Tumor-Reducing and Antioxidant Activities of Sydnone-Substituted Chalcones.

Tumor-reducing effect in vivo and antioxidant effect in vitro of 12 sydnone-substituted chalcones having various groups on the benzene ring were studied. All of them were found to be cytotoxic to tumor cells in vitro, while only methyl substitution increased the in vivo tumor-reducing activity. Some of the substituted chalcones were found to inhibit lipid peroxidation and scavenge superoxides and hydroxyl radicals in vitro. The biological activities of the chalcones were compared with those of curcumin I, an analog of chalcone with known antioxidant activity; and although the sydnone-substituted chalcones had higher cytotoxicity than curcumin I, their tumor-reducing and antioxidant activity were lower. Tumor-reducing activity was found to be independent of their antioxidant activity.