Cinnamon pretreatment modulates gene expression of tight junction proteins in a rat model of stroke.

Objective: Brain ischemia generally results in irreversible brain damage or death. One of the most important features of an ischemic stroke is disruption of the Blood-brain barrier (BBB). In this study, we examined the effect of cinnamon hydroalcoholic extract consumption on BBB permeability and expression of some genes regulating its function.

Materials and methods: Sixty male Wistar rats were divided into 5 groups; sham (high-fat diet+ sham surgery), Model (Middle Cerebral Artery Occlusion, MCAO+ high-fat diet), Lovastatin (high-fat diet + lovastatin + MCAO surgery), low and high dosage cinnamon (high-fat diet + cinnamon 130 or 260 mg, respectively+ MCAO surgery). The two doses of cinnamon (130 and 260 mg) were administered intraperitoneally. Twelve hours after ischemic stroke induction, brain right hemisphere tissues were collected and calpain I, calpainII, occludin and VEGF genes expression were quantified by Real-Time -PCR. Accordingly, p-selection protein levels were measured by ELISA method.

Results: Cinnamon hydroalcoholic extract reduced the BBB permeability compared with the model group (p<0.05). Stroke increased calpain and VEGF genes while decreased occludin gene expression (p<0.001). Conversely, cinnamon administration increased occludin gene expression while calpain and VEGF genes were down-regulated (p<0.01). Pretreatment with cinnamon significantly diminished the P-Selectin protein levels as compared with the model group dose dependently (p<0.001).

Conclusion: It seems that cinnamon restores BBB function by regulating the elements involved in its permeability.