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Liu Q, Li W, Huang S, Zhao L, Zhang J, Ji C, Ma Q. R- Is Superior to S-Form of α-Lipoic Acid in Anti-Inflammatory and Antioxidant Effects in Laying Hens. Antioxidants (Basel) 2022; 11:antiox11081530. [PMID: 36009249 PMCID: PMC9405457 DOI: 10.3390/antiox11081530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 12/02/2022] Open
Abstract
The development of single enantiomers with high efficiency and low toxic activity has become a hot spot for the development and application of drugs and active additives. The aim of the present study was to investigate the effectiveness of the application of α-lipoic acid with a different optical rotation to alleviate the inflammation response and oxidative stress induced by oxidized fish oil in laying hens. Sixty-four 124-week-old Peking Red laying hens were randomly allocated to four groups with eight replicates of two birds each. The normal group was fed basal diets supplemented with 1% fresh fish oil (FO), and the oxidative stress model group was constructed with diets supplemented with 1% oxidized fish oil (OFO). The two treatment groups were the S-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + S-LA) and the R-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + R-LA) added at 100 mg/kg, respectively. Herein, these results were evaluated by the breeding performance, immunoglobulin, immune response, estrogen secretion, antioxidant factors of the serum and oviduct, and pathological observation of the uterus part of the oviduct. From the results, diets supplemented with oxidized fish oil can be relatively successful in constructing a model of inflammation and oxidative stress. The OFO group significantly increased the levels of the serum inflammatory factor (TNF-α, IL-1β, IL-6, and IFN-γ) and the oxidative factor MDA and decreased the activity of the antioxidant enzyme (T-AOC, T-SOD, GSH-Px, GSH, and CAT) in the oviduct. The addition of both S-LA and R-LA significantly reduced the levels of serum inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), increased the activity of antioxidant indexes (T-AOC, T-SOD, GSH-Px, GSH, and CAT), and decreased the MDA contents in the serum and oviduct. Meanwhile, the supplementation of S-LA and R-LA also mitigated the negative effects of the OFO on the immunoglobulins (IgA and IgM) and serum hormone levels (P and E2). In addition, it was worth noting that the R-LA was significantly more effective than the S-LA in some inflammatory (IL-1β) and antioxidant indices (T-SOD, GSH, and CAT). Above all, both S-LA and R-LA can alleviate the inflammation and oxidative damage caused by oxidative stress in aged laying hens, and R-LA is more effective than S-LA. Thus, these findings will provide basic data for the potential development of α-lipoic acid as a chiral dietary additive for laying hens.
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Yoon J, Moon SJ, Lee KO, Yoon SH, Jang IJ, Yu KS, Lee S. Comparison ofR(+)-α-lipoic acid exposure afterR(+)-α-lipoic acid 200 mg and 300 mg and thioctic acid 600 mg in healthy Korean male subjects. Transl Clin Pharmacol 2016. [DOI: 10.12793/tcp.2016.24.3.137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Jangsoo Yoon
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea
| | - Seol Ju Moon
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea
| | | | - Seo Hyun Yoon
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea
| | - In-Jin Jang
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea
| | - Kyung-Sang Yu
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea
| | - SeungHwan Lee
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea
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3
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Ripcke J, Zarse K, Ristow M, Birringer M. Small-Molecule Targeting of the Mitochondrial Compartment with an Endogenously Cleaved Reversible Tag. Chembiochem 2009; 10:1689-96. [DOI: 10.1002/cbic.200900159] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Ambrus A, Tretter L, Adam-Vizi V. Inhibition of the alpha-ketoglutarate dehydrogenase-mediated reactive oxygen species generation by lipoic acid. J Neurochem 2009; 109 Suppl 1:222-9. [PMID: 19393031 DOI: 10.1111/j.1471-4159.2009.05942.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Dihydrolipoamide dehydrogenase (LADH) is a flavo-enzyme that serves as a subunit of alpha-ketoglutarate dehydrogenase complex (alpha-KGDHC). Reactive oxygen species (ROS) generation by alpha-KGDHC has been assigned to LADH (E3 subunit) and explained by the diaphorase activity of E3. Dysfunctions of alpha-KGDHC and concurrent ROS production have been implicated in neurodegeneration, ischemia-reperfusion, and other pathological conditions. In this work we investigated the in-depth details of ROS generation by isolated LADH and alpha-KGDHC. We found a parallel generation of superoxide and hydrogen peroxide by the E3 subunit of alpha-KGDHC which could be blocked by lipoic acid (LA) acting on a site upstream of the E3 subunit. The pathologically relevant ROS generation (at high NADH/NAD+ ratio and low pH) in the reverse mode of alpha-KGDHC could also be inhibited by LA. Our results contradict the previously proposed mechanism for pH-dependent ROS generation by LADH, showing no disassembling of the E3 functional homodimer at acidic pH using a physiologically relevant method for the examination. It is also suggested that LA could be beneficial in reducing the cell damage related to excessive ROS generation under pathological conditions.
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Affiliation(s)
- Attila Ambrus
- Department of Medical Biochemistry, Neurobiochemical Research Group, Hungarian Academy of Sciences and Szentagothai Janos Knowledge Center, Semmelweis University, Budapest, Hungary
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Ronowska A, Gul-Hinc S, Bielarczyk H, Pawełczyk T, Szutowicz A. Effects of zinc on SN56 cholinergic neuroblastoma cells. J Neurochem 2007; 103:972-83. [PMID: 17662047 DOI: 10.1111/j.1471-4159.2007.04786.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Zinc is a trace element necessary for proper development and function of brain cells. However, excessive accumulation of zinc exerts several cytotoxic effects in the brain. The aim of this work was to see whether cytotoxic effects of zinc are quantitatively correlated with changes in acetyl-CoA metabolism. The zinc levels up to 0.20 mmol/L caused concentration-dependent inhibition of pyruvate dehydrogenase (PDH) activity that correlated with the increase in trypan blue-positive fraction and the decrease in cultured cell number (r = 0.96, p = 0.0001). Chronic exposure of cells to 0.15 mmol/L zinc decreased choline acetyltransferase and aconitase activities, cytoplasmic acetyl-CoA and whole cell ATP level by 38%, 57%, 35%, and 62%, respectively but caused no change in mitochondrial acetyl-CoA level and activities of other enzymes of glycolytic and tricarboxylic acid cycle. dl-alpha-lipoamide when added simultaneously with zinc to cultured cells or their homogenates attenuated its chronic or acute suppressive effects. In homogenates of chronically Zn-treated cells, lipoamide overcame PDH but not aconitase inhibition. Presented data indicate that acute-transient elevation of zinc caused reversible inhibition of PDH, aconitase activities and acetyl-CoA metabolism, which when prolonged could lead to irreversible enzyme inactivation yielding decrease in cell viability and secondary suppression of their cholinergic phenotype.
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Affiliation(s)
- Anna Ronowska
- Department of Laboratory Medicine, Medical University of Gdańsk, Poland
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6
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Bielarczyk H, Gul S, Ronowska A, Bizon-Zygmanska D, Pawelczyk T, Szutowicz A. RS-alpha-lipoic acid protects cholinergic cells against sodium nitroprusside and amyloid-beta neurotoxicity through restoration of acetyl-CoA level. J Neurochem 2006; 98:1242-51. [PMID: 16787407 DOI: 10.1111/j.1471-4159.2006.03966.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The work presented here verifies the hypothesis that RS-alpha-lipoic acid may exert its cholinoprotective and cholinotrophic activities through the maintenance of appropriate levels of acetyl-CoA in mitochondrial and cytoplasmic compartments of cholinergic neurons. Sodium nitroprusside (SNP) and amyloid-beta decreased pyruvate dehydrogenase, choline acetyltransferase activities, acetyl-CoA content in mitochondria and cytoplasm, as well as increased fraction of non-viable, trypan blue positive cells in cultured differentiated cholinergic SN56 neuroblastoma cells. Lipoic acid totally reversed toxin-evoked suppression of choline acetyltrasferase and pyruvate dehydrogenase activities, as well as mitochondrial and cytoplasmic acetyl-CoA levels, and partially attenuated increase of cell mortality. Significant negative correlations were found between enzyme activities, acetyl-CoA levels and cell mortality in different neurotoxic and neuroprotective conditions employed here. The level of cytoplamic acetyl-CoA correlated with mitochondrial acetyl-CoA, whereas choline acetyltransferase activity followed shifts in cytoplasmic acetyl-CoA. Thus, we conclude that, in cholinergic neurons, particular elements of the pyruvate-acetyl-CoA-acetylcholine pathway form a functional unit responding uniformly to nerotoxic and neuroprotectory conditions.
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Affiliation(s)
- Hanna Bielarczyk
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
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7
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Sheline CT, Wei L. Free radical-mediated neurotoxicity may be caused by inhibition of mitochondrial dehydrogenases in vitro and in vivo. Neuroscience 2006; 140:235-46. [PMID: 16563643 DOI: 10.1016/j.neuroscience.2006.02.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 02/03/2006] [Accepted: 02/08/2006] [Indexed: 11/28/2022]
Abstract
We previously demonstrated that copper facilitated the formation of reactive oxygen species, and inhibited pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in vitro and in animal models of Wilson's disease in vivo. However, direct Cu(2+) toxicity has only been demonstrated for Wilson's disease. We now hypothesize that inhibition of these mitochondrial dehydrogenases might also contribute to many other injuries and disorders that are reactive oxygen species-mediated. We have modeled reactive oxygen species-mediated injuries using inducers of reactive oxygen species such as hydrogen peroxide, ethacrynic acid or menadione, or another redox active metal (Cd(2+)). Here we demonstrated that these toxic exposures were accompanied by an early marked reduction in both pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase activities, followed by a decrease in neuronal mitochondrial transmembrane potential and ATP, prior to murine cortical neuronal death. Thiamine (6 mM), and dihydrolipoic acid (50 microM), required cofactors for pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase (thiamine as thiamine pyrophosphate), attenuated the reactive oxygen species-induced reductions in these enzyme activities, as well as subsequent loss of mitochondrial transmembrane potential and ATP, and neuronal death. We next tested the effect of thiamine supplementation on an in vivo model of reactive oxygen species-mediated injury, transient middle cerebral artery occlusion, and reperfusion in rats. Oral or i.p. thiamine administration reduced the middle cerebral artery occlusion-induced infarct. These data suggest that reactive oxygen species-induced neuronal death may be caused in part by reactive oxygen species-mediated inhibition of pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in vitro and in vivo, and that thiamine or dihydrolipoic acid may constitute potential therapeutic agents not just against Cu(2+) neurotoxicity, but may reduce neuronal degeneration in the broader range of diseases mediated by free radical stress.
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Affiliation(s)
- C T Sheline
- Department of Neurology and Center for the Study of Nervous System Injury, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Morera E, Nalli M, Mollica A, Paglialunga Paradisi M, Aschi M, Gavuzzo E, Mazza F, Lucente G. Peptides containing 4-amino-1,2-dithiolane-4-carboxylic acid (Adt): conformation of Boc-Adt-Adt-NHMe and NH...S interactions. J Pept Sci 2005; 11:104-12. [PMID: 15635640 DOI: 10.1002/psc.602] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To study the conformational preferences induced by the insertion of the 4-amino-1,2-dithiolane-4-carboxylic acid (Adt) residue into a peptide backbone, the achiral N-protected dipeptide methylamide Boc-Adt-Adt-NHMe (1) was synthesized and its crystal state and solution conformation studied and compared with that exhibited by its carba-analogue Boc-Ac5c-Ac5c-NHMe containing two residues of 1-aminocyclopentane-1-carboxylic acid (Ac5c). Compound 1 in the crystal adopts a type-III beta-turn conformation and an analogous structure is that preferred in chloroform solution as established by 1H-NMR and NOE information. In the crystal packing three different Adt rings form a cavity and the involved sulphur atoms give rise to unusual multiple interactions with one NH group. The chemical nature of these intermolecular and intramolecular main-chain...side-chain NH...S interactions are discussed in terms of quantum chemical calculations.
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Affiliation(s)
- Enrico Morera
- Dipartimento di Studi Farmaceutici, Università di Roma La Sapienza and Istituto di Chimica Biomolecolare, Sezione di Roma, CNR, 00185 Roma, Italy
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9
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Hill AS, Werner JA, Rogers QR, O'Neill SL, Christopher MM. Lipoic acid is 10 times more toxic in cats than reported in humans, dogs or rats. J Anim Physiol Anim Nutr (Berl) 2004; 88:150-6. [PMID: 15059240 DOI: 10.1111/j.1439-0396.2003.00472.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The antioxidant lipoic acid (LA) is administered to humans and pets. We described acute toxicity and maximum tolerated dose (MTD) of LA in cats. In progression, 10 healthy adult male cats received orally 60 (high), 30 (low), or 0 mg LA/kg (control). Serum enzyme activities and concentrations of bile acids, ammonia, amino acids (AA), LA and dihydrolipoic acid (DHLA) were measured, and tissues examined microscopically. Significant clinical toxicity with changes in ammonia and AA concentrations occurred in all high-dose cats. Oral LA produced hepatocellular toxicity and MTD was < 30 mg/kg in cats.
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Affiliation(s)
- A S Hill
- Department of Molecular Biosciences Clinical Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA.
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Walgren JL, Amani Z, McMillan JM, Locher M, Buse MG. Effect of R(+)alpha-lipoic acid on pyruvate metabolism and fatty acid oxidation in rat hepatocytes. Metabolism 2004; 53:165-73. [PMID: 14767867 DOI: 10.1016/j.metabol.2003.09.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
R-(+)-alpha-lipoic acid (R-LA) is the naturally occurring enantiomer of LA. It is a strong antioxidant and cofactor of key metabolic enzyme complexes catalyzing the decarboxylation of alpha-keto acids. Racemic LA (rac-LA) has shown promise in treating diabetic polyneuropathy, and some studies suggest that it improves glucose homeostasis in patients with type 2 diabetes. We examined the effects of R-LA on pyruvate metabolism and free fatty acid (FFA) oxidation in primary cultured hepatocytes isolated from 24-hour fasted rats. After overnight culture in serum-free medium, cells were pre-exposed to R-LA for 3 hours before assays. R-LA (25 to 200 micromol/L) significantly increased pyruvate oxidation ( approximately 2-fold at the highest dose tested) measured as (14)CO(2) production from [1-(14)C]pyruvate by the cells over 1 hour post-treatment. These effects correlated with proportional, significant increases in the activation state of the pyruvate dehydrogenase (PDH) complex. R-LA treatment inhibited glucose production from pyruvate by approximately 50% at 50 micromol/L R-LA and approximately 90% at 200 micromol/L. Palmitate oxidation was measured in hepatocytes cultured in the presence of albumin and physiological (0.1 mmol/L) or high (1.5 mmol/L) concentrations of FFA. The latter markedly enhanced FFA oxidation. R-LA treatment significantly inhibited FFA oxidation in both media, but was more effective in high FFA, where it reduced FFA oxidation by 48% to 82% at 25 to 200 micromol/L, respectively. Identical doses of R-LA did not affect FFA oxidation by L6 myotubes (a cell culture model for skeletal muscle) in either high or low FFA medium, but enhanced pyruvate oxidation. In conclusion, 3-hour exposure of primary cultured rat hepatocytes to R-LA at therapeutically relevant concentrations increased pyruvate oxidation, apparently by activation of the PDH complex, and decreased gluconeogenesis and FFA oxidation. These features may prove useful in the control of type 2 diabetes.
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Affiliation(s)
- Jennie L Walgren
- Department of Pharmacology, Medical University of South Carolina, Charleston, SC, USA
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11
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Sheline CT, Choi DW. Cu2+ toxicity inhibition of mitochondrial dehydrogenases in vitro and in vivo. Ann Neurol 2004; 55:645-53. [PMID: 15122704 DOI: 10.1002/ana.20047] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Wilson's disease results from mutations in the P-type Cu(2+)-ATPase causing Cu(2+) toxicity. We previously demonstrated that exposure of mixed neuronal/glial cultures to 20 microM Cu(2+) induced ATP loss and death that were attenuated by mitochondrial substrates, activators, and cofactors. Here, we show differential cellular sensitivity to Cu(2+) that was equalized to 5 microM in the presence of the copper exchanger/ionophore, disulfiram. Because Cu(2+) facilitates formation of oxygen radicals (ROS) which inhibit pyruvate dehydrogenase (PDH) and alpha-ketoglutarate dehydrogenase (KGDH), we hypothesized that their inhibition contributed to Cu(2+)-induced death. Toxic CU(2+) exposure was accompanied by early inhibition of neuronal and hepatocellular PDH and KGDH activities, followed by reduced mitochondrial transmembrane potential, DeltaPsi(M). Thiamine (1-6 mM), and dihydrolipoic acid (LA, 50 microM), required cofactors for PDH and KGDH, attenuated this enzymatic inhibition and subsequent death in all cell types. Furthermore, liver PDH and KGDH activities were reduced in the Atp7b mouse model of Wilson's disease prior to liver damage, and were partially restored by oral thiamine supplementation. These data support our hypothesis that Cu(2+)-induced ROS may inhibit PDH and KGDH resulting in neuronal and hepatocellular death. Therefore, thiamine or lipoic acid may constitute potential therapeutic agents for Wilson's disease.
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Affiliation(s)
- Christian T Sheline
- Department of Neurology and Center for the Study of Nervous System Injury Washington University School of Medicine, St. Louis, MO 63110, USA.
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Sheline CT, Choi EH, Kim-Han JS, Dugan LL, Choi DW. Cofactors of mitochondrial enzymes attenuate copper-induced death in vitro and in vivo. Ann Neurol 2002; 52:195-204. [PMID: 12210790 DOI: 10.1002/ana.10276] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Copper toxicity contributes to neuronal death in Wilson's disease and has been speculatively linked to the pathogenesis of Alzheimer's and prion diseases. We examined copper-induced neuronal death with the goal of developing neuroprotective strategies. Copper catalyzed an increase in hydroxyl radical generation in solution, and the addition of 20 microM copper for 22 hours to murine neocortical cell cultures induced a decrease in ATP levels and neuronal death without glial death. This selective neuronal death was associated with activation of caspase-3 and was reduced by free radical scavengers and Z-Val-Ala-Asp fluoromethylketone, consistent with free radical-mediated injury leading to apoptosis. Pyruvate dehydrogenase is especially vulnerable to inhibition by oxygen free radicals, and the upstream metabolites, pyruvate, phosphoenolpyruvate, and 2-phosphoglycerate were elevated in cortical cells after toxic exposure to copper. One approach to protecting pyruvate dehydrogenase from oxidative attack might be to enhance binding to cofactors. Addition of thiamine, dihydrolipoic acid, or pyruvate reduced copper-induced neuronal death. To test efficacy in vivo, we added 1% thiamine to the drinking water of Long Evans Cinnamon rats, an animal model of Wilson's disease. This thiamine therapy markedly extended life span from 6.0 +/- 1.6 months to greater than 16 months.
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Affiliation(s)
- Christian T Sheline
- Center for the Study of Nervous System Injury and Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Madar Z, Stark AH, Ilan E, Timar B, Borenshtein D. Alpha-Lipoic Acid Inhibits Glycogen Synthesis and Modifies Glucose Metabolism and Signaling Pathways in Soleus Muscles from Healthy Rats. Prev Nutr Food Sci 2002. [DOI: 10.3746/jfn.2002.7.2.113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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14
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Abstract
In a previous article we present results that demonstrated that the enzyme, choline acetyl transferase, was strongly activated by dihydrolipoic acid and that the oxidized form of this substance, lipoic acid itself, was an inhibitor of the enzyme and overcame the stimulatory effects of reduced lipoic acid. The experiments presented in this article show that dialysis of a partially purified preparation of choline acetyl transferase causes complete disappearance of enzyme activity and that addition of dihydrolipoic acid restores activity towards normal. In addition we present experiments with extracts of rat brain and heart as well as rabbit bladder tissue. In these extracts dihydrolipoic acid strongly activates the enzyme. Dialysis of brain and heart extracts causes loss of activity with partial restoration of activity by addition of dihydrolipoic acid. Reduced glutathione has no ability to stimulate activity of the enzyme. We conclude that the results of these experiments strongly support the view that dihydrolipoic acid acts as a coenzyme in the choline acetyl transferase reaction.
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Affiliation(s)
- Niels Haugaard
- Division of Urology, School of Medicine, University of Pennsylvania, Philadelphia 19104-4283, USA
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Packer L, Kraemer K, Rimbach G. Molecular aspects of lipoic acid in the prevention of diabetes complications. Nutrition 2001; 17:888-95. [PMID: 11684397 DOI: 10.1016/s0899-9007(01)00658-x] [Citation(s) in RCA: 335] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alpha-lipoic acid (LA) and its reduced form, dihydrolipoic acid, are powerful antioxidants. LA scavenges hydroxyl radicals, hypochlorous acid, peroxynitrite, and singlet oxygen. Dihydrolipoic acid also scavenges superoxide and peroxyl radicals and can regenerate thioredoxin, vitamin C, and glutathione, which in turn can recycle vitamin E. There are several possible sources of oxidative stress in diabetes including glycation reactions, decompartmentalization of transition metals, and a shift in the reduced-oxygen status of the diabetic cells. Diabetics have increased levels of lipid hydroperoxides, DNA adducts, and protein carbonyls. Available data strongly suggest that LA, because of its antioxidant properties, is particularly suited to the prevention and/or treatment of diabetic complications that arise from an overproduction of reactive oxygen and nitrogen species. In addition to its antioxidant properties, LA increases glucose uptake through recruitment of the glucose transporter-4 to plasma membranes, a mechanism that is shared with insulin-stimulated glucose uptake. Further, recent trials have demonstrated that LA improves glucose disposal in patients with type II diabetes. In experimental and clinical studies, LA markedly reduced the symptoms of diabetic pathologies, including cataract formation, vascular damage, and polyneuropathy. To develop a better understanding of the preventative and therapeutic potentials of LA, much of the current interest is focused on elucidating its molecular mechanisms in redox dependent gene expression.
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Affiliation(s)
- L Packer
- Department of Molecular Pharmacology and Toxicology, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90098-9121, USA.
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Mugesh G, du Mont WW, Sies H. Chemistry of biologically important synthetic organoselenium compounds. Chem Rev 2001; 101:2125-79. [PMID: 11710243 DOI: 10.1021/cr000426w] [Citation(s) in RCA: 1230] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- G Mugesh
- Institut für Anorganische und Analytische Chemie, Technischen Universität, Postfach 3329, D-38023 Braunschweig, Germany
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Liang JF, Akaike T. Inhibition of nitric oxide synthesis in primary cultured mouse hepatocytes by alpha-lipoic acid. Chem Biol Interact 2000; 124:53-60. [PMID: 10658901 DOI: 10.1016/s0009-2797(99)00146-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent work shows that septic or endotoxic shock is associated with lipopolysaccharide and cytokine mixture-induced nitric oxide (NO) synthesis in liver. Here we found that DL-alpha-lipoic acid inhibited but other thiol-containing antioxidants such as glutathione and N-acetylcysteine enhanced lipopolysaccharide and cytokine mixture (referred as LPS/CM)-induced NO synthesis in hepatocytes. The inhibitory action of alpha-lipoic acid on hepatocyte NO synthesis was as potent as that of NG-monomethyl-L-arginine without obvious cytotoxicity. Deletion by diethylmaleate or inhibition by buthionine sulfoximine of intracellular glutathione caused a significant decrease in hepatocyte NO synthesis, implying that increased intracellular reduced glutathione levels could not be the reason for alpha-lipoic acid inhibited NO synthesis. alpha-Lipoic acid inhibition of NO synthesis seems to be from alpha-lipoic acid improved carbohydrate metabolism in hepatocytes. Since alpha-lipoic acid is an essential compound existing naturally in physiological systems, it may serve as both a research and therapeutic agent for sepsis.
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Affiliation(s)
- J F Liang
- Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan.
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