Oral administration of naturally occurring chitosan based nanoformulated green tea polyphenol EGCG effectively inhibits prostate cancer cell growth in a xenograft model
Menée à l'aide d'une xénogreffe sur un modèle murin, cette étude montre que l'administration orale de nanoparticules de chitosane contenant de l'épigallocatéchine-3-gallate de thé vert peut inhiber la croissance des cellules cancéreuses de la prostate
In preclinical animal models, several phytochemicals have shown excellent potential to be used as effective agents in preventing and treating many cancers. However, the limited bioavailability of active agents could be one reason for their limited usefulness for human consumption. To overcome this limitation, we recently introduced the concept of nanochemoprevention by encapsulating useful bioactive food components for their slow and sustained release. Here we report the synthesis, characterization, and efficacy assessment of a nanotechnology-based oral formulation of chitosan nanoparticles encapsulating epigallocatechin-3-gallate (Chit-nanoEGCG) for the treatment of prostate cancer (PCa) in a preclinical setting. Chit-nanoEGCG with a size of <200 nm diameter and encapsulating EGCG as determined by Dynamic Light Scattering and Transmission Electron Microscope showed slow release of EGCG in simulated gastric juice acidic pH and faster release in simulated intestinal fluid. The antitumor efficacy of Chit-nanoEGCG was assessed in subcutaneously implanted 22Rν1 tumor xenografts in athymic nude mice. Treatment with Chit-nanoEGCG resulted in significant inhibition of tumor growth and secreted prostate specific antigen levels as compared to EGCG and control groups. In tumor tissues of mice treated with Chit-nanoEGCG, as compared to groups treated with EGCG and controls, there was significant (i) induction of poly (ADP-ribose) polymerases cleavage, (ii) increase in the protein expression of Bax with concomitant decrease in Bcl2, (iii) activation of caspases and, (iv) reduction in Ki-67 and proliferating cell nuclear antigen. Through this study, we propose a novel preventive and therapeutic modality for PCa using EGCG that addresses issues related to bioavailability.
http://carcin.oxfordjournals.org/content/early/2013/09/25/carcin.bgt321.abstract