This study reports preliminary data on the antioxidant and protective effects of dietary essential oils during cerebral ischemia/reperfusion (I/R) injury in Wistar rat frontal cortex. Cerebral ischemia was produced by a 20 min bilateral common carotid artery occlusion followed by 30 min reperfusion. A mixture of essential oils enriched with polyphenols (200 mg/0, 45 ml of sunflower oil as vehicle) was administered via gavage 6 hours prior to ischemia. Rats were randomly assigned to four groups, ischemic/reperfused (I/R) and sham-operated rats treated with the vehicle or with essential oils. Different brain areas were analysed for fatty acid changes. Expression of ciclooxygenase-2 (COX-2) and phospholipase A-2 (PLA-2) was also evaluated by western blot (WB) and immunohistochemistry (IHC). A significant decrease of docosahexaenoic acid (DHA) was detected only in the frontal cortex of vehicle treated I/R rats, accompanied by a parallel increase of conjugated hexadecadienoic acid (CD16:2), a marker of peroxisomal beta-oxidation. By contrast, no significant changes were evident in I/R rats treated with essential oils as compared to either vehicle or essential oil treated sham-operated rats. WB and IHC, performed in the counterlateral hemisphere of the same animals, revealed a marked decrease of COX-2 expression in the frontal cortex of I/R rats treated with essential oils as compared to those treated with the vehicle only. As for PLA-2, IHC showed a slight decrease in number and staining intensity of positive neurons in frontal cortex, whereas no changes could be detected by WB analysis. Our data suggest that cerebral I/R induces a region specific lipid peroxidation as evidenced by the decrease of DHA, and concomitant increase of peroxisomal beta-oxidation, as evidenced by the increase of CD16:2, which reveals a physiological response aimed at decreasing potentially dangerous lipid peroxidation products by increasing their catabolism in peroxisomes. We may conclude that treatment with poliphenol-enriched essential oils exerts a neuroprotective action during cerebral I/R, preventing lipid peroxidation and, by the modulation of COX-2 availability, reducing inflammatory response. This work was supported by Fondazione Banco di Sardegna.
Polyphenol-enriched essential oils prevent cerebral ischemia/reperfusion-induced lipid peroxidation in the rat frontal cortex
QUARTU, MARINA;SERRA, MARIA PINA;BOI, MARIANNA;
2010-01-01
Abstract
This study reports preliminary data on the antioxidant and protective effects of dietary essential oils during cerebral ischemia/reperfusion (I/R) injury in Wistar rat frontal cortex. Cerebral ischemia was produced by a 20 min bilateral common carotid artery occlusion followed by 30 min reperfusion. A mixture of essential oils enriched with polyphenols (200 mg/0, 45 ml of sunflower oil as vehicle) was administered via gavage 6 hours prior to ischemia. Rats were randomly assigned to four groups, ischemic/reperfused (I/R) and sham-operated rats treated with the vehicle or with essential oils. Different brain areas were analysed for fatty acid changes. Expression of ciclooxygenase-2 (COX-2) and phospholipase A-2 (PLA-2) was also evaluated by western blot (WB) and immunohistochemistry (IHC). A significant decrease of docosahexaenoic acid (DHA) was detected only in the frontal cortex of vehicle treated I/R rats, accompanied by a parallel increase of conjugated hexadecadienoic acid (CD16:2), a marker of peroxisomal beta-oxidation. By contrast, no significant changes were evident in I/R rats treated with essential oils as compared to either vehicle or essential oil treated sham-operated rats. WB and IHC, performed in the counterlateral hemisphere of the same animals, revealed a marked decrease of COX-2 expression in the frontal cortex of I/R rats treated with essential oils as compared to those treated with the vehicle only. As for PLA-2, IHC showed a slight decrease in number and staining intensity of positive neurons in frontal cortex, whereas no changes could be detected by WB analysis. Our data suggest that cerebral I/R induces a region specific lipid peroxidation as evidenced by the decrease of DHA, and concomitant increase of peroxisomal beta-oxidation, as evidenced by the increase of CD16:2, which reveals a physiological response aimed at decreasing potentially dangerous lipid peroxidation products by increasing their catabolism in peroxisomes. We may conclude that treatment with poliphenol-enriched essential oils exerts a neuroprotective action during cerebral I/R, preventing lipid peroxidation and, by the modulation of COX-2 availability, reducing inflammatory response. This work was supported by Fondazione Banco di Sardegna.
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