• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.213-218
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• 2000

The purpose of the study was to investigate the effects of dietary green tea catechin and vitamin E on the phospholipse {TEX}$A_{2}${/TEX} activity and th antioxidative defense system in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing 100$\pm$10 gm were randomly assigned to one normal and five STZ-induced diabetic groups. The diabetic groups were assigned either a catechin-free diet (DM group), 0.5% catechin diet (DM-0.5C group), 1% catechin diet (DM-1C group), vitamin E-free diet (DM-0E group), and 400 mg vitamin E per kg diet (DM-400E group) according to the levels of dietary catechin or vitamin E supplementation. The vitamin E levels of the normal, DM, DM-0.5C, and DM-1C groups were 40 mg per kg diet. Diabetes was experimentally induced by an intravenous injection of streptozotocin after 4 weeks of feeding the five experimental diets. The animals were sacrificed on the 6th day of he diabetic state. The body weight gains were lower in all five diabetic groups after the STZ injection. The platelet phospholipase {TEX}$A_{2}${/TEX}({TEX}$PLA_{2}${/TEX}) activity in the diabetic groups was higher than that in the normal group. However, the enzyme activity in the DM-0.5C, DM-1C, and DM-400E groups was lower than that in the DM and DM-0E groups. The cytochrome {TEX}$P_{450}${/TEX} and cytochrome {TEX}$b_{5}${/TEX} content and NADPH-cytochrome {TEX}$P_{450}${/TEX} reductase activity were about 50~110% higher in the DM and DM-0E groups than in the normal group, yet significantly reduced by either catechin or vitamin E supplementation. The superoxide dismutase (SOD) content in the liver did not differ significantly in any of the groups. However, the glutathione peroxidase (GSHpx) activity was generally lower in the diabetic groups, compared with the normal group, whereas that of the DM-0.5C, DM-1C, and DM-400E groups was significantly higher compared with that of the DM and DM-0E groups. The levels of thiobarbituric acid reactive substances (TBARS) in the liver tissue were 148% and 201% higher in the DM and DM-0E groups, respectively, compared with the normal group, however, these levels were reduced by either catechin or vitamin E supplementation (DM-0.5, DM-1C and DM-400E). Accordingly, the present results indicate that STZ-induced diabetic rats exhibited an imbalance between free radical generation and scavenger systems in the liver which led to the acceleration of lipid peroxidation. However, these abnormalities were reduced and the antioxidative defense system was restored by either dietary catechin or vitamin E supplementation. In conclusion, the effects of dietary catechin or vitamin E in streptozotocin-induced diabetic rats would appear to inhibit lipid peroxidation as an anti-oxidant by regulating the activity of {TEX}$PLA_{2}${/TEX}.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.53-57
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• 2004

The purpose of this study was to investigate the effects of green tea catechin on mixed function oxidase system (MFO), lipofuscin contents, carbonyl value, oxidative damage and the antioxidative defense system in lung of microwave exposed rats. Experimental groups were divided to normal group and microwave exposed group. The microwave exposed groups were subdivided into three groups: catechin free diet (MW-0C) group, 0.25% catechin (MW-0.25C) group and 0.5 ％ catechin (MW-0.5C) group according to the levels of dietary catechin supplementation. The rats were irradiated with microwave at frequency of 2.45 GHz for 15 min. Experimental animals were sacrificed at 6th day after microwave irradiation. The contents of cytochrome P$_{450}$ contents in MW-0C group was increased to 95% , compared with normal group. MW-0.25C and MW-0.5C groups were reduced to 16% and 31%, respectively, compared with MW-0C group. The activity of NADPH-cytochrome P$_{450}$ reductase in MW-0C group was increased to 44%, compared with normal group. MW-0.25C and MW-0.5C groups were reduced to 12% and 17％, respectively, compared with MW-0C group. The activity of superoxide dismutase (SOD) in MW-0C group was decreased to 21 ％, compared with normal group. MW-0.25C and MW-0.5C group were significantly (p < 0.05) increased, compared with MW-0C group. The activity of glutathione peroxidase (GSHpx) in MW-0C group was significantly decreased, compared with normal group. MW-0.25C and MW-0.5C groups were recovered to the level of normal group. The thiobarbituric acid reactive substances (TBARS) content in MW-0C group was increased to 34 ％, compared with normal group. Catechin supplementation groups were maintained the level of normal group. The levels of caybonyl value in MW-0C group was increased to 21 ％, compared with normal group. MW-0.25C and MW-0.5C groups were reduced to 14% and 12%, respectively, compared with MW-0C group. The lipofuscin contents in MW-0C group were increased to 23.4 ％, compared with normal group. That of MW-0.5C group was significantly reduced, compared with MW-0C group. In conclusion, MFO system was activated and the formation of oxidized protein, lipofuscin was increased and antioxidative defense system was weakened of lung tissue in microwave exposed rats, thus oxidative damage was increased. But it was rapidly recovered to normal level by green tea catechin supplementation.n.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1065-1070
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• 2002

The purpose of this study was investigated the effects of YK-209 mulberry leaves on antioxidative defense system of liver in diabetic rats induced with streptozotocin (STZ). Male Sprague-Dawley rats weighing 100$\pm$10 g were randomly assigned to one normal and four STZ-induced diabetic groups; YK-209 mulberry leaves free diet (DM group),0.1% YK-209 mulberry leaves diet (DM-0.1Y group),0.2% YK-209 mulberry leaves diet (DM-0.2Y group) and 0.4% YK-209 mulberry leaves diet (DM-0.4Y group). Diabetes was induced by intravenous Injection of 55 mg/kg body weight of STZ in sodium citrate buffer (pH 4.3) via tail vein after 4 weeks feeding of experimental diets. Rats were sacrificed at the 9th day of diabetic states. Liver weight in all four diabetic groups were higher than normal group, but YK-209 mulberry supplementation groups were lower than DM group. Hepatic superoxide dismutase (SOD) activity was significantly decreased in all diabetic groups, compared with normal group. Hepatic glutathione peroxidase (GSHpx) activity was 7.3% decreased in DM group, compared with normal group, but those of DM-0.1Y and DM-0.2Y groups were maintained the normal level. The hepatic thiobarbituric acid reactive substances was markedly increased by 144% in DM group, compared with normal group, but those of DM-0. 1Y, DM-0.2Y groups were maintained the normal level. The contents of lipofuscin in liver were increased by 100% in DM group compared with normal group, but those of DM-0. 1Y, DM-0.2Y and DM-0.4Y groups were decreased to 42% 43% and 44%, respectively, compared with DM group. The hepatic superoxide radical (0$^2$-) contents in DM group were increased to 81%, compared with normal group, but those of DM-0.1Y and DM-0.4Y groups were similar to those of normal group. The present result indicate that YK-209 mulberry leaves regarded to suppress lipid peroxidation as an free radical scavenger system by the inhibition of oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.570-576
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• 2013

The purpose of this study was to investigate the effect of turmeric on antioxidative systems and oxidative damage in rats fed a high fat and cholesterol diet. A total 40 rats were divided into four experimental groups: a normal diet group (N), a high fat and cholesterol diet group (HF), a high fat and cholesterol diet group supplemented with 2.5% turmeric powder (TPA group) and a high fat and cholesterol diet group supplemented with 5% turmeric powder (TPB group). The serum glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activity of the turmeric supplemented groups were decreased compared to the HF group. The GPT activity of the TPB group was especially and significantly decreased compared to the HF group. Hepatic superoxide dismutase (SOD) of the TPB group was significantly increased compared to the HF group. However, there were no significant differences in the activities of hepatic glutathione peroxidase (GSHpx) and catalase (CAT) among all experimental groups. Hepatic glutathione S-transferase (GST) activity in the TPA and TPB groups were increased compared to the HF group. Hepatic superoxide radical content in mitochondria of the 5% turmeric supplemented group was significantly decreased compared to the HF group. Hepatic hydrogen peroxide content in the cytosol and mitochondria of the turmeric-supplemented groups were decreased compared to the HF group. Hepatic carbonyl values in the mitochondria of the turmeric supplemented groups were significantly decreased compared to the HF group. Thiobarbituric acid reaction substance (TBARS) values in the liver were significantly reduced in turmeric supplemented groups compared to the HF group. These result suggest that turmeric powder may reduce oxidative damage through the activation of antioxidative defense systems in rats fed high fat and cholesterol diets.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1161-1166
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• 2009

The purpose of the present study was to effect of red pepper seeds powder on antioxidative defense system and oxidative damage in rats fed high fat high cholesterol diet. Rats were divided into five experimental groups which are composed of normal diet group, high fat high cholesterol diet group, high fat high cholesterol diet with 5% red pepper seeds powder supplemented group (SA group), high fat high cholesterol diet with 10% red pepper seeds powder supplemented group (SB group), and high fat.high cholesterol diet with 15% red pepper seeds powder supplemented group (SC group). Supplementation of red seed pepper groups (SA, SB, and SC groups) resulted in increased activities of hepatic glutathione peroxidase and superoxide dismutase. However, there was no significant difference in the activity of hepatic catalase among all experimental groups. Hepatic superoxide radical contents in microsome and mitochondria were significantly reduced in red pepper seeds powder supplemented groups. Hepatic hydrogen peroxide contents in mitochondria were significantly reduced 15% red pepper seeds powder supplemented group. Hepatic carbonyl values in microsome were significantly reduced in 10% and 15% red pepper seeds powder supplemented groups. Thiobarbituric acid reaction substance (TBARS) values in liver and plasma were reduced in red pepper seeds powder supplemented groups. These result suggest that red pepper seeds powder may reduce oxidative damage by the activation of antioxidative defense system in rats high fat.high cholesterol diets.