• Biomedical Science Letters
• /
• v.11 no.2
• /
• pp.175-183
• /
• 2005

The two major isoflavones in soy, genistein and daidzein, are well known to prevent hormone-dependent cancers by their anti estrogenic activity. The exact molecular mechanisms for the protective action are, however, not provided yet. It has been reported that genistein and daidzein have a potential anticancer activity through their antiproliferative effect in many hormone-dependent cancer cell lines. Transforming growth $factor-\beta1(TGF-\beta1)$ has also been found to have cell growth inhibitory effect, especially in mammary epithelial cells. This knowledge led to a hypothetical mechanism that the soy isoflavones-induced growth inhibitory effect can be derived from the regulation of $TGF-\beta1$ and $TGF-\beta$ receptors. In order to test this hypothesis, the effects of the soy isoflavones at various concentrations and periods on the expression of $TGF-\beta1$and $TGF-\beta$ receptors were investigated by using Northern blot analysis in human breast carcinoma epithelial cell lines, an estrogen receptor positive cell line (MCF-7) and an estrogen receptor negative cell line (MDA-MB-231). As a result, only genistein has shown a profound dose-dependent effect on $TGF-\beta1$ expression in the $ER^+$ cell line within the range of doses tested, and the expression levels are correspondent to their inhibitory activities of cell growth. Moreover, daidzein showed down-regulated $TGF-\beta1$ expression at a low dose, the cell growth proliferation was promoted at the same condition. Therefore, antiproliferative activity of the soy isoflavones can be mediated by $TGF-\beta1$ expression, and the effects are mainly, if not all, occurred by ER dependent pathway. The expression of $TGF-\beta$ receptors was induced at a lower dose than the one for $TGF-{\beta}1$ induction regardless of the presence of ER, and the expression patterns are similar to those of the cell growth inhibition. These results indicated that the regulation of $TGF-\beta$ receptor expression as well, prior to $TGF-\beta1$ expression, may be involved in the antiproliferative activity of soy isoflavones. Little or no expression of $TGF-\beta$ receptors was found in the MCF-7 and MDA-MB-231 cells, suggesting refractory properties of the cells to growth inhibitory effect of the $TGF-\beta$. The soy isoflavones can seemingly restore the sensitivity of growth inhibitory responses to $TGF-\beta1$ by re-inducing $TGF-\beta$ receptors expression. In conclusions, our findings presented in this study show that the antitumorigenic activity of the soy isoflavones could be mediated by not only $TGF-\beta1$induction but $TGF-\beta$ receptor restoration. Thus, soy isoflavones could be good model molecules to develop new nonsteroidal antiestrogenic chemopreventive agents, associated with, regulation of $TGF-\beta$ and its receptors.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.10
• /
• pp.1514-1519
• /
• 2005

This study was performed to investigate the effects of Porphyra tenera (PT) on cytotoxicity and quinone reductase (QR) activity in the cancer cells. PT was extracted with methanol and further fractionated into five different types: hexane (PTMH), ethyl-ether (PTMEE), ethylacetate (PTMEA) butanol (PTMB) and aquous (PTMA) partition layers. We determined the cytotoxic effect of these layers on C6, HepG2, MCF-7, and HT-29 cell lines by MTT assay. Among the various fractions, hexane (PTMH) of PT showed the strongest cytotoxic effect on C6, HepG2 and MCF-7 cell lines. PTMH displayed very low level of cytotoxicity at the lower concentration levels and at 300 $\mu$g/mL. PTMH resulted in 87.5$\%$ growth inhibition on C6 cell 70 $\%$ on the HepG2 cell and 89$\%$ on the MCF-7 cell, which were significantly high compared to other fractions. A 400 $\mu$g/mL PTMH concentration level, 99$\%$, 94.5$\%$ and 99$\%$ of cell growth inhibition were resulted on the same cell lines. On HT-29 cell line, both hexane (PTMH) and aqueous (PTMA) fraction of PT showed cytotoxic effects, but the Percentage was not as high as previous results tested on other cell lines such as C6 HepG2 and MCF-7 cell lines. Also, we observed quinone reductase (QR) inducing-effects in all fractions of PT on HepG2 cells. The QR inducing effects of the PTMH on HepG2 cells at 150 $\mu$g/mL concentration was 6.6 times higher than the control. Although further studies are needed, the present work suggests that PT was a potential to be used as a chemopreventive.

• Journal of Life Science
• /
• v.18 no.6
• /
• pp.884-890
• /
• 2008

Genistein, an isoflavone in soybean products, is a potential chemopreventive agent against various types of cancer. There are several studies documenting molecular alterations leading to cell cycle arrest at G2/M phase and induction of apoptosis; however, its mechanism of action and its molecular targets on the prostaglandin $E_2$ ($PGE_2$) production and telomere length regulation in human cancer remain unclear. In this study, we investigated the effect of genistein on the levels of cyclooxygenases (COXs) and telomere regulatory components of several human cancer cell lines (T24, human bladder carcinoma cells; U937, human leukemic cells; AGS, human stomach adenocarcinoma cells and SK-MEL-2, human skin melanoma cells). Genistein treatment resulted in the inhibition of cancer cell proliferation in a concentration-dependent manner. It was found that genistein treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in $PGE_2$ synthesis. Genistein treatment also partly inhibited the levels of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR) and telomerase-associated protein (TEP)-1, and the activity of telomerase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of genistein.

• Korean Journal of Food Science and Technology
• /
• v.39 no.6
• /
• pp.688-693
• /
• 2007

The hepatoprotective effects of water extracts composed of Adenophora triphylla var japonica Hara (ATJH) on acetaminophen (APAP)-induced hepatotoxicity were investigated in vivo and in vivo. The effects of ATJH on liver toxicity induced by APAP were assessed by blood biochemical and histopathological analyses. APAP treatment (350 mg/kg) caused severe liver injury in mice as indicated by their significantly elevated plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Pretreatment with ATJH for 3 or 7 days attenuated the increases in ALT and AST when challenged with APAP. The reductions in viability caused by high dose of APAP (450 mg/kg) in vivo were reversed by pretreatment with ATJH. These protective effects of ATJH against APAP-induced toxicity were consistent with the results from the histopathological examinations. We next examined the effects of ATJH on the gene expression of glutathione S-transferases (GSTs) that detoxify the metabolic intermediates of APAP in H4IIE cells. The hepatic GST protein levels [$\alpha$ class (GSTA2, GSTA3/5)] were significantly elevated in a dose-dependent manner by ATJH treatment. In summary, ATJH is effective at protecting against APAP-induced hepatotoxicity by GST induction, implying that ATJH should be considered a potential chemopreventive agent.

• Archives of Pharmacal Research
• /
• v.25 no.5
• /
• pp.655-663
• /
• 2002

Liver fibrosis is a prepathological state wherein damaged liver tissues in chronic liver diseases, such as hepatitis, are not repaired to normal tissues, but converted to fibrous tissue. 5-(2-Pyrazinyl)-4-methyl-1,2-dithiol-3-thione (oltipraz), a cancer chemopreventive agent, is effective against a wide variety of chemical carcinogens. Recently, we reported that oltipraz inhibits liver fibrogenesis (Kang et al., 2002). In the present study, the effects of oltipraz in combination with dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDb) on dimethylnitrosamine (DMN)-induced liver fibrogenesis were assessed in rats. Oltipraz (30 mg/kg body weight, po, 3 times per week for 4 weeks) was found to inhibit the increases in plasma ALT, AST and bilirubin by DMN, whereas DDB (30 mg/kg body weight, po, 3 times per week for 4 weeks) attenuated the increases in the plasma ALT and bilirubin. The lowered plasma protein and albumin contents in DMN-treated rats were completely restored by oltipraz, but not by DDB. DDB decreases liver cell injury and inflammation through inhibition of nuclear factor-kB. DMN increased the accumulation of liver collagen, as indicated by the increase in the 4-hydroxyproline content in liver homogenates, which was reduced by treatment with oltipraz, but not by DDB. Given the differential effect between oltipraz and DDB, the potential enhancement of antifibrotic efficacy by the drugs was assessed in the animal model. Despite the minimal effect of DDB on DMN-induced fibrogenesis, DDB (5-25 mg/kg), administered together with oltipraz (25-5 mg/kg), showed an additive protective effect against hepatotoxicity and fibrosis induced by DMN, which was shown by the blood chemistry parameters and histopathological analysis. The adequate composition ratio of oltipraz to DDB was 5:1. These results provide information on the pharmaceutical composition, comprising of oltipraz and DDB as the active components, for the treatment and/or prevention of liver fibrosis and cirrhosis.

• Archives of Pharmacal Research
• /
• v.29 no.10
• /
• pp.911-920
• /
• 2006

Phenolic antioxidant butylated hydroxyanisole (BHA) is a commonly used food preservative with broad biological activities, including protection against chemical-induced carcinogenesis, acute toxicity of chemicals, modulation of macromolecule synthesis and immune response, induction of phase II detoxifying enzymes, as well as its undesirable potential tumor-promoting activities. Understanding the molecular basis underlying these diverse biological actions of BHA is thus of great importance. Here we studied the pharmacokinetics, activation of signaling kinases and induction of phase II/III drug metabolizing enzymes/transporter gene expression by BHA in the mice. The peak plasma concentration of BHA achieved in our current study after oral administration of 200 mg/kg BHA was around $10\;{\mu}M$. This in vivo concentration might offer some insights for the many in vitro cell culture studies on signal transduction and induction of phase II genes using similar concentrations. The oral bioavailability (F) of BHA was about 43% in the mice. In the mouse liver, BHA induced the expression of phase II genes including NQO-1, HO-1, ${\gamma}-GCS$, GST-pi and UGT 1A6, as well as some of the phase III transporter genes, such as MRP1 and Slco1b2. In addition, BHA activated distinct mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), as well as p38, suggesting that the MAPK pathways may play an important role in early signaling events leading to the regulation of gene expression including phase II drug metabolizing and some phase III drug transporter genes. This is the first study to demonstrate the in vivo pharmacokinetics of BHA, the in vivo activation of MAPK signaling proteins, as well as the in vivo induction of Phase II/III drug metabolizing enzymes/transporters in the mouse livers.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.3
• /
• pp.350-355
• /
• 2010

The hepatoprotective effects of theanine on acetaminophen (APAP)-induced hepatotoxicity were investigated in vivo and in vitro. The effects of theanine on liver toxicity induced by APAP were assessed by blood biochemical and histopathological analyses. APAP treatment (400 mg/kg) caused severe liver injury in mice as indicated by their significantly elevated plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Pretreatment with theanine for 3 days attenuated the increase in ALT and AST when challenged with APAP. These protective effects of theanine against APAP-induced toxicity were consistent with the results from the histopathological examinations. We next examined the effects of theanine on the GSH concentration in liver plasma. The hepatic GSH level was significantly elevated in a dose-dependent manner by theanine treatment. The results suggest that the protective effects of theanine APAP-induced hapatotoxicity by antioxidative effect and GSH induction, implying that theanine should be considered a potential chemopreventive agent.

• Tuberculosis and Respiratory Diseases
• /
• v.56 no.4
• /
• pp.381-392
• /
• 2004

Arsenic trioxide($As_2O_3$) was introduced into the treatment of refractory or relapsed acute promyelocytic Ieukemia. Some investigators have reported that arsenic trioxide had induced apoptosis in a variety of solid human tumor cell lines, including non-small cell lung cancer. Non-steroidal anti-inflammatory drugs(NSAIDs) are powerful chemopreventive agents for gastrointestinal cancers and the growth of established tumors are reduced by inducing apoptosis. It's also reported that NSAIDs enhanced tumor response to chemotherapeutic drugs or radiation. In this study, we aimed to determine whether combination of arsenic trioxide with sulindac augmented its apoptotic potential in NCI-H157 human lung cancer cells. The human lung cancer cell line NCI-H157 was treated with arsenic trioxide and sulindac. Cell viability was measured by the MTT assay. Apoptosis was measured by nuclear staining and flow cytometric analysis. The catalytic activity of the caspase families were measured by the fluorogenic cleavage of biosubstrates. The western blotting were also performed to define the mechanical basis of apoptosis. Combination treatment of arsenic trioxide and sulindac decreased the viability of NCI-H157 human lung cancer cells in a dose-dependent manner. The catalytic activity of caspase-3, 8 and 9 proteases were increased after combination treatment. Consistently PARP was cleaved from 116kDa to 85kDa fragments, and the expression of ICAD was decreased by time-dependent manner. Also combination treatment increased the expression of Fas and Fas/L. Combination therapy of arsenic trioxide with sulindac augments cell death and induces apoptosis via the activation of caspase cascade in NCI-H157 human lung carcinoma cells.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.2
• /
• pp.148-153
• /
• 2008

We investigated the growth inhibitory effect of Salicornia herbacea L. (SH) on human cancer cell lines in vitro. SH was extracted with methanol (SHM), followed by further fractionation into four subfractions according to polarity: hexane (SHMH), methanol (SHMM), butanol (SHMB), and aqueous (SHMA) soluble fractions. We determined the growth inhibitory effect of these fractions against human cancer cell lines using MTT assay. Among the four subfractions of SHM, the SHMM showed the strongest cytotoxic effects on cancer cell lines. We also observed quinone reductase (QR)-inducing effect of methanol layer (SHMM) on HepG2 cells and it was determined to be 3.00 at $100\;{\mu}g/mL$ level compared to the control value of 1.0. The SHMM showed the highest induction activity of quinone reductase on HepG2 cells among the partition layers. The present work suggests that SH merits further study to confirm its chemopreventive potential.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.3
• /
• pp.288-293
• /
• 2008

In this study, we investigated the anticancer activity of Makgeoly (MG). MG was fractionated into four fractions by using solvent partition method, affording hexane (MGH), methanol (MGM), butanol (MGB) and aquous (MGA) soluble fractions. We determined the cytotoxicity of these four fractions in four kinds of cancer cell lines, such as HepG2, MCF-7, B16-F10 and HT29 by MTT assay. Among the various fractions, the MGM showed the strongest cytotoxic effects on all cancer cell lines. The morphological changes such as membrane shrinking and blebbing of cells were also observed by MGM treatment in HepG2 cell. In addition, we observed quinone reductase (QR) activity stimulating effects in all fraction layers of MG on HepG2 cells. QR activity increased approximately 2.6 and 2.1 times in MGM and MGH treated HepG2 cell at $100{\mu}g/mL$, respectively, compared to that in control value. Although further studies are needed, the present work could suggest that the fin of MG has a potential to be used as a chemopreventive agent against cancer.