Endophytes and their importance in drug discovery

An endophyte is a microorganism such as fungi or bacteria that expends either the complete or part of its lifecycle within the healthy tissues of a living plant, typically causing no symptoms of disease. Endophytic microorganisms that reside in the tissues of living plants are promising, less explored and useful sources of novel natural products for exploitation in agriculture, medicine, and industry. Following the importance of secondary metabolites from medicinal plant and their influence on synthetic ability of endophytes, researchers have been interested in exploring of medicinal plants for isolation of endophytes. The ability of endophytes to mimic the biosynthesis mechanism of their host plant to produce alternative bioactive agents is another reason to attract researchers. Moreover, endophytes originated from medicinal plants may result in the inexhaustible and cost-effective production of interesting novel compounds associated with diverse biological activities and thereby helping to conserve the biodiversity. Therefore, it is noteworthy to explore endophytes from their host medicinal plants which have been claimed as a source of bioactive compounds. Of the nearly 300,000 plant species that exist on the earth, each individual plant is expected to host to one or more endophytes. This course covers how to select traditional medicinal plants and their parts for the study, isolation and purification of bacterial or fungal endophytes, methods for pre-treatment and surface sterilization, test for effectiveness of surface sterilization, media for isolating endophytic bacteria or fungi, techniques for isolation, purification of endophytes, methods for characterization of endophytes, bioassay guided methods of extraction, isolation and characterization of bioactive compounds from purified endophytes. Additionally, bioactive compounds reported from endophytes will be summarized.