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Jibril TI, Alzoubi KH, Mhaidat NM, Khabour OF, Alqudah MA, Rababa’h AM, Alrabadi N, Al-udatt D. Sildenafil prevents chronic psychosocial stress-induced working memory impairment: Role of brain-derived neurotrophic factor. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2024; 6:100182. [PMID: 38706525 PMCID: PMC11067328 DOI: 10.1016/j.crphar.2024.100182] [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: 02/02/2024] [Revised: 03/29/2024] [Accepted: 04/12/2024] [Indexed: 05/07/2024] Open
Abstract
Background Psychosocial stress, a common feature in modern societies, impairs cognitive functions. It is suggested that stress hormones and elevated excitatory amino acids during stress are responsible for stress-induced cognitive deficits. Reduced brain-derived neurotrophic factor (BDNF) levels, increased oxidative stress, and alteration of synaptic plasticity biomarkers are also possible contributors to the negative impact of stress on learning and memory. Sildenafil citrate is a selective phosphodiesterase type 5 (PDE5) inhibitor and the first oral therapy for the treatment of erectile dysfunction. It has been shown that sildenafil improves learning and memory and possesses antioxidant properties. We hypothesized that administering sildenafil to stressed rats prevents the cognitive deficit induced by chronic psychosocial stress. Methods Psychosocial stress was generated using the intruder model. Sildenafil 3 mg/kg/day was administered intraperitoneally to animals. Behavioral studies were conducted to test spatial learning and memory using the radial arm water maze. Then, the hippocampal BDNF level and several antioxidant markers were assessed. Results This study revealed that chronic psychosocial stress impaired short-term but not long-term memory. The administration of sildenafil prevented this short-term memory impairment. Chronic psychosocial stress markedly reduced the level of hippocampal BDNF (P˂0.05), and this reduction in BDNF was normalized by sildenafil treatment. In addition, neither chronic psychosocial stress nor sildenafil significantly altered the activity of measured oxidative parameters (P > 0.05). Conclusion Chronic psychosocial stress induces short-term memory impairment. The administration of sildenafil citrate prevented this impairment, possibly by normalizing the level of BDNF.
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Affiliation(s)
- Tareq I. Jibril
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Karem H. Alzoubi
- Department of Pharmacy Practice and Pharmacotherapeutics, College of Pharmacy, University of Sharjah, Sharjah, United Arab Emirates
- Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Nizar M. Mhaidat
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Omar F. Khabour
- Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Mohammad A.Y. Alqudah
- Department of Pharmacy Practice and Pharmacotherapeutics, College of Pharmacy, University of Sharjah, Sharjah, United Arab Emirates
- Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Abeer M. Rababa’h
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Nasr Alrabadi
- Department of Pharmacology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Doaa Al-udatt
- Department of Physiology and Biochemistry, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
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2
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Li D, Huang Z, Xu X, Li Y. Promising derivatives of rutaecarpine with diverse pharmacological activities. Front Chem 2023; 11:1199799. [PMID: 38025082 PMCID: PMC10646507 DOI: 10.3389/fchem.2023.1199799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Rutaecarpine (RUT) is a natural pentacyclic indolopyridoquinazolinone alkaloid first isolated from one of the most famous traditional Chinese herbs, Evodia rutaecarpa, which is used for treating a variety of ailments, including headaches, gastrointestinal disorders, postpartum hemorrhage, amenorrhea, difficult menstruation, and other diseases. Accumulating pharmacological studies showed that RUT possesses a wide range of pharmacological effects through different mechanisms. However, its poor physicochemical properties and moderate biological activities have hampered its clinical application. In this regard, the modification of RUT aimed at seeking its derivatives with better physicochemical properties and more potency has been extensively studied. These derivatives exhibit diverse pharmacological activities, including anti-inflammatory, anti-atherogenic, anti-Alzheimer's disease, antitumor, and antifungal activities via a variety of mechanisms, such as inhibiting cyclooxygenase-2 (COX-2), acetylcholine (AChE), phosphodiesterase 4B (PDE4B), phosphodiesterase 5 (PDE5), or topoisomerases (Topos). From this perspective, this paper provides a comprehensive description of RUT derivatives by focusing on their diverse biological activities. This review aims to give an insight into the biological activities of RUT derivatives and encourage further exploration of RUT.
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Affiliation(s)
- Deping Li
- Department of Pharmacy, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Ziqian Huang
- Department of Pharmacy, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Xiaojun Xu
- Department of Party and Government Office, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Yan Li
- Department of Pharmacy, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
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Hainsworth AH, Arancio O, Elahi FM, Isaacs JD, Cheng F. PDE5 inhibitor drugs for use in dementia. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2023; 9:e12412. [PMID: 37766832 PMCID: PMC10520293 DOI: 10.1002/trc2.12412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/07/2023] [Accepted: 07/08/2023] [Indexed: 09/29/2023]
Abstract
Alzheimer's disease and related dementias (ADRD) remain a major health-care challenge with few licensed medications. Repurposing existing drugs may afford prevention and treatment. Phosphodiesterase-5 (PDE5) is widely expressed in vascular myocytes, neurons, and glia. Potent, selective, Food and Drug Administration-approved PDE5 inhibitors are already in clinical use (sildenafil, vardenafil, tadalafil) as vasodilators in erectile dysfunction and pulmonary arterial hypertension. Animal data indicate cognitive benefits of PDE5 inhibitors. In humans, real-world patient data suggest that sildenafil and vardenafil are associated with reduced dementia risk. While a recent clinical trial of acute tadalafil on cerebral blood flow was neutral, there may be chronic actions of PDE5 inhibition on cerebrovascular or synaptic function. We provide a perspective on the potential utility of PDE5 inhibitors for ADRD. We conclude that further prospective clinical trials with PDE5 inhibitors are warranted. The choice of drug will depend on brain penetration, tolerability in older people, half-life, and off-target effects. HIGHLIGHTS Potent phosphodiesterase-5 (PDE5) inhibitors are in clinical use as vasodilators.In animals PDE5 inhibitors enhance synaptic function and cognitive ability.In humans the PDE5 inhibitor sildenafil is associated with reduced risk of Alzheimer's disease.Licensed PDE5 inhibitors have potential for repurposing in dementia.Prospective clinical trials of PDE5 inhibitors are warranted.
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Affiliation(s)
- Atticus H. Hainsworth
- Molecular & Clinical Sciences Research InstituteSt George's University of LondonLondonUK
- Department of NeurologySt George's University Hospitals NHS Foundation TrustLondonUK
| | - Ottavio Arancio
- Department of Pathology and Cell BiologyTaub Institute for Research on Alzheimer's Disease and the Aging BrainDepartment of MedicineColumbia UniversityNew YorkNew YorkUSA
| | - Fanny M. Elahi
- Departments of Neurology and NeuroscienceRonald M. Loeb Center for Alzheimer's DiseaseFriedman Brain InstituteIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Jeremy D. Isaacs
- Molecular & Clinical Sciences Research InstituteSt George's University of LondonLondonUK
- Department of NeurologySt George's University Hospitals NHS Foundation TrustLondonUK
| | - Feixiong Cheng
- Genomic Medicine InstituteLerner Research InstituteCleveland ClinicClevelandOhioUSA
- Department of Molecular MedicineCleveland Clinic Lerner College of MedicineCase Western Reserve UniversityClevelandOhioUSA
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4
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On making (and turning adaptive to) maladaptive aversive memories in laboratory rodents. Neurosci Biobehav Rev 2023; 147:105101. [PMID: 36804263 DOI: 10.1016/j.neubiorev.2023.105101] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/03/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Fear conditioning and avoidance tasks usually elicit adaptive aversive memories. Traumatic memories are more intense, generalized, inflexible, and resistant to attenuation via extinction- and reconsolidation-based strategies. Inducing and assessing these dysfunctional, maladaptive features in the laboratory are crucial to interrogating posttraumatic stress disorder's neurobiology and exploring innovative treatments. Here we analyze over 350 studies addressing this question in adult rats and mice. There is a growing interest in modeling several qualitative and quantitative memory changes by exposing already stressed animals to freezing- and avoidance-related tests or using a relatively high aversive training magnitude. Other options combine aversive/fearful tasks with post-acquisition or post-retrieval administration of one or more drugs provoking neurochemical or epigenetic alterations reported in the trauma aftermath. It is potentially instructive to integrate these procedures and incorporate the measurement of autonomic and endocrine parameters. Factors to consider when defining the organismic and procedural variables, partially neglected aspects (sex-dependent differences and recent vs. remote data comparison) and suggestions for future research (identifying reliable individual risk and treatment-response predictors) are discussed.
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Development of a Rapid LC-MS/MS Method for Simultaneous Quantification of Donepezil and Tadalafil in Rat Plasma: Its Application in a Pharmacokinetic Interaction Study after Oral Administration in Rats. Molecules 2023; 28:molecules28052352. [PMID: 36903595 PMCID: PMC10005750 DOI: 10.3390/molecules28052352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
This study aimed to establish a simple and sensitive analytical method to simultaneously quantify donepezil (DPZ) and tadalafil (TAD) in rat plasma using lansoprazole (LPZ) as an internal standard (IS) by using liquid chromatography tandem mass spectrometry. The fragmentation pattern of DPZ, TAD, and IS was elucidated using multiple reaction monitoring in electrospray ionization positive ion mode for the quantification of precursor to production at m/z 380.1 → 91.2 for DPZ, m/z 390.2 → 268.1 for TAD, and m/z 370.3 → 252.0 for LPZ. The extracted DPZ and TAD from plasma using acetonitrile-induced protein precipitation was separated using Kinetex C18 (100 × 2.1 mm, 2.6 µm) column with a gradient mobile phase system consisting of 2 mM ammonium acetate and 0.1% formic acid in acetonitrile at a flow rate of 0.25 mL/min for 4 min. The selectivity, lower limit of quantification, linearity, precision, accuracy, stability, recovery, and matrix effect of this developed method was validated according to the guidelines of the U.S. Food and Drug Administration and the Ministry of Food and Drug Safety of Korea. The established method achieved acceptance criteria in all validation parameters, ensuring reliability, reproducibility, and accuracy, and was successfully implemented in a pharmacokinetic study on the co-administration of DPZ and TAD orally in rats.
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Huang XF, Dong YH, Wang JH, Ke HM, Song GQ, Xu DF. Novel PDE5 inhibitors derived from rutaecarpine for the treatment of Alzheimer’s disease. Bioorg Med Chem Lett 2020; 30:127097. [DOI: 10.1016/j.bmcl.2020.127097] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/04/2020] [Accepted: 03/04/2020] [Indexed: 12/23/2022]
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Hafez MH, El-Kazaz SE. The impact of phosphodiesterase-5 inhibitor (sildenafil citrate) on some hippocampal neurotransmitters, oxidative stress status, minerals, and anxiety-like behavior in rats. J Adv Vet Anim Res 2020; 7:281-289. [PMID: 32607359 PMCID: PMC7320816 DOI: 10.5455/javar.2020.g419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/25/2020] [Accepted: 03/30/2020] [Indexed: 01/07/2023] Open
Abstract
Objective: The purpose of this work was to investigate the effect of phosphodiesterase type 5 (PDE-5) inhibitor sildenafil citrate (SC) on the level of brain hippocampal neurophysiological parameters (inhibitory and excitatory neurotransmitters), oxidant/antioxidant status, minerals, and anxiety-like behavior using albino male rats. Materials and methods: A total of 24 albino male rats were allocated to three separate groups (each one had eight rats): control and SC 5 and 10 mg/kg treatments via i.p. infusion every 3 days for 12 injections. For the behavior of anxiety evaluation, the elevated plus maze test was conducted 1 day after the last treatment, and then all the rats were killed. For serum separation, the blood samples were taken, and hippocampus was dissected from the brain and stored frozen until analysis. Results: Both doses of sildenafil significantly improved brain hippocampal neurotransmitter [norepinephrine, serotonin (5-hydroxytryptamine), and gamma-aminobutyric acid] values accompanied by a decreased dopamine level. Interestingly, the SC higher given dose (10 mg/kg) increased the malondialdehyde level with the reduction of the antioxidant parameters [reduced glutathione (GSH) level, catalase (CAT), and superoxide dismutase (SOD) activities] although the lower dose of SC did not cause oxidative stress. Serum and brain hippocampal K, Cu, and Se concentrations were also increased with SC treatments. Moreover, the test of elevated plus maze revealed an anxiolytic impact of sildenafil. Conclusion: It was concluded that SC improved the parameters of some hippocampal neurotransmitters and minerals accompanied by anxiolytic impact with the test of elevated plus maze, with a state of oxidative stress revealed with the higher dose of SC which was not recorded with the lower dose.
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Affiliation(s)
- Mona Hafez Hafez
- Physiology Department, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - Sara Elsayed El-Kazaz
- Animal Husbandry and Animal Wealth Development Department, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
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8
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Nabavi SM, Talarek S, Listos J, Nabavi SF, Devi KP, Roberto de Oliveira M, Tewari D, Argüelles S, Mehrzadi S, Hosseinzadeh A, D'onofrio G, Orhan IE, Sureda A, Xu S, Momtaz S, Farzaei MH. Phosphodiesterase inhibitors say NO to Alzheimer's disease. Food Chem Toxicol 2019; 134:110822. [PMID: 31536753 DOI: 10.1016/j.fct.2019.110822] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 09/13/2019] [Accepted: 09/14/2019] [Indexed: 12/18/2022]
Abstract
Phosphodiesterases (PDEs) consisted of 11 subtypes (PDE1 to PDE11) and over 40 isoforms that regulate levels of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), the second messengers in cell functions. PDE inhibitors (PDEIs) have been attractive therapeutic targets due to their involvement in diverse medical conditions, e.g. cardiovascular diseases, autoimmune diseases, Alzheimer's disease (AD), etc. Among them; AD with a complex pathology is a progressive neurodegenerative disorder which affect mostly senile people in the world and only symptomatic treatment particularly using cholinesterase inhibitors in clinic is available at the moment for AD. Consequently, novel treatment strategies towards AD are still searched extensively. Since PDEs are broadly expressed in the brain, PDEIs are considered to modulate neurodegenerative conditions through regulating cAMP and cGMP in the brain. In this sense, several synthetic or natural molecules inhibiting various PDE subtypes such as rolipram and roflumilast (PDE4 inhibitors), vinpocetine (PDE1 inhibitor), cilostazol and milrinone (PDE3 inhibitors), sildenafil and tadalafil (PDE5 inhibitors), etc have been reported showing encouraging results for the treatment of AD. In this review, PDE superfamily will be scrutinized from the view point of structural features, isoforms, functions and pharmacology particularly attributed to PDEs as target for AD therapy.
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Affiliation(s)
- Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
| | - Sylwia Talarek
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St, 20-093, Lublin, Poland.
| | - Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St, 20-093, Lublin, Poland.
| | - Seyed Fazel Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
| | - Kasi Pandima Devi
- Department of Biotechnology, Alagappa University, Karaikudi, 630003, Tamil Nadu, India.
| | - Marcos Roberto de Oliveira
- Departamento de Química (DQ), Instituto de Ciências Exatas e da Terra (ICET), Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil.
| | - Devesh Tewari
- Department of Pharmacognosy, School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India.
| | - Sandro Argüelles
- Department of Physiology, Faculty of Pharmacy, University of Seville, Seville, Spain.
| | - Saeed Mehrzadi
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Azam Hosseinzadeh
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Grazia D'onofrio
- Geriatric Unit and Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS "Casa Sollievo della Sofferenza", Viale Cappuccini 1, 71013, San Giovanni Rotondo, FG, Italy.
| | - Ilkay Erdogan Orhan
- Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330, Ankara, Turkey.
| | - Antoni Sureda
- Research Group on Community Nutrition and Oxidative Stress, University of Balearic Islands, CIBEROBN (Physiopathology of Obesity and Nutrition), E-07122, Palma de Mallorca, Balearic Islands, Spain.
| | - Suowen Xu
- Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, 14623, USA.
| | - Saeedeh Momtaz
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran; Toxicology and Diseases Group, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hosein Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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9
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Liu L, Xu H, Ding S, Wang D, Song G, Huang X. Phosphodiesterase 5 inhibitors as novel agents for the treatment of Alzheimer's disease. Brain Res Bull 2019; 153:223-231. [PMID: 31493542 DOI: 10.1016/j.brainresbull.2019.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/18/2019] [Accepted: 09/01/2019] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD), characterized by a progressive impairment of memory and cognition, is a major health problem in both developing and developed countries. Currently, no drugs can reverse the progression of AD. Phosphodiesterase 5 (PDE5) is a critical component of the cyclic guanosine monophosphate/protein kinase G (cGMP/PKG) signaling pathway in neurons, the inhibition of which has produced neuroprotective effects, and PDE5 inhibitors have recently been thought to be potential therapeutic agents for AD. In this paper, we summarized the outstanding progress that has been made in PDE5 inhibitors as anti-AD agents with encouraging results in animal studies, clinical trials and the investigations on the underlying mechanisms. The novel PDE5 inhibitors reported recently in the treatment of AD were also reviewed and discussed.
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Affiliation(s)
- Li Liu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Huang Xu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Shumin Ding
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Dongyan Wang
- Department of Medicine, Yangzhou Polytechnic College, Yangzhou, Jiangsu 225009, China
| | - Guoqiang Song
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China.
| | - Xianfeng Huang
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China.
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10
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de Carvalho MAJ, Chaves-Filho A, de Souza AG, de Carvalho Lima CN, de Lima KA, Rios Vasconcelos ER, Feitosa ML, Souza Oliveira JV, de Souza DAA, Macedo DS, de Souza FCF, de França Fonteles MM. Proconvulsant effects of sildenafil citrate on pilocarpine-induced seizures: Involvement of cholinergic, nitrergic and pro-oxidant mechanisms. Brain Res Bull 2019; 149:60-74. [PMID: 31004733 DOI: 10.1016/j.brainresbull.2019.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 03/26/2019] [Accepted: 04/09/2019] [Indexed: 12/12/2022]
Abstract
Sildenafil is a phosphodiesterase 5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. Proconvulsant effect is a serious adverse event associated with sildenafil use. Here, we investigated the possible proconvulsant effects of sildenafil in pilocarpine (PILO)-induced seizures model, which mimics some aspects of temporal lobe epilepsy. We also evaluated sildenafil's effects on hippocampal markers related to PILO-induced seizure, for instance, acetylcholinesterase (AChE) activity, oxidative stress and nitric oxide (NO) markers, namely nitrite, inducible NO synthase (iNOS) and neuronal NOS (nNOS). The influences of muscarinic receptors blockade on sildenafil proconvulsant effects and brain nitrite levels were also evaluated. Male mice were submitted to single or repeated (7 days) sildenafil administration (2.5, 5, 10 and 20 mg/kg). Thirty minutes later, PILO was injected and mice were further evaluated for 1 h for seizure activity. Sildenafil induced a dose- and time-progressive proconvulsant effect in PILO-induced seizures. Sildenafil also potentiated the inhibitory effect of PILO in AChE activity and induced a further increase in nitrite levels and pro-oxidative markers, mainly in the hippocampus. Repeated sildenafil treatment also increased the hippocampal expression of iNOS and nNOS isoforms, while the blockade of muscarinic receptors attenuated both sildenafil-induced proconvulsant effect and brain nitrite changes. Our data firstly demonstrated the proconvulsant effect of sildenafil in PILO-model of seizures. This effect seems to be related to an increased cholinergic-nitrergic tone and pro-oxidative brain changes. Also, our findings advert to caution in using sildenafil for patients suffering from neurological conditions that reduces seizure threshold, such as epilepsy.
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Affiliation(s)
- Michele Albuquerque Jales de Carvalho
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Adriano Chaves-Filho
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Alana Gomes de Souza
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Camila Nayane de Carvalho Lima
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Klistenes Alves de Lima
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Emiliano Ricardo Rios Vasconcelos
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Mariana Lima Feitosa
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - João Victor Souza Oliveira
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Denia Alves Albuquerque de Souza
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Danielle S Macedo
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq), Ribeirão Preto, Brazil
| | - Francisca Cléa Florenço de Souza
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Marta Maria de França Fonteles
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Department of Physiology and Pharmacology, Universidade Federal do Ceará, Fortaleza, CE, Brazil; Pharmacy Department, Faculty of Dentistry, Nursing and Pharmacy, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
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11
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Kelly SP, Risley MG, Miranda LE, Dawson-Scully K. Contribution of a natural polymorphism in protein kinase G modulates electroconvulsive seizure recovery in Drosophila melanogaster. ACTA ACUST UNITED AC 2018; 221:jeb.179747. [PMID: 29798846 DOI: 10.1242/jeb.179747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 05/21/2018] [Indexed: 11/20/2022]
Abstract
Drosophila melanogaster is a well-characterized model for neurological disorders and is widely used for investigating causes of altered neuronal excitability leading to seizure-like behavior. One method used to analyze behavioral output of neuronal perturbance is recording the time to locomotor recovery from an electroconvulsive shock. Based on this behavior, we sought to quantify seizure susceptibility in larval D. melanogaster with differences in the enzymatic activity levels of a major protein, cGMP-dependent protein kinase (PKG). PKG, encoded by foraging, has two natural allelic variants and has previously been implicated in several important physiological characteristics including: foraging patterns, learning and memory, and environmental stress tolerance. The well-established NO/cGMP/PKG signaling pathway found in the fly, which potentially targets downstream K+ channel(s), ultimately impacts membrane excitability, leading to our hypothesis: altering PKG enzymatic activity modulates time to recovery from an electroconvulsive seizure. Our results show that by both genetically and pharmacologically increasing PKG enzymatic activity, we can decrease the locomotor recovery time from an electroconvulsive seizure in larval D. melanogaster.
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Affiliation(s)
- Stephanie P Kelly
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA
| | - Monica G Risley
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA.,International Max-Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, FL 33431, USA
| | - Leonor E Miranda
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA
| | - Ken Dawson-Scully
- Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431, USA
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12
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Yanai S, Ito H, Endo S. Long-term cilostazol administration prevents age-related decline of hippocampus-dependent memory in mice. Neuropharmacology 2017; 129:57-68. [PMID: 29122629 DOI: 10.1016/j.neuropharm.2017.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/30/2017] [Accepted: 11/04/2017] [Indexed: 12/17/2022]
Abstract
Phosphodiesterases (PDEs) are enzymes that hydrolyze and inactivate 3', 5'-cyclic adenosine monophosphate (cAMP) and/or 3', 5'-cyclic guanosine monophosphate (cGMP). The regulation of intracellular signaling pathways mediated by cyclic nucleotides is imperative to synaptic plasticity and memory in animals. Because PDEs play an important role in this regulation, PDE inhibitors are considered as candidate compounds for treating cognitive and memory disorders. In the present study, we tested whether cilostazol, a selective PDE3 inhibitor, prevents the cognitive deterioration that occurs during the course of normal aging in mice. Ten months of cilostazol administration (1.5%) in 13-month-old mice improved spatial memory when tested at 23 months of age. First, it prevented the decline in the ability of these aged mice to recognize a change in an object's location in the object recognition task. Second, spatial memory of these cilostazol-treated aged mice in the Morris water maze was comparable to that of untreated middle-aged mice (13 months old). Cilostazol administration had no effect on the emotional states and physical ability of aged mice. Thus, long-term cilostazol administration prevented hippocampus-dependent memory decline in aged mice, allowing them to achieve a level of cognitive performance similar to middle-aged mice and without negative behavioral side effects. Considering its well-established safety in other medical contexts, cilostazol may be a potential therapeutic candidate drug for staving off cognitive decline in the aging human population.
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Affiliation(s)
- Shuichi Yanai
- Aging Neuroscience Research Team, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo 173-0015, Japan
| | - Hideki Ito
- Department of CNS Research, Otsuka Pharmaceutical Co., Ltd., Tokushima, 771-0192, Japan
| | - Shogo Endo
- Aging Neuroscience Research Team, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo 173-0015, Japan.
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Yanai S, Toyohara J, Ishiwata K, Ito H, Endo S. Long-term cilostazol administration ameliorates memory decline in senescence-accelerated mouse prone 8 (SAMP8) through a dual effect on cAMP and blood-brain barrier. Neuropharmacology 2016; 116:247-259. [PMID: 27979612 DOI: 10.1016/j.neuropharm.2016.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/18/2016] [Accepted: 12/09/2016] [Indexed: 12/12/2022]
Abstract
Phosphodiesterases (PDEs), which hydrolyze and inactivate 3', 5'-cyclic adenosine monophosphate (cAMP) and 3', 5'-cyclic guanosine monophosphate (cGMP), play an important role in synaptic plasticity that underlies memory. Recently, several PDE inhibitors were assessed for their possible therapeutic efficacy in treating cognitive disorders. Here, we examined how cilostazol, a selective PDE3 inhibitor, affects brain functions in senescence-accelerated mouse prone 8 (SAMP8), an animal model of age-related cognitive impairment. Long-term administration of cilostazol restored the impaired context-dependent conditioned fear memory of SAMP8 to match that in normal aging control substrain SAMR1. Cilostazol also increased the number of cells containing phosphorylated cAMP-responsive element binding protein (CREB), a downstream component of the cAMP pathway. Finally, cilostazol improves blood-brain barrier (BBB) integrity, demonstrated by reduced extravasation of 2-deoxy-2-18F-fluoro-d-glucose and Evans Blue dye in the brains of SAMP8. This improvement in BBB integrity was associated with an increased amount of zona occludens protein 1 (ZO-1) and occludin proteins, components of tight junctions integral to the BBB. The results suggest that long-term administration of cilostazol exerts its beneficial effects on age-related cognitive impairment through a dual mechanism: by enhancing the cAMP system in the brain and by maintaining or improving BBB integrity.
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Affiliation(s)
- Shuichi Yanai
- Aging Neuroscience Research Team, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo 173-0015, Japan
| | - Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo 173-0015, Japan
| | - Kiichi Ishiwata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo 173-0015, Japan; Institute of Cyclotron and Drug Discovery Research, Southern TOHOKU Research Institute for Neuroscience, Koriyama, Fukushima 963-8052, Japan; Department of Biofunctional Imaging, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Hideki Ito
- Department of CNS Research, Otsuka Pharmaceutical Co., Ltd., Tokushima 771-0192, Japan
| | - Shogo Endo
- Aging Neuroscience Research Team, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo 173-0015, Japan.
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The fate of memory: Reconsolidation and the case of Prediction Error. Neurosci Biobehav Rev 2016; 68:423-441. [DOI: 10.1016/j.neubiorev.2016.06.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 05/07/2016] [Accepted: 06/06/2016] [Indexed: 11/22/2022]
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Krawczyk M, Blake M, Baratti C, Romano A, Boccia M, Feld M. Memory reconsolidation of an inhibitory avoidance task in mice involves cytosolic ERK2 bidirectional modulation. Neuroscience 2015; 294:227-37. [DOI: 10.1016/j.neuroscience.2015.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 03/05/2015] [Accepted: 03/09/2015] [Indexed: 01/23/2023]
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Sabphon C, Temkitthawon P, Ingkaninan K, Sawasdee P. Phosphodiesterase Inhibitory Activity of the Flavonoids and Xanthones from Anaxagorea luzonensis. Nat Prod Commun 2015. [DOI: 10.1177/1934578x1501000222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Five flavonoids, one isoflavone and five xanthones were isolated from Anaxagorea luzonensis. Of these eleven isolated compounds, 1,3,5-trihydroxy-4-prenylxanthone (3) was a relatively potent inhibitor of phosphodiesterase type 5 (PDE5), with an IC50 value of 3.0 μM. This is the first report showing that natural xanthones can exhibit promising PDE5 inhibitory activity. Moreover, this study revealed that the presence of the C-4 prenyl residue attached to the xanthone core is correlated with the significant PDE5 inhibitory activity.
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Affiliation(s)
- Chalisa Sabphon
- Program of Biotechnology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
| | - Prapapan Temkitthawon
- Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences and Center of Excellence for Innovation in Chemistry, Naresuan University, Phitsanulok 65000, Thailand
| | - Kornkanok Ingkaninan
- Natural Products Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
| | - Pattara Sawasdee
- Natural Products Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
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Akkerman S, Prickaerts J, Bruder AK, Wolfs KHM, De Vry J, Vanmierlo T, Blokland A. PDE5 inhibition improves object memory in standard housed rats but not in rats housed in an enriched environment: implications for memory models? PLoS One 2014; 9:e111692. [PMID: 25372140 PMCID: PMC4221101 DOI: 10.1371/journal.pone.0111692] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/29/2014] [Indexed: 12/20/2022] Open
Abstract
Drug effects are usually evaluated in animals housed under maximally standardized conditions. However, it is assumed that an enriched environment (EE) more closely resembles human conditions as compared to maximally standardized laboratory conditions. In the present study, we examined the acute cognition enhancing effects of vardenafil, a PDE5 inhibitor, which stimulates protein kinase G/CREB signaling in cells, in three different groups of male Wistar rats tested in an object recognition task (ORT). Rats were either housed solitarily (SOL) or socially (SOC) under standard conditions, or socially in an EE. Although EE animals remembered object information longer in the vehicle condition, vardenafil only improved object memory in SOL and SOC animals. While EE animals had a heavier dorsal hippocampus, we found no differences between experimental groups in total cell numbers in the dentate gyrus, CA2-3 or CA1. Neither were there any differences in markers for pre- and postsynaptic density. No changes in PDE5 mRNA- and protein expression levels were observed. Basal pCREB levels were increased in EE rats only, whereas β-catenin was not affected, suggesting specific activation of the MAP kinase signaling pathway and not the AKT pathway. A possible explanation for the inefficacy of vardenafil could be that CREB signaling is already optimally stimulated in the hippocampus of EE rats. Since previous data has shown that acute PDE5 inhibition does not improve memory performance in humans, the use of EE animals could be considered as a more valid model for testing cognition enhancing drugs.
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Affiliation(s)
- Sven Akkerman
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Ann K. Bruder
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Kevin H. M. Wolfs
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Jochen De Vry
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Tim Vanmierlo
- Department of Immunology and Biochemistry, Biomedical research institute, Hasselt University, Hasselt, Belgium
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
- * E-mail:
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Yanai S, Semba Y, Ito H, Endo S. Cilostazol improves hippocampus-dependent long-term memory in mice. Psychopharmacology (Berl) 2014; 231:2681-93. [PMID: 24464529 DOI: 10.1007/s00213-014-3442-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 12/31/2013] [Indexed: 12/15/2022]
Abstract
RATIONALE Phosphodiesterases (PDEs) play an important role in the regulation of intracellular signaling mediated by cyclic adenosine monophosphate (cAMP). Recently, several PDE inhibitors were assessed for their possible cognitive enhancing properties. However, little is known about the effect of PDE3 inhibitors on memory function. OBJECTIVES We examined how the PDE3 inhibitor cilostazol affects C57BL/6 J mice as they perform various behavioral tasks. After behavioral assessment, brains of the mice were analyzed immunohistochemically to quantify the phosphorylation of cAMP-responsive element binding protein (CREB), a downstream component of the cAMP pathway. RESULTS Oral administration of cilostazol significantly enhanced recollection of the exact platform location in the Morris water maze probe test. Cilostazol also improved context-dependent long-term fear memory, without affecting short-term memory. No apparent effect was observed in cue-dependent fear memory. The results suggest that cilostazol selectively improves hippocampus-dependent long-term memory in these tasks. Cilostazol also significantly increased the number of phosphorylated-CREB-positive cells in hippocampal dentate gyrus. CONCLUSIONS These results suggest that cilostazol may exert its beneficial effects on learning and memory by enhancing the cAMP system in hippocampus, where it increases intracellular cAMP activity.
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Affiliation(s)
- Shuichi Yanai
- Aging Neuroscience Research Team, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo, 173-0015, Japan
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Zhuang XD, Long M, Li F, Hu X, Liao XX, Du ZM. PDE5 inhibitor sildenafil in the treatment of heart failure: A meta-analysis of randomized controlled trials. Int J Cardiol 2014; 172:581-7. [DOI: 10.1016/j.ijcard.2014.01.102] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 10/30/2013] [Accepted: 01/19/2014] [Indexed: 12/15/2022]
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Demirci D, Mutlu O, Akar F, Komsuoglu Celikyurt I, Ulak G. Sildenafil enhances locomotor activity in young mice and exerts anxiogenic effects in both young and aged mice. Med Sci Monit Basic Res 2014; 20:15-21. [PMID: 24500039 PMCID: PMC3936918 DOI: 10.12659/msmbr.890280] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background Sildenafil is a selective PDE5 inhibitor that increases cGMP levels in the target tissues and is an effective treatment agent for erectile dysfunction. The nitric oxide-cGMP pathway might be implicated in regulation of certain CNS functions, including locomotor activity and anxiety. Material/Methods The aim of the current study was to investigate effects of sildenafil (3 and 10 mg/kg) on anxiety and locomotor activity in open field and elevated plus maze (EPM) tests in young and aged mice. Results Sildenafil (3 and 10 mg/kg) significantly decreased the percent of time spent in the open arms compared to the control group in young animals in the EPM test, but only the 10 mg/kg dose significantly decreased the percentage of total number of entries to the open arms in young animals. Sildenafil (3 and 10 mg/kg) significantly decreased the percentage of total number of entries to the open arms in aged animals in the EPM test, but it significantly increased total distance moved and speed of the animals in the locomotor activity test in young animals. The total distance moved and the speed of the animals significantly decreased in aged animals compared to the young control group, although sildenafil (3 and 10 mg/kg) did not alter these parameters in aged mice. Conclusions Our results show that sildenafil had anxiogenic effects in young as well as aged mice, but it enhanced locomotor activity only in the young mice in the EPM test. Thus, sildenafil seems to exert different effects on anxiety and locomotion in young and aged animals.
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Affiliation(s)
- Deniz Demirci
- Department of Trainer Education, Kocaeli University Physical Education and Sports School, Kocaeli, Turkey
| | - Oguz Mutlu
- Department of Pharmacology, Kocaeli University Medical Faculty, Kocaeli, Turkey
| | - Furuzan Akar
- Department of Pharmacology, Kocaeli University Medical Faculty, Kocaeli, Turkey
| | | | - Guner Ulak
- Department of Pharmacology, Kocaeli University Medical Faculty, Kocaeli, Turkey
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Reichelt AC, Lee JLC. Memory reconsolidation in aversive and appetitive settings. Front Behav Neurosci 2013; 7:118. [PMID: 24058336 PMCID: PMC3766793 DOI: 10.3389/fnbeh.2013.00118] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/20/2013] [Indexed: 11/16/2022] Open
Abstract
Memory reconsolidation has been observed across species and in a number of behavioral paradigms. The majority of memory reconsolidation studies have been carried out in Pavlovian fear conditioning and other aversive memory settings, with potential implications for the treatment of post-traumatic stress disorder. However, there is a growing literature on memory reconsolidation in appetitive reward-related memory paradigms, including translational models of drug addiction. While there appears to be substantial similarity in the basic phenomenon and underlying mechanisms of memory reconsolidation across unconditioned stimulus valence, there are also notable discrepancies. These arise both when comparing aversive to appetitive paradigms and also across different paradigms within the same valence of memory. We review the demonstration of memory reconsolidation across different aversive and appetitive memory paradigms, the commonalities and differences in underlying mechanisms and the conditions under which each memory undergoes reconsolidation. We focus particularly on whether principles derived from the aversive literature are applicable to appetitive settings, and also whether the expanding literature in appetitive paradigms is informative for fear memory reconsolidation.
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Affiliation(s)
- Amy C Reichelt
- School of Psychology, University of Birmingham Birmingham, UK
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Involvement of nNOS/NO/sGC/cGMP signaling pathway in cocaine sensitization and in the associated hippocampal alterations: does phosphodiesterase 5 inhibition help to drug vulnerability? Psychopharmacology (Berl) 2013; 229:41-50. [PMID: 23579428 DOI: 10.1007/s00213-013-3084-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/20/2013] [Indexed: 02/07/2023]
Abstract
RATIONALE Repeated cocaine administration induces behavioral sensitization in about 50 % of treated animals. Nitric oxide could be involved in the acquisition and maintenance of behavioral cocaine effects, probably by activation of neuronal nitric oxide synthase (nNOS)/NO/soluble guanylyl cyclase (sGC)/cyclic guanosine monophosphate (cGMP) signaling pathway, since inhibition of the nNOS enzyme attenuates development of sensitization in rats. On the other hand, increased cGMP availability by phosphodiesterase 5 inhibitors has been correlated to the misuse and recreational use of these agents and also to the concomitant use with illicit drugs in humans. Hippocampus is an important brain region for conditioning to general context previously associated to drug availability, influencing drug-seeking behavior and sensitization. Moreover, cocaine and other drugs of abuse can affect the strength of glutamate synapses in this structure, lastly modifying neuronal activity in main regions of the reward circuitry. OBJECTIVE The objective of this study is to determine whether the pharmacological manipulation of nNOS/NO/sGC/cGMP signaling pathway altered changes induced by repeated cocaine exposure. RESULTS The present investigation showed a relationship between behavioral cocaine sensitization, reduced threshold to generate long-term potentiation (LTP) in hippocampal dentate gyrus, and increased nNOS activity in this structure. However, when nNOS or sGC were inhibited, the number of sensitized animals was reduced, and the threshold to generate LTP was increased. The opposite occurred when cGMP availability was increased. CONCLUSION We demonstrate a key role of the nNOS activity and NO/sGC/cGMP signaling pathway in the development of cocaine sensitization and in the associated enhancement of hippocampal synaptic transmission.
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Uthayathas S, Parameshwaran K, Karuppagounder SS, Ahuja M, Dhanasekaran M, Suppiramaniam V. Selective inhibition of phosphodiesterase 5 enhances glutamatergic synaptic plasticity and memory in mice. Synapse 2013; 67:741-7. [PMID: 23620198 DOI: 10.1002/syn.21676] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 04/11/2013] [Indexed: 01/06/2023]
Abstract
Phosphodiesterases (PDEs) belong to a family of proteins that control metabolism of cyclic nucleotides. Targeting PDE5, for enhancing cellular function, is one of the therapeutic strategies for male erectile dysfunction. We have investigated whether in vivo inhibition of PDE5, which is expressed in several brain regions, will enhance memory and synaptic transmission in the hippocampus of healthy mice. We have found that acute administration of sildenafil, a specific PDE5 inhibitor, enhanced hippocampus-dependent memory tasks. To elucidate the underlying mechanism in the memory enhancement, effects of sildenafil on long-term potentiation (LTP) were measured. The level of LTP was significantly elevated, with concomitant increases in basal synaptic transmission, in mice treated with sildenafil (1 mg/kg/day) for 15 days compared to control mice. These results suggest that moderate PDE5 inhibition enhances memory by increasing synaptic plasticity and transmission in the hippocampus.
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Affiliation(s)
- Subramaniam Uthayathas
- Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, Alabama; Department of Pharmacology, Howard University College of Medicine, Washington, DC
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Phosphodiesterase-5 inhibitor sildenafil prevents neuroinflammation, lowers beta-amyloid levels and improves cognitive performance in APP/PS1 transgenic mice. Behav Brain Res 2013; 250:230-7. [PMID: 23685322 DOI: 10.1016/j.bbr.2013.05.017] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/05/2013] [Accepted: 05/09/2013] [Indexed: 12/30/2022]
Abstract
Memory deficit is a marker of Alzheimer's disease (AD) that has been highly associated with the dysfunction of cyclic GMP (cGMP) signaling and an ongoing inflammatory process. Phosphodiesterase-5 (PDE5) inhibitors prevent the breakdown of cGMP and are currently studied as a possible target for cognitive enhancement. However, it is still unknown whether inhibition of PDE5 reversed β-amyloid peptide (Aβ)-induced neuroinflammation in APP/PS1 transgenic (Tg APP/PS1) mice. The present study evaluated the cognitive behaviors, inflammatory mediators, and cGMP/PKG/pCREB signaling in 15-month-old Tg APP/PS1 mice and age-matched wild-type (WT) mice that were treated with PDE5 inhibitor sildenafil and the inhibitor of cGMP-dependent protein kinase Rp-8-Br-PET-cGMPS. In comparison with WT mice, Tg APP/PS1 mice were characterized by impaired cognitive ability, neuroinflammatory response, and down-regulated cGMP signaling. Sildenafil reversed these memory deficits and cGMP/PKG/pCREB signaling dysfunction; it also reduced both the soluble Aβ1-40 and Aβ1-42 levels in the hippocampus. These effects of sildenafil were prevented by intra-hippocampal infusion of the Rp-8-Br-PET-cGMPS. These results suggest that sildenafil could restore cognitive deficits in Tg APP/PS1 mice by the regulation of PKG/pCREB signaling, anti-inflammatory response and reduction of Aβ levels.
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García-Osta A, Cuadrado-Tejedor M, García-Barroso C, Oyarzábal J, Franco R. Phosphodiesterases as therapeutic targets for Alzheimer's disease. ACS Chem Neurosci 2012; 3:832-44. [PMID: 23173065 DOI: 10.1021/cn3000907] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 10/01/2012] [Indexed: 01/10/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia among the elderly. In AD patients, memory loss is accompanied by the formation of beta-amyloid plaques and the appearance of tau in a pathological form. Given the lack of effective treatments for AD, the development of new management strategies for these patients is critical. The continued failure to find effective therapies using molecules aimed at addressing the anti-beta amyloid pathology has led researchers to focus on other non-amyloid-based approaches to restore memory function. Promising non-amyloid related candidate targets include phosphosdiesterases (PDEs), and indeed, Rolipram, a specific PDE4 inhibitor, was the first compound found to effectively restore cognitive deficits in animal models of AD. More recently, PDE5 inhibitors have also been shown to effectively restore memory function. Accordingly, inhibitors of other members of the PDE family may also improve memory performance in AD and non-AD animal models. Hence, in this review, we will summarize the data supporting the use of PDE inhibitors as cognitive enhancers and we will discuss the possible mechanisms of action underlying these effects. We shall also adopt a medicinal chemistry perspective that leads us to propose the most promising PDE candidates on the basis of inhibitor selectivity, brain distribution, and mechanism of action.
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Affiliation(s)
- Ana García-Osta
- Molecular and Cell Neuropharmacology
Laboratory, Neurosciences Division, CIMA (Centro de investigación Médica Aplicada), Avda Pio
XII, Pamplona, Spain
| | - Mar Cuadrado-Tejedor
- Molecular and Cell Neuropharmacology
Laboratory, Neurosciences Division, CIMA (Centro de investigación Médica Aplicada), Avda Pio
XII, Pamplona, Spain
| | - Carolina García-Barroso
- Molecular and Cell Neuropharmacology
Laboratory, Neurosciences Division, CIMA (Centro de investigación Médica Aplicada), Avda Pio
XII, Pamplona, Spain
| | - Julen Oyarzábal
- Molecular and Cell Neuropharmacology
Laboratory, Neurosciences Division, CIMA (Centro de investigación Médica Aplicada), Avda Pio
XII, Pamplona, Spain
- Small
Molecule Discovery Platform, CIMA (Centro
de investigación Médica
Aplicada), Avda Pio XII, Pamplona, Spain
| | - Rafael Franco
- Molecular and Cell Neuropharmacology
Laboratory, Neurosciences Division, CIMA (Centro de investigación Médica Aplicada), Avda Pio
XII, Pamplona, Spain
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Besnard A, Caboche J, Laroche S. Reconsolidation of memory: A decade of debate. Prog Neurobiol 2012; 99:61-80. [PMID: 22877586 DOI: 10.1016/j.pneurobio.2012.07.002] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 06/13/2012] [Accepted: 07/08/2012] [Indexed: 10/28/2022]
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Sildenafil influences the anticonvulsant activity of vigabatrin and gabapentin in the timed pentylenetetrazole infusion test in mice. Prog Neuropsychopharmacol Biol Psychiatry 2012; 39:129-35. [PMID: 22683320 DOI: 10.1016/j.pnpbp.2012.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 05/18/2012] [Accepted: 05/30/2012] [Indexed: 11/23/2022]
Abstract
Sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, has recently been reported to affect convulsant activity in some animal models of seizures and epilepsy. Moreover, its influence on the protective activity of some antiepileptic drugs (AEDs) was also noted. The aim of the present study was to investigate the effect of sildenafil on the anticonvulsant potential of gabapentin (GBP) and vigabatrin (VGB) in the timed intravenous (i.v.) pentylenetetrazole (PTZ) test in mice. The chimney test, the passive avoidance task and the grip strength test were used to estimate some possible side effects caused by the studied AEDs and their combinations with sildenafil. Total brain and free plasma concentrations of GBP and VGB were determined to evaluate the characteristics of interactions. Our studies revealed that GBP (25-100 mg/kg) increases the threshold for the forelimb tonic extension, whereas VGB raises thresholds both, for myoclonic (200-600 mg/kg) and generalized clonic (400-600 mg/kg) seizures in the used model of seizures. GBP at sub-effective dose of 12.5 mg/kg co-administered with sildenafil at doses of 10 and 20 mg/kg significantly increases the threshold for tonic seizures in the i.v. PTZ test in mice. Combination of sub-effective dose of VGB (200 mg/kg) with sildenafil at a dose of 5mg/kg also showed significant anticonvulsant activity against clonic seizures. The studied AEDs and their combinations with sildenafil did not produce any changes in the motor coordination, long-term memory and muscular strength in mice. Sildenafil did not influence total brain and free plasma concentrations of GBP and VGB. Interactions between the studied AEDs and sildenafil were pharmacodynamic in nature and for that reason they are worthy of consideration in the clinical practice.
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Abstract
The search for reconsolidation blockers may uncover clinically relevant drugs for disrupting memories of significant stressful life experiences, such as those underlying the posttraumatic stress disorder. Considering the safety of systemically administered cannabidiol (CBD), the major non-psychotomimetic component of Cannabis sativa, to animals and humans, the present study sought to investigate whether and how this phytocannabinoid (3-30 mg/kg intraperitoneally; i.p.) could mitigate an established memory, by blockade of its reconsolidation, evaluated in a contextual fear-conditioning paradigm in rats. We report that CBD is able to disrupt 1- and 7-days-old memories when administered immediately, but not 6 h, after their retrieval for 3 min, with the dose of 10 mg/kg being the most effective. This effect persists in either case for at least 1 week, but is prevented when memory reactivation was omitted, or when the cannabinoid type-1 receptors were antagonized selectively with AM251 (1.0 mg/kg). Pretreatment with the serotonin type-1A receptor antagonist WAY100635, however, failed to block CBD effects. These results highlight that recent and older fear memories are equally vulnerable to disruption induced by CBD through reconsolidation blockade, with a consequent long-lasting relief in contextual fear-induced freezing. Importantly, this CBD effect is dependent on memory reactivation, restricted to time window of <6 h, and is possibly dependent on cannabinoid type-1 receptor-mediated signaling mechanisms. We also observed that the fear memories disrupted by CBD treatment do not show reinstatement or spontaneous recovery over 22 days. These findings support the view that reconsolidation blockade, rather than facilitated extinction, accounts for the aforementioned CBD results in our experimental conditions.
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Reneerkens OA, Rutten K, Akkerman S, Blokland A, Shaffer CL, Menniti FS, Steinbusch HW, Prickaerts J. Phosphodiesterase type 5 (PDE5) inhibition improves object recognition memory: Indications for central and peripheral mechanisms. Neurobiol Learn Mem 2012; 97:370-9. [DOI: 10.1016/j.nlm.2012.02.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 02/16/2012] [Accepted: 02/27/2012] [Indexed: 01/10/2023]
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Bazzaz B, Lavaei S, Hosseinzadeh H. Interaction of methylxanthines and gentamicin against Staphylococcus aureus and Pseudomonas aeruginosa: role of phosphodiesterase inhibition. Acta Microbiol Immunol Hung 2012; 59:13-20. [PMID: 22510283 DOI: 10.1556/amicr.59.2012.1.2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous studies showed that methylxanthines increased the antimicrobial activity of gentamicin against Staphylococcus aureus and Pseudomonas aeruginosa. In this study, the effect of non-selective phosphodiesterase (PDE) inhibitors (methylxanthines: aminophylline and caffeine) and partially selective PDE inhibitors, dipyridamole and sildenafil, was evaluated on the antimicrobial activity of gentamicin using checkerboard method. Aminophylline at concentrations of 0.5 and 1 mg/ml reduced the minimal inhibitory concentration (MIC) of gentamicin (2 μg/ml) 2 and 4 times against S. aureus, and at concentrations of 0.5 and 2 mg/ml reduced the MIC of gentamicin (4 μg/ml) 2 and 4 times, respectively, against P. aeruginosa. Caffeine at concentrations of 1 and 2 mg/ml reduced the MIC of gentamicin (2 μg/ml) 4 and 32 times against S. aureus, and at concentrations of 0.12 and 2 mg/ml reduced the MIC of gentamicin (4 μg/ml) 2 and 4 times, respectively, against P. aeruginosa. However, dipyridamole and sildenafil (32 μg/ml) did not show any effect on MIC of gentamicin against S. aureus and P. aeruginosa. These results suggest that methylxanthines could increase gentamicin effects against S. aureus and P. aeruginosa but this effect is not mediated by inhibition of PDE 5, 6, 8, 10 and 11.
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Affiliation(s)
- Bibi Bazzaz
- 1 Mashhad University of Medical Sciences Biotechnology Research Center, School of Pharmacy Mashhad Iran
| | | | - Hossein Hosseinzadeh
- 3 Mashhad University of Medical Sciences Pharmaceutical Research Center, School of Pharmacy Mashhad Iran
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