Effect of extract from rhei rhizoma on urea-nitrogen concentration in rat serum.

Abstract

Intraperitoneal administration of the extract from Rhei Rhizoma decreased the urea-nitrogen (BUN) concentration in rat serum. An attempt was made to extract and partially purify the active substance(s), monitoring the BUN-decreasing activity. The activity was detected in the aqueous extract. After partition between butanol and water, biological activity was detected in both fractions. Further purification was carried out by dialysis and Sephadex LH-20 column chromatography, by which small molecular compounds, including anthraquinone glycosides, were eliminated. The BUN-decreasing activity was detected in fractions 3-2-1B, 3-2-2B, and 4-2-3-S1.