Sustained Release Oral Nanoformulated Green Tea for Prostate Cancer Prevention
Abstract
The size and morphology of chitosan-based nanoparticles encapsulating EGCG (CHI-EGCG-NPs) were examined by transmission electron microscopy (TEM). This technique allowed us to directly visualize the CHI-EGCG-NPs. It was found that the nanoparticles had a size of around 200 nm, which is further supported by what we observed earlier with our dynamic light scattering (DLS) data. Additionally, from the TEM picture, it is clear that the nanoparticles are spherical in shape. We also studied the release kinetics of EGCG from CHI-EGCG-NPs in simulated gastric juice and simulated intestinal fluid. It became clear from the data that the release of EGCG from these nanoparticles is very slow in acidic medium, even at 24 hrs only ~10% of EGCG was released. On the other hand, release of intestinal fluid is much faster, and around 50% of EGCG was released in 24 hrs. We have earlier shown that treatment with CHI-EGCG-NPs (3 and 6 mg/kg body wt.) resulted in significant inhibition of tumor growth in athymic nude mice implanted with 22R 1 cells. Further extending this work, we report here that in tumor tissues of mice treated with both doses of CHI-EGCG-NPs as compared to group treated with EGCG and controls, there was significant (i) reduction in Ki-67 and proliferating cell nuclear antigen (PCNA) (ii) induction of poly (ADP-ribose) polymerases (PARP) cleavage, (iii) activation of caspases and, (iv) increase in the protein expression of Bax and decrease in Bcl2. Through this study, we propose a novel preventive and therapeutic modality using EGCG that addresses issues related to bioavailability, that is a major reason for its limited success in humans.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2012
- Accession Number
- ADA589659
Entities
People
- Hasan Mukhtar
- Naghma Khan
- Nihal Ahmad
- Vaqar M. Adhami
Organizations
- University of Wisconsin–Madison