Plant Products as Antimicrobial Agents
The use and search for drugs and dietary supplements derived from plants has accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the earth for phytochemicals and ‘‘leads’’ that could be developed as antimicrobial agents. While currently 25% to 50% of current pharmaceuticals are derived from plants, only a small percentage of these are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Some of these plant extracts may be desirable as cosmetic antimicrobial agents because they also impart pleasant fragrances or provide other beneﬁts to a cosmetic formulation. Plants are rich in a wide variety of secondary metabolites such as tannins, terpenoids, alkaloids, and ﬂavonoids that have been found to have antimicrobial properties in vitro. This chapter discusses the structure and antimicrobial properties of several phytochemicals and attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity.