Anti-Cancerous Metabolites and Extracellular Enzyme Production by Endophytic Penicillium and Paecilomyces Strains

Abstract

Fungal endophytes colonize an important niche within the plants through secretion of secondary metabolites. The metabolites and extracellular enzymes produced by endophytic fungi regulate the growth of the host plant and contribute in defence mechanisms.The medicinal plants Caralluma acutangula and Boswellia sacra were used for the isolation of endophytic fungi. The endophytic fungi were identified as Penicillium citrinum, Paecilomyces variotii, Aspergillus nidulans, Fusarium oxysporum, Epicucum nigram, Penicillium purpurogenum, Penicillium spinulosum, Aspergillus caespitosus, Phoma and Alternaria sp. and were assessed for their potential to produce anti-cancerous metabolites by performing MTT assay and extracellular enzymes such as cellulases, phosphatases and glucosidases in growth media. P. variotii, P. citrinum and F. oxysporum showed significantly higher amount of phosphatases and glucosidases as compared to other strains. Additionally, P. variotii and F. oxysporum showed significantly higher potential of indole acetic acid production (tryptophan-dependent and independent pathways). ACC (1-Aminocyclopropane-1-carboxylate) deaminase results showed that P.citrinum, P. purpurogenum and P. Variotii had shown prominent ACC deaminase activity (300 nmol α- ketobutyrate mg-1h-1). Fluorescence-based MUB (4-methyl umbelliferone) standards were used to analyze the presence of extracellular enzymes glucosidase, phosphatase and cellulase. The bioactive secondary metabolites from endophytic P. citrinum also revealed some prominent results by performing MTT assay on breast cancer cell line (MCF-7). The current study concludes that these fungi are producing bioactive constituents that could provide unique niche of ecological adaptation by symbiosis and greatly contributing to the healthy life of their host plant. However, some of the endophytic fungi offer a great potential to produce anti-cancerous metabolites and extracellular enzymes.