Table of Contents Author Guidelines Submit a Manuscript
Journal of Toxicology
Volume 2009, Article ID 530279, 16 pages
http://dx.doi.org/10.1155/2009/530279
Research Article

Molecular and Biochemical Effects of a Kola Nut Extract on Androgen Receptor-Mediated Pathways

1Department of Environmental Toxicology, Southern University and A&M College, P.O. Box 9264, 108 Fisher Hall, Baton Rouge, LA 70813, USA
2Department of Chemistry, Southern University and A&M College, P.O. Box 9716, 116 Lee Hall, Baton Rouge, LA 70813, USA

Received 9 March 2008; Accepted 5 June 2008

Academic Editor: Margaret James

Copyright © 2009 Rajasree Solipuram et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The low incidence of prostate cancer in Asians has been attributed to chemopreventative properties of certain chemicals found in their diet. This study characterized the androgenic and chemopreventative properties of the Jamaican bush tea “Bizzy,” using androgen receptor positive and negative cell lines. Exposure of prostate cells to Biz-2 resulted in a growth inhibition ( ) of 15 ppm in LNCaP cells and 3.6 ppm in DU145 cells. Biz-2 elicited a 2-fold increase in the mRNA of the anti-apoptotic gene Bcl2, with a 10-fold increase in that of the proapoptotic gene Bax. We observed a 2.4- to 7.5-fold change in apoptotic cells in both cell lines. Biz-2 at 10 ppm elicited a time- and dose-dependent stimulation of both the protein and mRNA levels of several androgen-regulated genes. Biz-2 caused a 36% decrease in PSA secretion and a significant increase in PSA mRNA. The relative binding affinity ( ) of Biz-2 for AR was 2- to 5-fold lower than that of the synthetic androgen R1881. Biz-2 was found to be a specific ligand for the AR in that the natural ligand, DHT, and the anti-androgen, flutamide, displaced Biz-2 bound to AR and inhibited Biz-2-induced transcription and PSA secretion. This study provided evidence that Biz-2 extract possesses the ability to modulate prostate cancer cell biology in an AR-dependent manner.