Minocycline reduces astrocytic reactivation and neuroinflammation in the hippocampus of a vascular cognitive impairment rat model

Objective To study the neuroprotective mechanism of minocycline against vascular cognitive impairment after cerebral ischemia. Methods The rat model with vascular cognitive impairment was established by permanent bilateral common carotid artery occlusion (BCCAO). The observing time-points were determined at 4, 8 and 16 weeks after BCCAO. Animals were randomly divided into sham-operated group (n = 6), model group (subdivided into 3 groups: 4 weeks after BCCAO, n = 6; 8 weeks after BCCAO, n = 6; and 16 weeks after BCCAO, n = 6), and minocycline group (subdivided into 3 groups: 4 weeks after BCCAO, n = 6; 8 weeks after BCCAO, n = 6; and 16 weeks after BCCAO, n = 6). Minocycline was administered by douche via stomach after BCCAO until sacrifice. Glial fibrillary acidic protein (GFAP) was examined by Western blotting and immunohistochemistry. Levels of cyclooxygenase-2 (COX-2) and nuclear factor-kappaB (NF-kappa B) were measured by immunohistochemistry. IL-1 beta and TNF-alpha levels were tested with ELISA method. Results Levels of GFAP, COX-2, NF-kappa B, IL-1 beta and TNF-alpha were all up-regulated after permanent BCCAO, which could be significantly inhibited by minocycline. Conclusion Minocycline could ameliorate the inflammation and oxidative stress in the hippocampus of the vascular cognitive impairment rat model.