Herbal Medicine Traditions

Herbal therapies have become an integral part of the American health care scene. Since 1991, public use of herbal products has increased quite markedly, with over $5 billion spent annually. This does not include the many (up to 25%) pharmaceutical products used in conventional practice that originally were, and in some cases still are, derived from plants (Table 69.1). The perennial appeal of herbs may stem from their “natural” origin, giving them the reputation of being somehow safer and better tolerated than prescription drugs. In addition, they are available without prescription, often at much lower cost. For much of the world’s population, herbal treatments remain the first and sometimes the only available treatment. Proponents of herbal therapy also state that the multiple compounds found in most herbal preparations have the advantage of acting synergistically; that is, they act in concert to produce a more enhanced effect than would a single isolated component. An example is St. John’s wort (Hypericum perfoliatum), which contains not only hypericin, the ingredient it is usually standardized for, but also hypaphorine and a variety of other compounds. It is now believed that these other ingredients, far from being extraneous, contribute significantly to the herb’s effectiveness. The study of natural product medicines is termed pharmacognosy, which includes the study of herbal medicine. The resurgence of herbal medicine use has once again made pharmacognosy extremely relevant to the medical curriculum.