Effects of electroacupuncture on the blood-brain-barrier and proinflammatory cytokine IL-1β and IL-18 in the hippocampus of rats with vascular dementia

Abstract

To observe the effect of electroacupuncture (EA) on blood-brain barrier (BBB) permeability and proinflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18) in the hippocampus of vascular dementia (VD) rats, so as to explore the mechanism of EA on treatment of VD. SD male rats were randomly divided into sham operation, model, and EA groups, with 15 rats in each group. The VD rat model was established by permanently occlusion of the bilateral middle cerebral artery. Rats of the EA group received EA at "Baihui" (GV20), "Dazhui" (GV14), and bilateral "Shenshu"(BL23) for 30 min, 6 days a week for a total of 4 weeks. Morris water maze test was used to assess the cognitive function of rats. Evans blue staining was used to detect the BBB permeability, transmission electron microscopy and ELISA were used to detect the ultrastructure of BBB and the contents of hippocampal IL-1β and IL-18, respectively. Following modeling, compared with the sham operation group, the mean escape latency of model group was significantly prolonged (P<0.01), the times of crossing the platform were significantly decreased (P<0.01), the content of Evans blue, and the contents of IL-1β and IL-18 in hippocampus were increased (P<0.01). After the intervention, comparison between the model and EA groups showed that the average escape latency of rats in EA group was significantly shortened (P<0.01), the times of crossing the platform were increased (P<0.05), the content of Evans blue, and the contents of IL-1β and IL-18 in hippocampus were significantly decreased (P<0.01). The ultrastructure of BBB was moderately damaged in the model group, which was evidenced by blurred endothelial cell membrane structure, obviously dropsical astrocyte foot process, and decreased tight junctions. The ultrastructure of BBB was slightly damaged and astrocyte foot had no obvious edema in the EA group. EA can significantly improve the learning and memory ability of VD rats and improve the BBB permeability, which may be related to its effect in inhibiting the expression of IL-1β and IL-18 in the hippocampus.