ABSTRACT
<p><b>OBJECTIVE</b>To investigate the protective effects of sodium tanshinone B (STB) on brain damage following focal ischemia-reperfusion (I/R) injury through interfering with N-methyl-D-aspartic acid receptor (NMDAR) and excitatory and inhibitory amino acids, and evaluate the potential mechanisms of the neuroprotective activity of STB.</p><p><b>METHODS</b>Transient forebrain ischemia was induced by middle cerebral artery occlusion (MCAO). The rats were randomized into a sham operated group, a model group (I/R) and three STB different dose groups. Rats were pretreated with STB at the doses of 4, 8, 16 mg/kg (STB(1), STB(2), STB(3)) for 3 days before MCAO. The expression of NMDAR1 was detected by immunohistochemistry and Western blotting. The concentrations of glutamate and γ-aminobutyric acid (GABA) were analyzed using high performance liquid chromatography.</p><p><b>RESULTS</b>STB treatment reduced neurological defect scores, cerebral infarction volume and brain water content. The levels of NMDAR1 were significantly higher in the l/R and STB(1) groups than that of the sham and the STB(3) groups (P<0.01). Optical density of NMDAR1 was significantly increased in cornu ammonis (CA)1 region of the l/R group (P<0.05). STB treatment reduced NMDAR1 optical density in the CA1 region (P<0.01). The levels of glutamate were significantly lower in the hippocampus in the STB(3) group than that of the l/R, STB(1) and STB(2) groups (P<0.01).</p><p><b>CONCLUSION</b>Preconditioning with STB appears to be a simple and promising strategy to reduce or even prevent cerebral l/R injury and has potential for future clinical application.</p>