Chloroform fraction of Chaetomorpha brachygona, a marine green alga from Indian Sundarbans inducing autophagy in cervical cancer cells in vitro

Sundarbans Mangrove Ecosystem (SME) is a rich repository of bioactive natural compounds, with immense nutraceutical and therapeutic potential. Till date, the algal population of SME was not explored fully for their anticancer activities. Our aim is to explore the potential of these algal phytochemicals against the proliferation of cervical cancer cells (in vitro) and identify the mode of cell death induced in them. In the present work, the chloroform fraction of marine green alga, Chaetomorpha brachygona was used on SiHa cell line. The algal phytochemicals were identified by GCMS, LCMS and column chromatography and some of the identified compounds, known for significant anticancer activities, have shown strong Bcl-2 binding capacity, as analyzed through molecular docking study. The extract showed cytostatic and cytotoxic activity on SiHa cells. Absence of fragmented DNA, and presence of increased number of acidic vacuoles in the treated cells indicate nonapoptotic cell death. The mode of cell death was likely to be autophagic, as indicated by the enhanced expression of Beclin 1 and LC3BII (considered as autophagic markers) observed by Western blotting. The study indicates that, C. brachygona can successfully inhibit the proliferation of cervical cancer cells in vitro.

Endophytic fungus, Chaetomium globosum, associated with marine green alga, a new source of Chrysin

The marine ecosystem is an extraordinary reserve of pharmaceutically important, bioactive compounds even in this “synthetic age”. Marine algae-associated endophytic fungi have gained prominence as an important source of bioactive compounds. This study was conducted on secondary metabolites of Chaetomium globosum-associated with marine green alga Chaetomorpha media from the Konkan coastline, India. Its ethyl acetate extract (CGEE) exhibited an IC50 value of 7.9 ± 0.1 µg/mL on MCF-7 cells. CGEE exhibited G2M phase cell cycle arrest, ROS production and MMP loss in MCF-7 cells. The myco-components in CGEE contributing to the cytotoxicity were found by Gas Chromatography/Mass Spectrometry analyses. Chrysin, a dihydroxyflavone was one of the forty-six myco-components which is commonly found in honey, propolis and passionflower extracts. The compound was isolated and characterized as fungal chrysin using HPLC, UV–Vis spectroscopy, LC–MS, IR and NMR analyses by comparing with standard chrysin. The purified compound exhibited an IC50 value of 49.0 ± 0.6 µM while that of standard chrysin was 48.5 ± 1.6 µM in MCF-7 cells. It induced apoptosis, G1 phase cell cycle arrest, MMP loss, and ROS production. This is the first report of chrysin from an alternative source with opportunities for yield enhancement.