Adjunction of the Lipase Inhibitor Orlistat Improves Grape Seed Extract Neuroprotection against Brain Ischemia/Reperfusion Injury in Rats

Abstract:

Aim: Stroke is a public health concern for which there is currently no prophylaxis. In this study, we assessed the protective effect of Grape Seed Extract (GSE) and Orlistat (ORL) against brain ischemia/reperfusion (I/R) injury. Methods: Adult male Wistar rats were treated either with GSE (2.5 g/kg), ORL (4 mg/kg) or both drugs for one week and ischemia performed during 30 min by a bilateral common carotid artery occlusion (BCCAO), followed by 60 min reperfusion. Rats were then sacrificed, their whole brain used for infarct size determination using TTC staining or dissected into cortex, hippocampus and cerebellum for biochemical analysis of I/R-induced oxidative stress and energy failure. Results: In the three brain regions of interest, I/R disturbed protein carbonylation, xanthine oxidase (XO), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities, as well as intracellular mediators as hydrogen peroxide (H₂O₂), calcium and iron. Furthermore I/R altered energy fueling through the decrease of α-ketoglutarate dehydrogenase (α-KGDH) and fumarase (FH) together with mitochondrial complexes I and II along with glutamatergic excitotoxicity through glutamate dehydrogenase (GDH) and glutamine synthetase (GS) activities into cortex and hippocampal areas but not into cerebellum. In addition I/R affected mitochondrial viability as assessed by MTT staining and the moonlighting apoptosis inducer glyceraldehyde-3- phosphate dehydrogenase (GAPDH). Conclusion: Interestingly, GSE prevented efficiently the deleterious effects of I/R and the best protection was obtained when combining the two drugs, especially within cortex and hippocampus compartments. Thus, adjunction of ORL to GSE treatment is a promising strategy to improve neuroprotection from stroke.

Key words: Brain I/R, GSE, Orlistat, Neuroprotection, Energy failure.