Diversity and Biological Activities of Endophytic Fungi from the Flowers of the Medicinal Plant Vernonia anthelmintica.

Secondary metabolites produced by endophytic fungi are an important source of biologically active compounds. The current research was focused on the biological activities of ethyl acetate extracts of fungi, isolated and identified from Vernonia anthelmintica flowers for the first time. In addition, an investigation of the non-polar chemical composition of dichloromethane-ethyl acetate extracts of the most active fungal strain was carried out. The isolates included Ovatospora senegalensis NR-03, Chaetomium globosum NR-04, Thielavia subthermophila NR-06, Aspergillus calidoustus NR-10, Aspergillus keveii XJF-23 and Aspergillus terreus XJF-3 species. Strains were identified by 18S rRNA gene sequencing methods and were registered in GenBank. Crude extracts of the fungi displayed in vitro biological activities, including antimicrobial and cytotoxic activities. A melanin content assay was performed on murine B16 cells. An ethyl acetate extract of O. senegalensis NR-03 showed high anticancer and antimicrobial activity; therefore, we also studied the non-polar chemical composition of the dichloromethane-ethyl acetate fraction and identified 52 non-polar compounds with the different medium. This investigation discovered that the secondary metabolites of the total extract of endophytic fungi could be a potential source of alternative natural antimicrobial, cytotoxic and melanin synthesis activity in their host plant, and the isolation of bioactive metabolites may provide a lead to new compounds of pharmaceutical significance.

Biological Activity of Endophytic Fungi from the Roots of the Medicinal Plant Vernonia anthelmintica.

Endophytic fungi were first isolated from the fresh root of the Chinese medicinal plant Vernonia anthelmintica collected from the Hotan Prefecture within the Xinjiang Autonomous region of the People's Republic of China. This plant has been used in Uyghur traditional medicine to treat vitiligo, a skin condition characterized by patches of the skin losing their pigment. In total, fifteen fungal strains were isolated. Among these, four endophytic fungi were identified by their DNA sequences and registered to GenBank with accession numbers. The isolates were identified as Schizophyllum commune XJA1, Talaromyces sp. XJA4, Aspergillus sp. XJA6, Aspergillus terreus XJA8. Ethyl acetate extracts of all fungal strains were used to quantify melanin content and to identify in vitro biological activity assays including antimicrobial, antioxidant, cytotoxic, antidiabetic and tyrosinase activity on B16 cells. Among the extracts of all four identified strains, the ethyl acetate extract of the Aspergillus sp. XJA6 was chosen for further characterization because it presented the highest biological activity against these tests. In addition, twenty four volatile compounds from the petroleum ether fraction were characterized by GC-MS.

Endophytic Bacteria Associated with Medicinal Plant Vernonia anthelmintica: Diversity and Characterization.

Increasing evidence shows that endophytic bacteria living inside plant tissue may possess similar biological activity and produce similar metabolites to their hosts. This study aimed to determine the diversity of endophytic bacteria associated with Vernonia anthelmintica and to evaluate their biological activity. The bacteria were isolated from the plant tissue using culture-dependent techniques. Comparison of the 16S rRNA gene sequences of endophytic bacteria isolated from V. anthelmintica showed that isolates belong to the species Micrococcus endophyticus VERA1, Bacillus megaterium VERA2, Pseudomonas chlororaphis VERA3, P. kilonensis VERA4, Stenotrophomonas pavanii VERA5, B. endophyticus VERA6, S. maltophilia VERA7, Pantoea ananatis VERA8, B. atrophaeus VERA9 and M. flavus VERA10. Activity studies showed that the endophytic bacteria share several similar biological properties with their host plant including antimicrobial, anti-vitiligo and antidiabetic activities. These findings indicate that plant phytochemical compounds and activity play an important role in the physiological properties of their endophytes.