well as establishing more efficient treatment strategies.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.2
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• pp.75-78
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• 2014

Green tea and tea polyphenols have been studied extensively as cancer chemopreventive agents in recent years. Epigallocatechin-3-gallate (EGCG) is widely recognized as a powerful antioxidant and a free radical scavenger. The purpose of this study was to evaluate the protective effects of green tea catechins (GTC) on the Bleomycin- and Cyclophosphamide-induced cytotoxicity. Cell viability was measured by MTT assay. In the protective effect of GTC, the cell viability was significantly increased by the treatment of GTC. Furthermore, GTC showed the higher protective effect than EGCG and vitamin E. These results suggest that GTC has the protective effect which is related to the prevention of cancer. Our studies show that the continuous presence of EGCG can reduce radical-induced DNA damage in Chinese hamster lung fibroblast cells (CHL cells).

• Archives of Pharmacal Research
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• v.22 no.3
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• pp.309-312
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• 1999

In searching for potent cancer chemopreventive agents from synthetic or natural products, 28 randomly selected flavonoids were screened for inhibitory effects against partially purified aromatase prepared form human placenta. Over 50% of the flavonoids significantly inhibited aromatase activity, with greatest activity being demonstrated with apigenin $(IC_{50}: 0.9{\mu}/mL)$, chrysin $(IC_{50}: 1.1{\mu}/mL)$ , and hesperetin $(IC_{50}:1.0{\mu}/mL)$.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.378.1-378.1
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• 2002

Prostaglandins (PGs) and nitric oxide (NO) are essential to maintain homeostasis and defensa systems in human beings. However. overproduced PGs and NO by inducible cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS), respectively. cause tissue damages. chronic inflammation. and carcinogenesis. In this view. the potential COX-2 or iNOS inhibitors have been considered as anti-inflammatory or cancer chemopreventive agents. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.113.2-113.2
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• 2003

Inducible cyclooxygenase-2 (COX-2) has been implicated in the processes of inflammation and carcinogenesis. Thus, the potential COX-2 inhibitors have been considered as anti-inflammatory or cancer chemopreventive agents. In this study, we investigated the effect of Caffeoyl-4-dihydrocaffeoyl quinic acid (CDCQ) isolated from Salicornia herbacea on the expression of cyclooxygenase (COX-2) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. When CDCQ was treated with LPS, the prostaglandin $E_2$ production and COX-2 gene expression induced by LPS were markedly reduced in a dose-dependent manner. (omitted)

• Journal of Digestive Cancer Research
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• v.8 no.2
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• pp.77-80
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• 2020

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. The increased expression of cyclooxygenase (COX)-2 has been implicated in the development and progression of gastric cancers. A number of recent studies have been published evaluating the chemopreventive effect of aspirin and non steroidal anti inflammatory drungs (NSAIDs) against gastric cancer. Aspirin and NSAIDs use may reduce the risk of gastric cancer incidence and death, whereas other studies have reported contradictory results. Therefore, further study should be needed to clarify the role of aspirin and NSAIDs in the chemoprevention of gastric cancer.

• Natural Product Sciences
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• v.5 no.2
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• pp.88-92
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• 1999

Inhibition of gap junction-mediated intercellular communication (GJIC) has been considered as an important factor in the tumor promotion phase of carcinogenesis. Recovery effects of natural products on gap junctional intercellular communication are measured by scrape-loading and dye transfer method using Lucifer yellow after administration of phorbol-12-myristate-13-acetate (PMA) on WBF344 cells. Among tested natural products, the hexane fraction and subfractions (F-01 and F-04) of Setaria italica were relatively effective for recovery of GJIC. The hexane fraction of Setaria italica $(EC_{25},\;12.14\;{\mu}g/ml)$ and subfractions $(F-01:EC_{50},\;10.74\;{\mu}g/ml;EC_{25},\;1.58\;{\mu}g/ml,\;F-04:EC_{50},\;11.03\;{\mu}g/ml;\;EC_{25},\;3.12\;{\mu}g/ml)$ revealed dose-dependent recovery effects on GJIC. Our data show GJIC activity measurement by Lucifer yellow spread on cells can be an effective tool for the screening of natural products with possible cancer chemopreventive effects.