45: Herbal Preparations

INTRODUCTION

Although there is increased awareness of the widespread use of herbal ­preparations in the United States, physicians frequently seek information about their usage only after the patient demonstrates toxicity.

HISTORY AND EPIDEMIOLOGY

Since ancient times and perhaps since prehistoric times, people of all cultures have used herbal preparations to treat disease and promote health.⁴⁰ A 60,000 year-old Iraqi burial site contained eight different medicinal plants, suggesting very early historical usage.¹⁴² The earliest surviving written account of medicinal plants is the Egyptian Ebers papyrus, circa 1500 b.c., which lists dozens of medicinal plants and their intended uses. In India, the Vedas, epic poems written in approximately 1500 b.c., contain references to herbal preparations of the time. In China, the Divine Husbandman’s Classic, written in the first century a.d., lists 252 herbal preparations. In ancient Europe, herbal medicines were the mainstay of healing. In the first century, the Greek physician Dioscorides wrote one of the first European herbal books, De Materia Medica, which listed 600 herbals and was translated into many languages. Shamans and folk healers from the Americas, Africa, Australia, and Asia continue to include herbals for spiritual and medicinal purposes based on oral traditions passed from generation to generation.

During the Scientific Revolution, European scientists began to isolate purified extracts of plant products for use as medicinal agents. In 1804 and 1832, morphine and codeine were isolated from the sap of the poppy plant Papaver somniferum.⁷³ In the mid-eighteenth century, Edward Stone described in a letter to the president of the Royal Society of Medicine the successful use of the bark of the willow tree in curing “agues” (fever).²⁰ In 1829, salicin, the active ingredient of the willow bark, was identified. Its derivative sodium salicylate was marketed in 1875 as a treatment for rheumatic fever and as an antipyretic. The enormous success of this drug led to the synthesis of acetylsalicylic acid in 1899. The original name, aspirin (a cetyl-spiric acid), is said to have been derived from Spiraea, the plant genus from which salicylic acid once was prepared. Even today, plant preparations still are being investigated for the development of modern drugs. Sweet wormwood (Artemisia annua, qing hao) was first described as a treatment for malaria in China in 168 b.c.⁸⁸ In 1971, the active parent compound artemisinin was first isolated by Chinese investigators. Artemisinin, when used in combination with other antimalarials, is considered the best ­treatment for falcipararum-resistant malaria.^85,107,134 Prescriptions from plant-derived medicines currently represent approximately 25% of prescriptions dispensed in the United States^2,163 and at least 60% of nonprescription medications contain one or more natural products as ingredients.⁴⁸

Herbal preparations continue to be the dominant form of healing in the developing world because of the high cost of ...