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Ma C, Li H, Lu S, Li X. The Role and Therapeutic Potential of Melatonin in Degenerative Fundus Diseases: Diabetes Retinopathy and Age-Related Macular Degeneration. Drug Des Devel Ther 2024; 18:2329-2346. [PMID: 38911030 PMCID: PMC11193467 DOI: 10.2147/dddt.s471525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Accepted: 06/13/2024] [Indexed: 06/25/2024] Open
Abstract
Degenerative fundus disease encompasses a spectrum of ocular diseases, including diabetic retinopathy (DR) and age-related macular degeneration (AMD), which are major contributors to visual impairment and blindness worldwide. The development and implementation of effective strategies for managing and preventing the onset and progression of these diseases are crucial for preserving patients' visual acuity. Melatonin, a neurohormone primarily produced by the pineal gland, exhibits properties such as circadian rhythm modulation, antioxidant activity, anti-inflammatory effects, and neuroprotection within the ocular environment. Furthermore, melatonin has been shown to suppress neovascularization and reduce vascular leakage, both of which are critical in the pathogenesis of degenerative fundus lesions. Consequently, melatonin emerges as a promising therapeutic candidate for degenerative ocular diseases. This review provides a comprehensive overview of melatonin synthesis, its localization within ocular tissues, and its mechanisms of action, particularly in regulating melatonin production, thereby underscoring its potential as a therapeutic agent for degenerative fundus diseases.
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Affiliation(s)
- Chao Ma
- Department of Ophthalmology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, People’s Republic of China
| | - Haoyu Li
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China
- Hunan Clinical Research Centre of Ophthalmic Disease, Changsha, Hunan, People’s Republic of China
| | - Shuwen Lu
- Department of Ophthalmology, the First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, Henan, People’s Republic of China
| | - Xian Li
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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Gubin D, Neroev V, Malishevskaya T, Cornelissen G, Astakhov SY, Kolomeichuk S, Yuzhakova N, Kabitskaya Y, Weinert D. Melatonin mitigates disrupted circadian rhythms, lowers intraocular pressure, and improves retinal ganglion cells function in glaucoma. J Pineal Res 2021; 70:e12730. [PMID: 33730443 DOI: 10.1111/jpi.12730] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 02/06/2023]
Abstract
Glaucoma is a progressive optic neuropathy associated with damage to retinal ganglion cells (RGCs) and disrupted circadian rhythms. Melatonin is a promising substance to ameliorate glaucoma-associated compromised circadian rhythms, sleep, mood, and retinal cells function. However, studies estimating melatonin effects in glaucoma are currently lacking. Therefore, In this study, we investigated the effect of long-term (daily at 10:30 pm for 90 days) oral melatonin administration on systemic (Tb) and local to the organ of vision (IOP) circadian rhythms, pattern electroretinogram (PERG), sleep, and mood, depending on glaucoma stage in patients diagnosed with stable or advanced primary open-angle glaucoma. In a laboratory study in 15 of them, 24-hour records of salivary melatonin were obtained and MTNR1B receptor gene polymorphism was assessed. Melatonin increased the stability of the Tb circadian rhythm by improving its phase alignment and alignment with IOP. Melatonin time-dependently decreased IOP and IOP standard deviation (SD). IOP 24-hour mean and IOP SD decreases were more pronounced in individuals with the higher initial 24-hour IOP mean. Melatonin improved RGCs function in advanced glaucoma; N95 amplitude increase correlated positively with RGCs loss. The beneficial effects of melatonin on sleep and mood were greater in advanced glaucoma. Finally, delayed salivary melatonin and Tb phases were observed in MTNR1B G-allele carriers with advanced glaucoma. Combined, these results provide evidence for melatonin efficiency in restoring disrupted circadian rhythms in glaucoma with different effects of melatonin on systemic vs. local circadian rhythms, indicating that a personalized strategy of melatonin administration may further refine its treatment benefits.
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Affiliation(s)
- Denis Gubin
- Department of Biology, Medical University, Tyumen, Russia
- Tyumen Cardiology Research Center, Tomsk National Research Medical Center, Russian Academy of Science, Tomsk, Russia
| | - Vladimir Neroev
- Helmholtz Moscow Research Institute of Eye Diseases, Moscow, Russia
| | | | - Germaine Cornelissen
- Department of Integrated Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Sergei Y Astakhov
- Pavlov First Saint Petersburg State Medical University, St. Petersburg, Russia
| | - Sergey Kolomeichuk
- Laboratory of Genetics, Institute of Biology of the Karelian Science Center of the Russian Academy of Sciences, Petrozavodsk, Russia
| | | | - Yana Kabitskaya
- Center for Genomic Technologies, Northern Trans-Ural State Agricultural University, Tyumen, Russia
| | - Dietmar Weinert
- Institute of Biology/Zoology, Martin Luther University, Halle-Wittenberg, Germany
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Scuderi L, Davinelli S, Iodice CM, Bartollino S, Scapagnini G, Costagliola C, Scuderi G. Melatonin: Implications for Ocular Disease and Therapeutic Potential. Curr Pharm Des 2020; 25:4185-4191. [PMID: 31724508 DOI: 10.2174/1381612825666191113110225] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/12/2019] [Indexed: 02/08/2023]
Abstract
Melatonin, an indoleamine secreted mainly by the pineal gland, is known to modulate a wide range of circadian functions. However, this neurohormone is also synthesized within the eye and acts directly on ocular structures to mediate a variety of physiological processes. This review is focused on the role and therapeutic potential of melatonin in ocular diseases. We summarize data indicating that melatonin may represent a powerful tool to counteract ocular dysfunctions such as uveitis, glaucoma, age-related macular degeneration, and diabetic retinopathy. A search strategy was conducted to identify studies in PubMed (January 1990 to September 2017). In particular, we included experimental studies, clinical trials, and reviews to provide suitable insights and elucidations regarding the action of melatonin on age-related ocular disorders. Literature data suggest that melatonin could potentially protect ocular tissues by decreasing the production of free radicals and pro-inflammatory mediators. Additionally, melatonin appears to be safe and well-tolerated, even at high doses, and no adverse/side effects were reported. Although this topic remains under intense investigation, we can conclude that melatonin, as a single agent or in combination with other drugs, is an attractive pharmacological candidate for age-related ocular diseases.
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Affiliation(s)
- Luca Scuderi
- Neuroscience, Mental Health and Sense Organs Department, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Rome, Italy
| | - Sergio Davinelli
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Clemente Maria Iodice
- Neuroscience, Mental Health and Sense Organs Department, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Rome, Italy
| | - Silvia Bartollino
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Giovanni Scapagnini
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Ciro Costagliola
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Gianluca Scuderi
- Neuroscience, Mental Health and Sense Organs Department, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Rome, Italy
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Alkozi HA, Navarro G, Aguinaga D, Reyes-Resina I, Sanchez-Naves J, Pérez de Lara MJ, Franco R, Pintor J. Adreno-melatonin receptor complexes control ion homeostasis and intraocular pressure - their disruption contributes to hypertensive glaucoma. Br J Pharmacol 2020; 177:2090-2105. [PMID: 31901203 DOI: 10.1111/bph.14971] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Often, glaucoma presents with elevated eye hydrostatic pressure, which is regulated by endogenous melatonin. Phenylephrine increases cytoplasmic [Ca2+ ], via α1 -adrenoceptor activation, that is detrimental in glaucoma. The aims of this study were (a) to elucidate the role of melatonin receptors in humour production and intraocular pressure (IOP) maintenance and (b) to identify glaucoma-relevant melatonin-adrenoceptor interactions. EXPERIMENTAL APPROACH Biophysical and proximity ligation assays were performed to identify interactions in heterologous expression systems, in cell lines and in human eyes. Gs /Gi /Gq signalling was investigated in these systems and in cells producing aqueous humour. IOP was determined in a mice model of glaucoma. Retinography and topically pharmacological treatment were performed in control and in glaucomatous mice. KEY RESULTS α1 -adreno- and melatonin receptors form functional complexes in which the C-terminal tail of the adrenoceptor plays a role. Remarkably, activation of α1 -adrenoceptors in these complexes did not lead to cytosolic Ca2+ increases, suggesting Gs instead of Gq coupling is involved. The number of these complexes significantly decreased in models of glaucoma and, importantly, in human samples from glaucoma patients. This has led to hypothesize that melatonin, a hypotensive agent, plus blockade of α1 -adrenoceptors could normalize pressure in glaucoma. Remarkably, co-instillation of melatonin and prazosin, an α1 -adrenoceptor antagonist, resulted in long-term decreases in IOP in a well-established animal model of glaucoma. CONCLUSIONS AND IMPLICATIONS The findings are instrumental to understand the physiological function of melatonin in the eye and its potential to address eye pathologies by targeting melatonin receptors and their complexes.
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Affiliation(s)
- Hanan Awad Alkozi
- Department of Biochemistry and Molecular Biology, Faculty of Optics and Optometry, University Complutense of Madrid, Madrid, Spain
| | - Gemma Navarro
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - David Aguinaga
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department of Biochemistry and Molecular Biomedicine, School of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Irene Reyes-Resina
- Department of Biochemistry and Molecular Biomedicine, School of Biology, Universitat de Barcelona, Barcelona, Spain.,Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Juan Sanchez-Naves
- Department of Ophthalmology, Balearic Islands Institute of Ophthalmology, Palma de Mallorca, Spain
| | - Maria J Pérez de Lara
- Department of Biochemistry and Molecular Biology, Faculty of Optics and Optometry, University Complutense of Madrid, Madrid, Spain
| | - Rafael Franco
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department of Biochemistry and Molecular Biomedicine, School of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Jesus Pintor
- Department of Biochemistry and Molecular Biology, Faculty of Optics and Optometry, University Complutense of Madrid, Madrid, Spain
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Tian T, Wang Z, Zhang J. Pathomechanisms of Oxidative Stress in Inflammatory Bowel Disease and Potential Antioxidant Therapies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4535194. [PMID: 28744337 PMCID: PMC5506473 DOI: 10.1155/2017/4535194] [Citation(s) in RCA: 355] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 05/22/2017] [Accepted: 05/31/2017] [Indexed: 12/22/2022]
Abstract
Inflammatory bowel disease (IBD) is a chronic gastrointestinal disease whose incidence has risen worldwide in recent years. Accumulating evidence shows that oxidative stress plays an essential role in the pathogenesis and progression of IBD. This review highlights the generation of reactive oxygen species (ROS) and antioxidant defense mechanisms in the gastrointestinal (GI) tract, the involvement of oxidative stress signaling in the initiation and progression of IBD and its relationships with genetic susceptibility and the mucosal immune response. In addition, potential therapeutic strategies for IBD that target oxidative stress signaling are reviewed and discussed. Though substantial progress has been made in understanding the role of oxidative stress in IBD in humans and experimental animals, the underlying mechanisms are still not well defined. Thus, further studies are needed to validate how oxidative stress signaling is involved in and contributes to the development of IBD.
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Affiliation(s)
- Tian Tian
- College of Life Science and Bioengineering, Beijing Jiaotong University, Beijing 100044, China
| | - Ziling Wang
- College of Life Science and Bioengineering, Beijing Jiaotong University, Beijing 100044, China
| | - Jinhua Zhang
- College of Life Science and Bioengineering, Beijing Jiaotong University, Beijing 100044, China
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Aranda ML, Fleitas MFG, Dieguez H, Iaquinandi A, Sande PH, Dorfman D, Rosenstein RE. Melatonin as a Therapeutic Resource for Inflammatory Visual Diseases. Curr Neuropharmacol 2017; 15:951-962. [PMID: 28088912 PMCID: PMC5652015 DOI: 10.2174/1570159x15666170113122120] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/15/2016] [Accepted: 01/06/2017] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Uveitis and optic neuritis are prevalent ocular inflammatory diseases, and highly damaging ocular conditions. Both diseases are currently treated with corticosteroids, but they do not have adequate efficacy and are often associated with severe side effects. Thus, uveitis and optic neuritis remain a challenging field to ophthalmologists and a significant public health concern. OBJECTIVE This review summarizes findings showing the benefits of a treatment with melatonin in experimental models of these inflammatory ocular diseases. RESULTS Oxidative and nitrosative damage, tumor necrosis factor, and prostaglandin production have been involved in the pathogeny of uveitis and optic neuritis. Melatonin is an efficient antioxidant and antinitridergic, and has the ability to reduce prostaglandin and tumor necrosis factor levels both in the retina and optic nerve. Moreover, melatonin not only prevents functional and structural consequences of experimental uveitis and optic neuritis, but it is also capable of suppressing the actively ongoing ocular inflammatory response. CONCLUSIONS Since melatonin protects ocular tissues against inflammation, it could be a potentially useful anti-inflammatory therapy in ophthalmology.
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Affiliation(s)
- Marcos L. Aranda
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - María Florencia González Fleitas
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Hernán Dieguez
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Agustina Iaquinandi
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Pablo H. Sande
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | | | - Ruth E. Rosenstein
- Address correspondence to this author at the Department of Human Biochemistry, School of Medicine, CEFyBO, University of Buenos Aires, CONICET, Paraguay 2155, 5th Floor, (1121), Buenos Aires, Argentina;, Tel: 54-11-45083672 (ext 37); Fax: 54-11-45083672 (ext 317);, E-mail:
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Mazzone G, Galano A, Alvarez-Idaboy JR, Russo N. Coumarin-Chalcone Hybrids as Peroxyl Radical Scavengers: Kinetics and Mechanisms. J Chem Inf Model 2016; 56:662-70. [PMID: 26998844 DOI: 10.1021/acs.jcim.6b00006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The primary antioxidant activity of coumarin-chalcone hybrids has been investigated using the density functional and the conventional transition state theories. Their peroxyl radical scavenging ability was studied in solvents of different polarity and taking into account different reaction mechanisms. It was found that the activity of the hybrids increases with the polarity of the environment and the number of phenolic sites. In addition, their peroxyl radical scavenging activity is larger than those of the corresponding nonhybrid coumarin and chalcone molecules. This finding is in line with previous experimental evidence. All the investigated molecules were found to react faster than Trolox with (•)OOH, regardless of the polarity of the environment. The role of deprotonation on the overall activity of the studied compounds was assessed. The rate constants and branching ratios for the reactions of all the studied compounds with (•)OOH are reported for the first time.
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Affiliation(s)
- Gloria Mazzone
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria , I-87036 Arcavacata di Rende, Italy
| | - Annia Galano
- Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa , San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, C. P. 09340 México, D. F. México
| | - Juan R Alvarez-Idaboy
- Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México , México DF 04510, México
| | - Nino Russo
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria , I-87036 Arcavacata di Rende, Italy
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Shen L, Walter S, Melles RB, Glymour MM, Jorgenson E. Diabetes Pathology and Risk of Primary Open-Angle Glaucoma: Evaluating Causal Mechanisms by Using Genetic Information. Am J Epidemiol 2016; 183:147-55. [PMID: 26608880 DOI: 10.1093/aje/kwv204] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/29/2015] [Indexed: 12/13/2022] Open
Abstract
Although type 2 diabetes (T2D) predicts glaucoma, the potential for unmeasured confounding has hampered causal conclusions. We performed separate sample genetic instrumental variable analyses using the Genetic Epidemiology Research Study on Adult Health and Aging cohort (n = 69,685; 1995-2013) to estimate effects of T2D on primary open-angle glaucoma (POAG; 3,554 cases). Genetic instrumental variables for overall and mechanism-specific (i.e., linked to T2D via influences on adiposity, β-cell function, insulin regulation, or other metabolic processes) T2D risk were constructed by using 39 genetic polymorphisms established to predict T2D in other samples. Instrumental variable estimates indicated that T2D increased POAG risk (odds ratio = 2.53, 95% confidence interval: 1.04, 6.11). The instrumental variable for β-cell dysregulation also significantly predicted POAG (odds ratioβ-cell = 5.26, 95% confidence interval: 1.75, 15.85), even among individuals without diagnosed T2D, suggesting that metabolic dysregulation may increase POAG risk prior to T2D diagnosis. The T2D risk variant in the melatonin receptor 1B gene (MTNR1B) predicted risk of POAG independently of T2D status, indicating possible pleiotropic physiological functions of melatonin, but instrumental variable effect estimates were significant even excluding MTNR1B variants. To our knowledge, this is the first genetic instrumental variable study of T2D and glaucoma, providing a novel approach to evaluating this hypothesized relationship. Our findings substantially bolster observational evidence that T2D increases POAG risk.
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Sande PH, Dorfman D, Fernandez DC, Chianelli M, Domínguez Rubio AP, Franchi AM, Silberman DM, Rosenstein RE, Sáenz DA. Treatment with melatonin after onset of experimental uveitis attenuates ocular inflammation. Br J Pharmacol 2015; 171:5696-707. [PMID: 25131343 DOI: 10.1111/bph.12873] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 06/26/2014] [Accepted: 07/28/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Uveitis is a prevalent intraocular inflammatory disease and one of the most damaging ocular conditions. Pretreatment with melatonin prevented ocular inflammation induced by an intravitreal injection of bacterial LPS in the Syrian hamster. Here, we have assessed the anti-inflammatory effects of melatonin administered after the onset of ocular inflammation. EXPERIMENTAL APPROACH The eyes of male Syrian hamsters were intravitreally injected with vehicle or LPS. Melatonin was injected i.p. every 24 h, starting 12 or 24 h after the LPS injection. A clinical evaluation (with a score index based on clinical symptoms), the number of infiltrating cells, protein concentration and PGE2 and PGF2α levels in the aqueous humour, as well as retinal NOS activity, lipid peroxidation and TNF-α levels were assessed. Retinal function was assessed by scotopic electroretinography, and light microscopy and immunohistochemistry were used to evaluate the state of the retinal structure. KEY RESULTS Both treatment regimens with melatonin decreased clinical symptoms, reduced the leakage of cells and proteins, and decreased PG levels in aqueous humour from eyes injected with LPS. In addition, melatonin treatment blocked the decrease in scotopic electroretinogram a- and b-wave amplitude, protected the retinal structure and reduced the increase in NOS activity, lipid peroxidation and TNF-α levels, induced by LPS. CONCLUSIONS AND IMPLICATIONS These results indicate that treatment with melatonin, starting after the onset of uveitis, attenuated ocular inflammation induced by LPS in the Syrian hamster and support the use of melatonin as a therapeutic resource for uveitis treatment.
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Affiliation(s)
- P H Sande
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
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Dortch-Carnes J, Tosini G. Melatonin receptor agonist-induced reduction of SNP-released nitric oxide and cGMP production in isolated human non-pigmented ciliary epithelial cells. Exp Eye Res 2012. [PMID: 23201027 DOI: 10.1016/j.exer.2012.11.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present study was designed to determine the effects of melatonin and its receptor agonists on SNP-released nitric oxide (NO) and cGMP production in aqueous humor producing cells of the ciliary body because these effects may play a role in melatonin receptor-mediated regulation of intraocular pressure (IOP). NO release protocols were carried out using human non-pigmented ciliary epithelial (hNPCE) cells treated in dye free DMEM containing l-arginine (10(-3) M). The cGMP experimental protocols were performed using dye free DMEM containing 3-isobutyl-1-methylxanthine (IBMX, 10(-4) M). The effects of varying concentrations (10(-13), 10(-11), 10(-9), 10(-7), and 10(-5) M) of melatonin, 5-MCA-NAT (putative MT(3) agonist), N-butanoyl-2-(2-methoxy-6H-isoindolo[2, 1-a]indol-11-yl)ethanamine (IIK7; selective MT(2) agonist) or S-27633-1 (selective MT(1) agonist) on sodium nitroprusside (SNP)-released NO or cGMP production were determined in separate experiments. NO and cGMP levels were measured using a colorimetric assay or enzyme immunoassay (EIA), respectively. Melatonin receptor selectivity was evaluated using luzindole (LUZ; nonselective MT(1)/MT(2) antagonist) or 4-phenyl-2-propionamidotetralin (4P-PDOT; selective MT(2) antagonist). Melatonin, 5-MCA-NAT, and IIK7 all caused concentration-dependent reduction of SNP-released NO and cGMP production. The inhibitory actions of melatonin, 5-MCA-NAT and IIK7 were either completely blocked at 10(-13), 10(-11), and 10(-9) M concentrations of the agonists or partially at 10(-7) and 10(-5) M in the presence of luzindole or 4P-PDOT. Results from this study suggest that melatonin and its analogs, 5-MCA-NAT and IIK7 inhibit SNP-released NO and cGMP production via activation of MT(2) receptors in human NPCE cells. These actions may play a role in melatonin agonist-induced regulation of aqueous humor secretion and IOP.
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Affiliation(s)
- Juanita Dortch-Carnes
- Department of Pharmacology and Toxicology Morehouse School of Medicine, 720 Westview Drive, SW, Atlanta, GA 30310-1495, USA.
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Boga JA, Coto-Montes A, Rosales-Corral SA, Tan DX, Reiter RJ. Beneficial actions of melatonin in the management of viral infections: a new use for this "molecular handyman"? Rev Med Virol 2012; 22:323-38. [PMID: 22511571 PMCID: PMC7169144 DOI: 10.1002/rmv.1714] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 02/08/2012] [Accepted: 02/09/2012] [Indexed: 12/24/2022]
Abstract
Melatonin (N‐acetyl‐5‐methoxytryptamine) is a multifunctional signaling molecule that has a variety of important functions. Numerous clinical trials have examined the therapeutic usefulness of melatonin in different fields of medicine. Clinical trials have shown that melatonin is efficient in preventing cell damage under acute (sepsis, asphyxia in newborns) and chronic states (metabolic and neurodegenerative diseases, cancer, inflammation, aging). The beneficial effects of melatonin can be explained by its properties as a potent antioxidant and antioxidant enzyme inducer, a regulator of apoptosis and a stimulator of immune functions. These effects support the use of melatonin in viral infections, which are often associated with inflammatory injury and increases in oxidative stress. In fact, melatonin has been used recently to treat several viral infections, which are summarized in this review. The role of melatonin in infections is also discussed herein. Copyright © 2012 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jose Antonio Boga
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, Texas, USA
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Srinivasan V, Spence DW, Pandi-Perumal SR, Brown GM, Cardinali DP. Melatonin in mitochondrial dysfunction and related disorders. Int J Alzheimers Dis 2011; 2011:326320. [PMID: 21629741 PMCID: PMC3100547 DOI: 10.4061/2011/326320] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Accepted: 03/02/2011] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial dysfunction is considered one of the major causative factors in the aging process, ischemia/reperfusion (I/R), septic shock, and neurodegenerative disorders like Parkinson's disease (PD), Alzheimer's disease (AD), and Huntington's disease (HD). Increased free radical generation, enhanced mitochondrial inducible nitric oxide (NO) synthase activity, enhanced NO production, decreased respiratory complex activity, impaired electron transport system, and opening of mitochondrial permeability transition pore all have been suggested as factors responsible for impaired mitochondrial function. Melatonin, the major hormone of the pineal gland, also acts as an antioxidant and as a regulator of mitochondrial bioenergetic function. Both in vitro and in vivo, melatonin was effective for preventing oxidative stress/nitrosative stress-induced mitochondrial dysfunction seen in experimental models of PD, AD, and HD. In addition, melatonin is known to retard aging and to inhibit the lethal effects of septic shock or I/R lesions by maintaining respiratory complex activities, electron transport chain, and ATP production in mitochondria. Melatonin is selectively taken up by mitochondrial membranes, a function not shared by other antioxidants. Melatonin has thus emerged as a major potential therapeutic tool for treating neurodegenerative disorders such as PD or AD, and for preventing the lethal effects of septic shock or I/R.
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Affiliation(s)
- Venkatramanujam Srinivasan
- Sri Sathya Sai Medical, Educational and Research Foundation, Prashanthi Nilayam 40, Kovai Thirunagar Coimbatore 641014, India
| | | | | | - Gregory M. Brown
- Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, Canada M5T 1R8
| | - Daniel P. Cardinali
- Departamento de Docencia e Investigación, Facultad de Ciencias Médicas, Pontificia Universidad Católica Argentina, Avenida Alicia Moreau de Justo 1500, 4 Piso, 1107 Buenos Aires, Argentina
- Departamento de Fisiologia, Facultad de Medicina, Universidad de Buenos Aires, 1121 Buenos Aires, Argentina
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Rastmanesh R. Potential of melatonin to treat or prevent age-related macular degeneration through stimulation of telomerase activity. Med Hypotheses 2011; 76:79-85. [DOI: 10.1016/j.mehy.2010.08.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Accepted: 08/07/2010] [Indexed: 12/15/2022]
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Srinivasan V, Kaur C, Pandi-Perumal S, Brown GM, Cardinali DP. Melatonin and its agonist ramelteon in Alzheimer's disease: possible therapeutic value. Int J Alzheimers Dis 2010; 2011:741974. [PMID: 21197086 PMCID: PMC3004402 DOI: 10.4061/2011/741974] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 10/08/2010] [Accepted: 10/27/2010] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is an age-associated neurodegenerative disease characterized by the progressive loss of cognitive function, loss of memory and insomnia, and abnormal behavioral signs and symptoms. Among the various theories that have been put forth to explain the pathophysiology of AD, the oxidative stress induced by amyloid β-protein (Aβ) deposition has received great attention. Studies undertaken on postmortem brain samples of AD patients have consistently shown extensive lipid, protein, and DNA oxidation. Presence of abnormal tau protein, mitochondrial dysfunction, and protein hyperphosphorylation all have been demonstrated in neural tissues of AD patients. Moreover, AD patients exhibit severe sleep/wake disturbances and insomnia and these are associated with more rapid cognitive decline and memory impairment. On this basis, the successful management of AD patients requires an ideal drug that besides antagonizing Aβ-induced neurotoxicity could also correct the disturbed sleep-wake rhythm and improve sleep quality. Melatonin is an effective chronobiotic agent and has significant neuroprotective properties preventing Aβ-induced neurotoxic effects in a number of animal experimental models. Since melatonin levels in AD patients are greatly reduced, melatonin replacement has the potential value to be used as a therapeutic agent for treating AD, particularly at the early phases of the disease and especially in those in whom the relevant melatonin receptors are intact. As sleep deprivation has been shown to produce oxidative damage, impaired mitochondrial function, neurodegenerative inflammation, and altered proteosomal processing with abnormal activation of enzymes, treatment of sleep disturbances may be a priority for arresting the progression of AD. In this context the newly introduced melatonin agonist ramelteon can be of much therapeutic value because of its highly selective action on melatonin MT1/MT2 receptors in promoting sleep.
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Affiliation(s)
- Venkatramanujam Srinivasan
- Sri Sathya Sai Medical Educational and Research Foundation, Prasanthi Nilayam, 40- Kovai Thirunagar, Coimbatore 641014, India
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