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

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