1. 9trans,11trans conjugated linoleic acid inhibits the development of azoxymethane-induced colonic aberrant crypt foci in rats.
- Author
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Yasui Y, Suzuki R, Kohno H, Miyamoto S, Beppu F, Hosokawa M, Miyashita K, and Tanaka T
- Subjects
- Animals, Azoxymethane toxicity, Biomarkers, Tumor analysis, Biomarkers, Tumor metabolism, Cell Division drug effects, Colon chemistry, Colon drug effects, Colonic Neoplasms chemically induced, Colonic Neoplasms epidemiology, Colonic Neoplasms metabolism, Cyclin D1 metabolism, Cyclooxygenase 2 metabolism, Disease Models, Animal, Dose-Response Relationship, Drug, Immunohistochemistry, Intestinal Mucosa metabolism, Lipids analysis, Male, PPAR gamma metabolism, Precancerous Conditions chemically induced, Precancerous Conditions epidemiology, Precancerous Conditions metabolism, Random Allocation, Rats, Rats, Inbred F344, Apoptosis drug effects, Colon pathology, Colonic Neoplasms prevention & control, Linoleic Acids, Conjugated pharmacology, Precancerous Conditions prevention & control
- Abstract
We investigated the effects of 9trans,11trans (9t,11t)-conjugated linoleic acid (CLA) isomer on azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) in rats. Male F344 rats were given 2 weekly subcutaneous injections of AOM (20 mg/kg bw) to induce colonic ACF. They also were fed a diet containing either 0.01%, 0.1%, or 1% 9t,11t-CLA for 4 wk starting 1 wk before the first dosing of AOM. The group that received a diet supplemented with 9t,11t-CLA had a significantly lower number of ACF/colon in comparison to the AOM alone group in a dose-dependent manner up to 0.1%. Furthermore, treatment with 9t,11t-CLA induced apoptosis and suppressed cell proliferation activity in the non-lesional crypts. The downregulation of cyclooxygenase-2 and cyclin D1 and the activation of peroxisome proliferators activated receptor gamma were observed in the colonic mucosa of rats fed a diet supplemented with 9t,11t-CLA. Our findings thus provide some novel insight into the chemopreventive effect of 9t,11t-CLA against preinitiation as well as postinitiation stages of colorectal carcinogenesis.
- Published
- 2007
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