|
|
||||||||
American Journal of Clinical Nutrition, Vol 53, 1071S-1075S, Copyright © 1991 by The American Society for Clinical Nutrition, Inc
ORIGINAL RESEARCH COMMUNICATIONS |
B Tan and FL Chu
Department of Food Science, Chenoweth Laboratory, University of Massachusetts, Amherst.
Using benzo(a)pyrene (BaP) metabolism as a probe for chemical carcinogenesis, in vitro and in vivo effects of palm-oil carotenoid [beta-carotene (BC), alpha-carotene (AC), or canthaxanthin (CTX)] on BaP metabolism in the rat hepatic cytochrome P450-mediated monooxygenase system were studied. Apparent Michaelis-Menten constants (Km) for formation of the precursor carcinogen, 7,8-dihydrodiol BaP, were found to be 14.4 (BC), 1.74 (AC), and 0.7 (CTX) mumol/L. The order of anticarcinogenic strength established in this study was BC much greater than AC greater than CTX. Increased formation of the detoxification intermediate, 3-hydroxy BaP, with increased carotenoid concentration was observed. The order of detoxification strength was BC greater than AC = CTX. The presence of carotenoids in vivo inhibited BaP metabolism. Using 9,10-dihydrodiol BaP as an indicator for inhibition, the order of the antioxidative activity was palm oil (with carotenoids) greater than BC greater than CTX greater than palm oil (without carotenoids). BC and AC may selectively modify the rat-liver microsomal enzymes, thus providing a biochemical mechanism for the inhibitory effect of palm carotenoids on chemical carcinogenesis.
This article has been cited by other articles:
![]() |
P. Bowen, L. Chen, M. Stacewicz-Sapuntzakis, C. Duncan, R. Sharifi, L. Ghosh, H.-S. Kim, K. Christov-Tzelkov, and R. van Breemen Tomato Sauce Supplementation and Prostate Cancer: Lycopene Accumulation and Modulation of Biomarkers of Carcinogenesis Experimental Biology and Medicine, November 1, 2002; 227(10): 886 - 893. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |