14.1 History of chemotherapy and antimicrobial discovery

Learning objectives

• Compare and contrast natural, semisynthetic, and synthetic antimicrobial drugs
• Describe the chemotherapeutic approaches of ancient societies
• Describe the historically important individuals and events that led to the development of antimicrobial drugs

Most people associate the term chemotherapy with treatments for cancer. However, chemotherapy is actually a broader term that refers to any use of chemicals or drugs to treat disease. Chemotherapy may involve drugs that target cancerous cells or tissues, or it may involve antimicrobial drugs that target infectious microorganisms. Antimicrobial drugs typically work by destroying or interfering with microbial structures and enzymes, either killing microbial cells or inhibiting of their growth. But before we examine how these drugs work, we will briefly explore the history of humans’ use of antimicrobials for the purpose of chemotherapy.

Use of antimicrobials in ancient societies

Although the discovery of antimicrobials and their subsequent widespread use is commonly associated with modern medicine, there is evidence that humans have been exposed to antimicrobial compounds for millennia. Chemical analyses of the skeletal remains of people from Nubia M.L. Nelson et al. “Brief Communication: Mass Spectroscopic Characterization of Tetracycline in the Skeletal Remains of an Ancient Population from Sudanese Nubia 350–550 CE.” American Journal of Physical Anthropology 143 no. 1 (2010):151–154. (now found in present-day Sudan) dating from between 350 and 550 AD have shown residue of the antimicrobial agent tetracycline in high enough quantities to suggest the purposeful fermentation of tetracycline-producing Streptomyces during the beer-making process. The resulting beer , which was thick and gruel-like, was used to treat a variety of ailments in both adults and children, including gum disease and wounds. The antimicrobial properties of certain plants may also have been recognized by various cultures around the world, including Indian and Chinese herbalists ( [link] ) who have long used plants for a wide variety of medical purposes. Healers of many cultures understood the antimicrobial properties of fungi and their use of moldy bread or other mold-containing products to treat wounds has been well documented for centuries. M. Wainwright. “Moulds in Ancient and More Recent Medicine.” Mycologist 3 no. 1 (1989):21–23. Today, while about 80% of the world’s population still relies on plant-derived medicines, S. Verma, S.P. Singh. “Current and Future Status of Herbal Medicines.” Veterinary World 1 no. 11 (2008):347–350. scientists are now discovering the active compounds conferring the medicinal benefits contained in many of these traditionally used plants.