• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.269-273
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• 2001

Ethanol extracts from Xanthii Fructus (XFE) and Prunellae Spica (PSE) were investigated for the effects on the induction of cancer chemoprevention-associated enzymes. The following effects were measured: (a) induction of quinone reductase (QR) (b) induction of glutathione S-transferase (GST) (c) reduced glutathione (GSH) level. XFE and PSE were potent inducers of quinone reductase activity in Hepa1c1c7 murine hepatoma cells. Glutathione levels were increased with XFE and PSE. In addition, glutathione S-transferase activity was increased with XFE. However, GST activity was not increased with PSE. These results suggest that XFE and PSE have chemopreventive potentials by inducing quinone reductase and increasing GSH levels.

• Korean Journal of Pharmacognosy
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• v.32 no.2 s.125
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• pp.168-174
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• 2001

Induction of phase II enzymes is a major mechanism of chemoprevention. The induction levels of quinone reductase (QR) activity in cultured murine hepatoma (Hepa 1c1c7) cells by 80%-methanol extracts of traditional medicinal plants were measured. Among the tested 81 plants, the extracts of Aralia continentalis, Magnolia obovata, and Viscum album were found to induce QR activities over 250%. The maximum induction levels obtained were 401.9%, 270.5%, and 301.8% by treatments of the extracts of A. continentalis $(318\;{\mu}g/ml)$, M. obovata $(53.8\;{\mu}g/ml)$ and V. album $(80.6\;{\mu}g/ml)$, respectively. These QR induction activities were more potent than those of the known QR inducers, t-butylhydroquinone (170.1%) and ${\beta}-naphthoflavone$ (320.0%).

• Natural Product Sciences
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• v.7 no.2
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• pp.38-44
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• 2001

NAD(P)H:quinone reductase (QR), known as DT-diaphorase, is a kind of detoxifying phase II metabolic enzyme catalyzing hydroquinone formation by two electron reduction pathway from quinone type compounds, and thus facilitating excretion of quinoids from human body. With the usefulness of QR induction activity assay system for the modulation of toxicants, in the course of searching for cancer chemopreventive agents from natural products, the methanolic extracts of approximately two hundreds of oriental medicines were primarily evaluated using the induction potential of quinone reductase (QR) activity in cultured murine Hepa1c1c7 cells. As a result, several extracts including Hordeum vulgare, Momordica cochinchinensis, Strychnos ignatii, Houttuynia cordata, and Polygala japonica were found to significantly induce QR activity. In addition, the methylene chloride fraction of H. vulgare, one major dietary food source, showed potent induction of QR activity $(CD=6.4{\mu}g/ml)$. Further study for isolation of active principles from these lead extracts is warranted for the discovery of novel cancer chemopreventive agents.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.972-977
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• 1995

The induction of phase II enzymes including quinone reductase [NAD(P)H dehydrogenase(quinone): NAD(P)H : (quinone acceptor) oxidoreductase, EC 1.6.99.2] is a major mechanism of whereby a large group of heterogeneous compounds prevent the toxic, mutagenic, and neoplastic effects of carcinogen. Using murine hepatoma cells(Hepalclc7 cells), quinone reductase(QR) inducers as the possible chemopreventive agents were screened from rice bran, wheat bran, soymilk residue, defatted soybean cake, defatted sesame and perilla residues. The 80% methanol extracts of defatted sesame and perilla residues induced quinone reductase significantly while the others did have little effect on the enzyme induction. Thin layer chromatography of the extracts showed that the fastest moving band(Rf=0.70) in the developing solvent of n-butanol : n-propanol : 2N ammonia(10 : 60 : 30) was responsible for the enzyme induction by the 80% methanol extracts of defatted sesame and perilla residues. Further identification of active component(s) is in progress.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.277-281
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• 1998

There is extensive evidence suggesting the protective role of fruits and vegetables against chemically induced carcinogenesis. We have tested the ability of a representative range of Korean vegetables to act as blocking agents against neoplastic initiation by determining the induction level of quinone reductase , an anticarcinogenci marker enzyme, in hepalclc 7 cells exposed to vegetable extracts. Among thirty vegetables tested, Arcitum lappa(Burdock), Brassica juncea (Mustard leaf), Pteridium aguilinum (Bracken) and Chrysanthemum cornoratium(Crown daisy) caused a significant induction of quinone teductase activity with a limited increase in arylhdrocarbon hydroxylase activity. Combination of crown daisy with burdock had synergistic effect on quinone reductase induction. Quinone reductase-inducing activity was found mostly in hesane and ehtylactate fractions of MeOH extract of crown daisy while it ws not quinone reductase activity in liver, kideny, lung, and small intestine, confirming the presence of potent QR inducer (s) in crown daisy. These sata suggest that some vegetables including crown daisy induced QR merits further investigation as a potential cancer preventive agent in human.

• Journal of Life Science
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• v.10 no.1
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• pp.79-85
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• 2000

Chemoprevention is one of the major strategies for cancer control. It is well established that dietary factors play an important role in modulating the development of certain types of human cancer. The experiment was conducted to determine quinone reductase(QR) activity induction of Daucus carota L. on HepG2 cells. Among various partition layers of roots of Daucus carota L., the ethyl acetate partition layer(DCMEA) and the n-hexane partition layer(DCMH) tested to be most effective which resulted 2.1 and 1.6 respectively compared to the control value of 1.0. In the case of seeds of Daucus carota L. n-butanol partition layer (DCMB) on HepG2 cells at a dose of 200 $\mu\textrm{g}$/$m\ell$ showed the highest induction activity of QR which was 3.0. These results suggest that potentially useful cancer chemoprevention chemicals could be isolated from DCMEA and DCMH of the roots and DCMB of the seeds of Daucus carota L.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.597-600
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• 2001

Based on the potential cancer chemoprebentive activity of resveratrol, a trihydroxystilbene with the induction of quinone reductase activeity this study was designed to determine if stilbene-related compounds were inducers of phase ll detoxifying metabolic enzyme quinone reductase (QR) in the mouse hepatoma Hepa 1c1c7 cells. Among the thirteen compounds tested, several compounds including 3,4,5,3',5'-pentamethoxy-trans-stibene were found to potentially induce QR activity in this cell line. In addition, substitution with 3-thiofurane ring instead of phenyl ring in the stilbene skeleton also exhibited potential induction of QR activity. This result will give primary information to design the potential inducers of QR activity in the stilbene analogs.

• Natural Product Sciences
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• v.3 no.2
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• pp.81-88
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• 1997

NAD(P)H:quinone reductase (QR) is one of the protective phase II enzymes against toxicity that accomplishes the capacity of detoxification by modulating the effects of mutagens and carcinogens. The detoxification mechanism is that quinone reductase promotes the 2-electron reduction of quinones to hydroquinones which are less reactive. This study is to search new inducers of quinone reductase from natural products, which can be used as cancer chemopreventive agents. Plant extracts were evaluated by using quinone reductase generating system With Hepa 1c1c7 murine hepatoma cell lines for enzyme inducing properties and crystal violet staining method for the measurement of cytotoxicity provoked. We have tested approximately 106 kinds of natural products after partition into n-hexane, ethyl acetate and aqueous layers from 100% methanol extracts of natural products. The ethyl acetate fractions of Vitex rotundifolia $(fruits,\;2FC:\;12.7\;{\mu}g/ml)$, Cnidium officinale $(aerial\;parts,\;2FC:\;10.5\;{\mu}g/ml)$, Chrysanthemum sinese $(flowers,\;2FC:\;17.4{\mu}g/ml)$ and the hexane fractions of Angelica gigas $(roots,\;2FC:\;13.2\;{\mu}g/ml)$, Smilax china $(roots,\;2FC:\;l1.9\;{\mu}g/ml)$, Sophora flavescens $(roots,\;2FC:\;16.3\;{\mu}g/ml)$ revealed the significant induction of quinone reductase in a murine hepatic Hepa 1c1c7 cell culture system.

• 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.

• Korean Journal of Acupuncture
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• v.20 no.1
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• pp.39-43
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• 2003

Sophorae Flos aqua-acupuncture solution(SFAS) was prepared and tested for the induction of quinone reductase and glutathione S-transferase activities and glutathione. SFAS significantly induced QR activity at the concentrations of $0.5{\times},\;1{\times}\;and\;3{\times}$ in cell culture. However, GST activity in murine Hepa 1c1c7 cells was slightly increased with SFAS. SFAS increased GSH levels.