Search for Bioactive Constituents of Botanical Dietary Supplements

Abstract

The field of cancer chemoprevention was defined some time ago as “a strategy of cancer control by administration of synthetic or natural products to reverse or suppress the process of carcinogenesis”[1]. There are a number of compounds of plant origin undergoing clinical trials as potential cancer chemopreventive agents through the auspices of the U.S. National Cancer Institute, and, of these, several such substances are categorized as constituents of botanical dietary supplements (http://www.clinicaltrials.gov). In a research program begun recently at The Ohio State University, a library of over 100 secondary metabolites has been obtained by isolation and spectroscopic characterization from the following species: açaí (Euterpe oleracea Mart.), barberry (Berberis vulgaris L.), licorice (Glycyrrhiza glabra L.), mangosteen (Garcinia mangostana L.), and noni (Morinda citrifolia L.). These compounds have been evaluated using various in vitro 2 [i.e., antioxidant (peroxynitrite; hydroxyl-radical scavenging; cytoprotective activity in cultured MCF-7 cells stressed with H2O2), quinone reductase induction in Hepa1c1c7 cells, aromatase inhibition in microsomes and in SK-BR-3 cells], ex vivo (mouse mammary organ culture[2,3]), and in vivo (full-term tumorigenesis inhibition in a 1,2-dimethylhydrazine-induced colon and lung cancer model[2,4]) assays, germane to cancer chemoprevention. It is concluded that the botanical dietary supplements investigated contain low concentration levels of quite potent biologically active compounds, and that some of these are useful lead compounds for cancer chemoprevention. Acknowledgements: Nature's Sunshine Products, Inc., Spanish Fork, UT 84660 (through Dr. William J. Keller) is thanked for the provision of botanical dietary supplement materials and for financial support. Additional research funding was provided from the Molecular Carcinogenesis and Cancer Chemoprevention Program of The Ohio State University Comprehensive Cancer Center.