Endophytic fungi of medicinal herbs: Basic science and source of new drug leads

Fungi are one of the most diverse organisms on the planet, second only to the insects. Estimates predict a range of 1.5 to 5.5 million fungi in the world, and yet, only about 100 thousand have been ascribed a name, and much fewer have been studied for drug leads. This is somewhat surprising given that the elixir of the 20^th century, penicillin, was derived from a fungal Petri dish. Endophytes represent a unique niche of fungi, as they live at least some portion of their life within plants, but do so symbiotically and without imparting disease. Questions abound, such as: Do the endophytes stimulate the biosynthesis of defense compounds in the plant? Does the secondary metabolite profile of the endophytes help the plant? Can the endophyte produce compounds similar to those found from the plant? Can the endophytes serve as a new source for drug leads? Can the endophytes be grown in culture, and if so, will they continue to biosynthesize a similar profile of secondary metabolites? Are the endophytes beneficial to the host, detrimental to the host, or simply saprobes in waiting? While we cannot provide definitive answers to any of these questions, we have amassed data that both probes some of the basic science questions, as well as, demonstrates the generation of new drug leads.