Background and purpose: We reported previously that ecdysterone (EDS) improves neurologic function after experimental stroke. However, the underlying mechanism remained unclear. The present study was conducted to test whether ecdysterone improves neurologic function by enhancing astrocyte activation and angiogenesis after focal cerebral ischemia in rats.
Methods: Focal cerebral ischemia model was conducted by middle cerebral artery occlusion (MCAO). EDS was intraperitoneally injected at 20 mg kg1 daily for 7 days after MCAO. Neurologic recovery was assessed using the neurologic severity scores. Microvessel density and GFAP expression were detected with immunostaining and analyzed quantitatively with image system.
Results: Treatment with EDS significantly improved functional recovery, along with increases in density of cerebral microvessels and astrocyte activation. Microvessel density was significantly higher in EDS treated group than in ischemia control group at all time points, and reached a peak on day 14. EDS treated group had substantial increment in GFAP immunoreactive cells, darker staining color, more and longer nerve processes, higher GFAP expression and area of immunoreactive cells at each time point.
Conclusion: Our data suggest that EDS treatment enhanced angiogenesis and astrocyte activation which could contribute to functional recovery.