Effect of potato glycoalkaloids, .alpha.-chaconine and .alpha.-solanine on membrane potential of frog embryos

To demonstrate whether potato glycoalkaloids can alter the integrity of membranes of frog embryo, albino frog embryos were incubated with alpha-chaconine and alpha-solanine. Di-4-ANEPPS, an electrochromic fluorescent dye, was added to measure embryonic membrane potential. alpha-Chaconine increased the Di-4-ANEPPS fluorescence up to 1600% of control, alpha-solanine increased the fluorescence up to 400%, and solanidine had no effect. Increases in fluorescence, when plotted in a concentration-response format, produced EC50 values near published values for FETAX (frog embryo teratogenicity assay--Xenopus). Possible mechanisms and the significance of the fluorescence results to food safety are discussed