Accession Number:

ADA589659

Title:

Sustained Release Oral Nanoformulated Green Tea for Prostate Cancer Prevention

Descriptive Note:

Annual rept. 15 Apr 2011-14 Apr 2012

Corporate Author:

WISCONSIN UNIV MADISON

Report Date:

2012-05-01

Pagination or Media Count:

15.0

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 mgkg 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.

Subject Categories:

  • Anatomy and Physiology
  • Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE