<i>Chloroxylon swietenia</i> (Roxb.) <scp>DC</scp> induces cell death and apoptosis by down‐regulating the <scp>NF‐κB</scp> pathway in <scp>MCF</scp>‐7 breast cancer cells: In vitro and in vivo investigations
Sonali S. Kamble, Jasoda Choudhari, Ramakrishna Nimma, Totakura Venkata Santosh Kumar, Kapil Patil, Shrikant V. Hese, Bhaskar S. Dawane, Rajesh N. Gacche
Abstract
BACKGROUND: Natural products with targeted bioactivity have gained major attention in the field of cancer research owing to emerging anti-cancer drug resistance and off target toxicities. Chloroxylon swietenia (Roxb.) DC is recognized as a folklore medicinal plant and has numerous therapeutic benefits in the folklore medicine system, however the anti-cancer potential of this plant and its mechanism of action is poorly understood. AIMS: The aim of the study was to investigate the anti-breast cancer efficacy of C. swietenia leaves methanol extract (CSLME) against MCF-7 hormone dependent human breast cancer cell line with possible mechanism of action. METHODS AND RESULTS: 20 μg/ml), inhibited cell migration, colony formation, and angiogenesis. It was observed that CSLME induces apoptosis by nuclear fragmentation and disruption of cytoskeleton by actin derangement. The results of Annexin V-FITC assay and cell cycle analysis by flow cytometry clearly pointed out the sizable fraction of apoptotic cells, and arrested the cells at G2/M phase of cell cycle. The results of the immunoblotting experiments showed that CSLME activates intrinsic pathway of apoptosis with down regulation of anti-apoptotic marker like Bcl2, up regulation of pro-apoptotic markers like Bax & Bad, along with successful cleavage of Caspase-9 and PARP-1. Further, western blot analysis revealed the possible down regulation of NF-κB pathway by CSLME, which may be responsible for anti-cancer activity in MCF-7 cells. In vivo animal model studies using NOD-SCID mice demonstrated impressive anti-tumor activity with significant reduction in tumor volume of MCF-7 tumor xenograft. Of note, in-vivo acute oral toxicity study as per Organization for Economic Cooperation and Development 423 revealed the nontoxic nature of CSLME. CONCLUSION: The in vitro and in vivo findings clearly outline the potential of CSLME as inhibitor of growth and proliferation of MCF-7 cells. Mechanistically, CSLME seems to activate intrinsic pathway of apoptosis, arrest cell cycle, target actin cytoskeleton, inhibit growth, colony formation, migration, and angiogenesis, with down regulation of NF-κB pathway leading to cell death.