Endophytic fungi residing in medicinal plants have the ability to produce the same or similar pharmacologically active secondary metabolites as their hosts

Medicinal plants have been used for thousands of years in folk medicines and still are used for their health benefits. In our days medicinal plants are exploited for the isolation of plant-derived drugs as they are very effective and have relatively less or no side effects. However, the natural resources of medicinal plants are gradually exhausted and access to plant bioactive compounds is challenged by the low levels at which these products accumulate in native medicinal plants. For instance, to meet the market demands of 3 Kg per year of vinca alkaloids, powerful plant-derived anticancer drugs, 1.5×10⁶ Kg dry leaves are required. In this regard, this review aims to highlight the fact that endophytic fungi residing in medicinal plants are capable to biosynthesize pharmacologically active secondary metabolites similar or identical to those produced by their host medicinal plant. Furthermore, the evolutionary origin of the genes involved in these metabolic pathways as well as the approaches designed to enhance the production of these metabolites by the isolated endophytic fungi are also discussed.