Effect of Extracts Obtained from Rhubarb in Rats with Chronic Renal Failure

An attempt made to clarify the nature of the active components contained in rhubarb which show the improving effects on uremic symptoms. The progress of fractionation and purification was monitored by measuring the levels of blood urea nitrogen, creatinine, methylguanidine, and guanidinosuccinic acid after administration of each fraction to rats. Fraction II was found to have a blood urea nitrogen-decreasing effect among fractions I to V obtained by Sephadex LH-20 column chromatography. Fraction II-3, obtained by further fractionation of fraction II, was found to have a uremia-alleviating effect, causing significant decreases in blood urea nitrogen, creatinine, methylguanidine, and guanidinosuccinic acid levels. Purification of fraction II-3 by partition between ethyl acetate and H2O resulted in recovery of the blood urea nitrogen-decreasing activity in the aqueous phase, which was found to contain mainly proanthocyanidin oligomers.