OBJECTIVETo 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.

METHODSThe 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.

RESULTSThree 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).

CONCLUSIONThese 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.