Antimutagenicity of secondary metabolites from higher plants.

Higher plants contain both mutagens and antimutagens and are susceptible to mutagenesis but screening programs for detection of antimutagenesis rarely employ higher plant systems. Short-term bacterial and mammalian tissue culture systems are the norm. Using modified screening tests for detecting antimutagenic agents, higher plants have been shown to contain a variety of structurally novel antimutagenic agents. Systematic bioassay-directed methodology resulted in the isolation in pure form and biological and chemical characterization of the responsible individual active components from various plants. The methodology in use is illustrated by the isolation of cinnamic acid, cinnamyl cinnamate and cinnamyl ricinoleate as the active constituents of the classic medicinal plant product, Styrax asiatica. The methods which may be used to reveal structure-activity relationships and to explore putative molecular modes of action are illustrated with excerpts from the same study.