Preliminary investigation of the fungal endophytic extract isolated from Tabernaemontana pandacaqui leaves and evaluation of its antioxidant and cytotoxic potentials

Objectives: Tabernaemontana pandacaqui is used in Indonesian folklore as a cure for ulcers, inflammation, skin sores and stomach pain, it was recently grown in Egypt for ornamental purposes.It can host endophytes which produce variety of secondary metabolites of potential biological activities. Based on traditional use of this plant, it was essential to study endophytes living in this host plant and evaluate their phytochemical and biological values. Methods: T. pandacaqui leaves were used as the microbial host material for the isolated fungus which was mass cultured and extracted. Fungal ethyl acetate extract was analyzed with GC-MS. Quantitative and qualitative identification of the compounds was performed based on the comparison of their retention times and mass spectra with those of the NIST, WILLY library data of the GC-MS system. Its antioxidant activity was evaluated using DPPH and ABTS assays and expressed as Trolox Equivalent Antioxidant Capacity (TEAC) and the cytotoxic screening against four cell lines was carried out using SRB assay. Results: The isolated fungus (TMP16) was identified as Aspergillus species.GC-MS analysis revealed the presence of high percentage of nitrogenous compounds (75.38%) of which porphyrin derivatives dominate (42.85%). The fungal extract gave antioxidant scavenging power of 881.49 ± 44.6 and 866.86 ± 50.0 μM TE/ mg extract (TEAC) in both DPPH and ABTS assays respectively. While it showed no cytotoxic activity against A-549, HepG2, PC-3 and MCF-7 cell lines with the used concentrations. Conclusion: Ethyl acetate extract of (TMP16), isolated from T. pandacaqui leaves for the first time, exhibited a significant antioxidant activity which may be attributed to high percentage of porphyrin derivatives.