Superiority of flavonol 2,3-dehydrosilybin than its parental silybin in inhibiting DNA topoisomerase I: An anti-cancer mechanism of 2,3-dehydrosilybin

Antioxidant silybin is the major compound found in silymarin extracts which have been used to treat liver diseases for several decades. Silybin is now being tested in clinical trials to treat prostate and breast cancers. We have previously reported that the oxidized form of silybin so-called 2,3-dehydrosilybin (DHS) exhibits more potent antioxidant activities than silybin by three folds in in vitro and in vivo systems. Compared with silybin, DHS was more cytotoxic and capable of inhibiting releases of metalloproteinase-2,-9 by five folds [BBA 1780(5): 837, 2008]. In addition, we have shown that DHS (but not sily…