title: Subthreshold Concentrations of Melatonin and Galantamine Improves Pathological AD-Hallmarks in Hippocampal Organotypic Cultures.
abstract: Melatonin is a neurohormone whose levels are significantly reduced or absent in Alzheimer's disease (AD) patients. In these patients, acetylcholinesterase inhibitors (AChEI) are the major drug class used for their treatment; however, they present unwanted cholinergic side effects and have provided limited efficacy in clinic. Because combination therapy is being extensively used to treat different pathological diseases such as cancer or acquired immune deficiency syndrome, we posed this study to evaluate if melatonin in combination with an AChEI, galantamine, could provide beneficial properties in a novel in vitro model of AD. Thus, we subjected organotypic hippocampal cultures (OHCs) to subtoxic concentrations of β-amyloid (0.5 μM βA) plus okadaic acid (1 nM OA), for 4 days. This treatment increased by 95 % cell death, which was mainly apoptotic as shown by positive TUNEL staining. In addition, the combination of βA/OA increased Thioflavin S aggregates, hyperphosphorylation of Tau, oxidative stress (increased DCFDA fluorescence), and neuroinflammation (increased IL-1β and TNFα). Under these experimental conditions, melatonin (1-1000 nM) and galantamine (10-1000 nM), co-incubated with the toxic stimuli, caused a concentration-dependent neuroprotection; maximal neuroprotective effect was achieved at 1 μM of melatonin and galantamine. Most effective was the finding that combination of sub-effective concentrations of melatonin (1 nM) and galantamine (10 nM) provided a synergic anti-apoptotic effect and reduction of most of the AD-related pathological hallmarks observed in the βA/OA model. Therefore, we suggest that supplementation of melatonin in combination with lower doses of AChEIs could be an interesting strategy for AD patients.
authors.affiliation: Instituto Teófilo Hernando (ITH), Departamento de Farmacología y Terapéutica. Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, Madrid, 28029, Spain.|Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, C/ Diego de León 62, Madrid, 28006, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Buendia
authors.affiliation: Instituto Teófilo Hernando (ITH), Departamento de Farmacología y Terapéutica. Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, Madrid, 28029, Spain.|Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, C/ Diego de León 62, Madrid, 28006, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Parada
authors.affiliation: Instituto Teófilo Hernando (ITH), Departamento de Farmacología y Terapéutica. Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, Madrid, 28029, Spain.|Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, C/ Diego de León 62, Madrid, 28006, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Navarro
authors.affiliation: Instituto Teófilo Hernando (ITH), Departamento de Farmacología y Terapéutica. Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, Madrid, 28029, Spain.|Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, C/ Diego de León 62, Madrid, 28006, Spain.
authors.forename: R
authors.initials: R
authors.lastname: León
authors.affiliation: Department of Anatomy, Histology and Neuroscience, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Negredo
authors.affiliation: Instituto Teófilo Hernando (ITH), Departamento de Farmacología y Terapéutica. Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, Madrid, 28029, Spain. javier.egea@uam.es.|Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, C/ Diego de León 62, Madrid, 28006, Spain. javier.egea@uam.es.
authors.forename: J
authors.initials: J
authors.lastname: Egea
authors.affiliation: Instituto Teófilo Hernando (ITH), Departamento de Farmacología y Terapéutica. Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo, 4, Madrid, 28029, Spain. manuela.garcia@uam.es.|Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, C/ Diego de León 62, Madrid, 28006, Spain. manuela.garcia@uam.es.
authors.forename: M G
authors.initials: MG
authors.lastname: López
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology*; D016229:Amyloid beta-Peptides / Q000633:toxicity; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D005702:Galantamine / Q000737:chemistry / Q000494:pharmacology*; D006624:Hippocampus / Q000473:pathology*; D008550:Melatonin / Q000737:chemistry / Q000494:pharmacology*; D008954:Models, Biological; D018696:Neuroprotective Agents / Q000494:pharmacology; D019319:Okadaic Acid / Q000633:toxicity; D010766:Phosphorylation / Q000187:drug effects; D066329:Protein Aggregates / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D046509:Tissue Culture Techniques; D016875:tau Proteins / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D018696:Neuroprotective Agents; D066329:Protein Aggregates; D016875:tau Proteins; D005702:Galantamine; D019319:Okadaic Acid; D008550:Melatonin
keywords: Alzheimer disease; Combined therapy; Galantamine; Inflammation; Melatonin; Oxidative stress