• 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 Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1763-1770
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• 2015

The effects of root of Taraxacum coreanum Nakai (TC), on the suppression of inflammation and oxidative stress induced by lipopolysaccharide (LPS) in ICR mice were studied. LPS (10 mg/kg body weight) was injected into ICR mice in between two consecutive oral administrations. Hot water extract of fresh TC (HWETC) was administered to mice immediately before and 24 h after LPS injection. The animal groups used in this study were as follows: NOR group (PBS injection, DW administration), CON group (LPS injection, DW administration), and TC group (LPS injection, 1.4 g/kg bw of HWETC administration). Mice in the CON group lost weight due to inflammation induced by LPS, while the body weight of the TC group mice increased significantly, indicating that inflammation was inhibited by HWETC administration. Compare with the CON group, plasma and hepatic triglyceride, reactive oxygen species, peroxynitrite, and hepatic thiobarbituric acid reactive substances concentrations of the TC group decreased significantly (P<0.05). The protein expression of a pro-inflammatory transcription factor, nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) and its target enzyme, cyclooxygenase 2, increased in response to LPS injection, but was suppressed by HWETC administration (P<0.05). In conclusion, HWETC appears to ameliorate the oxidative stress and inflammatory responses induced by LPS via inhibition of $NF-{\kappa}B$ activation.

• 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.50 no.2
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• pp.216-224
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• 2018

To evaluate physiological effect of Aralia elata, in vitro antioxidant activity and hepatic protective effects were investigated. Ethyl acetate fraction from Aralia elata (EFAE) had higher total phenolic content than other fractions (n-hexane, chloroform, and distilled water layers). EFAE also showed significantly greater radical scavenging activity against 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), than other fractions. Moreover, EFAE showed dose-dependent inhibitory effect of malondialdehyde (MDA). Hepatoprotective effects of EFAE against ethanol- and $H_2O_2$-induced oxidative stress and cytotoxicity in H4IIE and HepG2 hepatic cells were examined using 2',7'-dichlorofluorescein diacetate (DCF-DA) and 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The results showed that EFAE reduced cellular oxidative stress, and increased hepatic cell viability. In addition, EFAE inhibited ethanol-induced lipid accumulation in HepG2 cells. Finally, physiological substances of EFAE were analyzed using high performance liquid chromatography (HPLC), and the major bioactive compounds identified were 3,5-dicaffeoylquinic acid and chlorogenic acid.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.203-208
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• 2017

The antioxidant and anti-inflammatory effects of roasted dried radish (RDR) against renal oxidative stress were examined in high-fat diet (HFD)-fed mice. The HFD was prepared by adding lard to chow diet to provide 50% of the calories from fat. Hot water extracts of dried radish (DR) or RDR were administered orally to mice at 237 mg/kg bw/day, whereas distilled water was administered as a vehicle for 12 weeks. Compared to the control group, renal reactive oxygen species, peroxynitrite, and thiobarbituric acid reactive substance level in the DR or RDR group were significantly decreased, whereas the glutathione level was increased (p<0.05). Protein expressions of antioxidant factors such as nuclear factor erythroid 2-related factor-2, heme oxygenase-1, glutathione S-transferase, superoxide dismutase, catalase, and glutathione peroxidase were significantly increased in the DR and RDR groups; however, nuclear factor-kappa B expression was suppressed (p<0.05). These antioxidant and anti-inflammatory effects of RDR were found to be significantly greater than those of DR.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.659-667
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• 2017

The present study was designed to evaluate the antioxidant activity and radioprotective effects of Naringin and Naringenin in ${\gamma}$-irradiated mice. The antioxidant activity of Naringin and Naringenin was evaluated by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Healthy female BALB/c mice were administered Naringin and Naringenin orally ($90{\mu}M/dose$ and $180{\mu}M/dose$) for 7 consecutive days prior to ${\gamma}$-irradiation (6 Gy). Naringenin displayed a much higher antioxidant activity in ABTS and FRAP than naringin. ${\gamma}$-irradiation resulted in cellular damage with decreased spleen and thymus indices and white blood cells (WBC) count. Additionally, ${\gamma}$-irradiation significantly increased lipid peroxidation and decreased the levels of antioxidant enzymes and glutathione (GSH) in the liver tissue. Strikingly, prior administration of Naringenin resulted in considerable prevention of these symptoms. Protection against ${\gamma}$-irradiation-induced cellular damage by Naringenin is likely due to its higher its antioxidant activity. Together, these results confirm that Naringenin is a potent antioxidant and radioprotector.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.503-508
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• 2019

To evaluate the protective effect of Ecklonia cava on ultra-fine dust ($PM_{2.5}$)-induced cytotoxicity, we investigated the in vitro antioxidant activity and cell viability after exposure to $PM_{2.5}$. E. cava was extracted using water and 80% ethanol, and antioxidant activity was determined using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS)/2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation inhibition assays. The 80% ethanol extract showed relatively higher antioxidant activity than the water extract. The cell protective effects were determined by measuring the intracellular reactive oxygen species (ROS) content and viability of nasal epithelial (RPMI-2650), lung epithelial (A549), and brain neuroblastoma (MC-IXC) cells. Results showed that the 80% ethanol extract inhibited ROS production more than the water extract. In contrast, both extracts showed similar effects on cell viability in the $PM_{2.5}$-induced cell death assay. Thus, Ecklonia cava may act as an effective resource for preventing $PM_{2.5}$-induced cytotoxicity in nasal, lung, and brain cells.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.543-548
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• 2018

The current study examined antioxidant and neuronal cell protective effects of the crude polysaccharide fraction in Cudrania tricuspidata fruits (CTP). The radical scavenging activities of (1,1-diphenyl-picrylhydrazyl and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and reducing power and FRAP of CTP were increased dose-dependently. In addition, the expression of neuroprotective effect of CTP was tested in HT22 mouse hippocampal cells. CTP treatment exhibited non cytotoxicity at dose levels below $500{\mu}g/mL$. Within this optimal concentration range, CTP treatment significantly increased cell viability in $H_2O_2-treated$ HT22 cells. Furthermore, CTP treatment increased superoxide dismutase (SOD) activity and decreased malonaldehyde (MDA) levels in HT22 cells. Therefore, these results indicate that the crude polysaccharide fraction from Cudrania tricuspidata fruits (CTP) possesses antioxidant activities and displays therapeutic potential as a useful source material in the development of brain disorder treatments targeting oxidative stress in neuronal cells.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.472-477
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• 1996

This study was conducted to investigate the effect of old antler extracts on galactosamine-induced liver injuries in rats. Male rats of Sprague-Dawley strain with average weight of 110$\pm$10g were fed on diets containing three kinds of old antler extracts(water extract, neutral extract and ether extract) for four weeks. Galactosamine(400mg/kg body weight) was injected intraperitoneally at the same time every week in galactosamine treatment groups. Cytochrome P-450 content was decreased in galactosamine treatment groups and increased by old antler extracts administration. Glutathione-peroxidase activity was increased in water extract group. Hepatic glutathione content was not observed significant differences by the old antler extracts administration. Lipid peroxide content was higher in the galactosamine treatment groups than that of the control group and decreased in galactosamine administerd groups after pretreatment with water extract. Total lipid, triglyceride and total cholesterol contents of liver were decreased in old antler extracts administerd groups and decreased in water extract group.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.524-531
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• 2017

The study aimed to investigate the antioxidant activity and neuroprotective effect of the ethyl acetate fraction from Orostachys japonicus A. Berger extract (EFOJ) and its main constituent compounds. Among all fractions, the highest content of total phenolics was found in EFOJ. The antioxidant activity of EFOJ was confirmed through the 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 1-1-diphenyl-2-picryl-hydrazyl (DPPH), ferric reducing antioxidant power (FRAP) assays and the inhibitory effect of malondialdehyde (MDA). In addition, we ascertained that EFOJ not only decreased the intracellular ROS level, but also protected the neuronal cells against $H_2O_2$-induced oxidative stress. In liquid chromatography-mass spectrometry analysis, the following were found to be the main compounds of EFOJ: quercetin-3-O-glucoside, kaempferol-3-O-rutinoside, kaempferol-3-O-glucoside, and kaempferol-3-O-rhamnoside. Consequently, these results suggested that the protective effect on neuronal cells was based on the antioxidant activities of the physiologically active compounds of Orostachys japonicus A. Berger extract, which could therefore help to mitigate neurodegenerative diseases.