Cancer preventive agents. Part 6: Chemopreventive potential of furanocoumarins and related compounds

Twenty-one furanocoumarins and related compounds were synthesized and screened as potential antitumor promoters by using the in vitro short-term 12- O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) activation assay. Compounds 3a and 5a showed the greatest potency (96% inhibition at 1000 mol ratio/TPA). Consequently, they were further tested in an in vivo two-stage mouse skin carcinogenesis assay. Compounds 3a and 5a were slightly more potent than curcumin, a well-known antitumor promoter. These data suggested that furanocoumarins might be valuable antitumor promoters or chemopreventors.