• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.899-907
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• 1994

Accumulation of peroxidized lipid, fed or injected in the body of rats was investigated and the effect of peroxidized lipid on the antioxidative system was studied also. Three groups each having six of Sprague-dawley rats were raised for 8 weeks. the peroxide value(POV) of diet fed to the control and the peroxidized group was 5.47 and 22.14meq/kg , respectively. Injected group was given the control diet and peroxidized linoleic acid(POV 31.81meq/kg) was injected into the peritoneal area three times a week. The POV, MDA, and protein carbonyl values of the peroxidized and the injected group (experimental groups) were significantly higher (p<0.05) than those of the control group. Cu, Zn-SOD and M-SOD activity of the experimentla groups increased 1.6 times that of control group at 4 th week. and decreased by 60% of their activityafter 8 weeks of feeding (p<0.05) . Catalase activity, glutathione and Vt, E contents of the experimental groups were significantly lower (p<0.05) than those of the control group during 8 weeks. The accumulation of peroxidcized lipid in liver were ovserved both in the fed or the injected group. The increased of enzyme activity of the experimental group during 4 weeks suggests ianadaptation of antioxidative system to get rid of the peroxidized lipid. Decrease of enzyme activity and glutathione observed as the peroxidized lipid lipid accumulation proceeded further, however, seems to indicate the oxdiative damage of enzyme and protein . Determination of the protein carbonyl content may be used as a method for measuring the oxidative damaging effect of peroxidized lipid.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.590-595
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• 1990

The destructive effect of peroxidized lipid on the amino acid in protein isolate and the proteolytic activity of protease were studied in the model system of rice bran. The content of amino acids in the protein isolate decreased significantly when they reacted with peroxidized lipid (pov. 1200 meq/kg). Most of amino acids were lost by more than 90% in salt soluble protein isolates when analyzed by the method of enzyme hydrolysis. Formaldehyde reduced the activity most severely among peroxidized products. Formic acid, peroxidized lipid and hydroperoxide were also found to reduce the protease activity. The damaging effect of the secondary products on the protease activity was more serious than that of the primary products of lipid peroxidation. The destruction of amino acids in the total protein and Inhibition of protease activity by the peroxidized lipid were apparent.

• Journal of the Korean Applied Science and Technology
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• v.13 no.2
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• pp.55-65
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• 1996

The antioxidant effects of freeze-drying acorn were examined to find how much the freeze-drying acorn can reduce peroxidized corn oil poisoning, which influenced cholesterol, triglyceride, phospholipids, lipidperoxides, GOT(glutamate oxaloacetate transaminase), GPT(glutamate pyruvate transaminase) in serum, and cholesterol, triglyceride, lipidperoxides, fatty acid of phospholipids, SOD(superoxide dismutase), catalase in liver. In this experiment, male rats of Sprague-Dawley strain were used. The rats were divided into 6 groups, which were fed differently for 5 weeks : basal diet, 10% peroxidized corn oil added to basal diet, 1% acorn flour and 10% peroxidized corn oil added to basal diet, 5% acorn flour and 10% peroxidized corn oil added to basal diet, 10% acorn flour and 10% peroxidized corn oil added to basal diet, and 0.25% tannic acid and 10% peroxidized corn oil added to basal diet. The results were as follows : It was found that the peroxidized corn oil-fed 5 weeks induced the elevation of cholesterol, triglycerides, lipid peroxides, GOT, GPT in serum, and cholesterol, triglycerides, lipid peroxides in liver as compared to the basal diet-fed rats, but the acorn flour-fed rats reduced the elevation of these components. In addition, saturated fatty acid in rat liver phospholipids induced the elevation by feeding of peroxidized corn oil and, on the other hand, the acorn flour-fed rats reduced the elevation of saturated fatty acids. The acorn flour-fed rats reduced the activity of SOD in liver while they enhanced the activity of catalase in liver as compared with the peroxidized corn oil-fed rats.

• Korean Journal of Acupuncture
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• v.22 no.4
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• pp.83-90
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• 2005

Objectives : To investigate the effects of acupuncture at Gansoo (B-18) and Chungwan (CV-12) on lipid metabolism in rats fed peroxidized lipid diet. Methods : Effects of acupuncture at Gansoo and Chungwan on plasma and liver lipid composition and antioxidative capacity were investigated in rats fed peroxidized lipids. Results : Although the level of plasma total cholesterol and triglyceride showed a tendency to decrease in the acupuncture group, the plasma HDL-cholesterol concentration showed no significant difference. The level of liver total cholesterol and triglyceride showed no significant difference in all treatment groups. Thiobarbituric acid( TBARS ) values in plasma and liver showed a tendency to decrease in the acupuncture groups. The plasma GOT and GPT activities showed low values in the acupuncture groups. The liver glutathione peroxidase, superoxide dismutase and catalase activity showed high values in the acupuncture groups. Conclusions : The results suggest that acupuncture at Gansoo (B-18) and Chungwan (CV-12) may have an influence on lipid metabolism via enhancing antioxidative capacity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.867-878
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• 1994

A general overview of the lipid peroxidation and its nutritional significance are presented ,with emphasis on the reaction mechaisms, peroxidized products, further interaction and nutritional/biological deterioration in a series of oxidative process. Overall mechanism with various factors and elements for initiation , propagation and termination of free radical reaction is reviewed and the primary /secondary products of peroxidized lipids are defined. Since these products are potentially reactive substances that can cause deterioration of proteins /amino acids and vitamins (carotene, tocopherols and ascorbic acid etc), mechanism and actual damages of their deterioration in some foods and biological models are outlined. Especially , chemical changes caused by interaction of peroxidized products (related hydroperoxides, radicals and malonaldehye etc) and protein are emphasized here. And also, the detailed mechanisms on radical scavenging of the these vitamins which are the most prominent natural antioxidants are presented . Additionally , the possible roles of peroxidicaed lipids and their secondary products in the process of aging an carcinogenesis are briefly discussed . However, it is important to not that more detailed and integrated studies on the reaction kinetics, energetics of peroxidation, their decomposed products , biochemical interaction potential damaging/aging / carcinogenic effects, protection from their oxidative spoilage and novel antioxidants in food and heterogeneous biological systems will be essential in order to assessing the implication of lipid peroxidation to human nutrition and health.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.596-601
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• 1990

The effects of peroxidized lipid on the protein in the biological system of rice bran was studied by determining the changes in the content of functional groups under two different storage conditions. One stored at controlled atmosphere of $35^{\circ}C$ with relative humidity 65% and the other one was exposed to the air of $25^{\circ}-30^{\circ}C$ with relative humidity 70-90%. The lipid peroxidation started after the lipolysis was almost completed. The autoxidation occurred much faster in the bran exposed to the air than that stored in the controlled atmosphere. Substantial changes in the physiochemical characteristics were observed in all of the major functional groups in both of the samples. The content of sulfhydryl and available lysine decrease·1 as lipid peroxidation progressed. Protease activity was lost almost completely. Protein solubility and in vitro digestibility also decreased during storage. The lipid peroxidation and contents of major protein functional groups were significantly correlated (p<0.05) and the correlation coefficients were higher than -0.8, for the both of the sample. peroxidized lipid was found to deteriorate protein in the biological system as well.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.3
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• pp.214-219
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• 1991

The damaging effect of peroxidized lipid on amino acid was studied in rice bran by determining the free amino acid content in abiological system. The content of free amino acid in the rice bran stored in the controlled atomsphere of $35^{\circ}C$ with relative humidity of 65% for 180 days, increased during the first 60 days of storage, and then decreased as the lipid peroxidation proceeded. The content of free amino acid in the sample exposed to the air of $25-30^{\circ}C$ with relative humidity of 70-90% for 100 days decreased rapidly in the beginning period of the storage. The lipid oxidation developed much faster in the rice bran exposed to the air than in the rice bran stored in the controlled atmosphere. The correlation coefficients between the total content of free amino acid and degree of peroxidation for the samples of both conditions were above -0.8, which is significant(p<0.05). The changes in the concentration of serine, glutamic acid, proline, methionine, lysine, histidine, and arginine were significantly correlated with the degree of lipid oxidation(p<0.05) for the samples stored in the controlled atmosphere and the open air. It was observed that peroxidized lipid has damaging effects on protein in the bilogical system of rice bran.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.381-391
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• 1993

To evaluate the antioxidizing effect of flavonoid on fish oil and peroxidized fish oil, rats were fed with diets containing 5% corn oil (CO), 5% corn oil and 15% fresh fish oil (FO) or peroxidixed fish oil (PFO) for 4weeks. An half of FO and PFO group rats were injected with 10mg flavonoid (+)-catechin (a day per kg body weight) (FO-C and PFO-C). FO and FO-C group rats showed higher increase in body weight as compared to PFO, PFO-C group rats. Whereas, the opposite result was obtained in case of liver weight increase. In addition, catechin apparently reduced liver weight by 12~17%. Phospholipid, cholesterol, triglyceride and lipid peroxide content in serum and cholesterol, lipid peroxide content in liver and adipose tissue of PFO, PFO-C group rats were significantly higher than those of FO, FO-C one. These results suggested that catechin reduced the synthesis of lipid and protected effectively against lipid peroxidation. In fatty acids profile of neutral lipid and phospholipid, the ratio of polyunsaturated fatty acids (PUFA) versus saturated fatty acids (SFA) in PFO, PFO-C were lower than that of FO or FO-C because of ruduced PUFA. Contrary to our expectation, the enzyme activities of superoxide dismutase(SOD), catalase and glutathione peroxidase (GSH-Px) in rat liver of FO and FO-C group were lower than those of PFO and PFO-C group. These results were quite interesting and might be explained in terms of homeostasis. In case of total lipid in liver, $C_{20:5}$, $C_{22:6}$ fatty acids were decreased in rat fed peroxidized fish oil. In conclusion, catechin was considered to be an antioxidative and hepatoprotective drug and hypolipidemic agent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.166-172
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• 1994

To evalulate the antioxidant effect of flavonoid(+)-catechin on n-3 polyunsaturated fatty acids in vivo, rats were fed with diets containing $5\%$ corn oil(CO), $5\%$ corn oil and $15\%$ purified fresh fish oil(FO) or peroxidized fish oil(PFO) for 10 days. To accerelate lipid peroxidation, all of them were injected with 60mg phenobarbital(a day per kg body weight), and treated with phorone(diisopropylidene acetone) before the rats were killed. Contents of triglyceride, phospholipid, cholesterol and lipid peroxide and the activities of GOT, GPT in serum and total lipid and cholesterol content in liver of PFO group rats were significantly higher than those of the FO one. Contrary to our expectations, the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase(GSH-Px) in liver of the FO group were ]ewer than those of the PFO group. These results might be explained as the results of homeostasis. Even though the hepatic glutathione were depleted, catechin and a-tocopherol inhibited production of lipid peroxide effectively. These results suggested that catechin be considered an antioxidative and hepatoprotective agent.

• BMB Reports
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• v.29 no.1
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• pp.81-87
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• 1996

The relationship of S-thiolation and oxidation of glycogen phosphorylase b and peroxidation of phosphatidyl choline liposome by xanthine oxidase (XOD), 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH), and 2,2'-azobis(dimethylvaleronitrile) (AMVN)-generated free radicals was investigated, Glycogen phosphorylase b was S-thiolated in the presence of glutathione and oxidized in the absence of it by XOD, AAPH and AMVN. In XOD-initiated reaction, the rates of S-thiolation and oxidation of phosphorylase were very similar and addition of liposome to the reaction mixture showed little inhibition of the modifications. In AAPH-initiated reaction, the rate of oxidation was higher than that of S-thiolation and addition of liposome increased oxidation of the protein but had no effect on S-thiolation. In AMVN-initiated reaction, S-thiolation was higher than oxidation and addition of liposome increased S-thiolation remarkably but showed no effect on oxidation. The effect of liposome on modifications of protein in AAPH and AMVN reaction seemed to be caused by certain reactive degradation products or intermediates of liposome by free radical attack. Peroxidation of liposome was not observed in XOD-initiated reaction. Liposome was gradually peroxidized by AAPH reaction. The peroxidation was inhibited by addition of GSH and phosphorylase. Peroxidation of liposome by AMVN was extreamly fast, and was not affected by GSH and phosphorylase.