Ethyl Acetate Extract of <i>Colletotrichum gloeosporioides</i> Promotes Cytotoxicity and Apoptosis in Human Breast Cancer Cells

Abstract

Fungal endophytes are known to be a paragon for producing bioactive compounds with a variety of pharmacological importance. The current study aims to elucidate the molecular alterations induced by the bioactive compounds produced by the fungal endophyte <i>Colletotrichum gloeosporioides</i> in the tumor microenvironment of human breast cancer cells. GC/MS analysis of the ethyl acetate (EA) extract of <i>C. gloeosporioides</i> revealed the presence of bioactive compounds with anticancer activity. The EA extract of <i>C. gloeosporioides</i> exerted potential plasmid DNA protective activity against hydroxyl radicals of Fenton's reagent. The cytotoxic activity further revealed that MDA-MB-231 cells exhibit more sensitivity toward the EA extract of <i>C. gloeosporioides</i> as compared to MCF-7 cells, whereas non-toxic to non-cancerous HEK293T cells. Furthermore, the anticancer activity demonstrated by the EA extract of <i>C. gloeosporioides</i> was studied by assessing nuclear morphometric analysis and induction of apoptosis in MDA-MB-231 and MCF-7 cells. The EA extract of <i>C. gloeosporioides</i> causes the alteration in cellular and nuclear morphologies, chromatin condensation, long-term colony inhibition, and inhibition of cell migration and proliferation ability of MDA-MB-231 and MCF-7 cells. The study also revealed that the EA extract of <i>C. gloeosporioides</i> treated cells undergoes apoptosis by increased production of reactive oxygen species and significant deficit in mitochondrial membrane potential. Our study also showed that the EA extract of <i>C. gloeosporioides</i> causes upregulation of pro-apoptotic (<i>BAX</i>, <i>PARP</i>, <i>CASPASE-8</i>, and <i>FADD</i>), cell cycle arrest (<i>P21</i>), and tumor suppressor (<i>P53</i>) related genes. Additionally, the downregulation of antiapoptotic genes (<i>BCL-2</i> and <i>SURVIVIN</i>) and increased Caspase-3 activity suggest the induction of apoptosis in the EA extract of <i>C. gloeosporioides</i> treated MDA-MB-231 and MCF-7 cells. Overall, our findings suggest that the bioactive compounds present in the EA extract of <i>C. gloeosporioides</i> promotes apoptosis by altering the genes related to the extrinsic as well as the intrinsic pathway. Further in vivo study in breast cancer models is required to validate the <i>in vitro</i> observations.