• 제목/요약/키워드: Antioxidant mechanisms

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Lipid Peroxidation and Its Toxicological Implications

  • Nam, Tae-Gyu
    • Toxicological Research
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    • 제27권1호
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    • pp.1-6
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    • 2011
  • Lipid peroxidation is a free radical oxidation of polyunsaturated fatty acids such as linoleic acid or arachidonic acid. This process has been related with various pathologies and disease status mainly because of the oxidation products formed during the process. The oxidation products include reactive aldehydes such as malondialdehyde and 4-hydroxynonenal. These reactive aldehydes can form adducts with DNAs and proteins, leading to the alterations in their functions to cause various diseases. This review will provide a short summary on the implication of lipid peroxidation on cancer, atherosclerosis, and neurodegeneration as well as chemical and biochemical mechanisms by which these adducts affect the pathological conditions. In addition, select examples will be presented where antioxidants were used to counteract oxidative damage caused by lipid peroxidation. At the end, isoprostanes are discussed as a gold standard for the assessment of oxidative damages.

MODULATION OF CELL CYCLE-RELATED PROTEIN EXPRESSION BY RESVERATROL IN HUMAN LUNG CANCER CELLS

  • Kim, Young-Ae;Kong, Kyu-Ri;Lee, Won-Ho;Park, Kun-Young;Rhee, Suk-Hee;Park, Yung-Hyun
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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    • pp.149-149
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    • 2001
  • Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phytoalexin found in grapes and wines is a potent antioxidant with cancer-preventive properties, the mechanism by which resveratrol imparts cancer chemopreventive effect is poorly defined. The aim of the present study was to further elucidate the possible mechanisms by which resveratrol exerts its anti-proliferative action in cultured human lung cancer cells.(omitted)

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Cancer Chemoprevention by Dietary Proanthocyanidins

  • Jo, Jeong-Youn;Lee, Chang-Yong
    • Food Science and Biotechnology
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    • 제16권4호
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    • pp.501-508
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    • 2007
  • Proanthocyanidins (PACs), also named condensed tannins, are polymers of flavan-3-ols such as (+ )-(gallo)catechin and (-)-epi(gallo)catechin. A proper analysis of the PACs, with difficult challenges due to their complex structures, is crucial in studies of cancer chemoprevention. Cancer is a leading cause of mortality around the world. Many experimental studies have shown that dietary PACs are potential chemopreventive agents that block or suppress against multistage carcinogenesis in both in vitro and in vivo models. Cancer chemoprevention by dietary PACs has been shown effective through different mechanisms of action such as antioxidant, apoptosis-inducing, and enzyme inhibitory activities. Good sources of dietary PACs are nuts, fruits, beans, chocolate, fruit juice, red wine, and green tea. The chemopreventive potential of dietary PACs should be considered together with their bioavailability in humans. The safety issues regarding carcinogenesis and gastrointestinal disorder are also reviewed.

인삼이 신 질환 환자에서 신 기능에 미치는 영향 (Effect of Ginseng on Renal Function in Patient with Renal Injury)

  • 김형규;조원용;구자룡
    • Journal of Ginseng Research
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    • 제21권1호
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    • pp.49-52
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    • 1997
  • There are many mechanisms that mediate progression of renal injury, such as abnormalities of nitric oxide (NO) regulation, increased Platelet aggregatlon, and oxygen free radical injury. Ginseng has been known to have NO dependent vasorelaxant effect and antioxidant effect, also inhibit thrombin stimulated platelet aggregation. And these effects of ginseng may have some roles in prevention of renal injury. So we studied 24 patients with mild pathologic proteinuria and hypertension to evaluate the effect of ginseng on progression of renal injury. After 1 month treatment, creatinine clearance was significantly increased especially in the patient group with normal serum creatinine level without specific side effect. The result of this study suggest that ginseng may pre vent or retard the progression of renal injury especially in early stage.

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Inhibition of Atherosclerotic Lesion by KR-31378 in LDL Receptor Null Mice

  • Kim, Jiyun;Nam, Ki-Hoan;Choi, Jae-Hoon;Kim, Hyoung-Chin;Yang, Sung-Don;Kang, Joo-Hyung;Ryu, Young-Han;Kim, Eun-Young;Kim, Sun-Ok;Yoo, Sung-Eun;Oh, Goo-Taeg
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2003년도 추계학술대회
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    • pp.195-195
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    • 2003
  • The recruitment and infiltration of monocytes into the artery wall is a crucial early step in atherogenesis. KR-31378 has been shown to be a neuroprotective agent in rat brain via its potent antioxidant and antiapoptotic actions. Here, we report the effects of this compound on atherogenesis, and some possible mechanisms of action.(omitted)

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Thiol-Based Peroxidases and Ascorbate Peroxidases: Why Plants Rely on Multiple Peroxidase Systems in the Photosynthesizing Chloroplast?

  • Dietz, Karl-Josef
    • Molecules and Cells
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    • 제39권1호
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    • pp.20-25
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    • 2016
  • Photosynthesis is a highly robust process allowing for rapid adjustment to changing environmental conditions. The efficient acclimation depends on balanced redox metabolism and control of reactive oxygen species release which triggers signaling cascades and potentially detrimental oxidation reactions. Thiol peroxidases of the peroxiredoxin and glutathione peroxidase type, and ascorbate peroxidases are the main peroxide detoxifying enzymes of the chloroplast. They use different electron donors and are linked to distinct redox networks. In addition, the peroxiredoxins serve functions in redox regulation and retrograde signaling. The complexity of plastid peroxidases is discussed in context of suborganellar localization, substrate preference, metabolic coupling, protein abundance, activity regulation, interactions, signaling functions, and the conditional requirement for high antioxidant capacity. Thus the review provides an opinion on the advantage of linking detoxification of peroxides to different enzymatic systems and implementing mechanisms for their inactivation to enforce signal propagation within and from the chloroplast.

글루타메이트에 의해 산화적 스트레스를 받은 HT22 세포주에서 포공영의 신경세포 보호 활성 (Neuroprotective Effect of Taraxacum platycarpum Extract Against Glutamate-induced Oxidative Stress in HT22 Cells)

  • 이현우;마충제
    • 생약학회지
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    • 제50권2호
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    • pp.118-123
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    • 2019
  • Glutamate acts as an important neurotransmitter in brain. However, high concentration of glutamate showed an excitatory neurotoxicity and resulted to neuronal cell death. Neuronal cell death is known for one of the reason of Alzheimer's disease, a neurodegenerative disease. We tried to find neuroprotective medicinal plants by neuroprotection activity against glutamate injured HT22 cells as a model system. In the course of bioscreening of various medicinal plants, Taraxacum platycarpum extract showed significant neuroprotective activity. We tried to elucidate mechanisms of neuroprotective activity. T. platycarpum extract reduced ROS and intracellular $Ca^{2+}$ concentration increased by glutamate induced neurotoxicity. In addition, mitochondrial membrane potential was restored to the control level. Also, glutathione level, glutathione reductase and glutathione peroxidase activity were increased by T. platycarpum extract treatment. These data suggested that T. platycarpum showed neuroprotective activity via antioxidative activity.

생쥐에서 사간 추출물의 기억력 감퇴에 대한 개선 효과 (Belamcandae Rhizoma Extract Improves Memory Impairment in Mice)

  • 정지욱
    • 생약학회지
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    • 제52권1호
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    • pp.55-60
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    • 2021
  • Belamcandae Rhizoma (BR), the rhizome of Belamcanda chinensis (L.) DC., possesses various biological properties such as anti-inflammatory activity, antioxidant activity and antimutagenic activity. However, there have been no studies on the anti-amnesic effect of BR. In this study, we assessed the improvement effect of BR extract on scopolamine-induced amnesia in mice. ICR mice were administrated with BR (50, 100 or 200 mg/kg, p.o.) and were subsequently injected of scopolamine (1 mg/kg, i.p.) 30 min before behavioral tasks (Y-maze, passive avoidance and Morris water maze tasks). To further assess the possible mechanisms of BR, the ex vivo acetylcholinesterase (AChE) activity was also evaluated. BR could ameliorate scopolamine-induced memory impairment and could regulate the cholinergic function by inhibiting the AChE activity. These data demonstrated that BR exert candidate extract against amnesia by restoring the cholinergic activity.

Ameliorative effects of propolis upon reproductive toxicity in males

  • Saleem Ali Banihani
    • Clinical and Experimental Reproductive Medicine
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    • 제50권1호
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    • pp.12-18
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    • 2023
  • Propolis is a sticky natural product produced by honeybees. Research studies have discussed the effectiveness of propolis, directly or indirectly, for ameliorating reproductive toxicity in males; however, this research has not yet been reviewed. The current paper presents an integrative summary of all research studies in Scopus and PubMed that investigated the effects of propolis on semen quality, and hence on male fertility, in conditions of reproductive toxicity. The consensus indicates that propolis ameliorates reproductive toxicity and enhances semen quality in vivo in test animals. These effects may be attributable to the ability of propolis to reduce testicular oxidative damage, enhance testicular antioxidant defense mechanisms, increase nitric oxide production, reduce testicular apoptotic injury, and boost testosterone production. However, to generalize these effects in humans would require further research.

Molecular Basis of the KEAP1-NRF2 Signaling Pathway

  • Takafumi Suzuki;Jun Takahashi;Masayuki Yamamoto
    • Molecules and Cells
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    • 제46권3호
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    • pp.133-141
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    • 2023
  • Transcription factor NRF2 (NF-E2-related factor 2) is a master regulator of cellular responses against environmental stresses. NRF2 induces expression of detoxification and antioxidant enzymes and suppresses inductions of pro-inflammatory cytokine genes. KEAP1 (Kelch-like ECH-associated protein 1) is an adaptor subunit of CULLIN 3 (CUL3)-based E3 ubiquitin ligase. KEAP1 regulates the activity of NRF2 and acts as a sensor for oxidative and electrophilic stresses. NRF2 has been found to be activated in many types of cancers with poor prognosis. Therapeutic strategies to control NRF2-overeactivated cancers have been considered not only by targeting cancer cells with NRF2 inhibitors or NRF2 synthetic lethal chemicals, but also by targeting host defense with NRF2 inducers. Understanding precise molecular mechanisms how the KEAP1-NRF2 system senses and regulates the cellular response is critical to overcome intractable NRF2-activated cancers.