title: The single versus combinatorial effects of MK-801, CNQX, Nifedipine and AP-3 on primary cultures of cerebellar granule cells in an oxygen-glucose deprivation model.
abstract: The excitotoxicity cascade associated with energetic failure during and after cerebral ischemia involves the overactivation of glutamate receptors and intracellular calcium loading. We searched for synergistic neuroprotective effects of various drugs designed to prevent intracellular calcium influx in a model of oxygen-glucose deprivation (OGD) in cerebellar granule cells primary cultures. (5S,10R)-(-)-5-Methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (MK-801), D,L-2-Amino-3-phosphonopropionic acid (AP-3), 6-Cyano-7-nitroquinoxaline-2,3-dione disodium salt (CNQX) and Nifedipine were tested alone or in combinations. Treatments were applied during a two-hour OGD exposure and cellular outcome was assessed throughout 20-hour reoxygenation by the measurement of Propidium Iodide (PI) fluorescence. All treatments were able to prevent neuronal damage. OGD resulted in a mortality of 36.3±2.3% and 61.3±3.1% after 10 and 20 hours of reoxygenation, respectively. The most effective single treatment was AP-3 (3.3±1.4%; 17.9±2.6% mortality after 10 and 20 hours), followed in order by Nifedipine (7.2±1.6%; 20.1±3.0%), CNQX (8.5±2.5%; 20.0±3.5%), and MK-801 (14.9±2.6%; 39.3±6.4%). The combination of AP-3 with MK-801 showed a moderate synergistic effect (11.8±2.0% mortality at 20 hours), while the combinations of CNQX with Nifedipine and CNQX with MK-801, as well as the triple mix CNQX, Nifedipine and MK-801 failed to show a further improvement in the reduction of cellular death. In conclusion, targeting two mechanisms of cellular demise (ionotropic receptors and metabotropic glutamate receptors) provided an advantage against several unimodal strategies (blocking calcium entry through ionotropic glutamate receptors and L-type calcium channels). Our results suggest that a multimodal combinatorial treatment strategy in cerebral ischemia may increase neuroprotective efficacy and call for further research.
authors.affiliation: Division of Physiology and Fundamental Neuroscience, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania; azagrean@umf.ro, azagrean@gmail.com.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Zăgrean
authors.forename: Ana
authors.initials: A
authors.lastname: Spataru
authors.forename: Mihai
authors.initials: M
authors.lastname: Ceangă
authors.forename: Leon
authors.initials: L
authors.lastname: Zăgrean
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology*; D000409:Alanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D002531:Cerebellum / Q000473:pathology*; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D005453:Fluorescence; D005947:Glucose / Q000172:deficiency*; D009543:Nifedipine / Q000494:pharmacology*; D010100:Oxygen / Q000378:metabolism*; D011419:Propidium / Q000378:metabolism; D051381:Rats
chemical_list: C000211:2-amino-3-phosphonopropionic acid; D011419:Propidium; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D009543:Nifedipine; D005947:Glucose; D000409:Alanine; D010100:Oxygen