Effect of cimicifugoside H-1 on amino acid neurotransmitters in striatum of rats with cerebral ischemia

AIM: To study the neuroprotective effect of cimicifugoside H-1 and to explore the mechanism involved by determining the variation of amino acid neurotransmitters in extracellular fluid in the striatum of rats with cerebral ischemia. METHODS: The rats were randomly divided into sham-operated, cerebral ischemia, high-, middle- and low-dose cimicifugoside H-1, and ginkgo groups. Focal cerebral ischemia model was established by middle cerebral artery occlusion (MCAO) with sutures. Normal saline was intraperitoneally injected into the rats in sham-operated group and cerebral ischemia group, while ginkgo and different doses of cimicifugoside H-1 were injected into the rats in ginkgo group and high-, middle- and low-dose cimicifugoside H-1 groups, respectively, once a day for 7 d. The striatal fluids were gained in vivo by brain microdialysis. The contents of aspartic acid, glutamic acid, glycine and γ-aminobutyric acid were tested by high-performance liquid chromatography electrochemical detector system. RESULTS: Compared with sham-operated group, the contents of excitatory amino acids (aspartic acid and glutamic acid) were significantly increased 2 h after cerebral ischemia (P<0.05). Compared with cerebral ischemia group, the contents of aspartic acid and glutamic acid were significantly decreased 2 h after cerebral ischemia in high-dose cimicifugoside H-1 and ginkgo groups (P<0.05). Compared with cerebral ischemia group, the contents of aspartic acid and glutamic acid did not show significant decrease 2 h after cerebral ischemia in middle- and low-dose cimicifugoside H-1 groups. Compared with sham-operated group, the contents of inhibitory amino acid (γ-aminobutyric acid and glycine) were significantly decreased 3 h after cerebral ischemia in cerebral ischemia group (P<0.05). Compared with cerebral ischemia group, the contents of γ-aminobutyric acid and glycine were significantly increased 3 h after cerebral ischemia in high-dose cimicifugoside H-1 and ginkgo groups (P<0.05). Compared with cerebral ischemia group, the contents of γ-aminobutyric acid and glycine did not show significant decrease 3 h after cerebral ischemia in middle- and low-dose cimicifugoside H-1 groups. CONCLUSION: Cimicifugoside H-1 restrains the excessive releases of excitatory amino acids and increases the contents of inhibitory amino acids during cerebral ischemia. It doesn't only penetrate through the blood brain barrier, but also regulates the disorder of excitatory amino acid during cerebral ischemia, thus showing the protective function to cerebral neuron during cerebral ischemia.