Ficus religiosa (Linn.) bark extract secondary metabolites bestow antioxidant property inducing cell cytotoxicity to human breast cancer cells, MDA-MB-231 by apoptosis involving apoptosis-related proteins, Bax, Bcl-2 and PARP

Abstract

Ficus species, auspicious in many cultures worldwide are sources of novel bioactive secondary metabolites. The mechanism by which they exhibit antioxidant and apoptotic properties is scant. The main objective of the current study was to evaluate the properties of activity guided fractionated bark methanol extract of Ficus religiosa. As the methanol extract exhibited highest antioxidant activity it was evaluated for secondary metabolites and therapeutic properties. UPLC-MS analysis of the extract identified the 11 and five secondary metabolites including the rutin, 3-caffeoylquinic acid, luteolin 7-O-rutinoside, 6-C-glucosyl-8-C-arabinosylapigenin and kaempferol-3-O-rutinoside were reported. The MTT assay results identified minimal cytotoxicity for non-cancerous cell line (HEK 293 T) and maximum cell death for human breast cancer cells, MDA-MB-231 (EC50, 91.32 ± 4.21µ g.mL− 1). A high degree of DNA fragmentation in MDA-MB-231 cells subjected to the extract was observed. A clear indication of apoptosis via chromatin condensation was visualized by CLSM. The apoptotic response to treatment was also apparent in the increase in BAX along with the proteolytic cleavage of PARP-1 and a decreased Bcl-2 levels as revealed by Western blot analysis. The MDA-MB-231 cells upon exposure to the extract (91µ g.mL− 1), stimulated cells to early apoptosis (32.5%) and apoptosis (61.6%) as evidenced by flow cytometer studies. Apoptotic cells being represented by a sub G0/G1 population (86.25%) seen to the left of the G0/G1 peak were recorded. The presence of novel bioactive compounds has uncovered possible therapeutic values by modulating antioxidant and apoptosis leading to the development of potential alternative anticancer drugs.