Nature’s Pharmacopoeia: Exploring Bacterial Endophytes for Future Medicinal Advancements

Plant endophytes confer diverse advantages to their hosts by promoting growth and development. Beneficial plant-endophyte interactions are in use for sustainable agricultural practices and for enhanced phytoremediation of environmental pollutants. Production of “high-value” secondary metabolites, with diverse therapeutic potential, by the endophytes has also gained the attention of researchers paving the way for the application of such metabolites for pharmaceutical purposes. Bioactive secondary metabolites, such as alkaloids, phenolics, steroids, quinones, tannins, saponins, terpenoids, etc., produced by the endophytes, such as Streptomyces spp., Burkholderia spp., Bacillus spp., Serratia spp., Pseudomonas spp., Paenibacillus spp., etc., have been found to possess antibacterial, antiviral, antifungal, and anticancer properties, thus, having immense potential of usage as drugs against life-threatening diseases. However, the actual potential of the endophytes in this regard is underexplored due to limited knowledge of their diversity, molecular aspects of plant-microbe interactions, and their actual functional potentials and in-planta activities. Contemporary advanced omics-based, and genetic manipulation methods have allowed researchers to better explore and utilize endophytes in drug discovery. In this review, the potential applications of bacterial endophytes as important sources of drugs against various diseases have been discussed. Recent technological advancements and prospects of research on endophytes are also reviewed.