Abstract
Immunomodulators are substances that either enhance or suppress the
immunity of the host. Immunomodulators have been used for ages in Ayurvedic
Medicine and Traditional Chinese Medicine. In the surge of modern medicine, many
chemically derived substances are used as immunomodulators. Historically, plants
present a rich source of these therapeutic agents. Researchers have used these lead
structures for exploring the underlying mechanisms of immunomodulation so that
newer, safer agents can be designed and used clinically. Microbial sources have also
been tried in search of immunomodulators. Chemically, these are a diverse group of
substances that act on varied signaling pathways to cause immunomodulation. The
involvement of the immune system in many diseases and disorders makes these agents
essential in the treatment of these diseases, e.g., cancer. This chapter discusses the
chemistry of a selected few commonly known plant-derived immunomodulators along
with their biological evaluation methods and provides a broad overview of their
therapeutic potential with particular emphasis on the mechanism of
immunomodulation.