Cancer-chemopreventive effects of natural sweeteners and related compounds

Abstract

To search for possible cancer-chemopreventive agents from natural resources, several natural sweeteners were screened by the in vitro assay indicated by the inhibitory effects of Epstein-Barr virus early antigen (EBV-EA) induction. Of active compounds that showed the remarkable inhibitory effects on the EBV-EA induction, stevioside, from the leaves of Stevia rebaudiana, and mogroside V, from the fruits of Momordica grosvenori, exhibited significant inhibitory effects on the two-stage mouse skin carcinogenesis in vivo induced by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). The inhibitory effect of stevioside is stronger than that of glycyrrhizin, which had been known as an antitumor-promoter in chemical carcinogenesis. Furthermore, stevioside also inhibited mouse skin carcinogenesis initiated by peroxynitrite. These results suggest that stevioside and mogroside V might be valuable as chemopreventive agents for chemical carcinogenesis.