• Preventive Nutrition and Food Science
• /
• 제9권2호
• /
• pp.156-160
• /
• 2004

This study aims to investigate the changes in the lipid composition and angiotensin-converting enzyme activity in serum of rats exposed to microwave radiation, and to examine improving effects of green tea catechin to the lipid composition. The microwave-exposed rats received the normal and one of 3 diets: catechin free (MW-0C), 0.25% catechin (MW-0.25C) or 0.5% catechin (MW-0.5C). Rats were sacrificed 6th day after microwave radiation (2.45 ㎓, 15 min). The concentration of serum triglyceridein MW-0C group was increased by 85%, compared with the normal group, but that of MW-0.25C group with 0.25% catechin supplementation was to 17% lower, compared with the MW-0C group. There was no significant difference between normal group and MW-0.5C group. Total-cholesterol and LDL-cholesterol concentrations were increased by 21.4% and 38.6%, respectively, by microwave irradiation. The concentration of HDL-cholesterol in MW-0C group was lower to 29.3%, but it was maintained at the normal level by catechin supplementation. There was no significant difference among four groups in HLD-cholesterol/LDL-cholesterol. Atherogenic index in MW-0C group was increased by 56%, compared with the normal group. Angiotensin-converting enzyme (ACE) activity in lung tissue of MW-0C group was increased by 59 %, while that of MW -0.25C and MW -0.5C group were maintained at the normal level. ACE activity of MW-0C group in serum was increased by 122.8%, compared with the normal group. Catechin supplementation group was significantly reduced, compared with the MW-0C group ACE activity. In conclusion, microwave irradiation increased the serum triglyceride and cholesterol concentrations and ACE activity which are considered as the blood pressure increasing agents. However, catechin supplementation decreased the level of triglyceride, total cholesterol, LDL cholesterol, and ACE activity, which maybe consider catechin as being agent of lowering effect for blood lipid profile for athero-genesis.

• Preventive Nutrition and Food Science
• /
• 제9권1호
• /
• pp.53-57
• /
• 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.

• 동아시아식생활학회지
• /
• 제23권3호
• /
• pp.311-319
• /
• 2013

The purpose of the present study is to investigate the effects of green tea catechin on microsomal phospholipase $A_2(PLA_2)$ activity and the arachidonic acid (AA) cascade in hearts of microwave exposed rats. Sprague-Dawley male rats weighing $100{\pm}10$ g were randomly assigned to one normal group and three microwave exposed groups. The microwave exposed groups were subdivided into three groups: catechin free diet (MW) group, 0.25% catechin (MW-0.25C group and 0.5% catechin (MW-0.5C) group according to the levels of dietary catechin supplementation. Rats were sacrificed $6^{th}$ day after microwave irradiations (2.45 GHz, 15 min). The heart microsome $PLA_2$ activity in the MW group was 130% greater than that of normal groups, whereas there was no significant difference between normal group and MW-0.25C, MW-0.5C group. The per- centage phosphatidyl ethanolamine (PE) hydrolyzed in the heart microsome in the MW was increased 54% by microwave irra- diation, whereas there was no significant difference between normal group and MW-0.5C group. The percentage phosphatidyl choline (PC) hydrolyzed in the heart microsome in the MW group was increased by 104% and by microwave irradiation, whereas there was no significant difference between normal group and MW-0.5C group. The formation of thromboxane $A_2(TXA_2)$ in the heart microsome was 70% greater in the MW group than in the normal group. However, the MW-0.25C and MW-0.5C group maintained the normal level. The formation of prostacyclin ($PGI_2$) in the heart microsome was 21% lower in the MW group than in the normal group, while that of MW-0.25C and MW-0.5C group were maintained in the normal group. The heart microsomal thiobarbituric acid reactive substances (TBARS) concentrations, as an index of lipid peroxide, were 71% greater in the MW group, as compared with normal group. However, the MW-0.25C and MW-0.5C group were 4.6% and 9.2% lower, respectively, than that of MW group. In conclusion, heart function appeared to be improved by green tea catechin supplementation due to its antithrombus action, which in return controls the AA cascade system.

• 한국식품영양과학회지
• /
• 제29권1호
• /
• pp.168-173
• /
• 2000

The purpose of this study was to investigate the changes of microsomal mixed function oxidase (MFO) and xanthine oxidase activities (XOD) in the liver of rats exposed to microwave. Sprague-Dawley male rats weighing 200$\pm$10g body weight were randomly assigned to a normal and microwave exposed(MW) groups; microwave exposed groups were divided into two groups; microwave (MW) group and green tea(GT) gropu which were fed distilled water and green tea extracts during experimental periods, respectively. Rats were irradiated with microwave at the frequency of 2.45 GHz for 15min and rats wre sacrificed at the 4th day of the microwave irradiaton. The hemoglobin level of GT group was higher than that of the normal gropu and MW group, but the hematocrit value was not significantly different among all experimental gropus. The activity of serum GOT of MW group was significantly increased but that of GT group was similar to normal group. Activities of GPT were not significantly different among all experimental groups. Liver XOD activity was significantly increased in the microwave exposed groups but green tea normalized the XOD activity. The activity of hepatic microsomal cytochrome P450 was significantly increased in MW group compared to normal group and that of GT group was similar to that of the normal group. The activity of hepatic microsomal NADPH-cytochrome P450 reductase was also significantly increased in MW group compared to normal group, but that of GT group was similar to that fo the normal group. In conclusion, the activities of MFO and XOD were elevated by microwave irradiaton, but the activation of MFO system as well as the damage of the liver by microwave were reduced by green tea supplementation.

• Journal of Nutrition and Health
• /
• 제33권7호
• /
• pp.733-738
• /
• 2000

The purpose of this study was to investigate the effects of green tea on gene expression of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) in rat liver exposed to microwave. Sprague-Dawley male rats with 200$\pm$10g body weight were assigned to normal and microwave exposed groups : microwave exposed groups ; microwave exposed groups were divided two groups : microwave(MW) group which was administrated the distilled water and green tea(GT) group which was administrated the green tea extracts. The rats were irradiated with microwave at frequence of 2.45 GHz for 15 min and then the gene expression in the damaged tissue were investigated at 0.1, 3, 4,6 and 8 days after the microwave irradition to compared with the normal group. The level of SOD gene expression in MW group was lower than the normal group within 6 days but that of GT group as higher than MW group. These results may imply that green tea stimulates SOD expression and there by protecting tissues from free radicals. The GSH-Px gene was expressed a little bit lower than the normal group but that of GT group was expressed to higher lever than MW group from 4 days after irradiation. These results suggest that the administration of green tea extract may activate antioxidative gene expressions such as SOD and GSH-Px in rat and that may help to recover liver tissues from microwave damage by removing hazardous free radicals and oxidized by products from cells.

• 한국식품영양과학회지
• /
• 제41권7호
• /
• pp.936-942
• /
• 2012

본 연구에서는 흰쥐에 마이크로웨이브를 조사한 후 폐조직을 대상으로 폐조직 기능장애를 일으키는데 주된 역할을 하는 혈전생성능을 arachidonic acid(AA) cascade계를 통해 관찰하여 마이크로웨이브에 의한 폐혈관 기능장애와 그에 대한 녹차 catechin의 항혈전 효과를 규명하고자 하였다. 실험군은 마이크로웨이브를 조사하지 않은 정상군과 마이크로웨이브를 조사한 군으로 나누고 마이크로웨이브 조사 군은 다시 식이 중 catechin 공급수준에 따라 catechin을 넣지 않은 군(MW group), catechin을 0.25% 급여한 군(MW-0.25C group), catechin을 0.5% 급여한 군(MW-0.5C group)으로 나누었다. 식이와 음료는 자유 섭식시키면서 2주간 사육한 후 2.45 GHz 대역의 주파수를 15분간 1회 조사하였으며 마이크로웨이브 조사 후 6일째 동물을 희생시켜 본 실험에 사용하였다. 실험군의 실험동물 수는 각각 10마리로 실험하였다. $PLA_2$ 활성은 마이크로웨이브 조사로 30% 증가하였으며 MW-0.25C군은 15% 증가였으나 MW-0.5C군은 정상군 수준이었다. 인지질분자종의 변화를 관찰한 결과 lyso PE가 MW군에서 47% 증가되었으나 MW-0.25C군 및 MW-0.5C군에서는 각각 18%, 20% 증가되었다. $TXA_2$ 생성은 MW군에서 50%의 현저한 증가를 보였으나 catechin 공급군인 MW-0.25C군 및 MW-0.5C군은 정상군 수준이었다. $PGI_2$ 생성은 MW군에서 31%의 유의적인 감소를 보였으나 catechin 공급군인 MW-0.25C군 및 MW-0.5군은 정상군 수준이었다. 따라서 혈전생성지표인 $PGI_2/TXA_2$ ratio는 정상군에 비해 MW군에서 43% 유의적으로 감소되었으나 MW-0.25C군 및 MW-0.5C군은 정상군 수준이었다. 지질과산화물의 함량은 MW군에서 34% 유의적으로 증가하였으며 catechin 공급군은 정상군 수준이었다. 결론적으로 마이크로웨이브에 피폭된 흰쥐 폐조직에서는 AA cascade계의 율속 효소인 $PLA_2$ 활성의 증가와 혈전생성지표로 인식하는 $PGI_2/TXA_2$ ratio의 불균형이 초래되었으나 catechin은 TBARS 농도를 낮추면서 $PLA_2$ 활성을 저해시키고 AA cascade계를 개선시킴으로써 항혈전 작용을 나타내었다.

• Journal of Nutrition and Health
• /
• 제34권3호
• /
• pp.299-305
• /
• 2001

The purpose of this study was to investigate the effects of catechin on the changes of microsomal mixed function oxidase(MFO) system and oxidative damage in rat liver exposed to microwave. Sprague-Dawley male rats weighing 200$\pm$10g body weight were randomly assigned to one normal and microwave exposed groups: microwave exposed groups were divided three groups: catechin free diet(MW) group, 0.25% catechin(MW+0.25C) group and 0.5% catechin(MW+0.5C) group to the levels of dietary catechin supplementation. The rats were irradiated with microwave at frequency 2.45GHz for 15 min and then the changes pattern of mixed function oxidase system and oxidative damage were investigated for 16 days. The activity of XOD in MW group was increased from 4 day to 8 days after irradiation, compared to normal group and decreased to the level of normal group 16 days. But catechin supplementation group were maintained to the normal level. The contents of cytochrome P(sub)450 and NADPH cytochrome P(sub)450 reductase activities in liver of MW group was increased from 4 day to 8 day after irradiation, compared to normal group and decreased to the level of normal group at 16 day. But catechin supplementation group were recovered to the normal level. The contents of superoxide radical in liver of MW group was increased 1.28, 1.25, 1.17 fold of normal group at 4,6 and 8 days days after irradiation. respectively, but catechin supplementation group were maintained the normal level. The contents of lipifuscin in liver have a same tendency in superoxide radical contents. These result suggested that the supplementation of catechin have control the mixed function oxidase system and oxidative damage and that may help to recover tissues from microwave damage. (Korean J Nutrition 34(3) : 299~305, 2001)

• 한국식품과학회지
• /
• 제31권1호
• /
• pp.122-127
• /
• 1999

저출력 및 pulse를 이용한 마이크로파 건조 방법을 달리하여(3분 건조-2분 정지를 반복하여 24시간 건조하는 방법 : MW1, 5분 건조-2.5분 정지를 반복하여 24시간 건조하는 방법 : MW2, 열풍 건조기를 이용하여 $45^{\circ}C$에서 12시간 예비 건조 후 마이크로파 건조기를 이용하여 3분 건조-2분 정지를 반복하여 12시간 건조하는 방법 : MWH1, 5분 건조-2.5분 정지를 반복하여 12시간 건조하는 방법 : MWH2) 인삼을 건조한 후 품질특성을 검토하였다. 수분함량과 온도에 따른 수삼의 유전특성은 수분함량이 높을수록 유전상수값이 증가하였으며 유전손실계수와 침투깊이는 약간의 증가만 나타내었다. 온도에 따른 유전특성은 온도가 증가함에 따라서 $40^{\circ}C$에서 53.4로 유전상수값이 급격히 증가하다가 감소하는 경향을 나타내었으며 유전손실 계수와 침투깊이는 수분함량과 비슷한 증가의 경향을 나타내었다. 건조 후 일반성분의 차이는 조단백질, 조지방, 회분, 수분활성도 등은 차이가 없었으며 식이섬유(SDF)의 경우 MWH2 처리구를 제외하고는 차이가 없었다. Ginsenoside-Rb1의 함량은 MW1와 MW2 처리구에서 각각 0.65, 0.64로 MWH1와 MWH2 처리구 보다는 높은 함량을 나타내었으며 유리당의 함량은 각 처리구에 따라서 비슷한 경향을 나타내었다. 미세구조 관찰에서 MW2 처리구가 건조 후 가장 치밀한 내부 구조를 나타내었다.

• Journal of the Korean Wood Science and Technology
• /
• 제23권3호
• /
• pp.28-32
• /
• 1995

The presteamed or prefrozen persimmon blocks of 10cm ${\times}$ 10cm ${\times}$ 15cm were air-dried at room temperature until about 30% moisture content, and then were dried in a MW oven. During drying their internal temperatures were monitored with thermo-couple probes. The presteamed and prefrozen blocks didn't show any improvement in drying rate and moisture gradient when compared with the controls. Checks appeared on the surfaces of most presteamed blocks during air-drying. It has been clearly revealed that the maximum weight, loss must, be less than 2g/min during MW drying to prevent internal checking and that MW drying reduced moisture gradients inside blocks. MW dried the persimmon blocks 440 times faster than conventional kiln.

• 한국물환경학회지
• /
• 제23권4호
• /
• pp.498-503
• /
• 2007

The performance of elutriated acid fermentation to evaluate the effects of microwave irradiation and pH control as pretreatment was investigated. The MW pH 7 reactor which was used the pretreated primary sludge as microwave irradiation was operated at pH 7 and $35^{\circ}C$. The EAF pH 9 reactor was operated at pH 9 and $35^{\circ}C$ without pretreatment. The SCOD and VFAs production rate were 0.17 gSeOD/gVSrem. and 0.27 gVFAs as COD/gVSrem. in MW pH 7 reactor, 0.16 gSCOD/gVSrem. and 0.24 gVFAs as COD/gVSrem. in EAF pH 9 reactor, respectively. VS and Volume reduction were 54% and 48% in MW pH 7 reactor, 54.6% and 36% in EAF pH 9 reactor, respectively. A comparison of the microwave irradiation and controlled pH in elutriated acid fermentation showed that the former is more efficient in SCOD and VFAs production and it rises to slightly higher reduction in the volume of the sludge. In addition, E. coli. was not detected in the wasting sludge of MW pH 7 reactor. Based on the results, microwave irradiation appeared to be one of the viable options for generating class A sludge. According to the batch tests, sequencing batch test which was used the pretreated primary sludge as microwave was performed at pH 7 and $35^{\circ}C$, SCOD production was 0.16 gSCOD/gVSrem., VS reduction and volume reduction were 64% and 63%, respectively.