[ effect of various doses of olive leaf extract on brain lipid levels and blood brain barrier permeability in rat stroke model]

ABSTRACT

Recent studies suggest that olive extract can suppress inflammation and reduce stress oxidative injury. We sought to extend these observations in an in vivo study of rat cerebral ischemia-reperfusion injury. In this experimental study, five groups, each consisting of 12 male Wistar rats, were studied. First group [control] received distilled water, while three treatment groups received oral olive leaf extract [OLE] for 30 days [50, 75 and 100 mg/kg/day, respectively]. The last group [sham] underwent surgery without ischemia and did not receive OLE. Two hours after the last dose, each group was subdivided into two subgroups. In the first subgroup middle cerebral artery occlusion [MCAO] was induced during an operation, in order to assess neuropathology [blood brain barrier permeability], while the second subgroup remained intact and was used for brain lipid analysis. The brain cholesterol levels in 50, 75, and 100 mg/kg/day OLE group were 34.4 +/- 4.7, 35.9 +/- 5.8, and 38.3 +/- 2.1 mg/g brain tissue weight, respectively; the cholesterol ester levels in them were 15.2 +/- 1.8, 15.8 +/- 3.1 and 16.3 +/- 3.6 mg/g brain tissue weight, respectively. These numbers were greater than the controls. Brain triglyceride levels in the 50 mg/kg/day group were similar to that in controls; but it was higher in the 75 and 100 mg/kg/day groups [34.1 +/- 0.5 And 34.5 +/- 1.1 mg/g brain tissue weight, respectively]. The OLE reduced blood brain barrier permeability in 75 and 100 mg/kg/day group when compared to controls [p< 0.000, p< 0.000, respectively]. There was significant difference between right and left hemisphere in control group and 50 mg/kg/day group [p< 0.000]. Our data suggest that OLE reduced the blood brain barrier permeability and changed brain lipids which may be cerebroprotective in a rat model of ischemia-reperfusion. Further work is required to extend these observations