Endophytic fungi from Combretum leprosum with potential anticancer and antifungal activity

Abstract

The recent increase in human diseases and cancers requires new drugs to combat them. Sources have been found in rare microorganisms, those from extreme habitats, and from endophytes. In this study, the biological activity of endophytic fungi associated with the Brazilian medicinal plant Combretum leprosum was assessed. Cytotoxic and antiproliferative effects were evaluated using seven human cancer cells lines (HeLa, ECV304, B16F10, J744, P388, Jurkat and k562). In addition the minimum inhibitory concentration (MIC) against pathogenic human fungal was determined using four Candida species and the filamentous fungi Cryptococcus neoformans and Trichophyton rubrum. A compound from extracts of phylotype Aspergillus oryzae CFE108 exhibited the most significant cytotoxicity effect against histiocytic sarcoma J774 (IC50 of 0.80 μg mL−1), leukemia Jurkat (IC50 of 0.89 μg mL−1), bladder carcinoma ECV304 (IC50 of 3.08 μg mL−1) and cervical cancer HeLa (IC50 of 2.97 μg mL−1). The extract from phylotypes Fusarium oxysporum CFE177 displayed antifungal activity and inhibited the growth of Candida glabrata (4 μg mL−1) as well as that of C. neoformans and T. rubrum with the lowest MIC being 62.5 μg mL−1. In addition, the fractions from A. oryzae CFE108 showed marked morphological activity (rounding up) on endothelial cells (tEnd.1 cells), which is indicative of potential antivascular activity. Our results indicate that the endophytes associated with this medicinal plant may be a source of novel drugs.