Effects of echinacoside on histio-central levels of active mass in middle cerebral artery occlusion rats.

To investigate the effects of echinacoside on the extracellular striatal levels of norepinephrine (NE), dopamine (DA), homovanillic acid (HVA), 3, 4-dihydroxyphenylethanoid acid (DOPAC), 5-hydroxyindoleacetic acid (HIAA), and 5-hydroxytryptamine(5-HT) in middle cerebral artery occlusion (MCAO rats. The middle cerebral artery was occluded in male Sprague-Dawley rats. Three days later microdialysis probes were placed into the right striatum of MCAO rat brains and the brains were perfused with Ringer's solution at a rate of 1.5 microL/min. Cerebral microdialysates were collected every 30 minutes from awake and freely moving rats before assaying for NE, DA, HVA, DOPAC, HIAA, and 5-HT levels by reverse phase HPLC with electrochemistry. Three days after MCAO, the extracellular striatal levels of NE, DA, DOPAC, HIAA, HVA, and 5-HT of the MCAO rats increased significantly (at least P < 0.05 vs. control). However, simultaneous treatment with echinacoside (30.0 or 15.0 mg/kg) attenuated these increases (at least P < 0.05 vs. non-treated model rats). These results imply that echinacoside may protect striatal dopa minergic neurons from the injury induced by MCAO and may help prevent and treat cerebral ischemic diseases.