RESUMO
This study aims at the isolation of filamentous fungi, extraction of metabolites, and evaluation of the cytotoxic properties on HeLa cells and normal human lymphocytes. We isolated fungi from the soil by serial dilution method. One of the isolates was chosen and identified as Aspergillus ochraceus Wilhelm (Trichocomaceae) by standard techniques. The metabolites were extracted using methanol. Different concentrations of the extract were evaluated for their potential anticancer activity on HeLa cells by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide assay and the safety of the extract was checked on normal human lymphocytes. The extract was purified by chromatographic techniques like thin-layer chromatography and high-performance liquid chromatography, and subjected to mass spectrometric analysis. The extract showed significant cytotoxic potential on HeLa cells at low concentrations with a half maximal inhibitory concentration value of <50 µg/ml. The extract gave 10 fractions by thin layer chromatography, and fraction B had higher toxicity than the rest. This fraction gave a single peak by high-performance liquid chromatography and had a mass-to-charge ratio of 905.65, which did not match any of the earlier known fungal metabolites or metabolites from other strains of A. ochraceus. The metabolite from A. ochraceus is alkaloid in nature, cytotoxic to HeLa cells, and appears to be a novel with anticancer potentials, which could be explored further for characterization of the active component.
