• Nutritional Sciences
• /
• 제3권1호
• /
• pp.11-17
• /
• 2000

This study was intended to examine whether dehydroepiandrosterone (DHEA) and dietary fat level or source could modulate glutathione utilizing detoxifying system activity and the cytosolic NADPH generation in rat liver. Male Sprague-Dawley rats were fed semipurifed diet containing either 2%(w/w) corn oil (low level of corn oil diet: 5 ca% of fat) 15% corn oil (high level of corn oil diet: 31 cal% of fat) or 13% sardine oil plus 2% corn oil(high level of fish oil diet: 31 cal% of fat) for 9 weeks. Half of the rats in each diet group were fed a diet supplemented with 0.2% DHEA (w/w). DHEA administration increased plasma total cholesterol level in low corn oil diet-fed rats. The high fish oil diet significantly decreased plasma total cholesterol level compared to the high corn oil diet. Plasma triglyceride level was not significantly changed by DHEA administration and dietary fat level and source. Fasting plasma glucose level was increased by DHEA administration and fish oil diet. Glucose 6-phosphate dehydrogenase activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration. DHEA suppressed the glutathione peroxidase, glutathione-dependent enzymes compared to the low corn oil diet, while fish oil diet elevated the activity of glutathione peroxidase and glutathione reductase compared to corn oil diet. These results suggest that DHEA administration and high level of corn oil diet may suppress the cellular detoxifying system activity through reduction of glutathione utilization, while the fish oil diet did not show these effects.

• Applied Biological Chemistry
• /
• 제36권1호
• /
• pp.64-69
• /
• 1993

참잉어에 대한 해독효소 활성을 협력작용을 갖는 농약을 공시하여 조사하였고 잉어의 각 조직별 효소활성도 조사하였다. 협력작용을 갖는 약제의 독성증가에 따른 효소활성은 carboxylesterase와 GST 모두 준치사 농도에서는 활성의 증가를 보였으나 독성이 증가함에 따라 활성이 감소하였다. Carboxylesterase의 활성은 IBP와 isoprothiolane과의 협력작용으로 인해 현저한 감소를 보였으며 GST 활성 또한 isoprothiolane의 IBP, cartap과의 협력작용으로 인해 감소를 나타냈다. 한편 각 조직별 효소활성의 경우, carboxylesterase는 단일약제 처리시 공시어의 간(肝)에서, 혼합약제 처리시 장(腸)에서 그 활성이 높았으며 GST의 조직별 활성은 약제의 처리양상과는 관계없이 다양한 효과를 보였다. HPLC 방법에 의한 LDH의 활성은 isoprothiolane 단일처리구에서 활성이 가장 높았고 isoprothiolane+cartap 혼합처리구와 cartap 단일처리구에서는 가장 낮았다.

• Applied Biological Chemistry
• /
• 제35권5호
• /
• pp.367-374
• /
• 1992

이스라엘 잉어와 참잉어에 대한 농약의 독성 및 glycogen의 함량변화, 호소활성을 조사하고 농약 상호간의 협력작용의 여부를 조사하였다. $LC_{50}$치의 측정결과는 공시약제 중 endosulfan이 0.0079 ppm으로 가장 독성이 강했고 metalaxyl이 40 ppm 이상으로 가장 낮았다. 농약 상간의 협력작용은 IBP+isoprothiolane과 cartap+isoprothiolane 처리구에서 나타났으며 그 ratio(SR)는 각각 1.85, 1.53이었다. 효소활성의 경우 carboxylesterase와 glutathione S-transferase 모두 증가되었다. Esterase의 활성은 IBP 처리구에서 가장 높았고 isoprothiolane 처리구에서 제일 낮았으며, glutathione의 CDNB conjugation은 isoprothiolane 처리구에서 가장 높았고 isoprothiolane+cartap 처리구에서 가장 낮았다. LDH의 경우 isoprothiolane 처리구에서 활성이 가장 높았고 isoprothiolane+cartap 처리구에서는 가장 낮았다. Glycogen의 함량은 공시약제의 처리구 모두에서 감소를 보였으며 IBP 처리구에서 감소정도가 가장 높았다.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
• /
• pp.212.2-212.2
• /
• 2003

Primary cultured rat hepatocytes injured by carbon tetrachloride as a model to screen for hepatoprotective effect. Four flavonoid compounds showed anti-hepatotoxic effect by decrease GPT. LDH activity and MDA level. Also screen for hepatoprotective, anti-oxidative and anti-apoptosis effects of baicalin and baicalein on chang cell treated with t-BHP. Mesured radical detoxifying enzyme, GST and antioxidant enzyme SOD, Catalase activity, GSH level and Cellular glutathion peroxidase activity. (omitted)

• 한국환경농학회지
• /
• 제8권1호
• /
• pp.47-54
• /
• 1989

동양종(東洋種)꿀벌 (Apis cerana F.)에 대(對)한 살충제(殺蟲劑)의 독성(毒性) 및 해독능력(解毒能力)을 조사(調査)하고 농약한계 사용량 결정에 기여하기 위하여 7가지 대표적인 살충제의 꿀벌에 대한 독성 및 해독효소의 활성을 조사하였다. 효소 활성은 해독효소로 알려진 microsomal oxidases, glutathione S-transferasecs, esterase와 DDT-dehydrochlorinase를 조사했고 성충(成蟲)일벌의 중장(中腸)을 사용하여 측정하였다. $LC_{50}$치의 측정 결과는 다음과 같다. 1. 공시 살충제중 DDT가 19ppm으로 독성(毒性)이 가장 낮았고 EPN이 0.75ppm으로 독성(毒性)이 가장 강(强)했다. 2. 준치사농도(準致死濃度)의 농약(農藥)이 성충(成蟲)일벌의 microsomal oxidase에 미치는 영향은 malathion 및 demeton S-methyl 처리가 aldrin epoxidase활성을 저해시켰고 N-demethylase활성은 carbayl 처리구에서 증대(增大)되었다. 3. Glutathione S-transferase(DCNB conjugation)활성은 diazinon과 malathion처리구에서 증대되었다. 4. Esterase는 malathion 및 permethrin처리구에서 ${\alpha}-NA$ esterase 활성(活性)의 저해(沮害)를 보였고 carboxylesterase와 AchE 활성은 거의 영향이 없었다. 5. DDT-dehydrochlorinase 활성은 carbaryl, malathion과 demeton S-methyl 처리구에서 저해를 보였다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권9호
• /
• pp.4655-4660
• /
• 2012

Opuntia humifusa, member of the Cactaceae family, was previously demonstrated to have radical scavenging, anti-inflammatory and anti-proliferative effects in in vitro models. It was suggested that O. humifusa could function in the prevention of carcinogenesis. To investigate the in vivo chemopreventive effect of O. humifusa, mice were fed a diet containing either 1% or 3% following 7, 12-dimethylbenz[a] anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) induction of skin carcinogenesis. Significant decrease in the numbers of papilloma and epidermal hyperplasia were observed in mice fed with O. humifusa, compared to the control group. O. humifusa also upregulated high total antioxidant capacity and level of phase II detoxifying enzyme such as superoxide dismutase and glutathione S-transferase activity in the skin. Lipid peroxidation activity level was measured in skin cytosol and significantly inhibited in 3% OH fed group compared to the control group. These results suggest that O. humifusa exerts chemopreventive effects on chemical carcinogenesis in mouse skin and that prevention effects are associated with reduction of oxidative stress via the modulation of cutaneous lipid peroxidation, enhancing of total antioxidant capacity especially in phase II detoxifying enzyme system and partial apoptotic influence.

• Nutrition Research and Practice
• /
• 제4권2호
• /
• pp.93-98
• /
• 2010

Our previous study demonstrated that methanolic extract of Chrysanthemum zawadskii Herbich var. latilobum Kitamura (Compositae) has the potential to induce detoxifying enzymes such as NAD(P)H:(quinone acceptor) oxidoreductase 1 (EC 1.6.99.2) (NQO1, QR) and glutathione S-transferase (GST). In this study we further fractionated methanolic extract of Chrysanthemum zawadskii and investigated the detoxifying enzyme-inducing potential of each fraction. The fraction (CZ-6) shown the highest QR-inducing activity was found to contain (+)-(3S,4S,5R,8S)-(E)-8-acetoxy-4-hydroxy-3-isovaleroyloxy-2-(hexa-2,4-diynyliden)-1,6-dioxaspiro [4,5] decane and increased QR enzyme activity in a dose-dependent manner. Furthermore, CZ-6 fraction caused a dose-dependent enhancement of luciferase activity in HepG2-C8 cells generated by stably transfecting antioxidant response element-luciferase gene construct, suggesting that it induces antioxidant/detoxifying enzymes through antioxidant response element (ARE)-mediated transcriptional activation of the relevant genes. Although CZ-6 fraction failed to induce hepatic QR in mice over the control, it restored QR activity suppressed by $CCl_4$ treatment to the control level. Hepatic injury induced by $CCl_4$ was also slightly protected by pretreatment with CZ-6. In conclusion, although CZ-6 fractionated from methanolic extract of Chrysanthemum zawadskii did not cause a significant QR induction in mice organs such as liver, kidney, and stomach, it showed protective effect from liver damage caused by $CCl_4$.

• Nutrition Research and Practice
• /
• 제8권3호
• /
• pp.272-277
• /
• 2014

BACKGROUND/OBJECTIVES: This study investigated the antioxidant activities and hepatoprotective effects of Schisandra chinensis Baillon extract (SCE) against tert-butyl hydroperoxide (t-BHP)-induced oxidative hepatic damage in rats. MATERIALS/METHODS: Sprague-Dawley (SD) rats were pretreated with SCE (300, 600, and 1,200 mg/kg BW) or saline once daily for 14 consecutive days. On day 14, each animal, except those belonging to the normal control group, were injected with t-BHP (0.8 mmol/kg BW/i.p.), and all of the rats were sacrificed 16 h after t-BHP injection. RESULTS: Although no significant differences in AST and ALT levels were observed among the TC and SCE groups, the high-dose SCE group showed a decreasing tendency compared to the TC group. However, erythrocyte SOD activity showed a significant increase in the low-dose SCE group compared with the TC group. On the other hand, no significant differences in hepatic total glutathione (GSH) level, glutathione reductase (GR), and glutathione peroxidase (GSH-Px) activities were observed among the TC and SCE groups. Hepatic histopathological evaluation revealed that pretreatment with SCE resulted in reduced t-BHP-induced incidence of lesions, such as neutrophil infiltration, swelling of liver cells, and necrosis. In particular, treatment with a high dose of SCE resulted in induction of phase II antioxidant/detoxifying enzyme expression, such as glutathione S-transferase (GST) and glutamate-cysteine ligase catalytic subunit (GCLC). CONCLUSIONS: Based on these results, we conclude that SCE exerts protective effects against t-BHP induced oxidative hepatic damage through the reduction of neutrophil infiltration, swelling of liver cells, and necrosis. In addition, SCE regulates the gene expression of phase II antioxidant/detoxifying enzymes independent of hepatic antioxidant enzyme activity.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6403-6407
• /
• 2012

Detoxifying enzymes are present in most epithelial cells of the human gastrointestinal tract where they protect against xenobiotics which may cause cancer. Induction of examples such as glutathione S-transferase (GST) and its thiol conjugate, glutathione (GSH) as well as NAD(P)H: quinoneoxidoreductase (NQO1) facilitate the excretion of carcinogens and thus preventing colon carcinogenesis. Pterostilbene, an analogue of resveratrol, has demonstrated numerous pharmacological activities linked with chemoprevention. This study was conducted to investigate the potential of pterostilbene as a chemopreventive agent using the HT-29 colon cancer cell line to study the modulation of GST and NQO1 activities as well as the GSH level. Initially, our group, established the optimum dose of 24 hours pterostilbene treatment using MTT assays. Then, effects of pterostilbene ($0-50{\mu}M$) on GST and NQO1 activity and GSH levels were determined using GST, NQO1 and Ellman assays, respectively. MTT assay of pterostilbene ($0-100{\mu}M$) showed no cytotoxicity toward the HT-29 cell line. Treatment increased GST activity in the cell line significantly (p<0.05) at 12.5 and $25.0{\mu}M$. In addition, treatment at $50{\mu}M$ increased the GSH level significantly (p<0.05). Pterostilbene also enhanced NQO1 activity significantly (p<0.05) at $12.5{\mu}M$ and $50{\mu}M$. Hence, pterostilbene is a potential chemopreventive agent capable of modulation of detoxifiying enzyme levels in HT-29 cells.

• Natural Product Sciences
• /
• 제7권2호
• /
• pp.38-44
• /
• 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.