Erythrocyte membrane stabilization by plant saponins and sapogenins

Effects of saponins extracted from Bupleuri Radix (saikosaponin) and the corresponding aglycones on hypotonic or hyperthermic hemolysis were investigated. Low concentrations of saikosaponins protect or stabilize rat erythrocytes against both hypotonic and heat-induced hemolysis. Minor modifications of the aglyconic part of the saikosaponin have enormous effects on the membrane stabilizing potency. Saikogenins also protect erythrocytes from hypotonic hemolysis but do not show any prevention of heat-induced hemolysis. It is suggested that saikogenins react with erythrocyte membranes in a quite different manner from saponins and that the existence of the sugar moiety plays an important role in the reaction with membranes as does a slight modification of the molecular structure in the aglyconic part.