Soon-Jae Rhee

Action of green tea catechin on bone metabolic disorder in chronic cadmium-poisoned rats.

The purpose of this study was to investigate the effects of green tea catechin on bone metabolic disorders and its mechanism in chronic cadmium-poisoned rats. Sprague-Dawley male rats weighing 100+/-10 g were randomly assigned to one control group and three cadmium-poisoned groups. The cadmium groups included a catechin free diet (Cd-0C) group, a 0.25% catechin diet (Cd-0.25C) group and a 0.5% catechin diet (Cd-0.5C) group according to their respective levels of catechin supplement. After 20 weeks, the deoxypyridinoline and crosslink values measured in urine were significantly increased in the Cd-0C group. Cadmium intoxication seemed to lead to an increase in bone resorption. In the catechin supplemented group (Cd-0.5C group), these urinary bone resorption marks, were decreased. The serum osteocalcin content in the cadmium-poisoned group was significantly increased as compared with the control group. In the catechin supplemented group serum osteocalcin content values were lower than the control group. The cadmium-intoxicated group (Cd-0C group), had lower bone mineral density than the control group (total body, vertebra, pelvis, tibia and femur). The catechin supplement increased bone mineral density to about the same as the control group. Bone mineral content showed a similar trend to total bone mineral density. Therefore, the bone mineral content of the Cd-0C group at the 20th week was significantly lower than the control group. The catechin supplemented group (Cd-0.5C group) was about the same as the control group. The cause of decreasing bone mineral density and bone mineral content by cadmium poisoning was due to the fast bone turnover rate, where bone resorption occurred at a higher rate than bone formation. The green tea catechin aided in normalizing bone metabolic disorders in bone mineral density, bone mineral content and bone calcium content caused by chronic cadmium intoxication.

Effects of green tea catechin on enzyme activities and gene expression of antioxidative system in rat liver exposed to microwaves

Abstract The purpose of this study was to investigate the effect of green tea catechin on enzyme activities and gene expression of antioxidative system in rat liver exposed to microwaves. Sprague-Dawley male rats 100±10 g body weight were randomly divided into control group and microwave exposed group: Microwave exposed group was further divided into three groups: catechin free diet (MW) group, 0.25% catechin (MW-0.25C) group and 0.5% catechin (MW-0.5C) group. The rats were irradiated with microwave at frequency of 2.45 GHz for 15 min and then the changes in the pattern of antioxidative defense system and gene expression were investigated for 16 days (the 2nd, 4th, 6th, 8th and 16th days), and compared with the control group. The activity of superoxide dismutase (SOD) in MW group was lower on the 4th day after irradiation and increased in the catechin supplementation group were on the 8th day, compared with control group. The activity of glutathone peroxidase (GSHpx) in MW group was lower than that in the control group on the 8th day after irradiation, but increased to the level of the control group on the 16th day and those of MW-0.25C and MW-0.5C groups showed the same level as the control group but that was higher than the control group from 6 days after irradiation. The content of thiobarbituric acid reactive substances (TBARS) in liver of MW group was increased to 1.3, 1.5, and 1.7 fold of the control group at 2, 4, and 6 days after irradiation respectively but that in MW-0.25C and MW-0.5C groups was increased to 1.1, 1.3 and 1,3 fold of the control group at 2, 4, and 6 days but recovered to the level of the control group at 16 days after irradiation. The level of SOD gene expression in MW group was lower than that in the control group but that of MW-0.25C and MW-0.5C group were higher than the MW group. The GSHpx gene expression in MW group was expressed lower than in the control group, but expressed at a higher level in the MW-0.25C and MW-0.5C groups. It is suggested that the damage of liver tissues was alleviated and function rapidly recovered to the normal level due to probable to the correction of imbalances in the antioxidative system with the administration of green tea catechin

Effects of the Cellcultured Acanthopanax senticosus Extract on Antioxidative Defense System and Membrane Fluidity in the Liver of Type 2 Diabetes Mouse

This study examined the effect of cellcultured Acanthopanax senticosus (A. senticosus) extract on the antioxidative defense system, oxidative stress and cell membrane fluidity in the liver of type 2 diabetes in the C57BL/6J mouse as an animal which is genetically prone to develop insulin resistance and obesity/diabetes. C57BL/6J mice were randomly divided, control diet (N-C), high fat diet (DM-C), control diet plus A. senticosus extract (N-CASM), and high fat diet plus A. senticosus extract (DM-CASM). The mice were orally administered an A. senticosus extract (0.5 g/kg body weight) in the N-CASM and DM-CASM groups once a day for 12 weeks, and distilled water in the N-C and DM-C groups. Cellcultured A. senticosus extract was found to be excellent for strengthening the antioxidative defense system, reducing the generation of reactive oxygen species (ROS) and damaging oxidative substances, and maintaing membrane fluidity (MF) in the liver of type 2 diabetes mouse.

Effects of Green Tea Catechin on Polymorphonuclear Leukocyte 5′-Lipoxygenase Activity, Leukotriene B4 Synthesis, and Renal Damage in Diabetic Rats

The purpose of this study was to investigate the effects of green tea catechin on polymorphonuclear leukocyte 5′-lipoxygenase activity, leukotriene B4 synthesis, and renal damage in diabetic rats. Male Sprague-Dawley rats weighing 100 ± 10 g were randomly assigned to 1 normal group and 3 diabetic groups given a catechin-free diet (DM-0C group), 0.25% catechin diet (DM-0.25C group), or 0.5% catechin diet (DM-0.5C group), respectively. 5′-Lipoxygenase activity in the polymorphonuclear leukocytes significantly increased by 54% in the DM-0C group compared to the normal group, while the level in the DM-0.5C group remained the same as in the normal group. The leukotriene B4 content in the polymorphonuclear leukocytes increased 55% in the DM-0C group compared to the normal group, whereas the DM-0.25C and DM-0.5C groups exhibited the same level as the normal group. The superoxide radical content in the kidney microsomes increased 116% in the DM-0C group when compared to the normal group, yet decreased 29% in the DM-0.25C group and 50% in the DM-0.5C group compared to DM-0C group. The lipofuscin content was 197 and 136% higher in the DM-0C and DM-025C groups, respectively, than in the normal group, whereas the DM-0.5C group exhibited the same content as in the normal group. The carbonyl value increased 118% in the DM-0C group compared to the normal group, and the DM-0.25C and DM-0.5C groups were not significantly different from the DM-0C group. Accordingly, these results indicate that dietary catechin inhibited the generation of superoxide radicals, oxidized protein, and lipid peroxide in the kidney of streptozotocin-induced diabetic rats. Furthermore, green tea catechin supplementation in diabetic rats also appeared to inhibit the production of leukotriene B4 based on regulating the activity of 5′-lipoxygenase, thereby potentially reducing renal oxidative damage and inflammatory reactions.

Effects of Vitamin E on Phospholipase A2 Activity and Oxidative Damage to the Liver in Streptozotocin-Induced Diabetic Rats

Background: The purpose of the present study was to investigate the effects of vitamin E on oxidative stress and cell membrane fluidity in the liver of streptozotocin (STZ)-induced diabetic rats. Methods: Sprague-Dawley male rats weighing 100 ± 10 g were fed a vitamin E-free diet (the DM-0E group), a 40 mg vitamin E/kg diet (the DM-40E group), or a 400 mg vitamin E/kg diet (the DM-400E group). Result: Dietary vitamin E reduced the increased concentration of lipid peroxides in the liver tissues of diabetic rats through decreasing their increased phospholipase A2 (PLA2) activity and phosphatidylethanolamine hydrolysis. However, vitamin E reduced the accumulation of superoxide radical and decreased the generation of oxidative damage substances, such as the carbonyl value, increased membrane fluidity and lowered oxidative damage. Conclusions: Vitamin E was found to be excellent for regulating the activity of PLA2, reducing the generation of reactive oxygen species and damaging oxidative substances, and maintaining cell membrane fluidity in the liver of diabetic rats.

Effects of manufactured soluble dietary fiber from Quercus mongolica on hepatic HMG-CoA reductase and lipoprotein lipase activities in epididymal adipose tissue of rats fed high cholesterol diets.

This study investigated the effect of a manufactured soluble dietary fiber on lipid metabolism in rats fed high cholesterol diets. Soluble dietary fiber was prepared from wood chips of oak (Quercus mongolica). Male Sprague-Dawley rats weighing 100 +/- 10 g were randomly assigned to either a normal diet or five high cholesterol diets containing 1% cholesterol and different fiber supplements. The high cholesterol groups were subdivided into fiber-free diet (FF), 5% pectin (5P), 10% pectin (10P), 5% manufactured soluble dietary fiber (5QM), and 10% manufactured soluble dietary fiber (10QM) groups. Total serum cholesterol concentrations in all soluble dietary fiber-supplemented groups were lower than in the FF group. The high-density lipoprotein-cholesterol concentration in the FF group was significantly lower, compared with the normal group, but was increased in groups supplemented with soluble dietary fiber. Low-density lipoprotein-cholesterol levels and the atherogenic index had the same tendency as total cholesterol concentration. Compared with the FF group, in the 5P, 5QM, 10P, and 10QM groups hepatic triglyceride concentrations were 12%, 16%, 20%, and 24% lower, respectively, and hepatic cholesterol concentrations were 48%, 52%, 52%, and 58% lower, respectively. Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity in the soluble fiber groups was significantly higher than in the FF groups, but lower than the normal group. When hepatic tissue was observed under a light microscope, the FF group had completely formed lipomas in the hepatic tissue, which led to fat deposits and then a fatty liver. The size and number of lipomas were lower in the soluble dietary fiber-fed groups, as compared with the group not fed dietary fiber. In conclusion, improvements in lipid metabolism were observed as a result of the manufactured soluble dietary fiber from the oak chips, and were similar to that seen for pectin. The preparation method for the soluble dietary fiber from oak chips successfully produced a functional soluble fiber.

Acknowledgement to the 2005 Reviewers

Micksche M., Vienna, Austria Miller T.L., New York, USA Pallauf J., Giessen, Germany Palou A., Palma de Mallorca, Spain Pedersen J., Oslo, Norway Petersson Grawe K., Uppsala, Sweden Prentice A., London, UK Rieder A., Vienna, Austria Roche H.M., Dublin, Ireland Rodriguez-Amaya D.B., Campinos, Brasil Roky R., Casablanca, Morocco Rust P., Vienna, Austria Schweigert F.J., Potsdam-Rehbrücke, Germany Seidell J.C., Bilthoven, The Netherlands Shirwaikar A., Manipal, India Simopoulos A.P., Washington, USA Svensson J., Göteborg, Sweden Kajantie E., Helsinki, Finland Thorpe S.R., Columbo, USA Trautwein E.A., Vlaardingen, The Netherlands Trichopoulos D., Boston, USA Uauy R., Santiago, Chile Vajreswari A., India von Ruecker A., Bonn, Germany von Schacky C., Munich, Germany Walczyk T., Rüschlikon, Switzerland Walter D., Bergholz-Rehbrücke, Germany Yamamoto H., Kawasaki, Japan Zentek J., Vienna, Austria Zingg J.M., Bern, Switzerland Zunft H.-J., Potsdam-Rehbrücke, Germany Zwiauer K.F., St. Pölten, Austria Adam O., Munich, Germany Agustoni C., Milano, Italy Araya M., Santiago, Chile Arruda S.F., Asa Norte, Brasil Arthington J.D., Ona, USA Azevedo R.B., Brasil Biesalski K.H., Stuttgart, Germany Bode Ch., Stuttgart, Germany Boeing H., Bergholz-Rehbrücke, Germany Branca F., Copenhagen, Denmark Branger B., France Christophe A.B., Ghent, Belgium Dagnelie P.C., Maastricht, The Netherlands Decsi T., Pécs, Hungary DeRose D.J., USA Dixon J.B., Melbourne, Australia Dobos D., Essen, Germany Eder K., Halle, Germany Fournier P.A., Australia Garcia Monzon C., Madrid, Spain Haas K., Vienna, Austria Huyghebaert A., Ghent, Belgium Isnardy B., Vienna, Austria Kohlenberg-Müller K., Fulda, Germany Koletzko B., Munich, Germany Krejs G., Graz, Austria Ladeji O., Jos, Nigeria Laplace J.P., Paris, France Linseisen J., Heidelberg, Germany Ludvik B., Vienna, Austria Łukaszewicz M., Wrocław, Poland Marktl W., Vienna, Austria Martinez A., Pamplona, Spain