Treatment with nimesulide alone or combined with MgSO4 significantly suppressed MPO expression compared to the placebo group ( em p /em =0

Treatment with nimesulide alone or combined with MgSO4 significantly suppressed MPO expression compared to the placebo group ( em p /em =0.001 by Dunnett’s test), but the difference between these two groups was not significant. Caspase-3 expression in brain tissue Immunohistochemistry of the inner boundary zone of infarction showed that the presence of caspase-3-IR cells could be significantly suppressed only in the combination treatment group ( em p /em 0.001 by Dunnett’s test; Fig. combination treatment group showed a significant decrease in infarction volume (10.936.54% versus 26.437.08%, studies, ischemia, middle cerebral artery occlusion, therapeutic approach, stroke Introduction Brain ischemia remains a major health problem with high morbidity and mortality despite decades of research. Complicated mechanisms such as energy deprivation, glutamate-mediated excitotoxicity and ionic imbalance, oxidative/nitrosative stress, and apoptotic-like cell death are major mechanisms leading to cell death during ischemic insults (Lo, 2008; Mehta et al., 2007). These mechanisms demonstrate overlapping and redundant features, making the development of neuroprotective brokers a difficult task. Many neuroprotective brokers targeting specific mechanisms of ischemic injury are effective in preclinical trials, but fail in clinical trials (Ginsberg, 2008,2009). Magnesium is critical to cellular Uridine triphosphate energy metabolism (Lin et al., 2002). Inorganic magnesium ion (Mg2+) blocks synaptic transmission by preventing the release of neurotransmitters and blocking (Greensmith et al., 1995) and experiments (Izumi et al., 1991; Marinov et al., 1996) suggest that magnesium ions reduce the neuronal damage brought about by ischemia or excitatory amino acids. But despite favorable results in preclinical studies, the neuroprotective effects of Mg2+ are still controversial. Differences in dosage, time of administration, and hypothermia are contributing factors to the conflicting results (Meloni et al., 2006). Sufficient doses should be given as early as possible to block the deleterious cascade of cellular injury mechanisms induced by ischemia. Many studies showed a positive neuroprotective effect of magnesium sulfate (MgSO4) at a dosage of 90?mg/kg administered before or immediately after the onset of ischemia. It is well known that this adverse effects of MgSO4, such as cardiovascular depressive disorder, suppression of respiration, and central nervous system depressive disorder, are associated with rapid bolus infusions. To decrease the effective therapeutic dose and CD274 adverse effects of MgSO4, combination with another drug targeting the downstream pathophysiologic events is a reasonable approach. Ischemic injury also triggers inflammatory cascades in the parenchyma that further amplify tissue damage (Allan and Rothwell, 2001; Barone and ad Feuerstein, 1999). Numerous studies have found a dramatic increase in cyclooxygenase-2 (COX-2) expression following ischemia. Increased COX-2 activity may induce increased arachidonic acid levels, which may have direct excitotoxic effects (Katsuki and Okuda, 1995). Free radicals produced by COX-2 while converting arachidonic acid to eicosanoids may contribute to ischemic neuronal damage (Katsuki and Okuda, 1995). Prostaglandins may potentiate post-ischemic inflammation by increasing edema and by allowing entry of proinflammatory cells into the brain (Ferreira, 1972). These findings suggest that COX-2 has an important role in ischemic brain injury. The neuroprotective effect of COX-2 inhibitors has been widely studied in animal models of ischemic insults (Candelario-Jalil and Fiebich, 2008). Nimesulide is one of the few COX-2 inhibitors that has been extensively studied in different models of brain ischemia. Findings indicate that nimesulide may be a promising neuroprotective agent. It is a preferential COX-2 inhibitor widely used clinically as a non-steroidal anti-inflammatory drug. The recommended dose for the treatment of rheumatoid arthritis is usually Uridine triphosphate 3C6?mg/kg per day for adult patients. Adverse reactions include gastrointestinal damage, hepatic and renal toxicity, and cardiovascular complications (Rainsford, 2006). Several studies report significant neuroprotective effects of nimesulide at a dosage of 12?mg/kg (Candelario-Jalil and Fiebich, 2008; Candelario-Jalil et al., 2004,2007). However, a daily dose of 12?mg/kg increases the risk of adverse drug reactions (Singla et al., 2000). Combinations of established neuroprotective brokers with Uridine triphosphate distinct mechanisms has been considered Uridine triphosphate in stroke therapy. Combination therapy may reduce the dose of individual brokers, with a consequent reduction in the undesirable adverse effect of toxicity. The current study used an ischemia and reperfusion model of middle cerebral artery occlusion (MCAO) to test Uridine triphosphate the synergism of MgSO4 and nimesulide at half their usual dose. The neuroprotective effects of three protocols, MgSO4 alone, nimesulide alone, and a combination of both, were evaluated. Methods Animals The National Cheng Kung University Animal Ethics Committee approved all of the experimental procedures, and appropriate measures were taken to minimize the pain and distress of the animals used in this study. The animals were purchased from the Laboratory Animal Center of National Cheng Kung University and housed on bagasse bedding in groups of three in cages. The animals were given rodent pellet chow.