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Serreli G, Deiana M. Role of Dietary Polyphenols in the Activity and Expression of Nitric Oxide Synthases: A Review. Antioxidants (Basel) 2023; 12:antiox12010147. [PMID: 36671009 PMCID: PMC9854440 DOI: 10.3390/antiox12010147] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/10/2023] Open
Abstract
Nitric oxide (NO) plays several key roles in the functionality of an organism, and it is usually released in numerous organs and tissues. There are mainly three isoforms of the enzyme that produce NO starting from the metabolism of arginine, namely endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and neuronal nitric oxide synthase (nNOS). The expression and activity of these isoforms depends on the activation/deactivation of different signaling pathways at an intracellular level following different physiological and pathological stimuli. Compounds of natural origin such as polyphenols, which are obtainable through diet, have been widely studied in recent years in in vivo and in vitro investigations for their ability to induce or inhibit NO release, depending on the tissue. In this review, we aim to disclose the scientific evidence relating to the activity of the main dietary polyphenols in the modulation of the intracellular pathways involved in the expression and/or functionality of the NOS isoforms.
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Zhang Z, Zhang Y, Li J, Fu C, Zhang X. The Neuroprotective Effect of Tea Polyphenols on the Regulation of Intestinal Flora. Molecules 2021; 26:molecules26123692. [PMID: 34204244 PMCID: PMC8233780 DOI: 10.3390/molecules26123692] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
Tea polyphenols (TPs) are the general compounds of natural polyhydroxyphenols extracted in tea. Although a large number of studies have shown that TPs have obvious neuroprotective and neuro repair effects, they are limited due to the low bioavailability in vivo. However, TPs can act indirectly on the central nervous system by affecting the “microflora–gut–brain axis”, in which the microbiota and its composition represent a factor that determines brain health. Bidirectional communication between the intestinal microflora and the brain (microbe–gut–brain axis) occurs through a variety of pathways, including the vagus nerve, immune system, neuroendocrine pathways, and bacteria-derived metabolites. This axis has been shown to influence neurotransmission and behavior, which is usually associated with neuropsychiatric disorders. In this review, we discuss that TPs and their metabolites may provide benefits by restoring the imbalance of intestinal microbiota and that TPs are metabolized by intestinal flora, to provide a new idea for TPs to play a neuroprotective role by regulating intestinal flora.
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Affiliation(s)
- Zhicheng Zhang
- Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058, China;
- Taizhou Biomedical Industry Research Institute Co., Ltd., Taizhou 317000, China
- College of Life Sciences, Taizhou University, Taizhou 317000, China
| | - Yuting Zhang
- Department of Food Science and Engineering, Ningbo University, Ningbo 315211, China;
| | - Junmin Li
- Taizhou Biomedical Industry Research Institute Co., Ltd., Taizhou 317000, China
- College of Life Sciences, Taizhou University, Taizhou 317000, China
- Correspondence: (J.L.); (C.F.); (X.Z.)
| | - Chengxin Fu
- Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058, China;
- Correspondence: (J.L.); (C.F.); (X.Z.)
| | - Xin Zhang
- Department of Food Science and Engineering, Ningbo University, Ningbo 315211, China;
- Correspondence: (J.L.); (C.F.); (X.Z.)
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Tao T, Liu M, Chen M, Luo Y, Wang C, Xu T, Jiang Y, Guo Y, Zhang JH. Natural medicine in neuroprotection for ischemic stroke: Challenges and prospective. Pharmacol Ther 2020; 216:107695. [DOI: 10.1016/j.pharmthera.2020.107695] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/23/2020] [Accepted: 09/23/2020] [Indexed: 12/13/2022]
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Condensed tannins enhanced antioxidant capacity and hypoxic stress survivability but not growth performance and fatty acid profile of juvenile Japanese seabass (Lateolabrax japonicus). Anim Feed Sci Technol 2020. [DOI: 10.1016/j.anifeedsci.2020.114671] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhou T, Zhu M, Liang Z. (-)-Epigallocatechin-3-gallate modulates peripheral immunity in the MPTP-induced mouse model of Parkinson's disease. Mol Med Rep 2018; 17:4883-4888. [PMID: 29363729 PMCID: PMC5865947 DOI: 10.3892/mmr.2018.8470] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 03/16/2017] [Indexed: 12/27/2022] Open
Abstract
(-)-Epigallocatechin-3-gallate (EGCG) is the most widely studied catechin in green tea and has been identified to regulate immune function. The objective of the present study was to explore the possible application of EGCG in the treatment of Parkinson's disease (PD) by examining its effects on the peripheral immune system in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)‑induced PD mouse model. The results demonstrated that EGCG treatment restored the movement behavior of the mice impaired by MPTP, and protected tyrosine hydroxylase‑positive cells in the substantia nigra pars compacta region from MPTP toxicity. Flow cytometric analysis indicated that the ratio of CD3+CD4+ to CD3+CD8+ T lymphocytes in the peripheral blood increased in MPTP‑treated mice following treatment with EGCG, and EGCG reduced expression of inflammatory factors tumor necrosis factor‑α and interleukin‑6 in serum. The present findings indicated that EGCG serves neuroprotective effects in an MPTP‑induced PD mice model and may exert this through modulating peripheral immune response.
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Affiliation(s)
- Tingting Zhou
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Mengru Zhu
- Department of Plastic Surgery, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Zhanhua Liang
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
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Chen CN, Chang KC, Lin RF, Wang MH, Shih RL, Tseng HC, Soung HS, Tsai CC. Nitric oxide pathway activity modulation alters the protective effects of (-)Epigallocatechin-3-gallate on reserpine-induced impairment in rats. Behav Brain Res 2016; 305:198-211. [PMID: 26944334 DOI: 10.1016/j.bbr.2016.02.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/25/2016] [Accepted: 02/28/2016] [Indexed: 11/29/2022]
Abstract
Reserpine (RES) has been reported to increase the brain's neural oxidative stress and cause cognitive dysfunction. Having powerful antioxidative properties, green tea catechins, especially (-)epigallocatechin-3-gallate (EGCG), are able to protect against many oxidative injuries. In this study, we examined the protecting properties of EGCG on RES-induced impairment of short-term memory in three-month-old male Wistar rats. RES (1mg/kg i.p.) induced memory impairment (p<0.001) as evaluated by the social recognition task. EGCG treatment (100mg/kg i.p. for 7days, starting 6days before RES injection) was able to improve the impaired memory caused by RES. RES treatment increased the nitric oxide (NO) level and lipid peroxidation (LPO) production, and decreased the antioxidation power in hippocampi. EGCG treatment was able to counteract the RES-induced NO level and LPO production, as well as enhanced the hippocampal antioxidation power in RES-treated rats. In order to examine the implication of NO pathway activity in RES treatment, either NO precursor (L-arginine; L-A) or NO synthase inhibitor (L-NAME; L-N) was co-pretreated with EGCG; NO precursor treatment eliminated the protective effect of EGCG, in contrast to that NO synthase inhibitor treatment significantly increased the EGCG effects on cognitive and biochemical protection in RES-treated rats. These results suggested that the NO pathway was implicated, at least in part, in the RES-induced impairment, as well as in the protective effect of EGCG in treating RES-induced impairment of memory. The above evidence provides a clinically relevant value for EGCG in preventing RES-induced cognitive dysfunction.
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Affiliation(s)
- Cheng-Neng Chen
- Division of Neurosurgery, Department of Surgery, Taitung br. of Mackay Memorial Hospital, Taitung 95054, Taiwan, ROC
| | - Kuo-Chi Chang
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
| | - Rui-Feng Lin
- Department of Neurosurgery, Mackay Memorial Hospital, Taipei 10449, Taiwan, ROC
| | - Mao-Hsien Wang
- Department of Anesthesia, En Chu Kon Hospital, Sanshia District, New Taipei City 23702, Taiwan, ROC; Department of Optometry, Yuanpei University, Hsinchu 30015, Taiwan, ROC
| | - Ruoh-Lan Shih
- Department of Anesthesia, En Chu Kon Hospital, Sanshia District, New Taipei City 23702, Taiwan, ROC
| | - Hsiang-Chien Tseng
- Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 11101, Taiwan, ROC; School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan, ROC
| | - Hung-Sheng Soung
- Department of Psychiatry, Yuan-Shan br. of Taipei Veteran General Hospital, Yilan County 26604, Taiwan, ROC
| | - Cheng-Chia Tsai
- Department of Neurosurgery, Mackay Memorial Hospital, Taipei 10449, Taiwan, ROC; Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei 11031, Taiwan, ROC.
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Huang CC, Lai CJ, Tsai MH, Wu YC, Chen KT, Jou MJ, Fu PI, Wu CH, Wei IH. Effects of melatonin on the nitric oxide system and protein nitration in the hypobaric hypoxic rat hippocampus. BMC Neurosci 2015; 16:61. [PMID: 26443997 PMCID: PMC4594671 DOI: 10.1186/s12868-015-0199-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/08/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND It is well documented that the nitric oxide (NO) might be directly involved in brain response to hypobaric hypoxia, and could contribute to memory deficiencies. Recent studies have shown that melatonin could attenuate hypoxia or ischemia-induced nerve injuries by decreasing the production of free radicals. The present study, using immunohistochemical and immunoblot methods, aimed to explore whether melatonin treatment may affect the expression of nitric oxide system and protein nitration, and provide neuroprotection in the rat hippocampus injured by hypobaric hypoxia. Prior to hypoxic treatment, adult rats were pretreated with melatonin (100 mg/kg, i.p.) before they were exposed to the altitude chamber with 48 Torr of the partial oxygen concentration (pO2) for 7 h to mimic the ambience of being at 9000 m in height. They were then sacrificed after 0 h, 1, and 3 days of reoxygenation. RESULTS The results obtained from the immunohistochemical and immunoblotting analyses showed that the expressions of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), nitrotyrosine (Ntyr) and Caspase 3 in the hypoxic hippocampus were increased from 0 h to 3 days of reoxygenation. Interestingly, the hypoxia-induced increase of nNOS, eNOS, iNOS, Ntyr and Caspase 3 protein expression was significantly depressed in the hypoxic rats treated with melatonin. CONCLUSIONS Activation of the nitric oxide system and protein nitration constitutes a hippocampal response to hypobaric hypoxia and administration of melatonin could provide new therapeutic avenues to prevent and/or treat the symptoms produced by hypobaric hypoxia.
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Affiliation(s)
- Chih-Chia Huang
- Department of Psychiatry, China Medical University Hospital, No. 91 Hsueh-Shih Road, Taichung, Taiwan. .,Institute of Clinical Medical Science, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan. .,Department of Psychiatry, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
| | - Chia-Jou Lai
- Institute of Basic Medical Science, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
| | - Mang-Hung Tsai
- Department of Anatomy, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
| | - Ya-Chieh Wu
- Department of Nursing, Ching-Kuo Institute of Management and Health, 336, Fu-Hsin Road, Keelung, Taiwan.
| | - Kuang-Ti Chen
- Institute of Basic Medical Science, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
| | - Ming-Jia Jou
- School of Chinese Medicine for Post Baccalaureate, I Shou University, No. 1, Sec. 1, Syuecheng Road, Dashu District, Kaohsiung, Taiwan.
| | - Pin-I Fu
- Department of Anatomy, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
| | - Ching-Hsiang Wu
- Department of Anatomy and Cell Biology, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, Taiwan.
| | - I-Hua Wei
- Department of Anatomy, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
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Aqueous Extract of Agaricus blazei Murrill Prevents Age-Related Changes in the Myenteric Plexus of the Jejunum in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:287153. [PMID: 25960748 PMCID: PMC4415631 DOI: 10.1155/2015/287153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/15/2014] [Accepted: 12/16/2014] [Indexed: 01/27/2023]
Abstract
This study evaluated the effects of the supplementation with aqueous extract of Agaricus blazei Murrill (ABM) on biometric and blood parameters and quantitative morphology of the myenteric plexus and jejunal wall in aging Wistar rats. The animals were euthanized at 7 (C7), 12 (C12 and CA12), and 23 months of age (C23 and CA23). The CA12 and CA23 groups received a daily dose of ABM extract (26 mg/animal) via gavage, beginning at 7 months of age. A reduction in food intake was observed with aging, with increases in the Lee index, retroperitoneal fat, intestinal length, and levels of total cholesterol and total proteins. Aging led to a reduction of the total wall thickness, mucosa tunic, villus height, crypt depth, and number of goblet cells. In the myenteric plexus, aging quantitatively decreased the population of HuC/D(+) neuronal and S100(+) glial cells, with maintenance of the nNOS(+) nitrergic subpopulation and increase in the cell body area of these populations. Supplementation with the ABM extract preserved the myenteric plexus in old animals, in which no differences were detected in the density and cell body profile of neurons and glial cells in the CA12 and CA23 groups, compared with C7 group. The supplementation with the aqueous extract of ABM efficiently maintained myenteric plexus homeostasis, which positively influenced the physiology and prevented the death of the neurons and glial cells.
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Abstract
Polyphenols have been shown to have some of the neuroprotective effects against neurodegenerative diseases. These effects are attributed to a variety of biological activities, including free radical scavenging/antioxidant and anti-inflammatory and anti-apoptotic activities. In this regard, many efforts have been made to study the effects of various well-known dietary polyphenols on spinal cord injury (SCI) and to explore the mechanisms behind the neuroprotective effects. The aim of this paper is to present the mechanisms of neuroprotection of natural polyphenols used in animal models of SCI.
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Affiliation(s)
- Ali Reza Khalatbary
- Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, 18KM Khazar Blvd, Khazar Sq. Sari, Iran. m
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Xue R, Wu G, Wei X, Lv J, Fu R, Lei X, Zhang Z, Li W, He J, Zhao H, Zhao J, Ding X. Tea polyphenols may attenuate the neurocognitive impairment caused by global cerebral ischemia/reperfusion injury via anti-apoptosis. Nutr Neurosci 2014; 19:63-9. [DOI: 10.1179/1476830514y.0000000160] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Ghosh N, Ghosh R, Bhat ZA, Mandal V, Bachar SC, Nima ND, Sunday OO, Mandal SC. Advances in Herbal Medicine for Treatment of Ischemic Brain Injury. Nat Prod Commun 2014. [DOI: 10.1177/1934578x1400900739] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Ischemic brain injury is one of the leading causes of death worldwide and has attracted a lot of attention in the field of drug discovery. Cerebral ischemia is a complex pathological process involving a series of mechanisms, including generation of free radicals, oxidative stress, disruption of the membrane function, release of neurotransmitters and apoptosis. Thrombolytic therapy is the most effective therapeutic strategy, but the benefits are far from being absolute. Increased attention in the field of drug discovery has been focused on using natural compounds from traditional medicinal herbs for neuroprotection, which appears to be a promising therapeutic option for cerebral ischemia with minimal systemic adverse effects that could limit their long term use. The scenario calls for extensive investigations which can result in the development of lead molecules for neuroprotection in the future. In this context, the present review focuses on possible mechanisms underlying the beneficial effects of herbal drugs in patients with cerebral ischemic injury. Natural compounds have been demonstrated to have neurofunctional regulatory actions with antioxidative, anti-inflammatory, calcium antagonizing and anti-apoptotic activities. Among the several leads obtained from plant sources as potential neuroprotective agents, resveratrol, EGb761, curcumin and epigallocatechin-3-gallate have shown significant therapeutic benefits in cerebral ischemic conditions. However, ligustilide, tanshinone, scutellarin and shikonin are the few lead molecules which are under investigation for treatment of cerebral ischemia.
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Affiliation(s)
- Nilanjan Ghosh
- Dr B.C. Roy College of Pharmacy and Allied Health Sciences, Durgapur, India 713206
| | - Rituparna Ghosh
- Dr B.C. Roy College of Pharmacy and Allied Health Sciences, Durgapur, India 713206
| | - Zulfiqar A Bhat
- Department of Pharmaceutical Sciences, University of Kashmir, Srinagar, India 190006
| | - Vivekananda Mandal
- Institute of Pharmacy, Guru Ghasidas University, Bilaspur, India, 495009
| | - Sitesh C. Bachar
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Dhaka, Bangladesh
| | - Namsa D. Nima
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India 784028
| | - Otimenyin O. Sunday
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Plateau State, Nigeria
| | - Subhash C. Mandal
- Pharmacognosy and Phytotherapy Research Laboratory, Division of Pharmacognosy, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, India 700032
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Mähler A, Mandel S, Lorenz M, Ruegg U, Wanker EE, Boschmann M, Paul F. Epigallocatechin-3-gallate: a useful, effective and safe clinical approach for targeted prevention and individualised treatment of neurological diseases? EPMA J 2013; 4:5. [PMID: 23418936 PMCID: PMC3585739 DOI: 10.1186/1878-5085-4-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 01/25/2013] [Indexed: 12/12/2022]
Abstract
Neurodegenerative disorders show an increasing prevalence in a number of highly developed countries. Often, these diseases require life-long treatment mostly with drugs which are costly and mostly accompanied by more or less serious side-effects. Their heterogeneous manifestation, severity and outcome pose the need for individualised treatment options. There is an intensive search for new strategies not only for treating but also for preventing these diseases. Green tea and green tea extracts seem to be such a promising and safe alternative. However, data regarding the beneficial effects and possible underlying mechanism, specifically in clinical trials, are rare and rather controversial or non-conclusive. This review outlines the existing evidence from preclinical studies (cell and tissue cultures and animal models) and clinical trials regarding preventive and therapeutic effects of epigallcatechin-3-gallate in neurodegenerative diseases and considers antioxidative vs. pro-oxidative properties of the tea catechin important for dosage recommendations.
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Affiliation(s)
- Anja Mähler
- Experimental and Clinical Research Center, a joint cooperation between the Charité University Medicine Berlin and Max Delbrueck Center for Molecular Medicine, Berlin, D-13125, Germany.
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Espinosa C, López-Jiménez JÁ, Cabrera L, Larqué E, Almajano MP, Arnao MB, Zamora S, Pérez-Llamas F. Protective effect of white tea extract against acute oxidative injury caused by adriamycin in different tissues. Food Chem 2012; 134:1780-5. [PMID: 23442621 DOI: 10.1016/j.foodchem.2012.03.083] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 03/01/2012] [Accepted: 03/20/2012] [Indexed: 01/16/2023]
Abstract
Adriamycin (ADR) is an anticancer agent that increases oxidative stress in cells. We evaluated the protective effect of the long term consumption of white tea at two different doses against this drug. For this purpose rats were given distilled water (controls), 0.15 mg (Dose 1) or 0.45 mg (Dose 2) of solid tea extract/kg body weight for 12 months. All the animals received an injection of ADR, except half of the control group, which were given an injection of saline solution. This gave four experimental groups: Control (C), C+ADR, Dose 1+ADR, and Dose 2+ADR. The antioxidant activity (in liver, heart and brain microsomes) was analysed. White tea consumption for 12 months, at a non-pharmacological dose, reversed the oxidative damage caused by ADR, on both protein and lipid levels in all three organs. The heart recovered its antioxidant activity only at the highest dose of tea.
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Affiliation(s)
- Cristóbal Espinosa
- Physiology Department, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
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Wightman EL, Haskell CF, Forster JS, Veasey RC, Kennedy DO. Epigallocatechin gallate, cerebral blood flow parameters, cognitive performance and mood in healthy humans: a double-blind, placebo-controlled, crossover investigation. Hum Psychopharmacol 2012; 27:177-86. [PMID: 22389082 DOI: 10.1002/hup.1263] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The aim of the study was to assess the effects of oral ingestion of the 'green tea' polyphenol epigallocatechin gallate (EGCG) on cognitive performance, mood and localised cerebral blood flow (CBF) parameters in healthy human adults. METHOD In this double-blind, placebo-controlled, crossover study, 27 healthy adults received placebo and two doses (135 and 270 mg) of EGCG in counterbalanced order on separate days. Following a 45-min resting absorption period, participants performed a selection of computerised cognitive tasks that activate the frontal cortex for a further 42 min. CBF and haemodynamics, as indexed by concentration changes in oxygenated and deoxygenated haemoglobin, were assessed in the frontal cortex throughout the post-treatment period using Near-infrared spectroscopy (NIRS). RESULTS During the post-dose task performance period, the administration of 135 mg EGCG resulted in reduced CBF in the frontal cortex, as indexed by significantly lower concentrations of both oxygenated and total haemoglobin, in comparison with placebo. Heart rate was significantly reduced from pre dose to post dose across all treatments. No significant differences were observed for the level of deoxygenated haemoglobin or on any of the cognitive performance/mood measures. CONCLUSIONS These results demonstrate that a single dose of orally administered EGCG can modulate CBF parameters in healthy humans but that this is not associated with changes in cognitive performance or mood.
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Affiliation(s)
- Emma L Wightman
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle upon Tyne, United Kingdom
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Blaylock RL, Maroon J. Natural plant products and extracts that reduce immunoexcitotoxicity-associated neurodegeneration and promote repair within the central nervous system. Surg Neurol Int 2012; 3:19. [PMID: 22439110 PMCID: PMC3307240 DOI: 10.4103/2152-7806.92935] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/11/2012] [Indexed: 12/14/2022] Open
Abstract
Our understanding of the pathophysiological and biochemical basis of a number of neurological disorders has increased enormously over the last three decades. Parallel with this growth of knowledge has been a clearer understanding of the mechanism by which a number of naturally occurring plant extracts, as well as whole plants, can affect these mechanisms so as to offer protection against injury and promote healing of neurological tissues. Curcumin, quercetin, green tea catechins, balcalein, and luteolin have been extensively studied, and they demonstrate important effects on cell signaling that go far beyond their antioxidant effects. Of particular interest is the effect of these compounds on immunoexcitotoxicity, which, the authors suggest, is a common mechanism in a number of neurological disorders. By suppressing or affecting microglial activation states as well as the excitotoxic cascade and inflammatory mediators, these compounds dramatically affect the pathophysiology of central nervous system disorders and promote the release and generation of neurotrophic factors essential for central nervous system healing. We discuss the various aspects of these processes and suggest future directions for study.
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Affiliation(s)
- Russell L Blaylock
- Theoretical Neurosciences, Department of Biology, Belhaven University, Jackson, MS 39157, USA
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Wei IH, Tu HC, Huang CC, Tsai MH, Tseng CY, Shieh JY. (-)-Epigallocatechin gallate attenuates NADPH-d/nNOS expression in motor neurons of rats following peripheral nerve injury. BMC Neurosci 2011; 12:52. [PMID: 21627848 PMCID: PMC3121620 DOI: 10.1186/1471-2202-12-52] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 06/01/2011] [Indexed: 01/19/2023] Open
Abstract
Background Oxidative stress and large amounts of nitric oxide (NO) have been implicated in the pathophysiology of neuronal injury and neurodegenerative disease. Recent studies have shown that (-)-epigallocatechin gallate (EGCG), one of the green tea polyphenols, has potent antioxidant effects against free radical-mediated lipid peroxidation in ischemia-induced neuronal damage. The purpose of this study was to examine whether EGCG would attenuate neuronal expression of NADPH-d/nNOS in the motor neurons of the lower brainstem following peripheral nerve crush. Thus, young adult rats were treated with EGCG (10, 25, or 50 mg/kg, i.p.) 30 min prior to crushing their hypoglossal and vagus nerves for 30 seconds (left side, at the cervical level). The treatment (pre-crush doses of EGCG) was continued from day 1 to day 6, and the animals were sacrificed on days 3, 7, 14 and 28. Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry were used to assess neuronal NADPH-d/nNOS expression in the hypoglossal nucleus and dorsal motor nucleus of the vagus. Results In rats treated with high dosages of EGCG (25 or 50 mg/kg), NADPH-d/nNOS reactivity and cell death of the motor neurons were significantly decreased. Conclusions The present evidence indicated that EGCG can reduce NADPH-d/nNOS reactivity and thus may enhance motor neuron survival time following peripheral nerve injury.
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Affiliation(s)
- I-Hua Wei
- Department of Anatomy and Cell Biology, College of Medicine, China Medical University, Taichung, Taiwan.
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Wu YC, Wang YJ, Tseng GF. Ascorbic acid and α-tocopherol supplement starting prenatally enhances the resistance of nucleus tractus solitarius neurons to hypobaric hypoxic challenge. Brain Struct Funct 2011; 216:105-22. [PMID: 21287201 DOI: 10.1007/s00429-010-0300-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 12/30/2010] [Indexed: 12/15/2022]
Abstract
Hypobaric hypoxia, encountered at high altitude, could result in severe consequences. Ascorbic acid (AA) and α-tocopherol (αTC), the two readily available over-the-counter antioxidants, are known to protect nervous tissue against oxidative stress. Here we study whether AA or αTC supplement starting prenatally protects animals against hypobaric hypoxic challenge at adulthood. Expressions of c-fos and the NR1 subunit of the N-methyl-D-aspartate receptors in the nucleus tractus solitarius (NTS) subserving cardiorespiratory functions were investigated. AA and αTC supplement reduced the number of c-fos immunoreactive neurons and intensity of NR1 expression in young and adult animals under normoxia. The treatment, in addition, attenuated the activation of NTS neurons, in terms of c-fos and NR1 expressions, and reduced the anxiety behaviors of adult rats subjected to hypobaric hypoxic challenge. Reduction of c-fos immunoreactive neurons was found concentrated in the chemoreceptor, baroreceptor, and tracheobronchial tree NTS subnuclei that receive corresponding afferents. The protective effect was not found in normal adult animals supplemented with AA or αTC a week before hypobaric hypoxic challenge. In short, prenatal and sustained AA or αTC supplement altered NTS substrate and ameliorated animals' reactions to hypobaric hypoxic insult, suggesting that this may be considered to protect animals from hypoxic insults from young to adult.
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Affiliation(s)
- Ya-Chieh Wu
- Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, Taiwan
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Mazzio EA, Close F, Soliman KFA. The biochemical and cellular basis for nutraceutical strategies to attenuate neurodegeneration in Parkinson's disease. Int J Mol Sci 2011; 12:506-69. [PMID: 21340000 PMCID: PMC3039966 DOI: 10.3390/ijms12010506] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 01/05/2011] [Accepted: 01/14/2011] [Indexed: 12/19/2022] Open
Abstract
Future therapeutic intervention that could effectively decelerate the rate of degeneration within the substantia nigra pars compacta (SNc) could add years of mobility and reduce morbidity associated with Parkinson’s disease (PD). Neurodegenerative decline associated with PD is distinguished by extensive damage to SNc dopaminergic (DAergic) neurons and decay of the striatal tract. While genetic mutations or environmental toxins can precipitate pathology, progressive degenerative succession involves a gradual decline in DA neurotransmission/synaptic uptake, impaired oxidative glucose consumption, a rise in striatal lactate and chronic inflammation. Nutraceuticals play a fundamental role in energy metabolism and signaling transduction pathways that control neurotransmission and inflammation. However, the use of nutritional supplements to slow the progression of PD has met with considerable challenge and has thus far proven unsuccessful. This review re-examines precipitating factors and insults involved in PD and how nutraceuticals can affect each of these biological targets. Discussed are disease dynamics (Sections 1 and 2) and natural substances, vitamins and minerals that could impact disease processes (Section 3). Topics include nutritional influences on α-synuclein aggregation, ubiquitin proteasome function, mTOR signaling/lysosomal-autophagy, energy failure, faulty catecholamine trafficking, DA oxidation, synthesis of toxic DA-quinones, o-semiquinones, benzothiazolines, hyperhomocyseinemia, methylation, inflammation and irreversible oxidation of neuromelanin. In summary, it is clear that future research will be required to consider the multi-faceted nature of this disease and re-examine how and why the use of nutritional multi-vitamin-mineral and plant-based combinations could be used to slow the progression of PD, if possible.
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Affiliation(s)
- Elizabeth A Mazzio
- Florida A&M University, College of Pharmacy and Pharmaceutical Sciences, Tallahassee, FL 32307, USA; E-Mails: (E.A.M.); (F.C.)
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Weinreb O, Amit T, Mandel S, Kupershmidt L, Youdim MBH. Neuroprotective multifunctional iron chelators: from redox-sensitive process to novel therapeutic opportunities. Antioxid Redox Signal 2010; 13:919-49. [PMID: 20095867 DOI: 10.1089/ars.2009.2929] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Accumulating evidence suggests that many cytotoxic signals occurring in the neurodegenerative brain can initiate neuronal death processes, including oxidative stress, inflammation, and accumulation of iron at the sites of the neuronal deterioration. Neuroprotection by iron chelators has been widely recognized with respect to their ability to prevent hydroxyl radical formation in the Fenton reaction by sequestering redox-active iron. An additional neuroprotective mechanism of iron chelators is associated with their ability to upregulate or stabilize the transcriptional activator, hypoxia-inducible factor-1alpha (HIF-1alpha). HIF-1alpha stability within the cells is under the control of a class of iron-dependent and oxygen-sensor enzymes, HIF prolyl-4-hydroxylases (PHDs) that target HIF-1alpha for degradation. Thus, an emerging novel target for neuroprotection is associated with the HIF system to promote stabilization of HIF-1alpha and increase transcription of HIF-1-related survival genes, which have been reported to be regulated in patient's brains afflicted with diverse neurodegenerative diseases. In accordance, a new potential therapeutic strategy for neurodegenerative diseases is explored, by which iron chelators would inhibit PHDs, target the HIF-1-signaling pathway and ultimately activate HIF-1-dependent neuroprotective genes. This review discusses two interrelated approaches concerning therapy targets in neurodegeneration, sharing in common the implementation of iron chelation activity: antioxidation and HIF-1-pathway activation.
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Affiliation(s)
- Orly Weinreb
- Eve Topf Centers of Excellence for Neurodegenerative Diseases Research and Department of Pharmacology, Rappaport Family Research Institute, Technion-Faculty of Medicine, Haifa, Israel.
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Peng N, Liu JT, Guo F, Li R. Epigallocatechin-3-gallate inhibits interleukin-6- and angiotensin II-induced production of C-reactive protein in vascular smooth muscle cells. Life Sci 2010; 86:410-5. [DOI: 10.1016/j.lfs.2010.01.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 01/13/2010] [Accepted: 01/14/2010] [Indexed: 11/16/2022]
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Kumar P, Kumar A. Protective effects of epigallocatechin gallate following 3-nitropropionic acid-induced brain damage: possible nitric oxide mechanisms. Psychopharmacology (Berl) 2009; 207:257-70. [PMID: 19763544 DOI: 10.1007/s00213-009-1652-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2009] [Accepted: 08/18/2009] [Indexed: 01/27/2023]
Abstract
INTRODUCTION The role of oxidative stress has been well known in neurodegenerative disorders. 3-Nitropropionic acid (3-NP) is a plant-based mycotoxin that produces HD like symptoms in animals. Oxidative stress and nitric oxide mechanisms have been recently proposed in the 3-NP-induced neurotoxicity. Epigallocatechin gallate (EGCG) is one of the major components of green tea, known for its potent antioxidant activity. Besides, neuroprotective effect of EGCG has also been suggested in different experimental models. OBJECTIVES The present study has been designed to examine possible effect of EGCG against 3-NP induced behavioral, oxidative stress, mitochondrial dysfunction, and striatal damage in rats and its possible interaction with nitric oxide modulators. MATERIAL AND METHODS Systemic 3-NP (10 mg/kg) administration for 14 days significantly reduced locomotor activity, body weight, grip strength, oxidative defense (raised levels of lipid peroxidation, nitrite concentration, depletion of antioxidant enzyme), and mitochondrial enzymes activity in striatum, cortex, and hippocampal regions of the brain. RESULTS Fourteen days of EGCG pretreatment (10, 20, and 40 mg/kg) significantly attenuated behavioral alterations, oxidative damage, mitochondrial complex enzymes dysfunction, and striatal damage in 3-NP-treated animals. L-arginine (50 mg/kg) pretreatment with sub-effective dose of EGCG (20 mg/kg) significantly reversed the protective behavioral, biochemical, cellular, and histological effects of EGCG. However, L-NAME (10 mg/kg) pretreatment with EGCG (20 mg/kg) significantly potentiated the protective effect of EGCG which was significant as compared to their effect per se. CONCLUSION The present study shows that EGCG attenuate 3-NP-induced neurotoxicity, and nitric oxide modulation might be involved in its protective action.
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Affiliation(s)
- Puneet Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study, Panjab University, Chandigarh, 160014, India
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Khalatbary AR, Tiraihi T, Boroujeni MB, Ahmadvand H, Tavafi M, Tamjidipoor A. Effects of epigallocatechin gallate on tissue protection and functional recovery after contusive spinal cord injury in rats. Brain Res 2009; 1306:168-75. [PMID: 19815005 DOI: 10.1016/j.brainres.2009.09.109] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 09/28/2009] [Accepted: 09/29/2009] [Indexed: 01/14/2023]
Abstract
Recent studies revealed the neuroprotective effects of epigallocatechin gallate (EGCG) on a variety of neural injury .The purpose of this study was to determine the effects of EGCG on the tissue protection and behavioral improvement after spinal cord injury (SCI). Rats were randomly divided into four groups of 18 rats each as follows: sham-operated group, trauma group, and EGCG treatment groups (50 mg/kg, i.p., immediately and 1 hour after SCI). Spinal cord samples were taken 24 hours after injury and studied for determination of malodialdehyde (MDA) levels, immunohistochemistry of Bax and Bcl-2, and TUNEL reaction. Behavioral testing was performed weekly up to 6 weeks post-injury. Then, the rats were euthanized for histopathological assessment. The results showed that MDA levels were significantly decreased in EGCG treatment groups. Greater Bcl-2 and attenuated Bax expression could be detected in the EGCG-treated rats. EGCG significantly reduced TUNEL-positive rate. Also, EGCG significantly reduced the percentage of lesion area and improved behavioral function than the trauma group. On the basis of these findings, we propose that EGCG may be effective in protecting rat spinal cord from secondary injury.
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Affiliation(s)
- Ali Reza Khalatbary
- Razi Herbal Medicine Research Center, Lorestan University of Medical Sciences, Khoramabad, Iran.
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McShea A, Ramiro-Puig E, Munro SB, Casadesus G, Castell M, Smith MA. Clinical benefit and preservation of flavonols in dark chocolate manufacturing. Nutr Rev 2008; 66:630-41. [DOI: 10.1111/j.1753-4887.2008.00114.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Yamakuchi M, Bao C, Ferlito M, Lowenstein CJ. Epigallocatechin gallate inhibits endothelial exocytosis. Biol Chem 2008; 389:935-41. [PMID: 18627310 DOI: 10.1515/bc.2008.095] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Consumption of green tea is associated with a decrease in cardiovascular mortality. The beneficial health effects of green tea are attributed in part to polyphenols, organic compounds found in tea that lower blood pressure, reduce body fat, decrease LDL cholesterol, and inhibit inflammation. We hypothesized that epigallocatechin gallate (EGCG), the most abundant polyphenol in tea, inhibits endothelial exocytosis, the initial step in leukocyte trafficking and vascular inflammation. To test this hypothesis, we treated human umbilical-vein endothelial cells with EGCG and other polyphenols, and then measured endothelial exocytosis. We found that EGCG decreases endothelial exocytosis in a concentration-dependent manner, with the effects most prominent after 4 h of treatment. Other catechin polyphenols had no effect on endothelial cells. By inhibiting endothelial exocytosis, EGCG decreases leukocyte adherence to endothelial cells. In searching for the mechanism by which EGCG affects endothelial cells, we found that EGCG increases Akt phosphorylation, eNOS phosphorylation, and nitric oxide (NO) production. NOS inhibition revealed that NO mediates the anti-inflammatory effects of EGCG. Our data suggest that polyphenols can decrease vascular inflammation by increasing the synthesis of NO, which blocks endothelial exocytosis.
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Affiliation(s)
- Munekazu Yamakuchi
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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26
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Yin ST, Tang ML, Su L, Chen L, Hu P, Wang HL, Wang M, Ruan DY. Effects of Epigallocatechin-3-gallate on lead-induced oxidative damage. Toxicology 2008; 249:45-54. [DOI: 10.1016/j.tox.2008.04.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 03/26/2008] [Accepted: 04/05/2008] [Indexed: 10/22/2022]
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Burckhardt IC, Gozal D, Dayyat E, Cheng Y, Li RC, Goldbart AD, Row BW. Green tea catechin polyphenols attenuate behavioral and oxidative responses to intermittent hypoxia. Am J Respir Crit Care Med 2008; 177:1135-41. [PMID: 18276944 DOI: 10.1164/rccm.200701-110oc] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE The intermittent hypoxia (IH) that characterizes sleep-disordered breathing impairs spatial learning and increases NADPH oxidase activity and oxidative stress in rodents. We hypothesized that green tea catechin polyphenols (GTPs) may attenuate IH-induced neurobehavioral deficits by reducing IH-induced NADPH oxidase expression, lipid peroxidation, and inflammation. OBJECTIVES To assess the effects of GTP administered in drinking water on the cognitive, inflammatory, and oxidative responses to long-term (>14 d) IH during sleep in male Sprague-Dawley rats. METHODS Cognitive assessments were conducted in the Morris water maze. We measured levels and expression of malondialdehyde (MDA), prostaglandin E(2), p47(phox) subunit of NADPH oxidase, receptor for advanced glycation end products (RAGE), and glial fibrillary acidic protein expression in rodent brain tissue. MEASUREMENTS AND MAIN RESULTS GTP treatment prevented IH-induced decreases in spatial bias for the hidden platform during the Morris water maze probe trails as well as IH-induced increases in p47phox expression within the hippocampal CA1 region. In untreated animals, IH exposure was associated with doubling of cortical MDA levels in comparison to room air control animals, and GTP-treated animals exposed to IH showed a 40% reduction in MDA levels. Increases in brain RAGE and glial fibrillary acidic protein expression were observed in IH-exposed animals, and these increases were attenuated in animals treated with GTP. CONCLUSIONS Oral GTP attenuates IH-induced spatial learning deficits and mitigates IH-induced oxidative stress through multiple beneficial effects on oxidant pathways. Because oxidative processes underlie neurocognitive deficits associated with IH, the potential therapeutic role of GTP in sleep-disordered breathing deserves further exploration.
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Affiliation(s)
- Isabel C Burckhardt
- Kosair Children's Hospital Research Institute, University of Louisville, 570 South Preston Street, Suite 204, Louisville, KY 40202, USA
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28
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Peng PH, Ko ML, Chen CF. Epigallocatechin-3-gallate reduces retinal ischemia/reperfusion injury by attenuating neuronal nitric oxide synthase expression and activity. Exp Eye Res 2008; 86:637-46. [PMID: 18289530 DOI: 10.1016/j.exer.2008.01.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 12/20/2007] [Accepted: 01/06/2008] [Indexed: 01/17/2023]
Abstract
Retinal ischemia/reperfusion (IR) injury causes profound tissue damage, especially retinal ganglion cell death. The aims of the study were twofold: (1) to investigate the benefits of epigallocatechin-3-gallate (EGCG), the major catechin found in tea, after IR challenge, and (2) to elucidate the mechanism of EGCG inhibition of nitric oxide synthase (NOS) expression. Wistar female rats were divided into four groups: normal control, EGCG with sham operation, retinal IR, and EGCG with IR groups. EGCG (50mg/kg) was administered by intraperitoneal injection 30 min before the experiment. IR injury to a rat's retina was induced by raising intraocular pressure to 150 mmHg for 60 min. With EGCG pretreatment, retinal ganglion cell death from IR was reduced by approximately 10% 3 days afterward. EGCG significantly downregulated IR-induced glial fibrillary acidic protein expression. EGCG treatment also reduced TUNEL-positive cells after IR in the inner retina as well as IR-induced lipid peroxidation. Histological analyses showed fewer neuronal NOS and nicotinamide adenine dinucleotide phosphate diaphorase-positive cells in the retina after IR with EGCG administration. Therefore, EGCG is effective in protecting retinal ganglion cells from IR challenge by ameliorating retinal nitrosactive stress and by regulating cell death through apoptotic pathways.
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Affiliation(s)
- Pai-Huei Peng
- Department of Ophthalmology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
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Wei IH, Huang CC, Tseng CY, Chang HM, Tu HC, Tsai MH, Wen CY, Shieh JY. Mild hypoxic preconditioning attenuates injury-induced NADPH-d/nNOS expression in brainstem motor neurons of adult rats. J Chem Neuroanat 2007; 35:123-32. [PMID: 17942275 DOI: 10.1016/j.jchemneu.2007.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 08/21/2007] [Accepted: 08/24/2007] [Indexed: 01/30/2023]
Abstract
Excessive production of nitric oxide (NO) might have detrimental effects on the hypoxia-related neuropathology. This study aimed to test if mild hypoxic preconditioning (MHPC) would attenuate the pathological changes in the brainstem motoneurons having a different functional component after peripheral nerve crush injury (PNCI). Prior to PNCI treatment, young adult rats were caged in the mild hypoxic altitude chamber with 79Torr of the partial oxygen concentration ( pO(2)) (i.e., 0.5atm at 5500m in height) for 4 weeks to adapt the environmental changes. After that, all the animals having successfully crushed both the hypoglossal and vagus nerves (left-side) were allowed to survive for 3, 7, 14, 30 and 60 successive days in normoxic condition. Nicotinamine adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry revealed that MHPC reduces NADPH-d/nNOS expression in the hypoglossal nucleus (HN) and the dorsal motor nucleus of the vagus (DMN) at different time points after PNCI. The morphological findings were further ascertained by Western blot analysis of nNOS and nitrite assay for NO production. Both the morphological and quantitative results peaked at 7 days in HN, whereas for those in DMN were progressively increased up to 60 days following PNCI. The staining intensity of NADPH-d/nNOS(+) neurons, expression of nNOS protein, NO production levels as well as the neuronal loss in HN and DMN of MHPC rats following PNCI were attenuated, especially for those having a longer survival period over 14 days. The MHPC treatment might induce minute amounts of NO to alter the state of milieu of the experimental animals to protect against the PNCI.
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Affiliation(s)
- I-Hua Wei
- Department of Anatomy and Cell Biology, College of Medicine, China Medical University, Taichung, Taiwan.
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Hou RR, Chen JZ, Chen H, Kang XG, Li MG, Wang BR. Neuroprotective effects of (-)-epigallocatechin-3-gallate (EGCG) on paraquat-induced apoptosis in PC12 cells. Cell Biol Int 2007; 32:22-30. [PMID: 17936647 DOI: 10.1016/j.cellbi.2007.08.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 04/15/2007] [Accepted: 08/21/2007] [Indexed: 01/01/2023]
Abstract
Green tea, owing to its beneficial effect on health, is becoming more and more popular worldwide. (-)-Epigallocatechin-3-gallate (EGCG), the main ingredient of green tea polyphenols, is a known protective effect on injured neurons in neurodegenerative disease, such as Alzheimer's disease and Parkinson's disease. Paraquat (PQ) is a widely used herbicide that possesses a similar structure to MPP(+) and is toxic to mesencephalic dopaminergic neurons. In the present study, PQ-injured PC12 cells were chosen as an in vitro cell model of Parkinson's disease and the neuroprotective effects of EGCG were investigated. The results showed that EGCG attenuated apoptosis of PC12 cells induced by PQ. The possible mechanism may be associated with maintaining mitochondrial membrane potential, inhibiting caspase-3 activity and downregulating the expression of pro-apoptotic protein Smac in cytosol. The present study supports the notion that EGCG could be used as a neuroprotective agent for treatment of neurodegenerative diseases.
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Affiliation(s)
- Rong-Rong Hou
- Laboratory of Integrated Traditional Chinese Medicine and Western Medicine on Elderly Encephalopathy, Research Center of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
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Kishido T, Unno K, Yoshida H, Choba D, Fukutomi R, Asahina S, Iguchi K, Oku N, Hoshino M. Decline in glutathione peroxidase activity is a reason for brain senescence: consumption of green tea catechin prevents the decline in its activity and protein oxidative damage in ageing mouse brain. Biogerontology 2007; 8:423-30. [PMID: 17310319 DOI: 10.1007/s10522-007-9085-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Abstract
The accumulation of oxidative damage is believed to contribute to senescence. We have previously found that the consumption of green tea catechins (GT-catechin), which are potent antioxidants, decreases oxidative damage to DNA and improves brain function in aged mice with accelerated senescence (SAMP10 mice). To investigate the mechanisms underlying the beneficial effects of GT-catechin, we measured the activities of antioxidative enzymes in the brains of aged SAMP10 mice. The activity of glutathione peroxidase (GPx), an essential enzyme for reduction of hydrogen and lipid peroxides, was significantly lower in aged mice than in younger ones. However, the decline in activity was prevented in aged mice that had consumed GT-catechin. The increased level of carbonyl proteins, a marker of oxidative damage in proteins, was also significantly reduced in aged mice that had consumed GT-catechin. The activities of superoxide dismutase and catalase were not decreased in aged mice. These results suggest that decreased activity of GPx importantly contributes to brain dysfunction in ageing SAMP10 mice. Furthermore, the intake of GT-catechin protected the decline in GPx activity and age-related oxidative damage in the brain.
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Affiliation(s)
- Takahiro Kishido
- Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
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Park HJ, Shin DH, Chung WJ, Leem K, Yoon SH, Hong MS, Chung JH, Bae JH, Hwang JS. Epigallocatechin gallate reduces hypoxia-induced apoptosis in human hepatoma cells. Life Sci 2006; 78:2826-32. [PMID: 16445947 DOI: 10.1016/j.lfs.2005.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Accepted: 11/02/2005] [Indexed: 10/25/2022]
Abstract
Cell detachment from extracellular matrix is closely related to induction of apoptosis. Epigallocatechin gallate (EGCG) has been shown to have antioxidant effect and to protect hypoxia-induced damage. We investigated whether EGCG reduced hypoxia-induced apoptosis and cell detachment in HepG2 cells. EGCG prevented cell death by hypoxia (0.5% O2) in a dose-dependent manner (hypoxic cell viability, 54.67%). RT-PCR and caspase3 activity assay showed that the hypoxia-induced cell death was caused by apoptosis increasing mRNA level of BAX, CASP3, and caspase3 activity. EGCG reduced increase of these mRNA and caspase3 activity. Western blot analysis and immunocytochemistry showed that EGCG increased cell adhesion proteins including E-cadherin (CDH1), tumor-associated calcium signal transducer 1 (TACSTD1), and protein tyrosine kinase 2 (PTK2) decreased by hypoxia. Hypoxia-induced apoptosis in HepG2 cells, and EGCG contributed to the HepG2 cell survival by attenuating the apoptosis.
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Affiliation(s)
- Hae Jeong Park
- Department of Pharmacology, Kohwang Medical Research Institute, College of Medicine, Kyung Hee University, Seoul 130-701, South Korea
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Sutherland BA, Rahman RMA, Appleton I. Mechanisms of action of green tea catechins, with a focus on ischemia-induced neurodegeneration. J Nutr Biochem 2005; 17:291-306. [PMID: 16443357 DOI: 10.1016/j.jnutbio.2005.10.005] [Citation(s) in RCA: 216] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2005] [Accepted: 10/11/2005] [Indexed: 02/02/2023]
Abstract
Catechins are dietary polyphenolic compounds associated with a wide variety of beneficial health effects in vitro, in vivo and clinically. These therapeutic properties have long been attributed to the catechins' antioxidant and free radical scavenging effects. Emerging evidence has shown that catechins and their metabolites have many additional mechanisms of action by affecting numerous sites, potentiating endogenous antioxidants and eliciting dual actions during oxidative stress, ischemia and inflammation. Catechins have proven to modulate apoptosis at various points in the sequence, including altering expression of anti- and proapoptotic genes. Their anti-inflammatory effects are activated through a variety of different mechanisms, including modulation of nitric oxide synthase isoforms. Catechins' actions of attenuating oxidative stress and the inflammatory response may, in part, account for their confirmed neuroprotective capabilities following cerebral ischemia. The versatility of the mechanisms of action of catechins increases their therapeutic potential as interventions for numerous clinical disorders. However, more epidemiological and clinical studies need to be undertaken for their efficacy to be fully elucidated.
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Affiliation(s)
- Brad A Sutherland
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, P.O. Box 913, Dunedin, New Zealand
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Chang HM, Tseng CY, Wei IH, Lue JH, Wen CY, Shieh JY. Melatonin restores the cytochrome oxidase reactivity in the nodose ganglia of acute hypoxic rats. J Pineal Res 2005; 39:206-14. [PMID: 16098100 DOI: 10.1111/j.1600-079x.2005.00238.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This study aimed to elucidate whether melatonin would exert beneficial effects on the neuronal functions of the nodose ganglion (NG) following acute hypoxic insult. The cytochrome oxidase (COX) and the nicotinamine adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry along with the nitric oxide synthase (NOS) immunofluorescence were used to examine the metabolic stage and nitric oxide production in nodose neurons respectively. Adult rats were injected intraperitoneally with melatonin at 5 or 100 mg/kg. Hypoxia was achieved by placing the rats into an altitude chamber (PO2 = 43 torr) for 4 hr. The results show that in normal untreated rats, nearly all and about 43% of the NG neurons displayed COX and NOS/NADPH-d reactivities with various staining intensities respectively. However, COX reactivity was drastically decreased while NOS/NADPH-d reactivity was significantly upregulated following hypoxia treatment. In melatonin pretreated rats, the hypoxia-induced reduction of COX reactivity was obviously prevented and the augmentation of NOS/NADPH-d reactivity was successfully suppressed. The deficit in the metabolic stage and the over-activation of NOS would contribute to the generation of oxidative stress. By effectively preventing the metabolic disruption, melatonin may have potential utility in therapeutic treatment of neuronal dysfunctions where oxidative stress is a participant.
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Affiliation(s)
- Hung-Ming Chang
- Department of Anatomy, College of Medicine, Chung Shan Medical University, Taichung, Taiwan
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Finley JW. Proposed criteria for assessing the efficacy of cancer reduction by plant foods enriched in carotenoids, glucosinolates, polyphenols and selenocompounds. ANNALS OF BOTANY 2005; 95:1075-96. [PMID: 15784686 PMCID: PMC4246895 DOI: 10.1093/aob/mci123] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2004] [Revised: 01/07/2005] [Accepted: 01/26/2005] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND AIMS The cancer-protective properties of vegetable consumption are most likely mediated through 'bioactive compounds' that induce a variety of physiologic functions including acting as direct or indirect antioxidants, regulating enzymes and controlling apoptosis and the cell cycle. The 'functional food' industry has produced and marketed foods enriched with bioactive compounds, but there are no universally accepted criteria for judging efficacy of the compounds or enriched foods. SCOPE Carotenoids, glucosinolates, polyphenols and selenocompounds are families of bioactive compounds common to vegetables. Although numerous studies have investigated the agricultural and human health implications of enriching foods with one or more of these compounds, inadequate chemical identification of compounds, lack of relevant endpoints and inconsistencies in mechanistic hypotheses and experimental methodologies leave many critical gaps in our understanding of the benefits of such compounds. This review proposes a decision-making process for determining whether there is reasonable evidence of efficacy for the both the compound and the enriched food. These criteria have been used to judge the evidence of efficacy for cancer prevention by carotenoids, polyphenols, glucosinolates and selenocompounds. CONCLUSIONS The evidence of efficacy is weak for carotenoids and polyphenols; the evidence is stronger for glucosinolates and lycopene, but production of enriched foods still is premature. Additionally there is unacceptable variability in the amount and chemical form of these compounds in plants. The evidence of efficacy for selenocompounds is strong, but the clinical study that is potentially the most convincing is still in progress; also the variability in amount and chemical form of Se in plants is a problem. These gaps in understanding bioactive compounds and their health benefits should not serve to reduce research interest but should, instead, encourage plant and nutritional scientists to work together to develop strategies for improvement of health through food.
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Affiliation(s)
- John W Finley
- United States Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202-9034, USA.
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Wei IH, Huang CC, Chang HM, Tseng CY, Tu HC, Wen CY, Shieh JY. Neuronal NADPH-d/NOS expression in the nodose ganglion of severe hypoxic rats with or without mild hypoxic preconditioning. J Chem Neuroanat 2005; 29:149-56. [PMID: 15652701 DOI: 10.1016/j.jchemneu.2004.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2004] [Revised: 09/20/2004] [Accepted: 11/22/2004] [Indexed: 12/25/2022]
Abstract
This study aimed to test the hypothesis that mild hypoxic preconditioning (MHPC)-induced NOS expression would attenuate the neuropathological changes in the nodose ganglion (NG) of severe hypoxic exposure (SHE) rats. Thus, the young adult rats were caged in the altitude chamber for 4 weeks prior to SHE for 4 h to gain hypoxic preconditioning. The altitude chamber was used to set the height at the level from 5500 m (0.50 atm; pO2=79 Torr) to 10,000 m (0.27 atm; pO2=43 Torr) for MHPC and SHE, respectively. The experimental animals were allowed to survive for 0, 7, 14, 30 and 60 successive days, respectively. Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry were used to detect NADPH-d/nNOS reactivity in the NG at various time points following hypoxic exposure. The present results showed that about 38% of the neurons in the NG displayed NADPH-d/nNOS positive [NADPH-d/nNOS(+)] in normoxic rats. In SHE rats, a peak in the percentage (71%) and staining intensity (230%) of NADPH-d/nNOS(+) nodose neurons at 0 day, which then gradually decreased at 7-60 days. About 25% of the nodose neurons died 60 days after SHE. However, in MHPC rats subjected to SHE, NADPH-d/nNOS(+) neurons peaked in the percentage (51%) and staining intensity (171%) at 0 day, which then decreased at 7-60 days. In addition, neuronal survival was markedly increased by MHPC. These results suggested that MHPC might have a neuroprotective effect that reduces the susceptibility of the nodose neurons to NOS mediated neuropathy subsequent to SHE.
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Affiliation(s)
- I-Hua Wei
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
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Sutherland BA, Shaw OM, Clarkson AN, Jackson DN, Sammut IA, Appleton I. Neuroprotective effects of (-)-epigallocatechin gallate following hypoxia-ischemia-induced brain damage: novel mechanisms of action. FASEB J 2004; 19:258-60. [PMID: 15569775 DOI: 10.1096/fj.04-2806fje] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
(-)-Epigallocatechin gallate (EGCG) is a potent antioxidant that is neuroprotective against ischemia-induced brain damage. However, the neuroprotective effects and possible mechanisms of action of EGCG after hypoxia-ischemia (HI) have not been investigated. Therefore, we used a modified "Levine" model of HI to determine the effects of EGCG. Wistar rats were treated with either 0.9% saline or 50 mg/kg EGCG daily for 1 day and 1 h before HI induction and for a further 2 days post-HI. At 26-days-old, both groups underwent permanent left common carotid artery occlusion and exposure to 8% oxygen/92% nitrogen atmosphere for 1 h. Histological assessment showed that EGCG significantly reduced infarct volume (38.0+/-16.4 mm(3)) in comparison to HI + saline (99.6+/-15.6 mm(3)). In addition, EGCG significantly reduced total (622.6+/-85.8 pmol L-[(3)H]citrulline/30 min/mg protein) and inducible nitric oxide synthase (iNOS) activity (143.2+/-77.3 pmol L-[(3)H]citrulline/30 min/mg protein) in comparison to HI+saline controls (996.6+/-113.6 and 329.7+/-59.6 pmol L-[(3)H]citrulline/30 min/mg protein for total NOS and iNOS activity, respectively). Western blot analysis demonstrated that iNOS protein expression was also reduced. In contrast, EGCG significantly increased endothelial and neuronal NOS protein expression compared with HI controls. EGCG also significantly preserved mitochondrial energetics (complex I-V) and citrate synthase activity. This study demonstrates that the neuroprotective effects of EGCG are, in part, due to modulation of NOS isoforms and preservation of mitochondrial complex activity and integrity. We therefore conclude that the in vivo neuroprotective effects of EGCG are not exclusively due to its antioxidant effects but involve more complex signal transduction mechanisms.
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Affiliation(s)
- Brad A Sutherland
- Department of Pharmacology and Toxicology, University of Otago, PO Box 913, Dunedin, New Zealand
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Choi YB, Kim YI, Lee KS, Kim BS, Kim DJ. Protective effect of epigallocatechin gallate on brain damage after transient middle cerebral artery occlusion in rats. Brain Res 2004; 1019:47-54. [PMID: 15306237 DOI: 10.1016/j.brainres.2004.05.079] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2004] [Indexed: 10/26/2022]
Abstract
Epigallocatechin gallate (EGCG), a major constituent of green tea, is a potent free radical scavenger. The purpose of this study was to verify whether EGCG reduces focal ischemia/reperfusion-induced brain injury in a rat model. Male Sprague-Dawley rats were anesthetized with chloral hydrate (400 mg/kg, i.p.) and subjected to a middle cerebral artery 2 h occlusion and then a 24-h reperfusion. The EGCG (25 mg and 50 mg/kg, i.p.) or vehicle was administered immediately after reperfusion. Twenty-four hours after reperfusion, infarction size, levels of oxidative stress markers (malondialdehyde and oxidized/total glutathione ratio) in the brain and neurological deficits were evaluated. The dose of 50 mg/kg of EGCG significantly reduced the infarction volume (9.9+/-3.2%) as compared to those (45.6+/-5.3%, 34.5+/-7.8%) of the control group and the EGCG 25 mg/kg treated group (p<0.01). The dose of 50 mg/kg of EGCG significantly reduced the neurological deficit total score (5.2+/-1.7) as compared to those (9.5+/-1.2, 8.5+/-2.5) of the control group and the EGCG 25 mg/kg treated group (p<0.05). The dose of 50 mg/kg of EGCG significantly attenuated the level of malondialdehyde and the level of oxidized/total glutathione ratio (281+/-66 nmol/g and 0.48+/-0.03) as compared to the those (415+/-46 nmol/g and 0.64+/-0.05, 381+/-51 nmol/g and 0.61+/-0.06) of the control group and the EGCG 25 mg/kg treated group (p<0.05). These results demonstrate the anti-oxidant effects of EGCG (50 mg/kg) in a rat model of transient focal ischemia, which is a likely explanation for EGCG's neuroprotective effects.
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Affiliation(s)
- Young Bin Choi
- Department of Neurology, College of Medicine, The Catholic University of Korea, South Korea
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