Disruption of Epigenetic Silencing in Human Colon Cancer Cells Lines Utilizing a Novel Supercritical CO2 Extract of Neem Leaf (Azadirachta indica)

Background/Aim: Aerial parts and seeds of the neem tree (Azadirachta indica) have long been used in traditional medicine such as Ayurveda for health-related purposes. Our interest in neem bioactives lies in their potential use as standalone anticancer agents, or as adjuvants to standard therapy. The aim of the present study was to explore a supercritical CO2 extract (SCNE) of neem leaf and a prominent liminoid in neem leaf, nimbolide, for epigenetic activity. Materials and Methods: Human colorectal cancer cell lines (HCT116 and HT29) were cultured for 48 h in the presence of neem extract or nimbolide and evaluated for growth inhibition and evidence of suppression of histone deacetylation and DNA methylation. Results: Both SCNE and nimbolide suppressed the proliferation of colon cancer cells by inducing epigenetic modifications. Conclusion: Neem leaf contains bioactive constituents which modify epigenetic activity.