Stimulatory effects of starfish sapogenins ( Asterias amurensis and Lethasterias nanimensis chelifera) on molluscan heart ( Spisula sachalinensis)

Abstract

Sapogenins from the starfish Asterias amurensis and Lethasterias nanimensis chelifera, 5 α-pregn-9(11)-ene-3 β,6 α-diol-20-one, 5 α-cholest-9(11)-ene-3 β,6 α-diol-23-one, 5 α-cholesta-9(11),24(25)-diene-3 β,6 α-diol-23-one, (20E)-5 α-cholesta-9(11),20(22)-diene-3 β,6 α-diol-23-one and 24 ξ-methyl-5 α-cholesta-9(11),20(22)-diene-3 β,6 α-diol-23-one, stimulated the contractile force of the heart of the mollusk Spisula sachalinensis at concentration of 5×10 −5 M. Ouabain, a specific inhibitor of Na +,K +-ATPase, at concentration of 5×10 −5 M had no effect on this physiological model. Starfish sapogenins of the cholestane series moderately inhibited rat brain cortex Na +,K +-ATPase and decreased Ca 2+ influx into Ehrlich carcinoma cells. In contrast, pregnane asterogenin asterone did not inhibit Na +,K +-ATPase and increased the influx of Ca 2+ into cells. These effects were not the result of cell membrane damage, because none of the compounds tested have hemolytic activity.