• Journal of Nutrition and Health
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• v.36 no.1
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• pp.9-17
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• 2003

The preparation method of a soluble dietary fiber from oak wood (Quercus mongolica) and the effect of the soluble dietary fiber on physiological function in rat fed high cholesterol diets was investigated. The best condition for steam explosion method was 25 kgf/㎤ pressure for 6 min. The exploded samples were delignified by the filtration treatment with 1% NaOH for several times, which is the best condition. The enzymatic hydrolysis of Cellusoft cellulase was more effective than Onozuka R-10 cellulase. The manufactured soluble dietary fiber was assayed using gel permeation chromatography (GPC) and it was dissolved in water. Average molecular weight distribution of manufactured soluble dietary fiber was about 348-1,200 and it was assumed the oligomer form fraction. In order to compare the manufactured soluble dietary fiber with commercial soluble dietary fiber (pectin) on the physiological function, Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to one normal diet and five high cholesterol diet containing 1% cholesterol. The high cholesterol diet groups were classified to fiber free diet (FF group), 5% pectin (5P group), 10% pectin (l0P group), 5% manufactured soluble dietary fiber (5M group) and 10% manufactured soluble dietary fiber (10M group). Body weight gains in all soluble dietary fiber groups were lower than FF group. Food intakes were increased in all soluble dietary fiber groups than that of FF group. Food efficiency ratio (FER) was significantly decreased in all soluble dietary fiber groups than that of the FF group, and it was especially was highest in 10% supplemented soluble dietary fiber group. The weight of liver of the soluble dietary fiber supplemented groups were lower than those of the FF group, but weights of cecum and small intestine of all supplemented soluble dietary fiber groups were significantly increased, compared with that of FF group. The weights and water contents in feces were significantly increased by the soluble dietary fiber. The activity of the glutamic oxaloacetic transaminase in soluble dietary fiber groups were significantly decreased than those of FF group. The hepatic glutathione S-transferase activity in all soluble dietary fiber supplemented groups were higher than that of FF group. The physiological effects of the manufactured soluble dietary fiber are the same as the commercial soluble dietary fiber (pectin). The preparation method of the soluble dietary fiber from the oak chips suited to its purpose. (Korean J Nutrition 36(1) : 9~17, 2003)

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.510-517
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• 2016

This study was conducted to investigate the antioxidant and hepatoprotective effects of eriodictyol compound against hydrogen peroxide-induced oxidative stress in HepG2 cells by measuring expression levels of antioxidant enzymes, liver function index enzyme activities, and inhibitory effects against reactive oxygen species (ROS) production. HepG2 cell viability was assessed using 3-(4,5-dimethyl thiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay. In the concentration range of $10{\sim}50{\mu}g/mL$, eriodictyol displayed over 98% cell viability in HepG2 cells. The effects of increased gene expression on hydrogen peroxide-induced oxidative stress were analyzed by monitoring antioxidant enzyme (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx) gene expression levels using real-time PCR. Eriodictyol compound significantly increased gene expression levels of SOD, CAT, and GPx in a dose-dependent manner ($10{\sim}50{\mu}g/mL$). Hepatoprotective effects against hydrogen peroxide-induced oxidative stress were analyzed by monitoring glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) activities in HepG2 cell culture medium using a biochemistry analyzer. Eriodictyol compound significantly reduced GOT, LDH, and GGT activities in a dose-dependent manner in HepG2 cells. ROS level in HepG2 cells was analyzed by 2',7'-dichlorofluorescein fluorescence diacetate assay, and eriodictyol compound effectively reduced the intracellular ROS level in HepG2 cells. The results reveal that eriodictyol compound can be useful for development of effective antioxidant and hepatoprotective agents.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.146-152
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• 2005

The objective of present study was to investigate the effect of onion extracts on mercuryinduced cytotoxicity, lipid peroxidation and antioxidant enzyme activities in primary monolayer cultures of rat hepatocytes. Primary cultures of rat hepatocytes were incubated for 6 hr in the presence of various concentrations (0, 1, 5, 10, 30 or 50 ppm) of $HgCl_2$. Cytotoxicity and cell viability were determined by measuring glutamic oxaloacetic transaminase (GOT) activity, lactate dehydrogenase (LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) value. Lipid peroxidation w as evaluated using thiobarbituric acid reactive substances (TBARS) assay. Effects of onion extract on antioxidant system were determined by measuring catalase, glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd) activities as well as DPPH free radical scavenging activity. $HgCl_2$ at the concentration of 10 ppm increased GOT activity and TBARS concentration but decreased %MTT reduction, whereas $HgCl_2$ at the concentration of 30 ppm increased LDH activity, representing that $HgCl_2$ caused cytotoxicity and lipid peroxidation in dose-dependent manner, $HgCl_2$ at the concentration of 30 ppm significantly decreased catalase, GSH-Px and GSH-Rd activities. When primary cultures of rat hepatocytes were incubated with various concentrations (0, 0.01, 0.05, 0.1 or 0.3 mg/ml) of onion extract for 6 hr in the presence of 30 ppm of $HgCl_2$, onion extracts at the concentration of 0.05 mg/ml decreased GOT activity, but increased %MTT reduction by 30 ppm of $HgCl_2$. $HgCl_2-induced$ LDH activity and TBARS concentration were decreased by onion extract at the concentration of 0.01 mg/ml. Taken together, onion extract prevented H$HgCl_2-induced$ hepatocyte injury and lipid peroxidation. Onion extracts at the concentration of 0.1 mg/ml almost or completely inhibited $HgCl_2-induced$ catalase and GSB-Px activities. GSH-Rd activity, however, was not affected by onion extract. Free radical scavengjing activity was increased as concentration of onion extract increased. Onion extract at the concentrion of 5 mg/ml possesed mote than 93% scavenging activity comparing to 100% radical scavenging activity by pyrogallol solution as a reference. These results demonstrate that onion extracts suppressed mercury-induced cytoctoxicity and lipid peroxidation by scavenging free radical and increasing catalase and GSH-Px activities.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.470-478
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• 2005

The objective of present study was to investigate the hepatoprotective and antioxidative effects of onion extracts. Primary cultures of rat hepatocytes were incubated with 1.5 mM tort-butyl hydroperoxide(t-BHP), potent oxidizing agent to liver, for 1 hr in the presence or absence of various concentrations (0, 0.01, 0.05, 0.1 or 0.3 mg/ml) of onion extract. Incubation with t-BHP increased glutamic oxaloacetic transaminase(GOT) and lactate dehydrogenase(LDH) acitivities and thiobarbituric acid reactive substances(TBARS) concentration but decreased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) reduction. Onion extracts at the concentration of 0.05 mg/ml decreased t-BHP-induced GOT and LDH activities. Onion extract at the concentration of 0.1 mg/ml increased t-BHP-induced MTT reduction. Onion extract at the concentration of 0.01 mg/ml decreased t-BHP-induced TBARS concentration. Taken together, onion extracts prevented t-BHP-induced hepatocyte injury and lipid peroxidation. Catalase, glutathione peroxidase(GSH-Px) and glutathione reductase(GSH-Rd) activities of hepatocytes were significantly decreased by t-BHP. Onion extracts at the concentration of 0.1 mg/ml prevented t-BHP-induced decrease in catalase, GSH-Px and GSH-Rd activities. Onion extracts prevented hydroxyl radical-induced single-strand breakage in dose-dependent manner when plasmid DNA was incubated with various concentrations of onion extracts in the presence of Fenton reagents producing hydroxyl radical. These results demonstrate that onion extracts suppressed t-BHP-induced cytoctoxicity, decreased viability and lipid peroxidation and increased GSH-Px, GSH-Rd and catalase activities. Thus hepatoprotective and antioxidant effects of onion extract seem to be due to, at least in part, the increase in antioxidant enzyme activities as well as prevention from hydroxyl radical-induced oxidation, followed by inhibition of lipid peroxidation.

• Journal of Life Science
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• v.24 no.6
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• pp.686-693
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• 2014

Restricted supply of nutrients may affect genes at the molecular level as well as physiological functions. Understanding the cellular responses during starvation is necessary for developing strategies to reduce damage caused by starvation stress. After 1 h of starvation, Got1 gene expression was increased but its expression returned to the normal state after 24 h. Mat1 gene expression continuously increased with starvation from 1 h until 24 hr. Rats starved for 1-3 days showed significant changes in expression of the Got1 and Mat1 genes, which were significantly reduced in the cerebral cortex and cerebellum. In the lung, gene expression was increased by starvation for 1-2 days but decreased on the third day. No differences were observed in gene expression in the heart. Strong Got1 lung gene expression was seen in the starvation group one day after restoration of the food supply. Muscle mass was significantly reduced at the start of starvation and remained the same after two days of starvation and one day after the food supply was restored. The Mat1 gene expression did not change. The Got1 was induced by NaCl and showed strong expression in the lung and the thymus, but the apparent decrease of the remaining changes were not observed in male rats. The Mat1 gene was not as sensitive as the Got1 gene to induction by NaCl. However, differences in gene induction by NaCl were evident between males and females, indicating that diet control of gene expression is associated with hormones.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1185-1193
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• 2006

This study investigated the effects of green tea on the disorders of lipid metabolism, oxidative system and hepatic functions induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using adult male rats (SD) for 3 weeks. These 36 animals were divided into four groups. TCDD ($50{\mu}g/kg$ BW) was intraperitoneally injected at the beginning of experiment. Green tea powder was added 1% or 3% levels in basal diets respectively. Relative weights of thymus were decreased about one-third of control group, but those of liver, brain and testis were significantly increased in rats treated TCDD. Neutrophill% and lymphocyte% by TCDD treatment was improved by green tea diets. In liver functional enzyme, elevation of glutamic oxaloacetic transaminase (GOT) and alkaline phosphatase (ALP) activities due to TCDD treatment was lowered by green tea diets. The concentrations of serum and liver lipids were significantly increased by TCDD treatment, however, those of serum and liver triglyceride tended to decrease by green tea diets. Fecal lipid excretion was increased in rats fed green tea diets. Especially, fecal total cholesterol level was significantly elevated by 3% green tea diets. The activities of superoxide dismutase (SOD) were increased in rats fed 3% green tea diets. Increment of benzphetamine N-demethylase (BPND) activity by TCDD treatment was declined by 1% green tea diets. These results indicate that green tea can exert improving effects on liver lipid accumulation and unfavorable hepatic functions, and elevate antioxidation.