Cassia fistula L. bark fraction modulated GSK3β/ p53 expression for mitochondrial mediated apoptosis in HeLa cells

Abstract

In Ayurveda, Cassia fistula L. commonly known as Aragvadha (disease killer) is highly valuable medicinal plant. In the present study, hexane fraction (CaMH), chloroform fraction (CaMC), ethyl acetate fraction (CaME) and methanol fraction (CaMM) isolated from C. fistula bark were explored for their cytotoxic potential against cervical carcinoma (HeLa), breast carcinoma (MCF-7) and osteosarcoma (MG-63) cell lines using MTT assay. Our results unveiled that C. fistula bark fractions were selectively cytotoxic to carcinoma cells and among the tested fractions CaMC fraction had highest selectivity index (SI) with a value of 9.77 in HeLa cells. CaMC fraction actuated apoptosis in HeLa cells, as evident from chromatin condensation, DNA fragmentation, externalization of phosphatidylserine, altered mitochondrial membrane potential and ROS generation. Moreover, CaMC fraction upregulated the expression of GSK3β and p53 which modulated the Bax/ Bcl-2 ratio and initiated the release of cytochrome c from mitochondria. The expression of caspase 3/9 was also found to be upregulated which ultimately induced apoptosis. We also found that CaMC induced cell cycle arrest at G0/G1 phase and significantly inhibited the migration in HeLa cells. GC–MS analysis showed Oleic Acid, Piperine, Isopiperine and Tris(2,4-di‑tert-butylphenyl) phosphate as major constituents which could be attributed to anticancer activity of CaMC. The present study affirms the potential of CaMC fraction in modulating the aberrant signaling pathway for the induction of apoptosis in HeLa cells.