• Korean journal of food and cookery science
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• v.25 no.2
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• pp.252-259
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• 2009

Ergosterol is the significant component of the cell wall of fungi. Its presence is regarded as evidence of fungi contamination in grain and other foods. Many studies on ergosterol detection have been carried out using chemical methods, but those methods required complicated pre-treatments and long analysis times. In this study, an amperometric biosensor was developed for fast and precise ergosterol detection. The biosensor system used the electron transfer of hydrogen peroxide produced from the reaction of ergosterol with cholesterol oxidase. The biosensor system consisted of a peristaltic pump, a syringe loading sample injector, an enzyme reactor, a fabricated flow-through cell containing a working electrode, a reference electrode and a counter electrode, and a potentiostat/recorder. The working electrode was prepared by coating modified multi-wall carbon nanotube (MWNT) on glassy carbon electrode. The $MWNT-NH_2$ coated glassy carbon electrode linearly responded to hydrogen peroxide in the range of $1{\times}10^{-5}{\sim}8{\times}10^{-5}$ M with a detection limit of $10^{-7}$ M in the basic performance test. The currents produced from the ergosterol biosensor showed the linearity in a range from $1.0{\times}10^{-6}$ M to $1.0{\times}10^{-5}$ M ergosterol.

• Journal of Nutrition and Health
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• v.37 no.2
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• pp.95-99
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• 2004

This study was designed to investigate the effects of ethyl acetate(EtOAc) fraction of pine (Pinus densiflora Sieb et Zucc) needle on cholesterol and lipofuscin(LF) accumulations, acetylcholine(ACh) and its related enzyme activities such as choline acetyltransferase(ChAT) and acetylcholinesterase(AChE), and monoamine oxidase-B(MAO-B) activity, which destroyed the catecholamine related neurotransmitters in brain membranes of Sprague- Dawley (SD) rats. Male SD rats were fed basic diets (control group) and experimental diets (EtOAc-25, EtOAc-50 and EtOAc-100) for 45 days. Cholesterol accumulations in mitocholndria and microsomes were significantly inhibited (11.8-12.1% and 9.6-13.0%, respectvely) in EtOAc-50 and EtOAc-100 groups. ACh levels and ChAT activities were significantly increased about 10% in membranes of EtOAc-100 group compared with control group. AChE activities were significantly increased about 8 -12% in membranes of EtOAc-50 and EtOAc-100 groups compared with control group. MAO-B activities were significantly inhibited about 10% in membrane of EtOAc-l00 group compared with control group. These results suggest that ethyl acetate fraction of pine needle may play an effective role in inhibiting cholesterol and improving a membrane fluidity, and learning and memory impairments. (Korean J Nutrition 37(2): 95 -99, 2004)

• Food Science and Preservation
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• v.14 no.6
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• pp.669-675
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• 2007

Quality characteristics of Kwamaegi (semi-dried saury) prepared by treatment of chitosan-ascorbate (CA) and vacuum drying at $40{\sim}60^{\circ}C$(VDK), and the effect of the Kwamaegi on serum lipid profiles and anti-oxidation-related enzyme activity in rats fed high fat diets were investigated. The preparation periods were $4.5{\sim}8.3$ hr in VDK, while naturally dried Kwamaegi (NDK) took 360480 hr. Total microbe contents of VDK and NDK were $0.2{\sim}0.5$ and 8.2 log CFU/g, respectively. There was no significant difference in amino-nitrogen content. Compared with NDK, the acid and peroxide value, and fishy flavor of VDK40 (dried at $40^{\circ}C$) were significantly lower, and the texture, color and overall acceptability were higher. In animal experiments, weight gain, content of LDL-cholesterol and lipid peroxide, activities of total (T) and O type (O) xanthine oxidase, and the O/T ratio (%) were significantly lower in the VDK40 diet group than in the NDK diet group. The content of HDL-cholesterol in the VDK40 diet group was higher than in the NDK diet group. These results suggest that preparing CA-treated Kwamaegi with vacuum-drying at $40^{\circ}C$ can be applied throughout the year, and may shorten preparation time and improve its microbiological safety and nutritional values.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.731-738
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• 2011

Cholesterol is the precursor of various steroid hormones, bile acid, and vitamin D with functions related to regulation of membrane permeability and fluidity. However, the presence of excess blood cholesterol may lead to arteriosclerosis and hypertension. Moreover, dietary cholesterol may affect blood cholesterol levels. Generally, cholesterol determination is performed by spectrophotometric or chromatographic methods, but these methods are very time consuming and costly, and require complicated pretreatment. Thus, the development of a rapid and simple analysis method for measuring cholesterol concentration in food is needed. Multi-walled carbon nanotube (MWCNT) was functionalized to MWCNT-$NH_2$ via MWCNT-COOH to have high sensitivity to $H_2O_2$. The fabricated MWCNT-$NH_2$ was attached to a glassy carbon electrode (GCE), after which Prussian blue (PB) was coated onto MWCNT-$NH_2$/GCE. MWCNT-$NH_2$/PB/GCE was used as a working electrode. An Ag/AgCl electrode and Pt wire were used as a reference electrode and counter electrode, respectively. The sensitivity of the modified working electrode was determined based on the amount of current according to the concentration of $H_2O_2$. The response increased with an increase of $H_2O_2$ concentration in the range of 0.5~500 ${\mu}M$ ($r^2$=0.96) with a detection limit of 0.1 ${\mu}M$. Cholesterol oxidase was immobilized to aminopropyl glass beads, CNBr-activated sepharose, Na-alginate, and toyopearl beads. The immobilized enzyme reactors with aminopropyl glass beads and CNBr-activated sepharose showed linearity in the range of 1~100 ${\mu}M$ cholesterol. Na-alginate and toyopearl beads showed linearity in the range of 5~50 and 1~50 ${\mu}M$ cholesterol, respectively. The detection limit of all immobilized enzyme reactors was 1 ${\mu}M$. These enzyme reactors showed high sensitivity; especially, the enzyme reactors with CNBr-activated sepharose and Na-alginate indicated high coupling efficiency and sensitivity. Therefore, both of the enzyme reactors are more suitable for a cholesterol biosensor system.

• Journal of Nutrition and Health
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• v.44 no.4
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• pp.284-291
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• 2011

The purpose of the present study was to examine the effects of water extracts from red pepper seeds powder on antioxidative enzyme activities and oxidative damage in groups of rrats fed high-fat and high-cholesterol diets group (HFC). The Rrats were divided into the following five experimental groups which are : composed of a normal diet group, a high fat high cholesterol diet group, and a high fat high cholesterol diet group supplemented with different amounts contents (1%, 2% and 4%) of red pepper seeds powder water extracts supplemented groups (HFCW1, HFCW2 and HFCW4, respectively). Body weight gains and food intake were lower ofin the red pepper seed water extracts groups were lower than those inof the HFC group. Hepartic xanthine oxidase (XOD) activity was decreased in the HFCW2 and HFCW4 groups compared to the HFC group. Hepartic glutathione peroxidase (GSH-px) activitiyactivity was increased in the HFCW4 group compared to the HFC group. Hepatic superoxide radicals within the mitochondria and microsomes of cells were significantly reduced in the HFCW2 and HFCW4 groups compared to the HFC group. Hepartic hydrogen peroxide in the cytosol was significantly reduced in the HFCW3 and HFCW4 groups compared to the HFC group. Hepatic carbonyl values in the microsomes and mitochondria were significantly reduced in the HFCW4 group compared to the HFC group. Hepartic thiobarbituric acid reaction substance (TBARS) activity was decreased in the HFCW2 group compared to the HFC group. These results suggest that water extracts of red pepper seeds powder may reduce oxidative damage by activation of antioxidative defense systems in rats fed high fat-high cholesterol diets.

• Journal of Nutrition and Health
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• v.36 no.10
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• pp.990-996
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• 2003

This study was conducted to investigate the effects of Forsythia viridissima Lindl. (FVL) on antioxidative defense system and lipid peroxidation of liver in rats fed high-cholesterol diet. Sprague-Dawley male rats weighing 100 $\pm$ 10 g were randomly assigned into five experimental groups fed 0.5％ cholesterol ; HC group which was not supplemented FVL extract, 0.05％ methanol extract diet group (MSI group), 0.1％ methanol extract diet group (MS2 group), 0.025％ ethylacetate-souble fraction diet group (ES1 group) and 0.05％ ethylacetate-souble fraction diet group (ES2 group). Experimental diets were fed ad libitum to the rats for 3 weeks. The hepatic xanthine oxidase (XOD) activity in the MS2 group was decreased to 20％ as compared to HC group. The activities of hepatic superoxide dismutase (SOD) and catalase (CAT) were not significantly different among all the high cholesterol diet groups. The hepatic glutathione peroxidase (GSHpx) activity in MS2, ES2 groups were significantly increased as compared to HC group. The hepatic glutathione S-transferase (GST) activity in the MS2 group was increased to 20％ as compared to HC group. The levels of hepatic TBARS in the MS1, MS2, ES1 and ES2 groups were reduced by 13％, 21％, 13％ and 21％, respectively, as compared with HC group. The contents of lipofuscin in liver tissue was not significantly different among all the experimental groups. The results indicate that FVL extract may reduce oxidative damage by activating antioxidative defense system of liver in rats fed high-cholesterol diets.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.312-319
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• 2007

This study was performed to investigate the effect of lecithin on lipid metabolism and antixidative capacity in 9-week-old rats. Forty-five male Sprague-Dawley rats weighing 249.8 g were blocked into three groups according to their body weight and raised for 8 weeks with experimental diets containing 1% (LM) or 5% lecithin (LH) and control (C) diet. Plasma and liver total lipids, triglyceride, total cholesterol and plasma HDL-cholesterol concenterations, and fecal total lipids, triglyceride, total cholesterol and bile acid excretions were measured. Malondialdehyde (MDA) levels in plasma, liver, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities in red blood cell and liver, xanthine oxidase (XO) activities in plasma and liver, and total antioxidant status (TAS) in plasma were also measured. Effect of lecithin intake on antioxidative capacity was not significantly different among all the groups. Plasma total lipids, triglyceride and total cholesterol levels were lower in lecithin groups compared to control group, and these three lipid levels of lecithin groups were lowered dose-dependently as dietary lecithin level increased. But liver total lipids, triglyceride and total cholesterol levels were not different among all the groups. Also fecal total lipids, triglyceride and total cholesterol excretions were highest in high lecithin groups compared to two other groups. Thus it is plausible that lecithin intake decreases plasma lipid levels through increasing fecal lipid excretions, and may be beneficial for treatment and prevention of hyperlipidemia, but has no effect on antioxidative capacity.

• KSBB Journal
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• v.8 no.4
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• pp.328-335
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• 1993

A flow injection analysis(FIA) system was developed for the determination of cholesterol using immobilized cholesterol oxidase and cholesterol ester hydrolase. The enzymes were immobilized on controlled pore galas(CPG) by the glutaraldehyde method. The glass colunms packed with immobilized enzymes were found to contain 3-5 I.U. for each enzyme. A hydrogen peroxide sensitive electrode was contructed and applied to the FIA system. The operational conditions for FIA response were investigated and optimized with variation of sampling volume, flow rate and composition of carrier solution. The FIA response were linear upto 60 and 400mg/m1 for free cholesterol and cholesterol ester, respectively. All samples were analyzed with a good precision (<2.5% CV) and accuracy. 23 samples were mea sured succesively within about an hour. Intermittent assays of more than 500 times caused 50% decrease in response sensitivity.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.209.3-209.3
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• 2003

Cordyceps species has been used as antiinflammatory, antitoxic, diuretic in folk remedies. Recent research has been reported the effect of anticancer, antidiabetic, antimutagenic, antilipid peroxidation. We examined the antidiabetic activity of cultivated Cordyceps pruinosa on streptozotocin-induced diabetic rats. The blood glucose level was recovered by treatment with Cordyceps pruinosa ethanol extract. The contents of GPT, total cholesterol and xanthine oxidase, glutathione peroxidase, catalase activities of the cytosol were significantly decreased as compared to the diabetic group. (omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.119-123
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• 2003

From the 80% ethanol extraction of onion flesh, fraction I,II and III were separated by Sephadex LH-20 column chromatography. Fraction II and III had a high inhibitory effect on ACE and xanthine oxidase. The ACE was about 80% at 50 ppm of fraction IIand III. The xanthine oxidase was about 82.5% at 100 ppm of fraction In. This research was studied to investigate the effects of the fraction In isolated from onion on the reduction of fat accumulation in rats fed high fat diet for 2 months. The metabolism was examined by analyzing the fat in serum and liver. It was shown that cholesterol in serum was remarkably reduced in onion fraction In as compared with those of control.