Safranal, an active ingredient of saffron, attenuates cognitive deficits in amyloid β-induced rat model of Alzheimer’s disease: underlying mechanisms

• Published in: Metabolic brain disease 2019-12, Vol.34 (6), p.1747-1759
• Main Authors: Baluchnejadmojarad, Tourandokht, Mohamadi-Zarch, Seyed-Mahdi, Roghani, Mehrdad
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Alzheimer Disease - complications; Alzheimer Disease - drug therapy; Alzheimer Disease - metabolism; Alzheimer's disease; Amyloid beta-Peptides; Animals; Antioxidants; Apoptosis; Apoptosis - drug effects; Behavior, Animal - drug effects; Biochemistry; Biomarkers; Biomedical and Life Sciences; Biomedicine; Carbonyl compounds; Carbonyls; Caspase; Caspase-3; Catalase; Cholinesterase; Cognition; Cognition Disorders - drug therapy; Cognition Disorders - etiology; Cognition Disorders - metabolism; Cognitive ability; Cyclohexenes - pharmacology; Cyclohexenes - therapeutic use; Cytokines; Disease Models, Animal; DNA fragmentation; DNA Fragmentation - drug effects; Essential oils; Glial fibrillary acidic protein; Glutathione; Hippocampus; Hippocampus - drug effects; Hippocampus - metabolism; Inflammation; Inflammation - metabolism; Interleukin 6; Learning; Male; Malondialdehyde; Malondialdehyde - metabolism; Maze Learning - drug effects; Membrane potential; Memory; Metabolic Diseases; Metastases; Neurology; Neurosciences; Oncology; Original Article; Oxidative stress; Oxidative Stress - drug effects; Peptide Fragments; Preservation; Proteins; Rats; Rats, Wistar; Reactive oxygen species; Reactive Oxygen Species - metabolism; Rodents; Saffron; Superoxide dismutase; Surgery; Terpenes - pharmacology; Terpenes - therapeutic use
• ISSN: 0885-7490; 1573-7365
• DOI: 10.1007/s11011-019-00481-6

Alzheimer’s disease (AD) is the most prevalent neurodegenerative amyloid disorder with progressive deterioration of cognitive and memory skills. Despite many efforts, no decisive therapy yet exists for AD. Safranal is the active constituent of saffron essential oil with antioxidant, anti-inflammatory, and anti-apoptotic properties. In this study, the possible beneficial effect of safranal on cognitive deficits was evaluated in a rat model of AD induced by intrahippocampal amyloid beta (Aβ 1–40 ). Safranal was daily given p.o. (0.025, 0.1, and 0.2 ml/kg) post-surgery for 1 week and finally learning and memory were evaluated in addition to assessment of the involvement of oxidative stress, inflammation, and apoptosis. Findings showed that safranal treatment of amyloid β-microinjected rats dose-dependently improved cognition in Y-maze, novel-object discrimination, passive avoidance, and 8-arm radial arm maze tasks. Besides, safranal attenuated hippocampal level of malondialdehyde (MDA), reactive oxygen species (ROS), protein carbonyl, interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor α (TNFα), nuclear factor-kappa B (NF- k B), apoptotic biomarkers including caspase 3 and DNA fragmentation, glial fibrillary acidic protein (GFAP), myeloperoxidase (MPO), and acetylcholinesterase (AChE) activity and improved superoxide dismutase (SOD) activity and mitochondrial membrane potential (MMP) with no significant effect on nitrite, catalase activity, and glutathione (GSH). Furthermore, safranal prevented CA1 neuronal loss due to amyloid β 1–40 . In summary, safranal treatment of intrahippocampal amyloid beta 1–40 -microinjected rats could prevent learning and memory decline via neuronal protection and at a molecular level through amelioration of apoptosis, oxidative stress, inflammation, cholinesterase activity, neutrophil infiltration, and also by preservation of mitochondrial integrity.