Effect of Buyang Huanwu decoction on amino acid content in cerebrospinal fluid of rats during ischemic/reperfusion injury

• Brain tissues of rats with MCAO displayed an infarct lesion and nerve injuries.
• We used brain microdialysis and HPLC-FD to moniter the levels of amino acids.
• The excitatory and inhibitory amino acids Increased in the CSF of ischemic rats.
• Treatment BYHWD improved nerve function and reduced the infarct volume.
• Treatment BYHWD significantly decreased EAAs and increased IAAs in the CSF.

The inhibitory effect of Buyang Huanwu decoction (BYHWD) on ischemic injury has been proven, but it is not clear how amino acid levels in cerebrospinal fluid (CSF) are associated with BYHWD treatment, nor the mechanism by which BYHWD protects the brain from ischemia/reperfusion injury. We investigated the effect of BYHWD on the amino acid content of CSF in rats during ischemia-reperfusion injury. Ischemia was imposed by right middle cerebral artery occlusion (MCAO). CSF was continuously collected from the striatum via brain microdialysis before and after ischemia/reperfusion. We used on-line derivatization combined with high-performance liquid chromatography with fluorescence detection (HPLC-FD) to determine levels of glutamate (Glu), aspartate (Asp), glycine (Gly), taurine (Tau), and γ-aminobutyric acid (GABA) in CSF. The MCAO model displayed an infarct lesion in the ipsilateral hemisphere and nerve injuries, as the left upper limb was unable to extend and turn leftward. Significant increases in excitatory and inhibitory amino acids were observed in the CSF of the ischemic rats relative to the sham-operated group (P < 0.01). Treatment with BYHWD reduced the areas of cerebral infarction and improved the neurological behavior scores of rats after MCAO. BYHWD treatment was also associated with a significant decrease in excitatory amino acids and increase in inhibitory amino acids in the CSF. Only the higher dose of BYHWD (20 mg/kg) affected all these levels significantly. Attenuated excitatory toxicity and reduced areas of cerebral infarction associated with BYHWD treatment might be due to a protective mechanism induced by BYHWD against ischemia/reperfusion injury.

Effect of Buyang Huanwu decoction on amino acid content in cerebrospinal fluid of rats during ischemic/reperfusion injury.Figure optionsDownload as PowerPoint slide