Cancer chemopreventive activity of phenylpropanoid esters of sucrose, vanicoside B and lapathoside A, from Polygonum lapathifolium

To search for cancer chemopreventive agents from natural resources, many ph ytochemicals have been screened using the in vitro synergistic assay indica ted by the inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O- tetradecanoylphorbol-13-acetate (TPA). Two phenyl propanoid esters of sucrose, varricoside B and lapathoside A, were isolated from the aerial part of Polygonum lapathifolium as inhibitors on the EBV-E A induction. These compounds also exhibited significant anti-tumor-promotin g effects on mouse two-stage skin carcinogenesis induced by 7,12-dimethylbe n-z[a]anthracene (DMBA, as an initiator) and TPA as a promoter. Further, va nicoside B exhibited the remarkable inhibitory effect on two-stage carcinog enesis test of mouse skin tumors initiated with an NO donor, NOR-1. (C) 200 1 Elsevier Science Ireland Ltd. All rights reserved.