Enhanced anticancer activity of (-)-epigallocatechin-3-gallate (EGCG) encapsulated NPs toward colon cancer cell lines.

Abstract

(-)-Epigallocatechin-3-gallate (EGCG), a bioactive polyphenol of green tea, has chemo-preventive effects against various cancer cells. Nanoparticles (NPs) carrying different ligands are able to specifically interact with their receptors on different cancer cells that can provide effective release of cytotoxic drugs. In the present study, we have prepared EGCG entrapped NPs using PLGA (poly(d,l-lactide-co-glycolide)). Polyethylene glycol (PEG) and folic acid (FA) via double emulsion solvent evaporation (DESE) method obtained PLGA-EGCG (P-E), PLGA-PEG-EGCG (PP-E), and PLGA-PEG-FA-EGCG (PPF-E). Nanoformulations had been characterized with ¹H NMR and FT-IR techniques, AFM, and DLS. PPF-E NPs showed an average size of 220 nm. Analysis of zeta potential confirmed the stability of NPs. HCT-116, HT-29, HCT-15, and HEK 293 cells were treated with both the prepared NPs and free EGCG (0-140 μM). Result showed PPF-E NPs had improved delivery, uptake and cell cytotoxicity toward human folic acid receptor-positive (FR+) colorectal cancer (CRC) cells as mainly on HCT-116 compared to HT-29, but not on the folic acid-negative cells (FR-) as HCT-15. PPF-E NPs enhanced intracellular reactive oxygen species (ROS) level in absence of N-acetyl-l-cysteine (NAC), elevated DNA fragmentation level, and increased apoptotic cell death at higher doses compared to other two NPs and free EGCG. In conclusion, PPF-E NPs exerted greater efficacy than PP-E, P-E, and free EGCG in HCT-116 cells.