RESUMO
<p><b>OBJECTIVE</b>To investigate the influences of ultrafiltration and alcohol sedimentation on protective effects of Radix Astragali and Radix Hedyseri against rat's cerebral ischemia.</p><p><b>METHODS</b>Using dexamethasone (im.) and ligating common carotid artery, the rat stasis model combined transient cerebral ischemia was established to evaluate the effects of the ultrafiltration and alcohol sedimentation through detecting antioxidant system and other indexes in brain tissue.</p><p><b>RESULTS</b>The results showed that the 6 g/kg water extract(crude drug), ultrafiltration and alcohol sedimentation of Radix Astragali and Radix Hedyseri could upgrade adenosine-triphosphate (ATP), superoxide dismutase (SOD) and catalase (CAT), and degrade malondialdehyde(MDA) and water content of brain tissue in rat stasis model combined transient cerebral ischemia, the water extract and ultrafiltration of them could degrade lactic acid (LD) of brain tissue, and the effects of alcohol sedimentation of Radix Astragali and Radix Hedyseri become weaker than water extract of them.</p><p><b>CONCLUSION</b>The water extract, ultrafiltration and alcohol sedimentation of Radix Astragali and Radix Hedyseri have some protective effects on cerebral ischemia in rats, the effective differences of the extract through the same extraction method are not remarkable, and alcohol precipitation method has obvious influences effect on Radix Astragali and Radix Hedyseri.</p>