• Nutrition Research and Practice
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• 제9권2호
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• pp.137-143
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• 2015

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-${\alpha}$, related to ${\beta}$-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing ${\beta}$-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake ($0.4{\times}10^{-5}$ vs $0.4{\times}10^{-5}$ mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.

• Nutrition Research and Practice
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• 제3권3호
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• pp.242-246
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• 2009

This study examined the anti-diabetic effect of onion (Allium cepa. Linn) in the streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were divided into normal rats fed control diet or supplemented with onion powder (7% w/w) and diabetic rats fed control diet or supplemented with onion powder. Diabetes was induced by a single injection of STZ (60 mg/kg, ip) in citrate buffer. The animals were fed each of the experimental diet for 5 weeks. Blood glucose levels of rats supplemented with onion were lower than those of rats fed control diet in the diabetic rats. Onion also decreased the total serum lipid, triglyceride, and atherogenic index and increased HDL-cholesterol/total cholesterol ratio in the diabetic rats. Glutathione peroxidase, glutathione reductase and glutathione S-transferase activities were high in the diabetic rats compared to normal rats and reverted to near-control values by onion. These results indicate that onion decreased blood glucose, serum lipid levels and reduced renal oxidative stress in STZ-induced diabetic rats and this effect might exert the anti-diabetic effect of onion.

• Advances in Traditional Medicine
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• 제5권1호
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• pp.62-68
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• 2005

Doxorubicin is a powerful anticancer antibiotic extensively used in the treatment of several types of cancers. Long-term administration of this drug results in cumulative dose related cardiotoxicity due to enhanced production of free radicals leading to oxidative stress. Our earlier investigations have demonstrated significant antioxidant, anti-inflammatory and antitumour properties of Ganoderma lucidum extracts. We extended our investigations to evaluate the protective effect of Ganoderma lucidum extract against doxorubicin-induced cardiotoxicity. Administration of 3 doses of doxorubicin, 6 mg/kg body weights, i.p. per each dose, alternative days, showed dear signs of cardiotoxicity in rats. The drug enhanced serum creatine kinase (CK) activity and lipid peroxidation in tissue drastically. The drug also induced significant decrease in GSH level and activities of CAT, SOD and GPx. Administration of methanolic extract of G.lucidum (500 and 1,000 mg/kg body weight) significantly increased the level of GSH and activities of CAT, SOD and GPx. Activity of CK was significantly lowered in a dose dependent manner. The treatment also caused significant decrease in lipid peroxidation (MDA). The results thus indicated that methanolic extract of G.lucidum prevented oxidative stress caused by doxorubicin administration and the increase in serum CK activity and lipid peroxidation in the tissue. The experimental findings suggest the therapeutic potential of G.lucidum as adjuvant in cancer chemotherapy.

• 대한약침학회지
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• 제25권4호
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• pp.344-353
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• 2022

Objectives: Auraptene is the most abundant natural prenyloxycoumarin. Recent studies have shown that it has multiple biological and therapeutic properties, including antioxidant properties. Erythrocytes are constantly subjected to oxidative damage that can affect proteins and lipids within the erythrocyte membrane and lead to some hemoglobinopathies. Due to the lack of sufficient information about the antioxidant effects of auraptene on erythrocytes, this study intended to evaluate the potential of this compound in protecting radical-induced erythrocytes damages. Methods: The antioxidant activity of auraptene was measured based on DPPH and FRAP assays. Notably, oxidative hemolysis of human erythrocytes was used as a model to study the ability of auraptene to protect biological membranes from free radical-induced damage. Also, the effects of auraptene in different concentrations (25-400 µM) on AAPH-induced lipid/protein peroxidation, glutathione (GSH) content and morphological changes of erythrocytes were determined. Results: Oxidative hemolysis and lipid/protein peroxidation of erythrocytes were significantly suppressed by auraptene in a time and concentration-dependent manner. Auraptene prevented the depletion of the cytosolic antioxidant GSH in erythrocytes. Furthermore, it inhibited lipid and protein peroxidation in a time and concentration-dependent manner. Likewise, FESEM results demonstrated that auraptene reduced AAPH-induced morphological changes in erythrocytes. Conclusion: Auraptene efficiently protects human erythrocytes against free radicals. Therefore, it can be a potent candidate for treating oxidative stress-related diseases.

• Molecules and Cells
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• 제46권3호
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• pp.165-175
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• 2023

The transcription factor Nrf2 was originally identified as a master regulator of redox homeostasis, as it governs the expression of a battery of genes involved in mitigating oxidative and electrophilic stress. However, the central role of Nrf2 in dictating multiple facets of the cellular stress response has defined the Nrf2 pathway as a general mediator of cell survival. Recent studies have indicated that Nrf2 regulates the expression of genes controlling ferroptosis, an iron-and lipid peroxidation-dependent form of cell death. While Nrf2 was initially thought to have anti-ferroptotic function primarily through regulation of the antioxidant response, accumulating evidence has indicated that Nrf2 also exerts anti-ferroptotic effects via regulation of key aspects of iron and lipid metabolism. In this review, we will explore the emerging role of Nrf2 in mediating iron homeostasis and lipid peroxidation, where several Nrf2 target genes have been identified that encode critical proteins involved in these pathways. A better understanding of the mechanistic relationship between Nrf2 and ferroptosis, including how genetic and/or pharmacological manipulation of Nrf2 affect the ferroptotic response, should facilitate the development of new therapies that can be used to treat ferroptosis-associated diseases.

• 한국식품영양과학회지
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• 제32권8호
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• pp.1337-1343
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• 2003

산화적 스트레스를 많이 받는 당뇨상태에서 항산화활성이 높은 부추의 섭취가 지질 및 단백질 산화, 활성산소종의 생성, 항산화 효소계 활성 변화 및 lipofuscin생성에 미치는 영향을 조사하고자 S.D.계 쥐에게 streptozotocin을 복강투여하여 당뇨병을 유발시킨 후 대조군 식이와 10% 부추식이를 14주간 섭취시켰다. 부추의 섭취는 대조군식이에 비해 간보다는 피부조직에서 지질 및 단백질 산화를 유의적으로 감소 시켰고(p<0.05), 반응성이 큰 활성산소종인 hydroxyl radical의 생성도 당뇨군에 비해 유의적으로 감소된 것으로 나타났다(p<0.05).부추의 섭취는 간과 피부조직의 항산화 효소계 활성을 증가시키는 것으로 나타났으며 심장과 눈 조직에서 노화색소인 lipofuscin을 측정한 결과 당뇨군에 비해 당뇨부추군에서 감소하였고 특히 눈에서 유의적으로 감소하였다(p<0.001). 이상의 결과로 부추의 섭취는 당뇨 합병증을 일으키는 주요 원인인 산화적 스트레스를 억제하는 효과를 나타내었고, 당뇨 합병증의 증상완화에 도움을 줄 것으로 기대되어 진다.

• Nutrition Research and Practice
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• 제8권6호
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• pp.638-643
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• 2014

BACKGROUND/OBJECTIVES: Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. MATERIALS/METHODS: Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress of kimchi during fermentation were investigated under in vitro and cellular systems using LLC-$PK_1$ cells. RESULTS: Kimchi exhibited strong radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, superoxide anion, and hydroxyl radical. In addition, the free radical generators led to loss of cell viability and elevated lipid peroxidation, while treatment with kimchi resulted in significantly increased cell viability and decreased lipid peroxidation. Furthermore, the protective effect against oxidative stress was related to regulation of cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-${\kappa}B$ p65, and $I{\kappa}B$ expression. In particular, OvR showed the strongest protective effect from cellular oxidative stress among other kimchi. CONCLUSION: The current study indicated that kimchi, particularly OptR and OvR, played a protective role against free radical-induced oxidative stress. These findings suggest that kimchi is a promising functional food with an antioxidative effect and fermentation of kimchi led to elevation of antioxidative activity.

• BMB Reports
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• 제34권6호
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• pp.544-550
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• 2001

In pre-transplant total-body irradiation (TBI), the lung is a critical dose-limiting organ. Also, the possible role of oxidative stress was suggested in the development of TBI-induced lung damage. This study explores the association between TBI-induced oxidative stress and the induction of lung pathogenesis by investigating TBI-induced oxidative stress in the lungs of male C57BL/6 mice after a single dose of 10 Gy TBI. We showed significant increases of reactive oxygen species (ROS) formation and lipid peroxidation, and also a depletion and oxidation of glutathione after TBI. There is evidence that pretreatment with 1,10-phenanthroline (o-phen) significantly reduces oxidative stress in the lung. This indicates that the TBI-induced ROS generation involves a metal-catalyzed Fenton-type reaction. A pretreatment of buthionine sulfoximine (BSO) augmented the glutathione depletion and oxidation, but had no effect on the ROS formation and lipid peroxidation up to 6 h after TBI. Histopathological features that are consistent with pneumonitis were observed in the BSO pretreated-mice 1 week after irradiation. The results suggest that TBI-induced oxidative stress in the lung involves a generation of ROS through a Fenton-type reaction. Also, glutathione plays an important inhibitory role in the radiation-induced lung pathogenesis by participating in the self-amplifying cascade subsequent to the ROS generation by irradiation.

• Food Science and Biotechnology
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• 제17권2호
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• pp.287-294
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• 2008

Protective effects of cheonggukjang fermented with 20% red ginseng (RC) were observed in streptozotocin (STZ)-induced diabetic rats by measuring levels of blood glucose, serum lipid profiles, and hepatic reactive oxygen species generating and scavenging enzymc activities. RC diet was prepared by mixing with AIN-76 diet at the final concentration 2%, and it was fed to STZ-induced diabetic rats for 3 weeks. The RC dict was significantly improved body weight, feed efficiency ratio, levels of serum glucose, and serum and hepatic lipids in diabetes. The significantly elevated O type activity of xanthine oxidase in diabetes was also greatly decreased by the RC diet. The treatment of RC showed the improved hepatic glutathione s-transferase activities in the diabetic animals. The present study indicates that cheonggukjang fermented with red ginseng could ameliorate STZ-induccd diabetic symptoms such as aggravated blood glucose levels, serum lipid profiles, and even the conditions of oxidative stress.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2005년도 제22차 정기총회 및 학술발표회
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• pp.8-16
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• 2005

비만유전자의 산물인 렙틴은 주로 지방세포에서 생성 분비된다. 렙틴은 뇌 시상하부에 작용하여 식이섭취량을 줄이고 에너지발산을 증가시켜 궁극적으로 체중을 감소시킨다. 따라서 렙틴 또는 렙틴 수용체의 이상은 극도의 대사증후군을 유발한다. 현재까지 렙틴에 관한 연구의 대부분은 사람을 포함한 포유류에서 수행되었다. 렙틴의 생리적 작용은 만복인자뿐만이 아니다. 본고에서는 현재까지 발표된 논문을 중심으로 닭에서 식이섭취, 면역, 지방대사, 번식과 발달, 그리고 스트레스에 관한 렙틴의작용을 검토했다.