Studies on Rehmanniae radix. III. The relation between changes of constituents and improvable effects on hemorheology with the processing of roots of Rehmannia glutinosa

Abstract

The relation between constituents and effects on hemorheology with processing of root of Rehmannia glutinosa was investigated. With the processing to dried or steamed root from crude root, the content of stachyose, which was the highest component in crude root, was decreased and the content of manninotriose was increased. Iridoid glycoside, catalpol, was gradually decreased with the processing. From these results, the content of carbohydrates and catalpol made it possible to estimate the quality of Rehmanniae Radix by processings. On the other hand, the change of pharmacological activities with the processing was investigated. The 50% ethanolic extract (BJ-ext) from steamed root of R. glutinosa increased erythrocyte deformability and erythrocyte ATP contents, inhibited polybrene-induced erythrocyte aggregation, and promoted an activity of fibrinolytic system. The extracts from crude or dried root had weak or no effect. The crude or dried root and steamed root of R. glutinosa showed the different pharmacological activities, and the quality of Rehamanniae Radix by processings may be estimated by investigation of correlation between the changes of constituents and improvable effects of hemorheology.