Metabolomik: Open Access

In Vitro Apoptotic Activity of Endophytic Fungal Lectin Isolated from Endophyte, Aspergillus flavus of Viscum album on Human Breast Adenocarcinoma Cell Line (MCF-7)

Abstract

Sadananda TS, Govindappa M, Ramachandra YL, Chandrappa CP and Umashankar T

Lectin was isolated and purified from the endophytic fungi Aspergillus flavus of Viscum album and it was a D-galactose and N-acetylgalactoseamine specific lectin capable of agglutinating A+ve blood group tested in hemeagglutination method. The lectin was confirmed a glycoprotein PAS staining on NATIVE-PAGE and it is having single band of 64 kDa protein (in SDS-PAGE) similar to plant lectin. The peptide sequences were identified from purified lectin 64 kDa protein band is shown. NVRFDLSGATSSSYK similar to Cucurbia pepo protein peptide sequence and it is a ribosome inactivating protein. Apoptotic activity was tested on human breast adenocarcinoma cancer (MCF-7) cell line and it is a time and dose dependent manner. Dose dependent inhibition of cancer cells was observed with IC50 values of 0.02 μg/ ml from Aspergillus flavus. MCF-7 cell death elicited by the lectin extract was found to be apoptotic in nature based the indication of nucleus condensation, shrinkage of nucleus membrane; membrane bebbling and also DNA fragmentation are the hallmark of apoptosis was observed in MCF-7 cells after staining with Hoechst 33342. Caspase mediated apoptosis was observed in lectin treated MCF-7 cells by cleaving fluorogenic peptide substrates, Ac-DEVD-AMC. The caspase-7 was observed as an effector in cleaving other caspases, further inhibition of caspase with an inhibitor provide clear evidence of caspase-7 mediated apoptosis in MCF-7 treated cells.