Mycopharmacological Properties of Endophytic Fungi Isolated from Cuban Oregano (Plectranthus amboinicus Lour.) Leaves

Endophytic fungi reside internally and asymptomatically in plant tissues and play significant role in the ecosystem. Medicinal plants, such as oregano (Plectranthus amboinicus Lour.), are valuable sources of important endophytic fungi which are known to confer several benefits to their hosts. In this study, endophytic fungi were isolated from the leaves of P. amboinicus and assessed for their mycopharmacological properties. The fungal endophytes were isolated then identified based on their morphological characteristics. They were subjected to qualitative mycochemical analysis and antibacterial screening. Three fungal endophytes were isolated from the leaves of Mexican oregano, all of which belong to the genus Aspergillus. The fungal endophytes were morphologically identified as Aspergillus niger, Aspergillus tamarii and Aspergillus terreus. Each endophytic fungus was determined to contain valuable mycochemical compounds such as alkaloids, flavonoids, saponins, tannins, glycosides, sterols, terpenoids, quinones and phenols which can be exploited for therapeutic development. In the antibacterial assay, preliminary screening using agar plug diffusion method revealed that the endophytes were able to impressively suppress the growth of both Escherichia coli and Staphylococcus aureus. The results were further affirmed by subjecting the ethanol extracts of the endophytes against the same test bacteria using the agar well diffusion method. This study shows the potential of these endophytic fungi for pharmaceutical exploitations.