Potatoes frequently contain
growth inhibitors and toxic compounds including digestive
enzyme inhibitors,
lectins and glycoalkaloids. The literature suggests that
Solanum alkaloids have the ability to induce neurological damage such as
spina bifida and other malformations. As part of a programme of improvement in the safety of potatoes using molecular plant genetics and parallel food safety evaluation, we evaluated the effect of several potato glycoalkaloids and aglycones in the frog embryo
teratogenesis assay--Xenopus (FETAX) with and without metabolic activation by
Aroclor 1254-induced rat liver microsomes. The data suggest that the glycoalkaloid
alpha-chaconine is teratogenic and more embryotoxic than
alpha-solanine, in terms of the median lethal concentration (LC50) after 96 hr of exposure, the concentration inducing gross terata in 50% of the surviving frog embryos (96-hr EC50, malformation), and the minimum concentration needed to inhibit the growth of the embryos. Since these two compounds differ only in the nature of the
carbohydrate side chain attached to the 3-OH group of
solanidine, the side chain appears to be an important factor in governing teratogenicity. The aglycones
demissidine,
solanidine and
solasodine were less toxic than the
glycosides alpha-chaconine and
alpha-solanine. The in vitro
teratogenesis assay should be useful for: (a) predicting the teratogenic potential of solanaceae
alkaloids, glycoalkaloids and related natural products; and (b) facilitating experimental approaches to suppress plant genes and
enzymes that control the biosynthesis of the most toxic compounds.