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Razavi SM, Khayatan D, Arab ZN, Momtaz S, Zare K, Jafari RM, Dehpour AR, Abdolghaffari AH. Licofelone, a potent COX/5-LOX inhibitor and a novel option for treatment of neurological disorders. Prostaglandins Other Lipid Mediat 2021; 157:106587. [PMID: 34517113 DOI: 10.1016/j.prostaglandins.2021.106587] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/17/2021] [Accepted: 09/04/2021] [Indexed: 12/13/2022]
Abstract
Neurological disorders result in disability and morbidity. Neuroinflammation is a key factor involved in progression or resolution of a series of neurological disorders like Huntington disease (HD), Parkinson's disease (PD), Alzheimer's disease (AD), Spinal Cord Injury (SCI), and Seizure. Thereby, anti-inflammatory drugs have been developed to improve the neurodegenerative impairments. Licofelone is an approved osteoarthritis drug that inhibits both the COX (cyclooxygenase) and 5-LOX (lipoxygenase) pathways. Licofelone has pain-relieving and anti-inflammatory effects and it was shown to have neuroprotective properties in the central nervous system, which is implicated in its regulatory effect on the COX/5-LOX pathway, inflammatory cytokines, and immune responses. In this study, we briefly review the various features of neurological disorders and the function of COX/LOX in their flare up and current pharmacological products for their management. Moreover, this review attempts to summarize potential therapeutics that target the immune responses within the central nervous system. A better understanding of the interactions between Licofelone and the nervous systems will be crucial to demonstrate the possible efficacy of Licofelone in neurological disorders.
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Affiliation(s)
- Seyed Mehrad Razavi
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Danial Khayatan
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Zahra Najafi Arab
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Saeideh Momtaz
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Tehran, Iran; Department of Toxicology and Pharmacology, School of Pharmacy, and Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran; GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Kimia Zare
- School of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
| | - Razieh Mohammad Jafari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Amir Hossein Abdolghaffari
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran; Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Tehran, Iran; Department of Toxicology and Pharmacology, School of Pharmacy, and Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran; GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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Paudel YN, Angelopoulou E, Piperi C, Gnatkovsky V, Othman I, Shaikh MF. From the Molecular Mechanism to Pre-clinical Results: Anti-epileptic Effects of Fingolimod. Curr Neuropharmacol 2021; 18:1126-1137. [PMID: 32310049 PMCID: PMC7709153 DOI: 10.2174/1570159x18666200420125017] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/13/2020] [Accepted: 04/14/2020] [Indexed: 02/08/2023] Open
Abstract
Epilepsy is a devastating neurological condition characterized by long-term tendency to generate unprovoked seizures, affecting around 1-2% of the population worldwide. Epilepsy is a serious health concern which often associates with other neurobehavioral comorbidities that further worsen disease conditions. Despite tremendous research, the mainstream anti-epileptic drugs (AEDs) exert only symptomatic relief leading to 30% of untreatable patients. This reflects the complexity of the disease pathogenesis and urges the precise understanding of underlying mechanisms in order to explore novel therapeutic strategies that might alter the disease progression as well as minimize the epilepsy-associated comorbidities. Unfortunately, the development of novel AEDs might be a difficult process engaging huge funds, tremendous scientific efforts and stringent regulatory compliance with a possible chance of end-stage drug failure. Hence, an alternate strategy is drug repurposing, where anti-epileptic effects are elicited from drugs that are already used to treat non-epileptic disorders. Herein, we provide evidence of the anti-epileptic effects of Fingolimod (FTY720), a modulator of sphingosine-1-phosphate (S1P) receptor, USFDA approved already for Relapsing-Remitting Multiple Sclerosis (RRMS). Emerging experimental findings suggest that Fingolimod treatment exerts disease-modifying anti-epileptic effects based on its anti-neuroinflammatory properties, potent neuroprotection, anti-gliotic effects, myelin protection, reduction of mTOR signaling pathway and activation of microglia and astrocytes. We further discuss the underlying molecular crosstalk associated with the anti-epileptic effects of Fingolimod and provide evidence for repurposing Fingolimod to overcome the limitations of current AEDs.
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Affiliation(s)
- Yam Nath Paudel
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Efthalia Angelopoulou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Vadym Gnatkovsky
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Iekhsan Othman
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Mohd Farooq Shaikh
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
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Lalitha S, Minz RW, Medhi B. Understanding the controversial drug targets in epilepsy and pharmacoresistant epilepsy. Rev Neurosci 2018; 29:333-345. [PMID: 29211683 DOI: 10.1515/revneuro-2017-0043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/11/2017] [Indexed: 12/18/2022]
Abstract
Accumulating experimental data suggests a number of successful drug targets against epilepsy which eventually failed in the clinical setup. Mammalian target of rapamycin inhibitors, multi-drug resistance transporter inhibitors, cyclo-oxygenase-2 inhibitors, statins, etc. are the most promising and well studied among them. Drugs aiming at these targets produced beneficial response in most of the in vitro and in vivo seizure models. However, in certain situations, they have produced differential rather controversial results. Their effects varied with the seizure model, species, time and route of administration, different drugs from the same class, etc. This review emphasises on such drugs which presented with variability in their beneficial effects against seizures and epilepsy. This review critically summarises the preclinical evidence of these targets in the context of seizures and the probable reasons for their variability and clinical failures.
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Affiliation(s)
- Sree Lalitha
- Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Ranjana W Minz
- Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Bikash Medhi
- Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
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Clossen BL, Reddy DS. Novel therapeutic approaches for disease-modification of epileptogenesis for curing epilepsy. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1519-1538. [PMID: 28179120 PMCID: PMC5474195 DOI: 10.1016/j.bbadis.2017.02.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 11/16/2022]
Abstract
This article describes the recent advances in epileptogenesis and novel therapeutic approaches for the prevention of epilepsy, with a special emphasis on the pharmacological basis of disease-modification of epileptogenesis for curing epilepsy. Here we assess animal studies and human clinical trials of epilepsy spanning 1982-2016. Epilepsy arises from a number of neuronal factors that trigger epileptogenesis, which is the process by which a brain shifts from a normal physiologic state to an epileptic condition. The events precipitating these changes can be of diverse origin, including traumatic brain injury, cerebrovascular damage, infections, chemical neurotoxicity, and emergency seizure conditions such as status epilepticus. Expectedly, the molecular and system mechanisms responsible for epileptogenesis are not well defined or understood. To date, there is no approved therapy for the prevention of epilepsy. Epigenetic dysregulation, neuroinflammation, and neurodegeneration appear to trigger epileptogenesis. Targeted drugs are being identified that can truly prevent the development of epilepsy in at-risk people. The promising agents include rapamycin, COX-2 inhibitors, TRK inhibitors, epigenetic modulators, JAK-STAT inhibitors, and neurosteroids. Recent evidence suggests that neurosteroids may play a role in modulating epileptogenesis. A number of promising drugs are under investigation for the prevention or modification of epileptogenesis to halt the development of epilepsy. Some drugs in development appear rational for preventing epilepsy because they target the initial trigger or related signaling pathways as the brain becomes progressively more prone to seizures. Additional research into the target validity and clinical investigation is essential to make new frontiers in curing epilepsy.
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Affiliation(s)
- Bryan L Clossen
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA.
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Du C, Zheng F, Wang X. Exploring novel AEDs from drugs used for treatment of non-epileptic disorders. Expert Rev Neurother 2016; 16:449-61. [PMID: 27010915 DOI: 10.1586/14737175.2016.1158101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Epilepsy is a chronic neurological disease. Although many anti-epileptic drugs (AEDs) have been developed for clinical use, they have no effect on 20-30% of patients and do not generally prevent epileptogenesis. Because of the long development cycle for new AEDs and the high cost, increasing efforts are being made to find anti-epileptic effects among drugs that are already listed for the treatment of other diseases and repurpose them as potential anti-epileptic treatments. Here, we review the progress that has been made in this field as a result of animal and clinical trials of drugs such as rapamycin, everolimus, losartan, celecoxib, bumetanide and other non-epileptic drugs. These drugs can prevent the epileptogenesis, reduce the epileptic pathological changes, and even be used to treat intractable epilepsy. Their mechanisms of action are completely different from those of existing AEDs, prompting researchers to change their perspectives in the search for new AEDs.
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Affiliation(s)
- Chao Du
- a Department of Neurology , The First Affiliated Hospital of Chongqing Medical University , Chongqing , China
| | - Fangshuo Zheng
- a Department of Neurology , The First Affiliated Hospital of Chongqing Medical University , Chongqing , China
| | - Xuenfeng Wang
- a Department of Neurology , The First Affiliated Hospital of Chongqing Medical University , Chongqing , China
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A COX/5-LOX Inhibitor Licofelone Revealed Anticonvulsant Properties Through iNOS Diminution in Mice. Neurochem Res 2015. [DOI: 10.1007/s11064-015-1669-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Serrano E, Kanner AM. Recent treatment advances and novel therapeutic approaches in epilepsy. F1000PRIME REPORTS 2015; 7:61. [PMID: 26097734 PMCID: PMC4447056 DOI: 10.12703/p7-61] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The purpose of this article is to review recent advances in the treatment of epilepsy. It includes five antiepileptic drugs that have been recently added to the pharmacologic armamentarium and surgical techniques that have been developed in the last few years. Finally, we review ongoing research that may have a potential role in future treatments of epilepsy.
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Citraro R, Leo A, Marra R, De Sarro G, Russo E. Antiepileptogenic effects of the selective COX-2 inhibitor etoricoxib, on the development of spontaneous absence seizures in WAG/Rij rats. Brain Res Bull 2015; 113:1-7. [DOI: 10.1016/j.brainresbull.2015.02.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Revised: 02/09/2015] [Accepted: 02/13/2015] [Indexed: 11/25/2022]
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Katyal J, Kumar H, Gupta YK. Anticonvulsant activity of the cyclooxygenase-2 (COX-2) inhibitor etoricoxib in pentylenetetrazole-kindled rats is associated with memory impairment. Epilepsy Behav 2015; 44:98-103. [PMID: 25660085 DOI: 10.1016/j.yebeh.2014.12.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/20/2014] [Accepted: 12/22/2014] [Indexed: 11/25/2022]
Abstract
PURPOSE Various selective and nonselective cyclooxygenase (COX) inhibitors are known to have effects on development and progression of seizures. In the present study, the effect of the selective COX-2 inhibitor etoricoxib on seizures, oxidative stress, and learning and memory was studied. METHOD Male Wistar rats were kindled using subconvulsant dose of pentylenetetrazole (PTZ) (30mg/kg, i.p.), on alternating days until animals were fully kindled. After a one-week PTZ-free period, kindled rats were challenged with PTZ 30mg/kg, and the latency, duration, and severity of seizures were recorded. Etoricoxib was then administered intraperitoneally at 1mg/kg and 10mg/kg in kindled rats for nine days (days 6-14). On the ninth day of etoricoxib treatment, PTZ challenge (30mg/kg) was given, and seizure parameters were noted. On day 15, behavioral assessment was carried out. The Morris water maze (MWM) apparatus and the passive avoidance (PA) apparatus were used for studying cognitive impairment. The rats were then sacrificed, and malondialdehyde (MDA) and glutathione (GSH), markers of oxidative stress, were estimated in the brain samples. RESULTS Etoricoxib at lower dose (1mg/kg) had an anticonvulsant effect which was reduced or reversed at higher dose (10mg/kg). Etoricoxib also impaired the learning and memory in rats as tested by passive avoidance and Morris water maze tests. CONCLUSION The results of the present study suggest that use of etoricoxib, especially at low dose, in patients with epilepsy may not be detrimental with regard to seizure control. However, attention should be paid to cognitive parameters.
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Affiliation(s)
- Jatinder Katyal
- Neuropharmacology Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi 110029, India.
| | - Hemant Kumar
- Neuropharmacology Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Yogendra Kumar Gupta
- Neuropharmacology Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi 110029, India
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Rathor N, Arora T, Manocha S, Patil AN, Mediratta PK, Sharma KK. Anticonvulsant activity of Aloe vera leaf extract in acute and chronic models of epilepsy in mice. J Pharm Pharmacol 2013; 66:477-85. [DOI: 10.1111/jphp.12181] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 10/15/2013] [Indexed: 01/18/2023]
Abstract
Abstract
Objectives
The effect of Aloe vera in epilepsy has not yet been explored. This study was done to explore the effect of aqueous extract of Aloe vera leaf powder on three acute and one chronic model of epilepsy.
Methods
In acute study, aqueous extract of Aloe vera leaf (extract) powder was administered in doses 100, 200 and 400 mg/kg p.o. Dose of 400 mg/kg of Aloe vera leaf extract was chosen for chronic administration. Oxidative stress parameters viz. malondialdehyde (MDA) and reduced glutathione (GSH) were also estimated in brain of kindled animals.
Key findings
In acute study, Aloe vera leaf (extract) powder in a dose-dependent manner significantly decreased duration of tonic hind limb extension in maximal electroshock seizure model, increased seizure threshold current in increasing current electroshock seizure model, and increased latency to onset and decreased duration of clonic convulsion in pentylenetetrazole (PTZ) model as compared with control group. In chronic study, Aloe vera leaf (extract) powder prevented progression of kindling in PTZ-kindled mice. Aloe vera leaf (extract) powder 400 mg/kg p.o. also reduced brain levels of MDA and increased GSH levels as compared to the PTZ-kindled non-treated group.
Conclusions
The results of study showed that Aloe vera leaf (extract) powder possessed significant anticonvulsant and anti-oxidant activity.
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Affiliation(s)
- Naveen Rathor
- Department of Pharmacology, University College of Medical Sciences, Delhi, India
| | - Tarun Arora
- Department of Pharmacology, Vardhman Mahavir Medical College, New Delhi, India
| | - Sachin Manocha
- Department of Pharmacology, Vardhman Mahavir Medical College, New Delhi, India
| | - Amol N Patil
- Department of Pharmacology, Vardhman Mahavir Medical College, New Delhi, India
| | - Pramod K Mediratta
- Department of Pharmacology, Sharda Institute of Medical Sciences and Research, Greater Noida, Uttar Pradesh, India
| | - Krishna K Sharma
- Department of Pharmacology, Sharda Institute of Medical Sciences and Research, Greater Noida, Uttar Pradesh, India
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Auvin S. Fatty acid oxidation and epilepsy. Epilepsy Res 2012; 100:224-8. [DOI: 10.1016/j.eplepsyres.2011.05.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 05/16/2011] [Accepted: 05/17/2011] [Indexed: 10/17/2022]
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milan, Italy.
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Shin EJ, Jeong JH, Chung YH, Kim WK, Ko KH, Bach JH, Hong JS, Yoneda Y, Kim HC. Role of oxidative stress in epileptic seizures. Neurochem Int 2011; 59:122-37. [PMID: 21672578 DOI: 10.1016/j.neuint.2011.03.025] [Citation(s) in RCA: 286] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 03/27/2011] [Accepted: 03/28/2011] [Indexed: 11/16/2022]
Abstract
Oxidative stress resulting from excessive free-radical release is likely implicated in the initiation and progression of epilepsy. Therefore, antioxidant therapies aimed at reducing oxidative stress have received considerable attention in epilepsy treatment. However, much evidence suggests that oxidative stress does not always have the same pattern in all seizures models. Thus, this review provides an overview aimed at achieving a better understanding of this issue. We summarize work regarding seizure models (i.e., genetic rat models, kainic acid, pilocarpine, pentylenetetrazol, and trimethyltin), oxidative stress as an etiologic factor in epileptic seizures (i.e., impairment of antioxidant systems, mitochondrial dysfunction, involvement of redox-active metals, arachidonic acid pathway activation, and aging), and antioxidant strategies for seizure treatment. Combined, this review highlights pharmacological mechanisms associated with oxidative stress in epileptic seizures and the potential for neuroprotection in epilepsy that targets oxidative stress and is supported by effective antioxidant treatment.
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Affiliation(s)
- Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 200-701, South Korea
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Régnier A, Vicaut E, Mraovitch S. Aggravation of seizure-associated microvascular injuries by ibuprofen may involve multiple pathways. Epilepsia 2010; 51:2412-22. [DOI: 10.1111/j.1528-1167.2009.02480.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Mehla J, Reeta K, Gupta P, Gupta YK. Protective effect of curcumin against seizures and cognitive impairment in a pentylenetetrazole-kindled epileptic rat model. Life Sci 2010; 87:596-603. [DOI: 10.1016/j.lfs.2010.09.006] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/21/2010] [Accepted: 09/01/2010] [Indexed: 11/29/2022]
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Jayaraman R, Manisenthil K, Anitha T, Joshi VD, Palei NN, Gajera K, Ladani K. Influence of etoricoxib on anticonvulsant activity of phenytoin and diazepam in experimental seizure models in mice. J Pharm Pharmacol 2010; 62:873-82. [DOI: 10.1211/jpp.62.05.0008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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van Vliet EA, Zibell G, Pekcec A, Schlichtiger J, Edelbroek PM, Holtman L, Aronica E, Gorter JA, Potschka H. COX-2 inhibition controls P-glycoprotein expression and promotes brain delivery of phenytoin in chronic epileptic rats. Neuropharmacology 2009; 58:404-12. [PMID: 19786037 DOI: 10.1016/j.neuropharm.2009.09.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 09/21/2009] [Accepted: 09/21/2009] [Indexed: 12/13/2022]
Abstract
Epileptic seizures drive expression of the blood-brain barrier efflux transporter P-glycoprotein via a glutamate/cyclooxygenase-2 mediated signalling pathway. Targeting this pathway may represent an innovative approach to control P-glycoprotein expression in the epileptic brain and to enhance brain delivery of antiepileptic drugs. Therefore, we tested the effect of specific cyclooxygenase-2 inhibition on P-glycoprotein expression in two different status epilepticus models. Moreover, the impact of a cyclooxygenase-2 inhibitor on expression of the efflux transporter and on brain delivery of an antiepileptic drug was evaluated in rats with recurrent spontaneous seizures. The highly selective cyclooxygenase-2 inhibitors SC-58236 and NS-398 both counteracted the status epilepticus-associated increase in P-glycoprotein expression in the parahippocampal cortex and the ventral hippocampus. In line with our working hypothesis, a sub-chronic 2-week treatment with SC-58236 in the chronic epileptic state kept P-glycoprotein expression at control levels. As described previously, enhanced P-glycoprotein expression in chronic epileptic rats was associated with a significant reduction in the brain penetration of the antiepileptic drug phenytoin. Importantly, the brain delivery of phenytoin was significantly enhanced by sub-chronic cyclooxygenase-2 inhibition in rats with recurrent seizures. In conclusion, the data substantiate targeting of cyclooxygenase-2 in the chronic epileptic brain as a promising strategy to control the expression levels of P-glycoprotein despite recurrent seizure activity. Cyclooxygenase-2 inhibition may therefore help to increase concentrations of antiepileptic drugs at the target sites in the epileptic brain. It needs to be further evaluated whether the approach also enhances efficacy.
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Affiliation(s)
- Erwin A van Vliet
- Epilepsy Institute in The Netherlands Foundation (SEIN), Heemstede, The Netherlands
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Zhang HJ, Sun RP, Lei GF, Yang L, Liu CX. Cyclooxygenase-2 inhibitor inhibits hippocampal synaptic reorganization in pilocarpine-induced status epilepticus rats. J Zhejiang Univ Sci B 2009; 9:903-15. [PMID: 18988310 DOI: 10.1631/jzus.b0820018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To examine modulations caused by cyclooxygenase-2 (COX-2) inhibitors on altered microenvironments and overbalanced neurotransmitters in pilocarpine-induced epileptic status rats and to investigate possible mechanisms. METHODS Celecoxib (a COX-2 inhibitor) was administered 45 min prior to pilocarpine administration. The effects of COX-2 inhibitors on mIPSCs (miniature GABAergic inhibitory postsynaptic currents) of CA3 pyramidal cells in the hippocampus were recorded. Expressions of COX-2, c-Fos, newly generated neurons, and activated microgliosis were analyzed by immunohistochemistry, and expressions of alpha-subunit of gamma-amino butyric acid (GABA(A)) receptors and mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK) activity were detected by Western blotting. RESULTS Pretreatment with celecoxib showed protection against pilocarpine-induced seizures. Celecoxib prevented microglia activation in the hilus and inhibited the abnormal neurogenesis and astrogliosis in the hippocampus by inhibiting MAPK/ERK activity and c-Fos transcription. Celecoxib also up-regulated the expression of GABA(A) receptors. NS-398 (N-2-cyclohexyloxy-4-nitrophenyl-methanesulfonamide), another COX-2 inhibitor, enhanced the frequency and decay time of mIPSCs. CONCLUSION The COX-2 inhibitor celecoxib decreased neuronal excitability and prevented epileptogenesis in pilocarpine-induced status epilepticus rats. Celecoxib regulates synaptic reorganization by inhibiting astrogliosis and ectopic neurogenesis by attenuating MAPK/ERK signal activity, mediated by a GABAergic mechanism.
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Affiliation(s)
- Hai-Ju Zhang
- Department of Pediatrics, Renmin Hospital of Wuhan University, Wuhan 430060, China
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Andrade C, Singh NM, Thyagarajan S, Nagaraja N, Sanjay Kumar Rao N, Suresh Chandra J. Possible glutamatergic and lipid signalling mechanisms in ECT-induced retrograde amnesia: experimental evidence for involvement of COX-2, and review of literature. J Psychiatr Res 2008; 42:837-50. [PMID: 17937934 DOI: 10.1016/j.jpsychires.2007.08.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 07/31/2007] [Accepted: 08/29/2007] [Indexed: 11/15/2022]
Abstract
We sought to explore nonselective vs. selective COX mechanisms in ECS-induced retrograde amnesia using indomethacin and celecoxib as in vivo probes. Adult Wistar rats (n=72) which showed adequate learning on a passive avoidance task received 5 once-daily 30 mC true or sham ECS. During the learning and ECS periods, indomethacin (4 mg/kg/day), celecoxib (15 mg/kg/day), or vehicle were orally administered. One day after the fifth ECS, recall of pre-ECS learning was tested. There were no baseline or pre-ECS differences in learning between groups. ECS seizure duration did not differ across groups. ECS-treated rats showed impaired recall in the vehicle but not indomethacin and celecoxib groups. Celecoxib but not indomethacin significantly protected against ECS-induced retrograde amnesia. We interpret these results as follows: ECS may impair cognition by pathologically upregulating glutmatergic signalling, thereby causing cation and water influx, oxidative stress, and saturation of hippocampal LTP. These may result from glutamatergic disinhibition through COX-2-mediated removal of endogenous cannabinoids, and by ECS-activated, NMDA-mediated upregulation of platelet activating factor and COX-2 signalling pathways. Thus, indomethacin and celecoxib, by inhibiting COX-2, may protect against ECS-induced amnesia. Furthermore, COX-2 mediated increase in hippocampal kynurenic acid may impair glutamate-dependent learning and memory processes at ionotropic glutamatergic receptor sites; the inhibition of kynurenic acid synthesis by celecoxib and its induction by indomethacin may explain the greater benefits with celecoxib. These findings suggest new avenues for the study of the neurobiology of ECT-induced amnesia and the attenuation thereof.
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Affiliation(s)
- Chittaranjan Andrade
- Department of Psychopharmacology, National Institute of Mental Health and Neurosciences, Bangalore, India.
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21
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Haiju Z, Ruopeng S, Gefei L, Lu Y, Chunxi L. Cyclooxygenase-2 inhibitor inhibits the hippocampal synaptic reorganization by inhibiting MAPK/ERK activity and modulating GABAergic transmission in pilocarpine-induced status epilepticus rats. Med Chem Res 2008. [DOI: 10.1007/s00044-008-9109-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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22
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Modulation of pentylenetetrazol-induced seizures by prostaglandin E2 receptors. Neuroscience 2008; 152:1110-8. [PMID: 18329178 DOI: 10.1016/j.neuroscience.2008.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 12/19/2007] [Accepted: 01/10/2008] [Indexed: 11/22/2022]
Abstract
There is evidence that prostaglandin E2 (PGE2) facilitates the seizures induced by pentylenetetrazol (PTZ), but the role of PGE2 receptors (EPs) in the development of seizures has not been evaluated to date. In the current study we investigated whether selective EP ligands alter PTZ-induced seizures in adult male Wistar rats by electrographic methods. Selective antagonists for EP1 (SC-19220, 10 nmol, i.c.v.), EP3 (L-826266, 1 nmol, i.c.v.) and EP4 (L-161982, 750 pmol, i.c.v.) receptors, and the selective EP2 agonist butaprost (100 pmol, i.c.v.) increased the latency for clonic and generalized tonic-clonic seizures induced by PTZ. These data constitute pharmacological evidence supporting a role for EPs in the seizures induced by PTZ. Although more studies are necessary to fully evaluate the anticonvulsant role these compounds and their use in the clinics, EP ligands may represent new targets for drug development for convulsive disorders.
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23
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Bauer B, Hartz AMS, Pekcec A, Toellner K, Miller DS, Potschka H. Seizure-induced up-regulation of P-glycoprotein at the blood-brain barrier through glutamate and cyclooxygenase-2 signaling. Mol Pharmacol 2007; 73:1444-53. [PMID: 18094072 DOI: 10.1124/mol.107.041210] [Citation(s) in RCA: 190] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased expression of drug efflux transporters at the blood-brain barrier accompanies epileptic seizures and complicates therapy with antiepileptic drugs. This study is concerned with identifying mechanistic links that connect seizure activity to increased P-glycoprotein expression at the blood-brain barrier. In this regard, we tested the hypothesis that seizures increase brain extracellular glutamate, which signals through an N-methyl-d-aspartate (NMDA) receptor and cyclooxygenase-2 (COX-2) in brain capillaries to increase blood-brain barrier P-glycoprotein expression. Consistent with this hypothesis, exposing isolated rat or mouse brain capillaries to glutamate for 15 to 30 min increased P-glycoprotein expression and transport activity hours later. These increases were blocked by 5H-dibenzo[a,d]cyclohepten-5,10-imine (dizocilpine maleate) (MK-801), an NMDA receptor antagonist, and by celecoxib, a selective COX-2 inhibitor; no such glutamate-induced increases were seen in brain capillaries from COX-2-null mice. In rats, intracerebral microinjection of glutamate caused locally increased P-glycoprotein expression in brain capillaries. Moreover, using a pilocarpine status epilepticus rat model, we observed seizure-induced increases in capillary P-glycoprotein expression that were attenuated by administration of indomethacin, a COX inhibitor. Our findings suggest that brain uptake of some antiepileptic drugs can be enhanced through COX-2 inhibition. Moreover, they provide insight into one mechanism that underlies drug resistance in epilepsy and possibly other central nervous system disorders.
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Affiliation(s)
- Björn Bauer
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University Munich, Koeniginstr. 16, 80539 Munich, Germany
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24
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Involvement of endogenous prostaglandin F2alpha on kainic acid-induced seizure activity through FP receptor: the mechanism of proconvulsant effects of COX-2 inhibitors. Brain Res 2007; 1193:153-61. [PMID: 18178179 DOI: 10.1016/j.brainres.2007.12.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 12/03/2007] [Accepted: 12/03/2007] [Indexed: 11/24/2022]
Abstract
COX-2 and prostaglandins (PGs) might play important roles in epilepsy. In kainic acid-induced seizures, the brain largely increases PGD(2), first from COX-1 and later COX-2-induced PGF(2alpha). Pre-treatment with COX-2 inhibitors such as indomethacin, nimesulide, and celecoxib is known to aggravate kainic acid (KA)-induced seizure activity. However it is not known whether the proconvulsant effect of those non-steroidal anti-inflammatory drugs (NSAIDs) is due to changes in endogenous prostaglandins (PGs), or what types of PGs are involved. The purpose of this study was to determine the effect of intracisternally administered PGs on KA-induced seizures aggravated by pre- or post-treatment with COX-2 inhibitors. Systemic KA injection (10 mg/kg i.p.) in mice evoked mild seizure activity within 15 min. PGs were administrated intracisternally 20 min prior to KA administration. COX inhibitors (indomethacin, nimesulide, and ketoprofen, 10 mg/kg i.p.) were injected 1 h before or 15 min after KA. An additional COX-2 inhibitor, celecoxib, was administered orally. Intracisternally administered PGF(2alpha) (700 ng), but not PGD(2) (700 ng) or PGE(2) (700 ng) completely alleviated KA-induced seizures potentiated by COX-2 inhibitors, and also reduced KA-induced hippocampal neuronal death aggravated by indomethacin. PGF(2alpha) alone did not affect KA-induced seizures. However, an FP receptor antagonist, AL 8810 (10 or 50 ng) which is an 11beta-fluoro analogue of PGF(2alpha) potentiated KA-induced seizure activity dose-dependently. In summary, pre- or post-treatment with COX-2 inhibitors aggravates KA-induced seizures, which suggests to change the endogenous PGF(2alpha). Seizure-induced PGF(2alpha) might act as an endogenous anticonvulsant through FP receptors.
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25
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Dhir A, Naidu PS, Kulkarni SK. Neuroprotective effect of nimesulide, a preferential COX-2 inhibitor, against pentylenetetrazol (PTZ)-induced chemical kindling and associated biochemical parameters in mice. Seizure 2007; 16:691-7. [PMID: 17604186 DOI: 10.1016/j.seizure.2007.05.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 05/07/2007] [Accepted: 05/23/2007] [Indexed: 11/19/2022] Open
Abstract
Brain cyclooxygenases (COX), the rate-limiting enzyme in prostaglandin synthesis, is rapidly and transiently induced by convulsions in hippocampal and cortical neurons. Previous studies have explored the protective effect of naproxen (non-selective COX-inhibitor) or rofecoxib (selective COX-2 inhibitor) against chemical kindling in mice. With this background, the present study was designed to explore the possible effect of nimesulide (a preferential COX-2 inhibitor) against pentylenetetrazol (PTZ)-induced kindling epilepsy in mice. To induce kindling, PTZ was injected in a subconvulsive dose (40 mg/kg, i.p.) every other day for 15 days. Nimesulide (2.5 or 5 mg/kg, p.o.) was administered each day 45 min before either PTZ or vehicle challenge. The intensity of kindling was assessed immediately after PTZ administration according to a prevalidated scoring scale. On 16th day i.e. 24 h after the last dose of PTZ, animals were sacrificed and various biochemical parameters were assessed in the whole brain. Compared with normal control group, PTZ-kindled mice had significantly higher levels of malondialdehyde, nitrite, myeloperoxidase but had lower levels of reduced glutathione in the whole brain homogenate. Chronic treatment with nimesulide (2.5 or 5 mg/kg, p.o.) for 15 days showed significant decrease in kindling score and could play a role in controlling the accompanying biochemical alterations due to PTZ. These results suggested that nimesulide, a preferential COX-2 inhibitor offered neuroprotection against PTZ-induced kindling in mice.
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Affiliation(s)
- Ashish Dhir
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014, India
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26
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Dhir A, Naidu PS, Kulkarni SK. Effect of cyclooxygenase inhibitors on pentylenetetrazol (PTZ)-induced convulsions: Possible mechanism of action. Prog Neuropsychopharmacol Biol Psychiatry 2006; 30:1478-85. [PMID: 16844276 DOI: 10.1016/j.pnpbp.2006.06.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cyclooxygenase (COX) is reported to play a significant role in neurodegenerative and neuropsychiatric disorders, and may play a significant role in the pathogenesis of epilepsy. Various neurotransmitter abnormalities, especially of GABA and glutamate, have been reported to play a key role in the pathophysiology of epilepsy. The objective of the present study was to elucidate the effect of cyclooxygenase inhibitors on pentylenetetrazol (PTZ)-induced (80 mg/kg) convulsions in mice with possible mechanism of action. Various COX-inhibitors were administered 45 min prior to the PTZ administration. Onset, duration of clonic convulsions and percentage mortality/recovery were recorded. Pretreatment with COX-inhibitors aspirin (10 and 20 mg/kg, p.o.), naproxen (7 and 14 mg/kg, p.o.), nimesulide (1-5 mg/kg, p.o.) or rofecoxib (1-4 mg/kg, p.o.) dose-dependently showed protection against PTZ-induced convulsions. COX-2 inhibitors were more effective as compared to non-selective COX-inhibitors. Rofecoxib (1 mg/kg) or nimesulide (1 mg/kg) also enhanced the sub-protective effect of diazepam or muscimol showing GABAergic modulation of COX-2 inhibitors. COX-2 inhibitors also antagonized the effect of flumazenil (4 mg/kg)- against PTZ-induced convulsions further confirming the GABAergic mechanism. In conclusion, the results of the present study strongly suggest the possible role of cyclooxygenase isoenzymes in the pathophysiology of epilepsy and the use of COX-inhibitors as an adjuvant therapy in the treatment of epilepsy.
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Affiliation(s)
- Ashish Dhir
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh-160014, India
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27
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Dhir A, Naidu PS, Kulkarni SK. Effect of rofecoxib, a cyclo-oxygenase-2 inhibitor, on various biochemical parameters of brain associated with pentylenetetrazol-induced chemical kindling in mice. Fundam Clin Pharmacol 2006; 20:255-61. [PMID: 16671960 DOI: 10.1111/j.1472-8206.2006.00398.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cyclo-oxygenase (COX) has been reported to play a significant role in neurodegeneration and other brain-related disorders. Recent studies have reported that COX plays a significant role in the pathophysiology of brain-related disorders and COX-2 inhibitors could be useful drug therapy in neurodegenerative disorders. The aim of the present study was to explore the possible role of COX and the effect of COX-2 inhibitor, rofecoxib in epilepsy. In the present study, kindling was induced in mice by chronic administration of a subconvulsive dose of pentylenetetrazol (PTZ, 40 mg/kg, i.p.) on every other day for a period of 15 days. Rofecoxib was administered orally daily 45 min before either PTZ or vehicle. The kindling score was recorded after PTZ administration. Seizure severity was measured according to a prevalidated scoring scale. Biochemical estimations were performed on the day 16 of PTZ treatment (24 h after the last dose of PTZ). Chronic treatment with selective COX-2 inhibitor, rofecoxib (2.0 and 5.0 mg/kg, p.o.) for 15 days showed significant decrease in PTZ-induced kindling score. Biochemical analysis showed that chronic treatment with PTZ significantly increased lipid peroxidation, nitrite levels (NO levels), and myeloperoxidase levels and decreased the reduced glutathione levels in brain homogenate. Chronic treatment with rofecoxib, a selective COX-2 inhibitor, significantly reversed the PTZ-induced kindling score as well as various biochemical alterations suggesting the use of COX-2 inhibitor rofecoxib in epilepsy. In conclusion, results of the present study suggested that COX-2 plays an important role in the pathophysiology of PTZ-induced kindling in mice and rofecoxib is protective against various biochemical alterations against PTZ-induced kindling in mice.
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Affiliation(s)
- Ashish Dhir
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014, India
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28
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Akarsu ES, Ozdayi S, Algan E, Ulupinar F. The neuronal excitability time-dependently changes after lipopolysaccharide administration in mice: Possible role of cyclooxygenase-2 induction. Epilepsy Res 2006; 71:181-7. [PMID: 16870400 DOI: 10.1016/j.eplepsyres.2006.06.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 06/16/2006] [Accepted: 06/19/2006] [Indexed: 01/21/2023]
Abstract
The parameters of pentylenetetrazol (PTZ)-induced seizures have been evaluated at various time intervals after lipopolysaccharide (LPS; Escherichia coli O111:B4, 100 microg/kg, i.p.) administration in mice. A proconvulsant effect occurred 4h after LPS injection with decreased seizure latency and enhanced seizure intensity. In contrast, the incidence of seizures was reduced 18 h after LPS injection. There were no significant alterations on seizure parameters 2, 8, 12, and 24h after LPS treatment. SC-58236, a selective cyclooxygenase (COX)-2 inhibitor (20 or 40 mg/kg, s.c.) treatment alone had no effect on PTZ-induced seizures, but reversed the antiseizure activity observed 18 h after LPS injection. However, SC-58236 treatment partially restored the proconvulsant changes that were observed 4h after LPS administration. On the other hand, COX-1-selective inhibitor valeryl salicylate (20 or 40 mg/kg, s.c.) itself facilitated PTZ-induced seizures. Thus, it was not possible to evaluate the effects of valeryl salicylate on the excitability changes after LPS injection. These results indicate that the parameters of PTZ-induced seizures change time-dependently after LPS treatment, in which proconvulsant and anticonvulsant states could be seen in a sequence. It seems that COX-2 isoenzyme may be involved in the neuronal excitability changes due to LPS.
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Affiliation(s)
- Eyup S Akarsu
- Ankara University, School of Medicine, Department of Pharmacology and Clinical Pharmacology, Ankara, Turkey.
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29
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Phillis JW, Horrocks LA, Farooqui AA. Cyclooxygenases, lipoxygenases, and epoxygenases in CNS: Their role and involvement in neurological disorders. ACTA ACUST UNITED AC 2006; 52:201-43. [PMID: 16647138 DOI: 10.1016/j.brainresrev.2006.02.002] [Citation(s) in RCA: 266] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Revised: 02/23/2006] [Accepted: 02/24/2006] [Indexed: 01/01/2023]
Abstract
Three enzyme systems, cyclooxygenases that generate prostaglandins, lipoxygenases that form hydroxy derivatives and leukotrienes, and epoxygenases that give rise to epoxyeicosatrienoic products, metabolize arachidonic acid after its release from neural membrane phospholipids by the action of phospholipase A(2). Lysophospholipids, the other products of phospholipase A(2) reactions, are either reacylated or metabolized to platelet-activating factor. Under normal conditions, these metabolites play important roles in synaptic function, cerebral blood flow regulation, apoptosis, angiogenesis, and gene expression. Increased activities of cyclooxygenases, lipoxygenases, and epoxygenases under pathological situations such as ischemia, epilepsy, Alzheimer's disease, Parkinson disease, amyotrophic lateral sclerosis, and Creutzfeldt-Jakob disease produce neuroinflammation involving vasodilation and vasoconstriction, platelet aggregation, leukocyte chemotaxis and release of cytokines, and oxidative stress. These are closely associated with the neural cell injury which occurs in these neurological conditions. The metabolic products of docosahexaenoic acid, through these enzymes, generate a new class of lipid mediators, namely docosatrienes and resolvins. These metabolites antagonize the effect of metabolites derived from arachidonic acid. Recent studies provide insight into how these arachidonic acid metabolites interact with each other and other bioactive mediators such as platelet-activating factor, endocannabinoids, and docosatrienes under normal and pathological conditions. Here, we review present knowledge of the functions of cyclooxygenases, lipoxygenases, and epoxygenases in brain and their association with neurodegenerative diseases.
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Affiliation(s)
- John W Phillis
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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Dhir A, Naidu PS, Kulkarni SK. EFFECT OF NAPROXEN, A NON-SELECTIVE CYCLO-OXYGENASE INHIBITOR, ON PENTYLENETETRAZOL-INDUCED KINDLING IN MICE. Clin Exp Pharmacol Physiol 2005; 32:574-84. [PMID: 16026518 DOI: 10.1111/j.1440-1681.2005.04233.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Epilepsy is one of the major neurological disorders of the brain, affecting approximately 0.5-1.0% of the population worldwide. Various neurotransmitter abnormalities, especially of GABA and glutamate, have been reported to play a key role in the pathophysiology of epilepsy. 2. Cyclo-oxygenase (COX) is the rate-limiting enzyme in the production of prostaglandins and, as such, is a key target for many anti-inflammatory drugs. Cyclo-oxygenase has been reported to play a significant role in neurodegeneration. Recent studies have reported that COX plays a significant role in the pathophysiology of epilepsy. 3. The aim of the present study was to explore the possible role of COX and the effect of COX inhibitors in epilepsy. 4. Kindling is a chronic model of epilepsy. In the present study, kindling was induced in mice by chronic administration of a subconvulsive dose of pentylenetetrazole (PTZ; 40 mg/kg) on every other day for a period of 15 days. Naproxen was administered daily 45 min before PTZ or vehicle. The kindling score was recorded after PTZ administration. Seizure severity was measured according to a prevalidated scoring scale. Biochemical estimations were performed immediately after recording behavioural parameters on the 16th day of PTZ treatment. 5. Chronic treatment with PTZ significantly induced kindling in mice. Pretreatment with the non-selective COX inhibitor naproxen (7 and 14 mg/kg, i.p.) showed significant protection against PTZ-induced kindling in mice. Biochemical analysis revealed that chronic treatment with PTZ significantly increased lipid peroxidation and nitrite levels (NO levels), but decreased reduced glutathione (GSH) levels in brain homogenates. 6. In conclusion, the results of the present study strongly suggest that COX plays an important role in the pathophysiology of PTZ-induced kindling in mice and that COX inhibitors could be a useful neuroprotective strategy for the treatment of epilepsy.
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Affiliation(s)
- Ashish Dhir
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
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