Studies on the biochemical action of ginseng saponin. I. Purification from ginseng extract of the active component stimulating serum protein biosynthesis.

Systematic isolation and purification of the biologically active component of ginseng extract were followed by observing the incorporation of labeled leucine into serum protein at 6 hr after a single intraperitoneal injection in a mouse. Ginseng saponin mixture (fraction 5) exhibited high activity for such incorporation. Seven saponins were isolated from fraction 5 by means of preparative TLC, and assayed. Administration of all these saponins (ginsenoside-Rb2, Rc, Rc2, Rd, Re, and Rg1)except for ginsenoside-Rb1, caused an increase of leucine incorporation over that in control animals. The incorporation rate was directly proportional to the dose in the case of ginsenoside-Rd, which had the highest activity. The increase specific radio-activity of serum protein was not due to a decrease in the pool size of free amino acids in the liver. It was conclusively shown that the active component stimulating serum protein biosynthesis is saponin.