Abstract
Silymarin (the standardized extract of mainly flavonolignans from silybum marianum) is approved for the adjuvant therapy of alcoholic liver disease and is also sold as an over the counter drug for miscelaneous purposes. Hence, the exposition of humans to these flavonolignans is not negligible.
In this study we tested the interaction of isolated optically pure flavonolignans from silymarin with iron and copper which is relevant in the gastrointestinal tract due to low biovailability of these compounds. Only 2,3-dehydrosilybin was found to be a potent or moderately active iron and copper chelator.
Silybin A, silybin B and silychristin A were less potent or inactive chelators. Both 2,3-dehydrosilybin enantiomers (A and B) were equally active iron and copper chelators, and the preferred stoichiometries were mainly 2:1 and 3:1 (2,3-dehydrosilybin:metal).
Additional experiments showed that silychristin was the most potent iron and copper reductant.