A POLYSACCHARIDE FRACTION OF SHOSAIKO-TO ACTIVE IN AUGMENTATION OF NATURAL-KILLER ACTIVITY BY ORAL-ADMINISTRATION

Shosaiko-to (Xiao-chai-hu-tang, SHO), which is a Kampo medicine prepar ed by decocting a prescription of 7 kinds of medical plants, has been used mainly to treat chronic hepatitis in Japan. Previously, we report ed that an oral administration of SHO augmented natural killer (NK) ac tivity in the peripheral blood. To characterize its active substance, SHO was fractionated. The high molecular weight fraction showed the ab ility to augment NK activity by oral administration, but the low molec ular weight fraction did not. Furthermore, we obtained an active acidi c polysaccharide from the high molecular weight fraction. This polysac charide fraction, with a molecular weight of approximately 1.2 x 10(5) , is probably responsible for the effect of the original Shosaiko-to. It contained no protein. The sugar moiety was composed of rhamnose, ar abinose, mannose, galactose, glucose and galacturonic acid in molar ra tios of 1:17:3:21:100:87.