Synergistic interaction between potato glycoalkaloidsα-solanine andα-chaconine in relation to destabilization of cell membranes: Ecological implications.

In studies of the lysis of rabbit erythrocytes, red beet cells, andPenicillium notatum protoplasts by the potato glycoalkaloids α-solanine and α-chaconine, the latter was consistently the more membrane-disruptive compound and erythrocytes the more susceptible cell type. A 1∶1 mixture of solanine and chaconine produced pronounced synergistic effects in all three test systems. In beet cells, such effects were apparent from an early stage of treatment and persisted over a period of several hours. With erythrocytes and fungal protoplasts, the synergism was maximal with mixtures containing approximately 70% chaconine, whereas with beet cells it peaked at approximately 40% chaconine. Synergistic interactions between solanine and chaconine also occurred with regard to cholesterol binding in vitro, with a maximum response corresponding to the 50% mixture. The implications of these findings for the nature and efficacy of chemical defense systems in plants are discussed.